Medical Management of Stable Coronary Artery Disease
How Safe Is Medical Management of Stable Coronary Artery Disease?
What is the problem and what is known about it so far?
Previous research has suggested that patients with stable coronary artery disease (CAD) fare well when treated with medical management (use of medications alone). Many patients with this particular disease profile, however, are often treated more aggressively with invasive procedures including the placement of coronary stents or bypass grafting procedures. It was not known if delaying invasive treatment and managing patients with stable coronary disease medically was a viable and safe alternative to immediate invasive treatment.
Why did the researchers do this particular study?
Reducing angina, the crushing chest pain associated with coronary artery disease, is an important goal of both medical and invasive therapies. Invasive interventions are typically more expensive and are associated with potentially severe complications. Furthermore, medical therapy has been shown in some studies to be as effective as invasive treatment in limiting angina and improving quality of life in elderly patients with advanced CAD. The researchers engaged in this study to demonstrate that managing patients medically until they exhibited signs of unstable coronary disease and delaying invasive treatment by applying more rigorous referral criteria was safe and effective.
Who was studied?
Between December 1992 and June 2000, patients were screened at outpatient cardiology clinics affiliated with tertiary medical centers and medical schools. 693 men and women with documented CAD were eventually enrolled in the study. Patients were excluded from the study if they had previously undergone invasive coronary procedures, were in congestive heart failure, had advanced heart valve disease, had other severe life-limiting conditions, or were examined for a 1-time consultation for their cardiac status.
How was the study done?
The treatment strategy used in the study emphasized maximal medical treatment (including but not limited to beta-blockers, long-acting nitrates, sublingual nitroglycerin, statins, aspirin) that could be tolerated by patients on an individual basis. Additionally, the researchers focused on modifying risk factors such as exercise, dietary changes and stress reduction. Periodically patients would undergo testing to assess cardiac function and the overall health of their hearts. While this study focused on medical management as a means to limit the risk of having a non-fatal heart attack or death, the researchers also recommended invasive procedures when these were absolutely necessary. Eventually, about one quarter of the participants required an invasive procedure.
What did the researchers find?
The researchers concluded that postponing invasive treatment until medical therapy had failed or until cardiac instability was observed was safe and was not associated with a higher risk of death or heart attack. In other words, rather than rush a patient into an invasive therapy good long-term outcomes could be achieved by delaying such treatment and using a conservative medical approach that emphasized the use of medicines and lowering of risk factors.
What were the limitations of the study?
This study is limited by the fact that it focused on a very specific group of patients. The study group was composed mainly of older white men of high socioeconomic status. These findings may not be applicable to the general population that includes women and minority groups. The study group also was made up of those cardiac patients with stable coronary disease. The positive outcomes that were observed may not be applicable to those patients with more severe forms of angina. Finally, the study was not designed in such a way to truly compare medical and invasive management of stable CAD patients as it referred to the results of other studies that focused on the outcomes of invasive therapy.
What are the implications of the study?
Using the standard approach to CAD many more patients than may be necessary are advised to undergo invasive procedures to restore blood flow to the heart. This study demonstrates that by holding off on such treatment until absolutely necessary and that by managing these patients in the meantime with medicines and with risk-factor modification, beneficial long-term outcomes can still be achieved.
Summarized by Stanley Kang, College of Medicine, University of Vermont
Summarized from "Long-Term Outcomes of Optimized Medical Management of Outpatients With Stable Coronary Artery Disease". Jabbour, S. et al. The American Journal of Cardiology, February 1, 2004, Volume 93, Number 3, Pages 294-299.
