Role of nitrates for the therapy of coronary artery disease patients in the years beyond 2000.

Abstract

Vasodilator therapy with nitrates has been used for almost a century to bring relief to patients suffering from angina. The acute anti-ischemic effects of nitro-vasodilators for the treatment and prevention of anginal attacks is unquestioned. In addition, nitrates are administered in order to reduce symptomatic and silent ischemic episodes, in patients with proven coronary heart disease who exert ST segment alterations on Holter monitoring. The reduction in total ischemic burden may result in an improved prognosis with regard to infarct prevention and possible prevention of deterioration of left ventricular function due to repetitive episodes of myocardial ischemia. In patients with unstable angina, administration of nitrates significantly diminishes ischemic episodes and reduces the number of clinically symptomatic anginal attacks. The prevention of left ventricular dilatation in patients within the first few days and months following acute myocardial infarction may be due to the reduced preload. In patients with heart failure, preload reduction with nitrates and afterload reduction with hydralazine was tested versus angiotensin converting enzyme (ACE) inhibitors. However, unfortunately, very few data are available concerning the combination therapy of ACE inhibitors and nitrates in heart failure and following acute myocardial infarction. Long-term continuous administration of high doses of nitrates may cause nitrate tolerance, thus reducing the vasodilator potency of these drugs. Since nitrates were introduced into medical therapy many decades before randomized controlled trials were performed, and evidence-based medicine became the basic principal for medical therapy, there are still indications and situations where the full therapeutic potential of nitrates is not being fully appreciated. During recent decades, other anti-ischemic drugs, i.e., beta-receptor agonists and calcium channel blockers, were introduced into the clinical setting and contributed to an optimized therapy for patients with coronary heart disease. Nevertheless, due to their proven and unsurmounted symptomatic efficacy, nitrates will remain one of the cornerstones of acute and long-term therapy of patients with coronary heart disease far beyond the year 2000.