Clinical outcome studies of anti-anginal drug therapy for patients with stable coronary disease: an indication for clinical trials

Despite recent advances in prevention and treatment, the number of individuals who suffer from chronic symptomatic coronary artery disease is rising. Past experience with clinical trials in cardiovascular disease has shown that the results are often unanticipated and at odds with the scientific rationale that existed beforehand. Also, important lessons have been learned concerning sample size and the choice of end-points. One of these has been the unreliability of surrogates (such as blood pressure, exercise capacity and number of anginal attacks) in predicting the effect of treatment on morbidity and mortality. The current drug therapy for stable angina in patients without a history of myocardial infarction has not been tested in large-scale clinical trials. No data exist for organic nitrates. The rationale for using beta-blockers comes from trials in patients who had a history of myocardial infarction. Recent experience with sustained release calcium channel antagonists suggests that they appear to be safe in patients with stable angina. Their effect on overall clinical outcome remains to be established, however. It is for this reason that trials such as ACTION are both justifiable and needed.