Quality of Life After Aortic Valve Replacement at the Age of >80 Years
Background—The optimal management of aortic valve disease in patients >80 years old depends on functional outcome as well as operative risks and late survival.
Methods and Results—We retrospectively identified 133 patients (62 men, 71 women) aged 80 to 91 years (mean 84±3 years) who underwent aortic valve replacement alone or in combination with another procedure between January 1, 1993, and April 31, 1998. Demographics included hypertension 68%, diabetes mellitus 17%, and history of stroke 11%. Operative (30 day) mortality rate was 11%. Urgent or emergent surgery, aortic insufficiency, and perioperative stroke or renal dysfunction were risk factors for operative death by multivariable analysis. Intensive care unit and total hospital length of stay were prolonged at 6.2 and 14.7 days, respectively. Late follow-up between July 1, 1998, and November 1, 1999, was 98% complete. Actuarial survival at 1 and 5 years was 80% and 55%, respectively. Predictors of late mortality were preoperative or perioperative stroke, chronic obstructive pulmonary disease, aortic stenosis, and postoperative renal dysfunction. The mean New York Heart Association functional class for 65 long-term survivors improved from 3.1 to 1.7. Quality of life assessed with the Medical Outcomes Study Short Form-36 was comparable to that predicted for the general population >75 years old.
Conclusions—Functional outcome after aortic valve replacement in patients >80 years old is excellent, the operative risk is acceptable, and the late survival rate is good. Surgery should not be withheld from the elderly on the basis of age alone.
The decision between continued medical management and surgical intervention for aortic valve disease in patients >80 years old may be difficult for both the physician and the patient. Despite a number of recent studies that demonstrate acceptable operative risk as well as satisfactory long-term survival rates,1 2 3 4 5 6 there remains significant reluctance to recommend aortic valve replacement (AVR) in this age group. This likely relates in part to uncertainty over the long-term functional results that can be expected. In some settings, the potential for increased resource utilization may enter into decision making as well. The advancing age of the general population makes this an increasingly frequently encountered dilemma. With these issues in mind, we sought to examine our results with AVR in patients >80 years old. Perioperative mortality and morbidity rates, as well as late survival and functional outcome, including measures of the quality of life, were assessed.
Between January 1, 1993, and April 31, 1998, 133 patients >80 years old underwent AVR with or without concomitant procedures at Washington University. Preoperative demographic information and perioperative events were retrieved from our computerized database. Late follow-up information was obtained through postal questionnaire or telephone interview between July 1, 1998, and November 1, 1999. Follow-up was 98% complete. Functional status was determined in 65 late survivors. New York Heart Association (NYHA) functional class was assessed, as was quality of life with the Medical Outcomes Study (MOS) Short Form-36 (SF-36) tool.7 Eight dimensions of health were investigated: physical functioning, physical health related to age- and role-specific activities (“Role-Physical”), bodily pain, general health, vitality, social functioning, personal feelings of performance in age- and role-specific activities (“Role-Emotional”), and mental health. Scores were compared with those expected for the general population of a similar age.
Members of the Division of Cardiothoracic Surgery carried out surgical procedures at Barnes and Jewish Hospitals. Although approaches varied somewhat among surgeons, all procedures were carried out with cardiopulmonary bypass and at least mild systemic hypothermia. Cardiac arrest was achieved with cold crystalloid or blood cardioplegia. All procedures were performed via the standard median sternotomy approach. The selection of prosthesis type was at the discretion of the operating surgeon. There is a strong institutional preference for biologic valves in this age group regardless of the preoperative presence of atrial fibrillation. Coronary bypass was performed whenever occlusive disease involved major epicardial vessels. All continuous data were expressed as mean±SD or as a percentage as indicated. The survival analysis was made with the Kaplan-Meier estimator. Univariable analysis of risk factors for early and late death was performed, and factors found to trend toward significance (P<0.15) were entered into multivariable analysis. A stepwise multivariable Cox regression model was then constructed with those factors to determine independent predictors of early and late death (P<0.05). The Friedman nonparametric t test was used to compare the preoperative and postoperative NYHA functional class. A value of P<0.05 was considered significant for all statistical calculations. The SYSTAT system for statistics was used for all data analyses (Version 6.0 for Windows; SPSS).
Demographics of the Study Population
As shown in Table 1⇓, men and women were approximately equally represented. Two thirds of patients had a history of hypertension but less than one fifth had diabetes mellitus. Chronic obstructive pulmonary disease, peripheral vascular disease, and cerebrovascular disease were less common. The majority of patients had predominant functional stenosis, with a mean peak gradient of 54±22 mm Hg and a calculated valve area of 0.6±0.2 cm2 in this subgroup. Atrial fibrillation was present preoperatively in one fifth of patients. Angina pectoris was a presenting complaint in the majority of patients, and >80% had NYHA functional class III or IV symptoms of heart failure. Few had undergone previous cardiac surgery or had a history of myocardial infarction. Less than 15% of patients had ejection fractions of <0.35.
Details of the operative procedures are presented in Table 2⇓. A significant percentage of procedures were performed urgently or emergently. Concomitant CABG was performed frequently. Biological prostheses predominated, and ≈50% of valves used were ≤21 mm. Of the 52 patients who received small valves, 40 (77%) were women.
The operative (30-day) mortality rate was 11.1% (Table 3⇓). Stepwise logistic regression analysis yielded urgent or emergent surgical status (P=0.005) as a strong predictor of operative death. The mortality rate for urgently operated patients was 21.4%, whereas that for emergently operated patients was 43%. Aortic insufficiency also was a predictor of operative risk (P<0.05). Among perioperative complications, perioperative renal dysfunction (P<0.05) and stroke (P<0.05) were risk factors for death within 30 days of surgery. Concomitant CABG was not a risk factor. As shown in Table 4⇓, the operative mortality rate was actually higher in those who underwent isolated AVR than in those who underwent concomitant CABG, although this difference did not reach statistical significance. Operative risk was not related to preoperative NYHA functional class, with similar operative mortality rates observed for individuals in NYHA functional class I or II as for those in class III or IV (Table 4⇓).
The morbidity rate was significant. More than 10% of patients experienced renal dysfunction defined as an increase in serum creatinine to >2.0 g/dL, and almost 4% of patients required hemodialysis after surgery. More than one fourth of patients required mechanical ventilation for >24 hours. Permanent stroke, however, was observed in only 4% of patients. Atrial fibrillation was common, and a relatively high percentage of patients experienced bleeding complications.
Although cost data are notoriously inaccurate, length of stay may be considered a surrogate for resource use. The postoperative length of stay in the intensive care unit was prolonged at a mean of 6.2 days (range 1 to 41 days). Forty-seven percent of patients spent >4 days in the intensive care unit. The overall postoperative hospital stay ranged from 4 to 92 days (mean of 14.7 days).
The actuarial survival rate was ≈80% at 1 year and ≈55% at 5 years (Figure 1⇓). Stepwise logistic regression analysis revealed preoperative history of stroke (P=0.01), chronic obstructive pulmonary disease (P<0.001), and aortic stenosis (P<0.001) as preoperative predictors of late death. Perioperative renal dysfunction (P=0.001) and perioperative stroke (P<0.001) were also predictive of late death. Late survival was not worse for those in an advanced NYHA functional class before surgery. Those in NYHA functional class I or II who underwent isolated AVR actually had a worse late survival rate than those in class III or IV (Table 4⇑), which reached statistical significance, likely due to the small number of individuals in this group.
Sixty-five long-term survivors responded to postal questionnaires or telephone interviews regarding their functional status. For this subgroup, the mean NYHA functional class improved from 3.1 to 1.7 (Figure 2⇓) with >80% of patients in class I or II (P<0.001). Scores on the SF-36 were comparable to those for the general population ≥75 years old (Figure 3⇓). Subjects actually scored higher than the control population in 5 areas, including Bodily Pain, General Health, Social Functioning, Role-Emotional, and Mental Health. Unfortunately, matched preoperative data on subjects are unavailable.
The results of the present study demonstrate that gratifying late results may be achieved with AVR in patients >80 years old. Survival rates at 1 and 5 years postoperatively were satisfactory, and there was marked improvement in NYHA functional class among long-term survivors. Furthermore, the quality of life as assessed with the MOS SF-36 survey was comparable to that is expected among the general elderly population. This can be accomplished at an acceptable operative risk even among patients with advanced symptoms of heart failure.
There are ample data in the literature that support the excellent late survival rates to be achieved in this age group. Remarkably, there have been multiple reports1 2 3 4 5 6 8 9 of similar 5-year survival rates of 55% to 66%. Less attention has been paid to functional outcome, however. A clear improvement in NYHA functional class has been reported,4 as have measures such as autonomy8 and “satisfaction” with present quality of life8 or with the decision to proceed with surgery.2 9 In recent years, interest has increased in more sophisticated and standardized measurement of functional outcome, and several previous studies have been published.
Khan et al4 evaluated 61 octogenarians (mean age 83.5 years) who underwent cardiac surgery and obtained Karnofski performance scores before and after surgery. Of these patients, 47 underwent isolated AVR. Functional improvement was significant, with an improvement in the Karnofski score of 50% by 1 month and a 2-class improvement in median NYHA status. Levin et al10 and Olsson et al11 also explored the measurement of quality of life with their own assessment tools, again with documented improvement. These studies share a significant strength in having both preoperative and postoperative data on subjects. Their use of nonstandardized instruments, however, may make their methodology of limited applicability.
We have chosen to explore the use of a widely accepted instrument for the assessment of quality of life, the MOS SF-36. Many such tools have been developed, and each may be more applicable to a specific disease state than to another; however, this instrument was previously used in a similar study of a somewhat younger patient population who underwent cardiac surgery at the Johns Hopkins School of Medicine. Tseng et al12 studied patients >70 years old who underwent AVR. The mean age of their study group was 76.2 years. In comparison with the general population, as in the present study, excellent functional recovery was achieved. A shortcoming of their study, like ours, was the lack of preoperative data on the study subjects, an inherent limitation of retrospective analysis. In addition, for any such study, the completion of even a “short-form” questionnaire can be a challenge for elderly individuals whose vision or mental faculties may be compromised. The result is a likely selection bias among responders for those with the best functional outcome. Nonetheless, the present study confirms in this older population the finding that even in elderly persons, an excellent quality of life can be anticipated in a significant proportion of individuals.
This improvement in functional status comes at some cost, however. In addition to the risk of perioperative death, the morbidity rate was considerable and the hospital length of stay was, for the current era, prolonged. This can be expected to translate into increased overall costs and should be taken into consideration when projecting health care expenditures.
Among the risk factors for operative death that were identified in the present study, only surgical status is potentially modifiable. The marked increase in operative risk for urgent and emergent procedures suggests that surgical intervention should be considered before hemodynamic decompensation has occurred. We favor an aggressive approach once a patient has been deemed a surgical candidate. In contrast, patients who present in a decompensated state may benefit from the optimization of hemodynamics before surgery.
The present study identified the presence of preoperative stroke and chronic obstructive pulmonary disease as predictors of late death. This finding also is consistent with previous studies2 9 12 and suggests that a less aggressive approach may be warranted in these individuals.
Concomitant CABG was performed in a significant number of patients in our series. Early studies of AVR in elderly persons suggested that the mortality rate for the combined procedure was increased, with mortality rates for the combined procedure ranging from 12% to 37% compared with rates of 5% to 7% for AVR alone.2 13 14 15 Concomitant revascularization was not a predictor of death in our more contemporary series, possibly due to the neutralizing effect of improved myocardial protection. Several other recent series have shown similar results, with no effect of CABG,8 or an affect only in women who underwent the combined procedure.16
A significant number of patients in this series received valves of ≤21 mm. Although body surface area data were not available, the majority of these valves were placed in women. This also reflects our reluctance to embark on more extensive procedures, such as root enlargement, in the very old. This practice is supported in the literature,5 and small valve size did not fall out as a risk factor for early or late death.
The present study was retrospective, and there are inherent weaknesses and limitations of any such analysis. Principal among these is the potential selection bias in favor of more robust patients imposed by the cardiologists who propose this intervention and the surgeons who accept the patients as candidates. This factor cannot be accounted for in any rigorous way, because there is no database of patients who were// refused surgery. A large number of surgeons and cardiologists were involved in the care of these patients, and there are no codified criteria for acceptance for surgery at our institution. Still the majority of patients were of advanced functional class, and many required concomitant bypass grafting suggesting that this is not a highly selected subgroup.
Reprint requests to Thoralf M. Sundt, MD, Suite 3106, Queeny Tower, One Barnes Hospital Plaza, St Louis, MO 63110.
- Copyright © 2000 by American Heart Association
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