New Roles for Statins
Treatment with statins seems to have reduced death rates at 30 days and at 6 months for patients undergoing percutaneous coronary intervention (PCI), according to researchers from the Cleveland Clinic, Cleveland, Ohio, in a report in this week’s Circulation (Circulation. 2002;105:691–696OpenUrl).
The authors, led by Albert W. Chan, MD, MS, of the Section of Interventional Cardiology, Department of Cardiovascular Medicine, noted in their report that long-term administration of statin therapy had been shown to reduce major coronary events and mortality in randomized clinical trials, and that not only had statin therapy been associated with lipid lowering, but it also had been shown to have a favorable effect on platelet adhesion, thrombosis, endothelial function, inflammation, and plaque stability. Because all of those factors could affect the course of PCI, the authors hypothesized that statin therapy also could have a favorable effect on the interventional procedure because coronary angioplasty and stent placement can produce platelet activation, clotting, and inflammation.
During a 7-year period from 1993 to 1999, the authors prospectively collected data on the first 1000 patients undergoing PCI at the institution, excluding those who were admitted with an acute or recent myocardial infarction (MI) or cardiogenic shock. They compared the data on statin-treated and non–statin-treated patients at baseline, during the procedure, and at 6 months. Of the 5052 patients for whom follow-up was completed, 26.5% received a statin at the time of the procedure.
In the analysis, patients who received statins were less likely to die at 30 days (0.8% versus 1.5%) and at 6 months (2.4% versus 3.6%). There was no significant difference, however, in the incidence of nonfatal MI or the need for repeat revascularization. When the combined end points of death, nonfatal MI, or revascularization were computed, they were 16.1% for the statin-treated group and 15.5% for the non–statin-treated group.
The authors postulated that the mortality reduction seen with statin therapy could be explained on the basis of antiinflammatory effects, saying that, “it appears plausible, but with the current evidence, remains speculative.”
They also pointed out that treatment with statin therapy was not randomized. Although they attempted to deal with this issue by statistical manipulation, “unmeasurable factors may still exist.” Physician or patient bias also could affect the rate of revascularization in the cohort, they noted. “Furthermore, adjustment for glycoprotein IIb/IIIa inhibitor use, which was associated with worse outcome in our multivariate model, might be able to adjust for some nonmeasured variables that were deemed important predictors of adverse outcomes by the operators.”
In addition, they noted, they did not know what discharge medicine was prescribed or how compliant the patients were in taking it. “Likewise, the length of statin pretreatment that would be required to produced the observed mortality reduction remains unknown,” they wrote.
“These data suggest the need to evaluate prospectively the impact of pretreatment with statins within a randomized trial design, in particular targeting patients with elevated inflammatory markers prior to coronary intervention,” they concluded.
Fever After Coronary Artery Bypass Graft Surgery Increases Likelihood of Cognitive Loss
The higher the patient’s fever in the first day after coronary artery bypass graft surgery, the more likely that patient is to suffer severe cognitive decline, according to researchers at Duke University Medical Center in Durham, NC.
In a report in the February issue of the American Heart Association journal Stroke (Stroke. 2002;33:537–541), the Neurologic Outcome Research Group (NORG) Cardiothoracic Anesthesiology Research Endeavors (CARE) investigators measured the hourly postoperative temperatures of 300 patients who had undergone coronary artery bypass graft surgery. The patients had undergone a battery of cognitive tests before surgery and then underwent a similar round of testing 6 weeks after surgery. They found that the maximum postoperative temperature was associated with a greater degree of cognitive dysfunction 6 weeks after surgery. In their study, 39% of patients had cognitive deficits 6 weeks after bypass surgery.
As the researchers have said, experimental design has proved that temperature can modulate the extent of cerebral injury. They have extended the testing of that hypothesis to the real world with this study. Fever is a common phenomenon after bypass surgery, but it previously was not considered a pressing medical issue, said the Duke researchers.
“This is the first study to look at early postoperative hyperthermia, and it shows a clear association between this hyperthermia and cognitive decline,” said Hilary Grocott, MD, Associate Professor of Anesthesiology and lead investigator of the Duke study.
“While this study does not answer the question of whether the cognitive decline develops as a result of the hyperthermia, or whether the cognitive decline and the hyperthermia are caused by the same underlying process, the association is definitely there,” he continued. “Clearly, this is a common phenomenon, and one in which we could potentially intervene to improve the cerebral outcome of heart surgery patients.”
Hormone Levels Predict Congestive Heart Failure, Mortality
Levels of B-type natriuretic peptide (BNP) that are as much as 4 times the normal level increase the risk that patients who come to the hospital with shortness of breath will return later with congestive heart failure or will die, said researchers from the Division of Cardiology and General Internal Medicine and the Departments of Medicine and Nursing at the Veterans Affairs Medical Center in San Diego, Calif. (Ann Emerg Med. 2002;39:131–138OpenUrlCrossRefPubMed.)
The researchers measured the BNP levels of 325 patients who came to the emergency department because of dyspnea or shortness of breath. The patients were followed for 6 months to monitor when they died, were readmitted to the hospital for a heart-related reason, or had repeated emergency department visits for congestive heart failure. They determined that patients with a level of BNP was that 4 times the normal level had a 51% chance of returning to the hospital with congestive heart failure or of dying within 6 months of their initial visit to the emergency department.
“The signs and symptoms of congestive heart failure are not easily discernible, which makes the diagnosis difficult,” said Alan Maisel, MD, of the Veterans Affairs Medical Center in San Diego, Calif. “This study supports emergency physicians’ use of BNP testing as another tool in their arsenal for diagnosing patients at risk of this disease.”