This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ivanov, J. Articles by Naylor, C. D. Search for Related Content PubMed PubMed Citation Articles by Ivanov, J. Articles by Naylor, C. D. Pubmed/NCBI databases Medline Plus Health Information Coronary Artery Bypass Surgery

(Circulation. 1998;97:673-680.)
© 1998 American Heart Association, Inc.

Clinical Investigation and Reports

Fifteen-Year Trends in Risk Severity and Operative Mortality in Elderly Patients Undergoing Coronary Artery Bypass Graft Surgery

Joan Ivanov, RN, MSc; Richard D. Weisel, MD; Tirone E. David, MD; ; C. David Naylor, MD, DPhil

From the Division of Cardiovascular Surgery (J.I., R.D.W., T.E.D.), The Toronto Hospital, Toronto Ontario; The Institute for Clinical Evaluative Sciences (C.D.N.), North York, Ontario; The University of Toronto (J.I., R.D.W., T.E.D., C.D.N.), Toronto, Ontario; and The Clinical Epidemiology and Health Services Research Program (C.D.N.), Sunnybrook Health Science Centre, North York, Ontario, Canada.

Correspondence to Dr C. David Naylor, Institute for Clinical Evaluative Sciences, G106–2075 Bayview Ave, North York, Ontario, Canada M4N 3M5. E-mail cdn{at}ices.on.ca

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Background—Trends in risk-severity and operative mortality (OM) were examined in 3330 consecutive patients aged 70 years and older who underwent isolated coronary artery bypass graft surgery (CABG) between 1982 and 1996.

Methods and Results—The proportion of elderly patients rose significantly over time (P<.001). Crude OM among the elderly was 7.2% in 1982 to 1986, fell to 4.4% in 1987 to 1991, but did not improve thereafter. Logistic regression analysis of OM was used to construct relative risk groups (low, medium, or high). The prevalence of high-risk elderly patients rose significantly over time (P=.001) from 16.2% in 1982 to 1986 to 19.5% in 1987 to 1991 and 26.9% in 1992 to 1996. OM in high-risk patients fell significantly (P=.044) from 17.2% in 1982 to 1986 to 9.1% in 1987 to 1991 and was 8.9% in 1992 to 1996. Contemporary independent predictors of OM among elderly patients were poor ventricular function (LV grade 2 to 3, odds ratio [OR], 2.6; 95% confidence interval [CI], 1.3 to 5.2; and LV grade 4, OR, 10.7; 95% CI, 4.4 to 26); previous CABG (OR, 3.7; 95% CI, 2.0 to 7.0), female sex (OR, 1.8; 95% CI, 1.1 to 2.8), peripheral vascular disease (OR, 1.8; 95% CI, 1.1 to 2.8), and diabetes (OR, 1.7; 95% CI, 1.1 to 2.7). Previous angioplasty was protective (OR, 0.3; 95% CI, 0.1 to 0.9).

Conclusions—OM in elderly patients has declined significantly in recent years despite an increase in the prevalence and severity of their risk factors. A careful weighing of risk, rather than advanced age alone, should determine who is offered surgical revascularization. In this regard, poor ventricular function and repeat CABG continue to have the greatest impact on OM in elderly patients.

Key Words: risk factors • bypass • coronary disease • mortality • surgery

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
The elderly compose the fastest growing segment of North American society, and the greatest increases in numbers are in the oldest group (ie, persons 85 years old).^{1 2 3 4} Increasing numbers of elderly patients now undergo CABG.^{3 5 6} Indeed, over the past 20 years, the definition of "elderly" in the literature on cardiac surgical outcomes has gradually increased from persons 65 to those 80 years old.^{5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22} This shift reflects reductions in the risks of surgery arising from improvements in technology, skills, and patient selection.^{1 4 5 9 10 11 15 23 24}

In Ontario, Canada's most populous province, the population-based utilization of CABG since 1985 has doubled among persons aged 65 to 74 years, and population-based service rates more than tripled among persons aged 75 years.²⁵ Despite these trends, the 1993 CABG service rate in Ontario was about half that of New York State for patients aged 65 to 74 and only one third the New York rate for those 75 years of age.²⁶ New York, in turn, is at the low end of the US range for population-based CABG rates.

Although there have been no randomized trials comparing the efficacy of surgery with that of medical therapy for ischemic heart disease in a targeted group of elderly patients, the lower rates of service among elderly Ontarians do raise questions about whether some patients are being denied procedures that may improve their quality of life. Stason et al²⁷ suggested that the elderly tend to value improved quality of life more highly than prolonged longevity. Furthermore, several studies have reported improved quality of life in elderly patients who underwent CABG.^{13 17 28 29 30} However, if the vital risk of surgery is large, then the risk-benefit ratio may be tipped toward medical therapy for the elderly.

We have accordingly examined the trends in postoperative mortality among elderly Ontarians undergoing CABG at Canada's largest teaching hospital. Multivariate methods have been used to calculate risk-adjusted outcomes, thereby creating a "level playing field" for temporal comparisons of outcomes. More specifically, we report on (1) the temporal changes in the prevalence of elderly patients (70 years of age) undergoing CABG over a 15-year period in Toronto, (2) the risk-adjusted temporal changes in clinical severity and in-hospital OM among these subjects, and (3) the contemporary predictors of postoperative mortality in a 1991-to-1996 cohort of elderly patients undergoing CABG.

	Methods

Top Abstract Introduction Methods Results Discussion References

 
Data Source
Clinical, operative, and outcome data were collected prospectively in a computerized database for 19 009 consecutive patients undergoing isolated CABG between January 1, 1982, and December 31, 1996, at The Toronto Hospital (formerly the Toronto Western and Toronto General Hospitals). Patients undergoing valve, congenital, aortic root, ventricular aneurysm repair, transplantation, ventricular mapping, etc were excluded from this study.

Outcome and Explanatory Variables
The outcome of interest for this study is OM, which is defined as any postoperative, in-hospital death.

Core baseline explanatory variables collected since the inception of the database in 1982 included age, sex, LV grade (1, EF >60%; 2, EF 40% to 60%; 3, EF 20% to 39%; 4, EF <20%), previous CABG, urgency of surgery (elective, semiurgent, surgery during the same admission as a cardiac catheterization or cardiac event; emergent, surgery within 12 hours of a cardiac catheterization or cardiac event), number of diseased coronary arteries, presence of a significant stenosis (>50% by visual evaluation of the cineangiogram) of the left main coronary artery, severity of angina, and New York Heart Association functional class.

In 1990, the database was expanded to more fully characterize our patients by adding information such as recent myocardial infarction, diabetes, peripheral vascular disease, previous angioplasty or stent, history of hypertension, renal failure (dialysis), preoperative stroke or transient ischemic attack, body size, and chronic obstructive lung disease, among others.. Details of this database have been published elsewhere.³¹

Analysis
Data were collected and managed in dBASE IV datasets. The SAS for PC³² and BMDP/DYN LR³³ programs were used for statistical analyses. The ² or Fisher's exact tests were used to evaluate categorical data univariately. Multivariate logistic regression methods were used to calculate risk-adjusted mortality and calculate factor-adjusted odds ratios. Model discrimination was evaluated by the area under the ROC curve,^{34 35} and the calibration was assessed with the Hosmer-Lemeshow goodness-of-fit statistic.³⁶ For goodness-of-fit, the null hypothesis is that the model fits the data. Therefore, a nonsignificant P value is desired because P<.05 would indicate a poor fit between predicted and observed results.

Evaluation of Temporal Trends
Rather than build a complex model to assess the temporal trends in incidence, risk profiles, and outcomes of elderly versus nonelderly patients, we used a simpler approach based on risk stratification and contingency tables, as outlined below.

The data before 1990 lacked the full range of potential predictors of postoperative mortality. Thus, any temporal comparative analysis required a simple predictive rule that included only key predictors. To this end, we started from the previously-validated predictive algorithm developed by Tu and colleagues³⁷ as a template. That algorithm was designed for both valve surgery and CABG and therefore included type of surgery (isolated CABG, isolated valve, or valve plus CABG) as a variable. Other validated models for predicting isolated CABG outcomes have included left mainstem disease as a prognostic variable; hence this item was added to the model instead of type of surgery.

To recalibrate the resulting six-variable algorithm for this one-center temporal analysis, we performed a logistic regression analysis in the entire 1982-to-1996 cohort of patients. The resulting adjusted odds ratios for six explanatory variables—age (<65, 65 to 74, 75), sex, previous CABG, urgency of surgery, LV dysfunction (LV grade 2 to 3, LV grade 4), and left main coronary artery disease—were rounded as in the algorithm of Tu et al. These rounded odds ratios served as risk weights for each level of the predictor variables. A risk score for each patient was calculated by summing the risk weights for the variables that described the patient's baseline characteristics. Observed mortality, determined by frequency analysis, for each risk score was used to construct relative risk groups (eg, low, medium, or high).

Next, data from 15 years were divided into three 5-year time cohorts based on date of operation: 1982 to 1986, 1987 to 1991, and 1992 to 1996. Patients were further divided into a younger cohort (<70 years) and an elderly cohort (70 years). This allowed us to use contingency table analysis to evaluate changes in the prevalence of elderly patients, their risk factors, and OM over time and among the three risk groups.

As a complementary method, logistic regression analysis for OM was performed solely for the elderly cohort (1982 to 1996). This allowed us to generate elderly-specific odds ratios for the six explanatory variables, as well as the risk reduction in OM associated with time after adjustment for those variables.

Contemporary Predictors of OM
In the final step of the analysis, we focused on the cohort of elderly patients undergoing CABG between 1991 and 1996, a group that was better characterized with additional data as outlined above. This enabled us to determine the contemporary predictors of OM as contrasted to the six core explanatory variables used for the temporal trend analysis. The following variables were tested by ² analysis for their univariate association with OM: diabetes, peripheral vascular disease, history of hypertension, previous angioplasty/stent, renal failure, New York Heart Association class, recent preoperative myocardial infarction, preoperative stroke/transient ischemic attack, number of diseased vessels, severity of angina, and body size. We included all variables with a value of P<.20, as well as those found to be clinically important in other models³⁸ regardless of whether they met the critical level for inclusion. These variables were submitted for consideration to a stepwise logistic regression analysis using forward selection combined with backward elimination. The best model was determined by two criteria: the area under the ROC curve, and the Hosmer-Lemeshow statistic. Because of the limited number of events, we did not undertake split-sample methods to validate the model. Such validation would in any case confirm the model's applicability in our setting but not prove generalizability to other centers. Thus, we simply present this set of predictors for information and as a hypothesis for consideration and validation by others.

	Results

Top Abstract Introduction Methods Results Discussion References

 
Knowledge to Date
Table 1 presents 18 reports retrieved from a Medline search that demonstrate the changing definition of "elderly" and the range of OM (5% to 20%) reported for isolated CABG over the past 20 years.

View this table: [in this window] [in a new window]   Table 1. Incidence and Outcomes of CABG in the Elderly: Changing Profile of Cohort Studies in the Literature

Generalizability
All 19 009 consecutive patients undergoing isolated CABG at The Toronto Hospital between January 1, 1982, and December 31, 1996, were examined. As noted, the core variables for this study were age, sex, LV grade, previous CABG, urgency of surgery, and left main disease. There were 346 patients with one or more of these data elements missing, making the database 98.2% complete for core information.

Increasing Prevalence of Elderly CABG Patients
There were 15 679 (OM=2.2%) patients under the age of 70 years who underwent CABG between 1982 and 1996. "Elderly" was defined as those patients 70 years of age at the time of surgery (3330, OM=4.95%). Fig 1 demonstrates the yearly increase in the prevalence of those patients aged 70 to 74 (top) and those 75 (bottom) over the 15 years of this study. Both groups increased significantly over time (P<.001). The absolute numbers for patients under 70 remained fairly stable for each 5-year time cohort (5300), but the number of elderly patients almost tripled from 593 in the 1982-to-1986 cohort to 1726 in the 1992-to-1996 group.

View larger version (29K): [in this window] [in a new window]   Figure 1. Significant increase in the prevalence of elderly patients undergoing isolated CABG at The Toronto Hospital between 1982 and 1996. The temporal change was significant (P<.001) for those those aged 70 to 74 years and those aged 75 years.

Changing Risk Severity and OM
There was a 34% overall relative risk reduction in the OM rate (all patients) from 1982 to 1986 (OM=3.52%) to the following time cohorts (OM=2.34% for both 1987-to-1991 and 1992-to-1996 cohorts).

The predictive rule, recalibrated in the 1982-to-1996 dataset of 19 009 patients, had a ROC area of 0.70 and a Hosmer-Lemeshow p-value of 0.53. Table 2 shows the risk weights for each level of the prognostic variables derived from the rounded odds ratios and the cutpoints of the total risk score used to define the relative risk groups.

View this table: [in this window] [in a new window]   Table 2. Odds Ratios, 95% CI, and Corresponding Risk Weights From Logistic Regression Analysis of 19 009 Patients Undergoing Isolated CABG Between 1982 and 1996

Table 3 shows the prevalence of individual risk factors as well as the changing distribution of overall risk severity. Combined prevalence of medium- and high-risk patients increased significantly (P<.001) over time for those patients over and under 70 years of age (Fig 2).

View this table: [in this window] [in a new window]   Table 3. Distribution of Risk Factors for 19 009 Patients Undergoing Isolated CABG Between 1982 and 1996 at the Toronto Hospital

View larger version (30K): [in this window] [in a new window]   Figure 2. Top, Prevalence of high-risk elderly patients increased significantly (P<.001) over time. Bottom, OM decreased significantly (P<.05 over time for both medium- and high-risk elderly patients.

Overall mortality and risk group–specific mortality data are presented in Table 4 and Fig 2. Significantly positive trends are seen for medium- and high-risk patients and for most, albeit not all, risk factor subgroups in the nonelderly and elderly. Age-specific mortality improved significantly for persons <70 years of age. Even larger absolute improvements were seen among persons aged 70 to 74 and 75 years. However, these did not reach significance due to smaller sample sizes. We accordingly turned to the overall logistic regression model for the elderly because this would allow us to factor in the temporal increases in severity.

View this table: [in this window] [in a new window]   Table 4. Distribution of Outcomes for 19 009 Patients Undergoing Isolated CABG Between 1982 and 1996 at the Toronto Hospital

For the overall logistic regression, we set aside the risk scores based on rounded odds ratios and used the ß-coefficients, calculating exact adjusted odds ratios and related CIs for all explanatory factors. Among 3330 elderly patients operated on between 1982 and 1996, there were 165 deaths. Compared with 1982 to 1986, operations in 1986 to 1991 and 1992 to 1996 were each associated with a significant 50% reduction in relative odds of death (Table 5). Adjusted odds ratios and their 95% CIs for all core risk factors are also shown in Table 5. Predictive accuracy measured by the area under the ROC curve was 0.69, and precision, measured by the Hosmer-Lemeshow goodness-of-fit statistic was 0.232.

View this table: [in this window] [in a new window]   Table 5. Logistic Regression of 3330 Elderly Patients Undergoing CABG Between 1982 and 1996 at the Toronto Hospital

Contemporary Predictors of OM in the Elderly
There were 2002 elderly patients (70 years old) who underwent isolated CABG between 1991 and 1996. OM was 4.6% in this group (n=92). The six core variables—age, (70 to 74 years or 75 years) sex, previous CABG, LV grade (1, 2 or 3, or 4) timing of surgery (elective, semiurgent, or emergent), and left main disease (>50% stenosis)—were submitted to a logistic regression analysis along with the following additional variables: diabetes, peripheral vascular disease, history of hypertension, previous angioplasty/stent, renal failure, New York Heart Association class, recent preoperative myocardial infarction, preoperative stroke/transient ischemic attack, number of diseased vessels, severity of angina, and body size. The contemporary, independent, multivariate predictors of OM are contained in Table 6. Particularly interesting is a risk reduction associated with previous angioplasty/stent. The Hosmer-Lemeshow goodness-of-fit was 0.932, and the area under the ROC curve was 0.713.

View this table: [in this window] [in a new window]   Table 6. Logistic Regression of Contemporary Elderly Patients (1991 to 1996)

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
Although advancing age remains a consistent predictor of OM after isolated CABG, a variety of reports in the literature have demonstrated that elderly patients previously thought to be at very high risk for adverse events can now undergo this beneficial procedure with acceptable postoperative risk.^{1 4 5 9 10 11 12 15 23 24} Many of these reports have been limited, however, either by not providing a long-term perspective on outcome trends among the elderly or by not incorporating risk-adjustment algorithms that take into account the temporal shifts in risk profiles among patients receiving CABG. In the latter respect, statistical power has been a problem for many reports of CABG in the elderly, with the obvious exception of the study by Hannan et al.¹⁸ Given the current convention that there should be 10 outcome events for every explanatory variable in an outcomes-prediction model,³⁹ many studies have sample sizes that permit only two or three variables to be considered adequately for risk-adjustment purposes.

Our analysis has provided a 15-year perspective on 19 009 consecutive isolated CABG procedures at Canada's largest hospital, and includes >3300 patients aged 70 years. We used a previously validated predictive rule³⁷ as a template for risk adjustment, added an additional explanatory variable (left main disease), and recalibrated the rule across the entire 15-year dataset to create a more level playing field for temporal comparisons of risk factor profiles and outcomes. Our findings confirm that there has been not only a time-related increase in the prevalence of older patients undergoing isolated CABG at our center but also an increase in the severity of the preoperative risk profile of those patients. However, risk-adjusted OM has decreased significantly for elderly patients. The current overall mortality rate for elderly patients is <5% and only 3% for low- and medium-risk patients.

Given the enthusiasm for outcomes "scorecards," it is also noteworthy that an improvement in outcomes was already evident in the 1987-to-1991 period for both older and younger patients. This occurred well before the current program of systematic outcomes monitoring was embarked on in Ontario, as described elsewhere.⁴⁰

Because patients' characteristics were not as exhaustively documented in earlier as in later years, we cannot absolutely rule out the possibility that the recent improvements in outcomes are partly an epiphenomenon of unmeasured changes in case selection. However, the model for mortality of elderly patients between 1982 and 1996 had an ROC curve area similar (0.69 versus 0.71) to that for elderly patients in the 1991-to-1996 model, which drew on additional risk factor data, and the trends to inclusion of higher-risk elderly patients are temporally consistent. Therefore, it is exceedingly unlikely that our findings are explained by unmeasured changes in patient characteristics working in the opposite direction, that is, toward lower-risk case selection.

Another hypothetical confounder is declining length of stay. Because patients in recent years would be discharged earlier, some who might otherwise have died in hospital would die at home and not be counted. However, this also is an implausible explanation for the observed trends. The mortality decrement was already evident for the 1987-to-1991 period, which antedates the contemporary move to much shorter lengths of stay after CABG. Second, postoperative stays among the elderly undergoing CABG remain relatively long; for our 1992-to-1996 cohort, the mean was 11.3 days (95% CI, 10.8, 11.8). Third, we have tracked patients after discharge in a major randomized trial.⁴¹ Deaths occurring between discharge and 30 days from the date of surgery were uncommon; >95% of deaths occurred on the index admission. Thus, any minor decrements in lengths of stay occurring from 1982 through 1986 to 1987 through 1991 are most unlikely to account for the dramatic decline in postoperative mortality observed in the same period.

The reasons for the improved outcomes nevertheless remain speculative. Possible factors include better myocardial protection during surgery (eg, by use of blood rather than crystalloid cardioplegia or warm/tepid rather than cold cardioplegia temperatures), greater use of left internal thoracic artery conduits, and improved cardiovascular anesthetic techniques. For that matter, most centers reporting temporal trends in overall CABG outcomes have noted improvements over the past decade. We found no evidence for further significant changes in outcomes for 1992 to 1996. However, ongoing improvements may be masked by the increasing prevalence of high-risk patients who are incompletely characterized by the simplified risk-adjustment algorithm used for the 15-year trend analysis.

Analysis of the 1982-to-1996 dataset obviously was not ideal for delineating predictors in current practice for two reasons. First, a richer set of variables did not become available until 1990; and second, as noted above, outcomes have been improving over time. Thus, to determine the contemporary predictors of OM in the elderly, a logistic regression analysis was performed on a database of 2002 well characterized elderly patients undergoing CABG between 1991 and 1996. Strong risk factors were presence of a grade 4 ventricle (odds ratio, 10.7; 95% CI, 4.4 to 26) or previous CABG (odds ratio, 3.73; 95% CI, 2.0 to 7.0). Some expected predictors—such as age of 75 years, urgent/emergent surgery, renal failure, number of diseased vessels, presence of left mainstem disease, or recent preoperative myocardial infarction—fell out of the final model. This is partly a function of statistical power, but it is instructive that other predictors, such as diabetes and peripheral vascular disease, took precedence in the risk-adjustment algorithm.

The protective effect of previous angioplasty/stenting in the algorithm is strikingly large. This finding is almost counterintuitive because one would expect individuals at higher risk from CABG to be more likely to undergo angioplasty as a temporizing measure, rather than proceeding directly to open heart surgery. There are two plausible explanations for the effect, which are not mutually exclusive. The first is that previous angioplasty/stenting is directly protective by reducing one or more of the critical coronary arterial stenoses before CABG. The second is that the prior occurrence of angioplasty/stenting is actually a proxy for less extensive or severe coronary atherosclerosis, independent of the number of diseased vessels. In the latter scenario, patients with a limited number of discrete lesions would be more likely to undergo a prior angioplasty than those with diffuse atheroma and distal vessel involvement.

Limitations of this analysis are those that apply in any observational outcomes analysis. First, miscoding of key risk factors is always a concern. The database in question is very well established and subject to systematic logic and range checks. Definitions for risk factors have remained unchanged since 1982 in some cases and since 1990 for those factors added later. Furthermore, the data are subject to random audits, which have consistently shown raw interabstractor agreement on major variables to be >98%. The dataset also is acceptably complete in terms of core variable information, with only 1.8% of patients missing one or more key data elements.

Second, we have demonstrated the improving outcomes of isolated CABG in the presence of growing numbers of procedures on high-risk elderly patients, but, in contrast to the accumulated trial data on younger persons, the risk-benefit ratios of surgery for the elderly are not precisely defined.^{23 42} The elderly are a very diverse group in terms of their physical and mental health, work capacity, and economic status. Prudent case selection obviously must take into account the baseline functional capacities and preferences of elderly patients. Furthermore, our results show that high-risk elderly patients still have a significantly increased OM rate (8.9%); those with poor ventricular function or previous CABG are at particularly high risk of postoperative mortality. These latter findings may help clinicians in counseling elderly patients about the risks of isolated CABG surgery.

Third, as noted in "Methods," the predictive algorithm for the most recent period is based on consecutive patients from a single center, without independent validation. With only 92 deaths among the 2002 elderly patients undergoing isolated CABG at our center between 1991 and 1996, it was not feasible to split the cohort into derivation and validation samples. That said, most risk-adjustment algorithms in the literature have been validated only in the centers from which they were derived. Other centers should ideally use their own outcomes data to validate and recalibrate the risk factors identified here.

Fourth, we focused exclusively on mortality as a postoperative complication. Additional work is needed to delineate trends in postoperative morbidity, not the least of which is stroke, an outcome particularly feared by the elderly. Furthermore, we do not have data on long-term life expectancy gains or quality of life enhancement. Linkage to provincial statistics is planned to address life-expectancy gains, but in the absence of prospective data collection, quality of life improvements cannot be quantified.

In conclusion, CABG surgery may sometimes be the best of the unattractive options for elderly patients who have a progression of disease and symptoms. OM after isolated CABG in the elderly declined significantly starting in the late 1980s for this important and growing group of patients, despite an increase in the prevalence and severity of their risk factors, and has been stable since the early 1990s at <5% overall for patients aged 70 years. A careful weighing of risk, rather than advanced age alone, should determine who is offered surgical revascularization. In this regard, poor ventricular function and repeat CABG continue to have the most impact on OM in elderly patients in our center. These and other risk factors noted here can serve as a starting point for cardiologists and surgeons who want to counsel elderly patients about the vital risks of isolated CABG or to delineate risk factors for adverse events in their own practices.

	Selected Abbreviations and Acronyms

 

CI = confidence interval CABG = coronary artery bypass graft surgery EF = ejection fraction LV = left ventricular, ventricle OM = operative mortality ROC = receiver-operator characteristic

	Acknowledgments

 
Ms Ivanov is supported by a fellowship from the Heart and Stroke Foundation of Canada. Dr Naylor is a Career Scientist of the Ontario Ministry of Health. Dr Naylor also receives personnel support from the Institute for Clinical Evaluative Sciences, which is funded by the Ontario Ministry of Health. The findings and views are those of the authors; no endorsement by the supporting agencies is implied. The authors wish to express their sincere appreciation to Susan Collins for data collection and management. We are deeply indebted to the contributing surgeons at The Toronto Hospital: R.J. Baird, Hugh E. Scully, Lynda L. Mickleborough,. Christopher M. Feindel, Charles M. Peniston, Irving H. Lipton, R.J. Cusimano, Anthony Ralph-Edwards, and Bernard S. Goldman (currently chief of Cardiovascular Surgery at Sunnybrook Health Science Center, Toronto, Canada).

Received June 9, 1997; revision received October 8, 1997; accepted October 21, 1997.

	References

Top Abstract Introduction Methods Results Discussion References

 
1. Arora R, Sager J, Butler RN. Therapeutic goals: quality of life. Cardiol Clin. 1986;4:305–312.[Medline] [Order article via Infotrieve]

2. Guralnik JM, Fitzsimmons SC. Aging in America: a demographic perspective. Cardiol Clin. 1986;4:175–183.[Medline] [Order article via Infotrieve]

3. Rowe JW. Health care of the elderly. N Engl J Med. 1985;312:827–835.[Medline] [Order article via Infotrieve]

4. Naylor CD, Ugnat AM, Weinkauf D, Anderson GM, Wielgosz A. Coronary artery bypass grafting in Canada: what is its rate of use? Which rate is right? Can Med Assoc J. 1992;146:851–859.[Abstract]

5. MacArthur AE, Hall RJ, Gray AG, Mathur VS, Cooley DA. Coronary revascularization in the elderly patient. J Am Coll Cardiol. 1984;3:1398–1402.[Abstract]

6. Freeman WK, Schaff HV, O'Brien PC, Orszulak TA, Naessens JM, Tajik AJ. Cardiac surgery in the octogenarian: perioperative outcome and clinical follow-up. J Am Coll Cardiol. 1991;18:29–35.[Abstract]

7. Gann D, Colin C, Hildner FJ, Samet P, Yahr WZ, Greenberg JJ. Coronary artery bypass surgery in patients seventy years of age and older. J Thorac Cardiovasc Surg. 1977;73:237–241.[Abstract]

8. Knapp WS, Douglas JS Jr, Craver JM, Jones EL, King SB III, Bone DK, Bradford JM, Hatcher CR Jr. Efficacy of coronary artery bypass grafting in elderly patients with coronary artery disease. Am J Cardiol. 1981;47:923–930.[Medline] [Order article via Infotrieve]

9. Gersh BJ, Kronmal RA, Frye RL, Schaff HV, Ryan TJ, Gosselin AJ, Kaiser GC, Killip T. Coronary arteriography and coronary artery bypass: morbidity and mortality in patients ages 65 years or older. Circulation. 1983;67:483–491.[Abstract/Free Full Text]

10. Hibler BA, Wright JO, Wright CB, Ehrenhaft JL, Doty DB, Rossi NP. Coronary artery bypass surgery in the elderly. Arch Surg. 1983;118:402–404.[Abstract/Free Full Text]

11. Hochberg MS, Levine FH, Daggett WM, Akins CW, Austen WG, Buckley MJ. Isolated coronary artery bypass grafting in patients seventy years of age and older. J Thorac Cardiovasc Surg. 1982;84:219–223.[Abstract]

12. Horneffer PJ, Gardner TJ, Manolio TA, Hoff SJ, Rykiel MF, Pearson TA, Gott VL, Baumgartner WA, Borkon AM, Watkins L, Reitz BA. The effects of age on outcome after coronary bypass surgery. Circulation. 1987;76(suppl V):V-6–V-12.

13. Loop FD, Lytle BW, Cosgrove DM, Goormastic M, Taylor PC, Golding LAR, Stewart RW, Gill CC. Coronary artery bypass graft surgery in the elderly. Cleve Clin J Med. 1988;55:23–34.[Medline] [Order article via Infotrieve]

14. Goldman BS, Scully HE, Tong CP, Lee JY, Weisel RD, Mickleborough LL, Baird RJ. Coronary artery bypass graft surgery in the elderly. Geriatric Cardiovasc Med. 1988;1:201–207.

15. Horvath KA, DiSesa VJ, Peigh PS, Couper GS, Collins JJ, Cohn LH. Favorable results of coronary artery bypass grafting in patients older than 75 years. J Thorac Cardiovasc Surg. 1990;99:92–96.[Abstract]

16. Ko W, Krieger KH, Lazenby WD, Shin YT, Goldstein M, Lazzaro R, Isom OW. Isolated coronary bypass grafting in one hundred consecutive octogenarian patients. J Thorac Cardiovasc Surg. 1991;102:532–538.[Abstract]

17. Tsai TP, Nessim S, Kass RM, Chaux A, Gray RJ, Khan SS, Blanche C, Utley C, Matloff JM. Morbidity and mortality after coronary bypass in octogenarians. Ann Thorac Surg. 1991;51:983–986.[Abstract]

18. Hannan EL, Burke J. Effect of age on mortality in coronary artery bypass surgery in New York, 1991–1992. Am Heart J. 1994;128:1184–1191.[Medline] [Order article via Infotrieve]

19. Curtis JJ, Walls JT, Boley TM, Schmaltz RA, Demmy TL, Salam N. Coronary revascularization in the elderly: determinants of operative mortality. Ann Thorac Surg. 1994;58:1069–1072.[Abstract]

20. He GW, Acuff TE, Ryan WH, Bowman RT, Douthit MB, Mack MJ. Determinants of operative mortality in elderly patients undergoing coronary artery bypass grafting: emphasis on the influence of internal mammary artery grafting on mortality and morbidity. J Thorac Cardiovasc Surg. 1994;108:73–81.[Abstract/Free Full Text]

21. Katz NM, Hannan RL, Hopkins RA, Wallace RB. Cardiac operations in patients aged 70 years and over: mortality, length of stay, and hospital charge. Ann Thorac Surg. 1995;60:96–100.[Abstract/Free Full Text]

22. Morris RJ, Strong MD, Grunewald KE, Kuretu ML, Samuels LE, Kresh JY, Brockman SK. Internal thoracic artery for coronary artery grafting in octogenarians. Ann Thorac Surg. 1996;62:16–22.[Abstract/Free Full Text]

23. Tsai TP, Matloff JM, Gray RJ, Chaux A, Kass RM, Lee ME, Czer LSC. Cardiac surgery in the octogenarian. J Thorac Cardiovasc Surg. 1986;91:924–928.[Abstract]

24. Pryor DB, Harrell FE, Jr, Rankin JS, Lee KL, Muhlbaier LH, Oldham HN, Hlatky MA, Mark DB, Reves JG, Califf RM. The changing survival benefits of coronary revascularization over time. Circulation. 1987;76(suppl V):V-13–V-21.

25. Goel V, Williams JI, Anderson GM, Blackstien-Hirsh P, Fooks C, Naylor CD (eds). Patterns of Health Care in Ontario: The ICES Practice Atlas. Toronto, Canada: Canadian Medical Association; 1997:99–104.

26. Tu JV, Naylor CD, Kumar D, DeBuono BA, McNeil BJ, Hannan EL. Coronary artery bypass graft surgery in Ontario and New York State: which rate is right? Steering Committee of the Cardiac Care Network of Ontario. Ann Intern Med. 1997;126:13–19.[Abstract/Free Full Text]

27. Stason WB, Sanders CA, Smith HC. Cardiovascular care of the elderly: economic considerations. J Am Coll Cardiol. 1987;10:18–21.

28. Gersh BJ, Kronmal RA, Schaff HV, Frye RL, Ryan TJ, Myers WO, Athearn MW, Gosselin AJ, Kaiser GC, Killip T. Long-term (5 year) results of coronary bypass surgery in patients 65 years old or older: a report from the Coronary Artery Surgery Study. Circulation. 1983;68(suppl II):II-190–II-199.

29. Cheitlin MD. Coronary bypass surgery in the elderly. Clin Geriatric Med. 1996;12:195–205.[Medline] [Order article via Infotrieve]

30. Cane ME, Chen C, Bailey BM, Fernandez J, Laub GW, Anderson WA, McGrath LB. CABG in octogenarians: early and late events and actuarial survival in comparison with a matched population. Ann Thorac Surg. 1995;60:1033–1037.[Abstract/Free Full Text]

31. Rao V, Ivanov J, Weisel RD, Ikonomidis JS, Christakis GT, David TE. Predictors of low cardiac output syndrome after coronary artery bypass. J Thorac Cardiovasc Surg. 1996;112:38–51.[Abstract/Free Full Text]

32. SAS Institute. SAS Language Guide for Personal Computers. Cary, NC: SAS Institute Inc; 1988.

33. Dixon WJ, ed. BMDP Statistical Software Manual. Berkeley, Calif: University of California Press; 1992.

34. Hanley JA, McNeil BJ. The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology. 1982;143:29–36.[Abstract/Free Full Text]

35. Hanley JA, McNeil BJ. A method for comparing the areas under receiver operating characteristic curves derived from the same cases. Radiology. 1983;148:839–843.[Abstract/Free Full Text]

36. Hosmer DW, Lemeshow S. Applied Logistic Regression. New York, NY: John Wiley & Sons; 1989.

37. Tu JV, Jaglal SB, Naylor CD, the Steering Committee of the Provincial Adult Cardiac Care Network of Ontario: Multicenter validation of a risk index for mortality, intensive care unit stay, and overall hospital length of stay after cardiac surgery. Circulation. 1995;91:677–684.[Abstract/Free Full Text]

38. Jones RH, Hannan EL, Hammermeister KE, DeLong ER, O'Connor GT, Luepker RV, Parsonnet V, Pryor DB. Identification of preoperative variables needed for risk adjustment of short-term mortality after coronary artery bypass graft surgery: the Working Group Panel on the Cooperative CABG Database Project. J Am Coll Cardiol. 1996;28:1478–1487.[Abstract]

39. Hsieh FY. Sample size tables for logistic regression. Stat Med. 1989;8:795–802.[Medline] [Order article via Infotrieve]

40. Tu JV, Naylor CD, the Steering Committee of the Provincial Adult Cardiac Care Network of Ontario. Coronary artery bypass mortality rates in Ontario: a Canadian approach to quality assurance in cardiac surgery. Circulation. 1996;94:2429–2433.[Abstract/Free Full Text]

41. The Warm Heart Investigators. Normothermic versus hypothermic cardiac surgery: a randomized trial in 1732 coronary bypass patients. Lancet. 1994;343:559–563.[Medline] [Order article via Infotrieve]

42. Dustan HP, Hamilton MP, McCullough L. Sociopolitical, ethical considerations in the treatment of cardiovascular disease in the elderly. J Am Coll Cardiol. 1987;10:14A–17A.

This article has been cited by other articles:

				C. Naughton, R. O. Feneck, and J. Roxburgh Early and late predictors of mortality following on-pump coronary artery bypass graft surgery in the elderly as compared to a younger population Eur. J. Cardiothorac. Surg., October 1, 2009; 36(4): 621 - 627. [Abstract] [Full Text] [PDF]

				A. Grover, K. Gorman, T. M. Dall, R. Jonas, B. Lytle, R. Shemin, D. Wood, and I. Kron Shortage of Cardiothoracic Surgeons Is Likely by 2020 Circulation, August 11, 2009; 120(6): 488 - 494. [Abstract] [Full Text] [PDF]

				B. F. Buxton, P. A.R. Hayward, A. E. Newcomb, S. Moten, S. Seevanayagam, and I. Gordon Choice of conduits for coronary artery bypass grafting: craft or science? Eur. J. Cardiothorac. Surg., April 1, 2009; 35(4): 658 - 670. [Abstract] [Full Text] [PDF]

				D. S. Likosky, L. J. Dacey, Y. R. Baribeau, B. J. Leavitt, R. Clough, R. P. Cochran, R. Quinn, D. A. Sisto, D. C. Charlesworth, D. J. Malenka, et al. Long-Term Survival of the Very Elderly Undergoing Coronary Artery Bypass Grafting Ann. Thorac. Surg., April 1, 2008; 85(4): 1233 - 1237. [Abstract] [Full Text] [PDF]

				M. A. Albert, N. Halevy, and E. M. Antman Preoperative Evaluation for Cardiac Surgery Card. Surg. Adult, January 1, 2008; 3(2008): 261 - 280. [Full Text]

				T. Palmerini, F. Barlocco, A. Santarelli, L. Bacchi-Reggiani, C. Savini, E. Baldini, L. Alessi, M. Ruffini, G. Di Credico, G. Piovaccari, et al. A comparison between coronary artery bypass grafting surgery and drug eluting stent for the treatment of unprotected left main coronary artery disease in elderly patients (aged >=75 years) Eur. Heart J., November 2, 2007; 28(22): 2714 - 2719. [Abstract] [Full Text] [PDF]

				D. C. Chang, D. L. Joyce, A. Shoher, and D. D. Yuh Simple Index to Predict Likelihood of Skilled Nursing Facility Admission After Coronary Artery Bypass Grafting Among Older Patients Ann. Thorac. Surg., September 1, 2007; 84(3): 829 - 835. [Abstract] [Full Text] [PDF]

				J. L. Anderson, C. D. Adams, E. M. Antman, C. R. Bridges, R. M. Califf, D. E. Casey Jr, W. E. Chavey II, F. M. Fesmire, J. S. Hochman, T. N. Levin, et al. ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction) Developed in Collaboration with the American College of Emergency Physicians, the Society for Cardiovascular Angiography and Interventions, and the Society of Thoracic Surgeons Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation and the Society for Academic Emergency Medicine J. Am. Coll. Cardiol., August 14, 2007; 50(7): e1 - e157. [Full Text] [PDF]

				M. J. Magee, M. A. Herbert, T. M. Dewey, J. R. Edgerton, W. H. Ryan, S. Prince, and M. J. Mack Atrial Fibrillation After Coronary Artery Bypass Grafting Surgery: Development of a Predictive Risk Algorithm Ann. Thorac. Surg., May 1, 2007; 83(5): 1707 - 1712. [Abstract] [Full Text] [PDF]

				G. S. Hillis, K. J. Zehr, A. W. Williams, H. V. Schaff, T. A. Orzulak, R. C. Daly, C. J. Mullany, R. J. Rodeheffer, and J. K. Oh Outcome of Patients With Low Ejection Fraction Undergoing Coronary Artery Bypass Grafting: Renal Function and Mortality After 3.8 Years Circulation, July 4, 2006; 114(1_suppl): I-414 - I-419. [Abstract] [Full Text] [PDF]

				S. S. Waikar, G. C. Curhan, R. Wald, E. P. McCarthy, and G. M. Chertow Declining Mortality in Patients with Acute Renal Failure, 1988 to 2002 J. Am. Soc. Nephrol., April 1, 2006; 17(4): 1143 - 1150. [Abstract] [Full Text] [PDF]

				V. Peric, M. Borzanovic, A. Jovanovic, R. Stolic, S. Sovtic, and G. Trajkovic The relationship between EuroSCORE preoperative risk prediction and quality of life changes after coronary artery by-pass surgery Interactive CardioVascular and Thoracic Surgery, December 1, 2005; 4(6): 622 - 626. [Abstract] [Full Text] [PDF]

				V. Aboyans, P. Lacroix, A. Postil, J. Guilloux, F. Rolle, E. Cornu, and M. Laskar Subclinical Peripheral Arterial Disease and Incompressible Ankle Arteries Are Both Long-Term Prognostic Factors in Patients Undergoing Coronary Artery Bypass Grafting J. Am. Coll. Cardiol., September 6, 2005; 46(5): 815 - 820. [Abstract] [Full Text] [PDF]

				J. Karski, G. Djaiani, J. Carroll, M. Iwanochko, P. Seneviratne, P. Liu, W. Kucharczyk, L. Fedorko, T. David, and D. Cheng Tranexamic acid and early saphenous vein graft patency in conventional coronary artery bypass graft surgery: A prospective randomized controlled clinical trial J. Thorac. Cardiovasc. Surg., August 1, 2005; 130(2): 309 - 314. [Abstract] [Full Text] [PDF]

				K. E. A. Burns, M. W. A. Chu, R. J. Novick, S. A. Fox, K. Gallo, C. M. Martin, L. W. Stitt, A. P. Heidenheim, M. L. Myers, and L. Moist Perioperative N-acetylcysteine to Prevent Renal Dysfunction in High-Risk Patients Undergoing CABG Surgery: A Randomized Controlled Trial JAMA, July 20, 2005; 294(3): 342 - 350. [Abstract] [Full Text] [PDF]

				F. Rosenfeldt, S. Marasco, W. Lyon, M. Wowk, F. Sheeran, M. Bailey, D. Esmore, B. Davis, A. Pick, M. Rabinov, et al. Coenzyme Q10 therapy before cardiac surgery improves mitochondrial function and in vitro contractility of myocardial tissue J. Thorac. Cardiovasc. Surg., January 1, 2005; 129(1): 25 - 32. [Abstract] [Full Text] [PDF]

				J. P. Mathew, M. L. Fontes, I. C. Tudor, J. Ramsay, P. Duke, C. D. Mazer, P. G. Barash, P. H. Hsu, and D. T. Mangano A Multicenter Risk Index for Atrial Fibrillation After Cardiac Surgery JAMA, April 14, 2004; 291(14): 1720 - 1729. [Abstract] [Full Text] [PDF]

				S. Karthik, G. Musleh, A. D. Grayson, D. J. M. Keenan, D. M. Pullan, W. C. Dihmis, R. Hasan, and B. M. Fabri Coronary surgery in patients with peripheral vascular disease: effect of avoiding cardiopulmonary bypass Ann. Thorac. Surg., April 1, 2004; 77(4): 1245 - 1249. [Abstract] [Full Text] [PDF]

				C. Muneretto, G. Bisleri, A. Negri, J. Manfredi, E. Carone, J. A. Morgan, M. Metra, and L. Dei Cas Left internal thoracic artery-radial artery composite grafts as the technique of choice for myocardial revascularization in elderly patients: A prospective randomized evaluation J. Thorac. Cardiovasc. Surg., January 1, 2004; 127(1): 179 - 184. [Abstract] [Full Text] [PDF]

				P. M. Davierwala, M. Maganti, and T. M. Yau Decreasing significance of left ventricular dysfunction and reoperative surgery in predicting coronary artery bypass grafting-associated mortality: A twelve-year study J. Thorac. Cardiovasc. Surg., November 1, 2003; 126(5): 1335 - 1344. [Abstract] [Full Text] [PDF]

				L. L. Mickleborough, S. Carson, and J. Ivanov Gender differences in quality of distal vessels: effect on results of coronary artery bypass grafting J. Thorac. Cardiovasc. Surg., October 1, 2003; 126(4): 950 - 958. [Abstract] [Full Text] [PDF]

				C. Muneretto, G. Bisleri, A. Negri, J. Manfredi, M. Metra, S. Nodari, L. Culot, and L. Dei Cas Total Arterial Myocardial Revascularization With Composite Grafts Improves Results of Coronary Surgery in Elderly: A Prospective Randomized Comparison With Conventional Coronary Artery Bypass Surgery Circulation, September 9, 2003; 108(90101): II-29 - 33. [Abstract] [Full Text] [PDF]

				M. Loubani, S. Ghosh, and M. Galinanes The aging human myocardium: tolerance to ischemia and responsiveness to ischemic preconditioning J. Thorac. Cardiovasc. Surg., July 1, 2003; 126(1): 143 - 147. [Abstract] [Full Text] [PDF]

				C. Muneretto, A. Negri, G. Bisleri, J. Manfredi, A. Terrini, M. Metra, S. Nodari, and L. D. Cas Is total arterial myocardial revascularization with composite grafts a safe and useful procedure in the elderly? Eur. J. Cardiothorac. Surg., May 1, 2003; 23(5): 657 - 664. [Abstract] [Full Text] [PDF]

				H. R. Mallidi, J. Sever, M. Tamariz, S. Singh, N. Hanayama, G. T. Christakis, G. Bhatnagar, C. A. Cutrara, B. S. Goldman, and S. E. Fremes The short-term and long-term effects of warm or tepid cardioplegia J. Thorac. Cardiovasc. Surg., March 1, 2003; 125(3): 711 - 720. [Abstract] [Full Text] [PDF]

				J. P. Mathew, H. P. Grocott, B. Phillips-Bute, M. Stafford-Smith, D. T. Laskowitz, D. Rossignol, J. A. Blumenthal, and M. F. Newman Lower Endotoxin Immunity Predicts Increased Cognitive Dysfunction in Elderly Patients After Cardiac Surgery Stroke, February 1, 2003; 34(2): 508 - 513. [Abstract] [Full Text] [PDF]

				M. A. Albert and E. M. Antman Preoperative Evaluation for Cardiac Surgery Card. Surg. Adult, January 1, 2003; 2(2003): 235 - 248. [Full Text]

				V. Rao, G. T. Christakis, R. D. Weisel, J. Ivanov, M. A. Borger, and G. Cohen The Insulin Cardioplegia Trial: Myocardial protection for urgent coronary artery bypass grafting J. Thorac. Cardiovasc. Surg., May 1, 2002; 123(5): 928 - 935. [Abstract] [Full Text] [PDF]

				C. D. Naylor Public Profiling of Clinical Performance JAMA, March 13, 2002; 287(10): 1323 - 1325. [Full Text] [PDF]

				N. Sadeghi, S. Sadeghi, Z. A. Mood, and A. Karimi Determinants of operative mortality following primary coronary artery bypass surgery Eur. J. Cardiothorac. Surg., February 1, 2002; 21(2): 187 - 192. [Abstract] [Full Text] [PDF]

				T. O. Stanley, G. B. Mackensen, H. P. Grocott, W. D. White, J. A. Blumenthal, D. T. Laskowitz, K. P. Landolfo, J. G. Reves, J. P. Mathew, M. F. Newman, et al. The Impact of Postoperative Atrial Fibrillation on Neurocognitive Outcome After Coronary Artery Bypass Graft Surgery Anesth. Analg., February 1, 2002; 94(2): 290 - 295. [Abstract] [Full Text] [PDF]

				P. Demers and R. Cartier Multivessel off-pump coronary artery bypass surgery in the elderly Eur. J. Cardiothorac. Surg., November 1, 2001; 20(5): 908 - 912. [Abstract] [Full Text] [PDF]

				J. Mariani, R. Ou, M. Bailey, M. Rowland, P. Nagley, F. Rosenfeldt, and S. Pepe Tolerance to ischemia and hypoxia is reduced in aged human myocardium J. Thorac. Cardiovasc. Surg., October 1, 2000; 120(4): 660 - 667. [Abstract] [Full Text] [PDF]

				E. Braunwald, E. M. Antman, J. W. Beasley, R. M. Califf, M. D. Cheitlin, J. S. Hochman, R. H. Jones, D. Kereiakes, J. Kupersmith, T. N. Levin, et al. ACC/AHA guidelines for the management of patients with unstable angina and non-st-segment elevation myocardial infarction: A report of the american college of cardiology/ american heart association task force on practice guidelines (committee on the management of patients with unstable angina) J. Am. Coll. Cardiol., September 1, 2000; 36(3): 970 - 1062. [Full Text] [PDF]

				N. Hirata, S. Ohtake, Y. Sawa, T. Takahashi, M. Yoshitatsu, H. Matsuda, N. Hirata, S. Ohtake, Y. Sawa, T. Takahashi, et al. Significance of Right Internal Thoracic Artery as Proximal Anastomotic Site Asian Cardiovasc Thorac Ann, September 1, 2000; 8(3): 221 - 223. [Abstract] [Full Text] [PDF]

				W. D. Boyd, N. D. Desai, R. J. Novick, F. N. McKenzie, D. F. DelRizzo, and A. H. Menkis Use of Cardiopulmonary Bypass in High-Risk Patients Is a Predictor of Adverse Outcome Seminars in Cardiothoracic and Vascular Anesthesia, July 1, 2000; 4(2): 86 - 91. [Abstract] [PDF]

				J. Ivanov, M. A. Borger, T. E. David, G. Cohen, N. Walton, and C. D. Naylor Predictive accuracy study: comparing a statistical model to clinicians' estimates of outcomes after coronary bypass surgery Ann. Thorac. Surg., July 1, 2000; 70(1): 162 - 168. [Abstract] [Full Text] [PDF]

				V. Rao, M. A. Borger, R. D. Weisel, J. Ivanov, G. T. Christakis, G. Cohen, and T. M. Yau INSULIN CARDIOPLEGIA FOR ELECTIVE CORONARY BYPASS SURGERY J. Thorac. Cardiovasc. Surg., June 1, 2000; 119(6): 1176 - 1184. [Abstract] [Full Text] [PDF]

				K. A. Eagle, R. A. Guyton, R. Davidoff, G. A. Ewy, J. Fonger, T. J. Gardner, J. P. Gott, H. C. Herrmann, R. A. Marlow, W. C. Nugent, et al. ACC/AHA guidelines for coronary artery bypass graft surgery: A report of the American College of Cardiology/ American Heart Association task force on Practice Guidelines (Committee to revise the 1991 Guidelines for Coronary Artery Bypass Graft Surgery) J. Am. Coll. Cardiol., October 1, 1999; 34(4): 1262 - 1347. [Full Text] [PDF]

				W. D. Boyd, N. D. Desai, D. F. Del Rizzo, R. J. Novick, F. N. McKenzie, and A. H. Menkis Off-pump surgery decreases postoperative complications and resource utilization in the elderly Ann. Thorac. Surg., October 1, 1999; 68(4): 1490 - 1493. [Abstract] [Full Text] [PDF]

				G. N. Djaiani, D. C. H. Cheng, J. A. Carroll, M. Yudin, and J. M. Karski Fast-Track Cardiac Anesthesia in Patients with Sickle Cell Abnormalities Anesth. Analg., September 1, 1999; 89(3): 598 - 598. [Abstract] [Full Text] [PDF]

				M. A. Borger, S. E. Fremes, R. D. Weisel, G. Cohen, V. Rao, T. F. Lindsay, and C. D. Naylor Coronary bypass and carotid endarterectomy: does a combined approach increase risk? A metaanalysis Ann. Thorac. Surg., July 1, 1999; 68(1): 14 - 20. [Abstract] [Full Text] [PDF]

				You're Never Too Old for CABG Surgery Journal Watch Cardiology, March 31, 1998; 1998(331): 1 - 1. [Full Text]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ivanov, J. Articles by Naylor, C. D. Search for Related Content PubMed PubMed Citation Articles by Ivanov, J. Articles by Naylor, C. D. Pubmed/NCBI databases Medline Plus Health Information Coronary Artery Bypass Surgery