[Prevention with vasoactive drugs].

Arterial hypertension is the most frequent cause of a disturbance of coronary microcirculation. Inspite of having normal epicardial coronary arteries, patients with arterial hypertension often have symptoms of angina pectoris and a positive exercise tolerance test. The angina pectoris symptoms in patients with arterial hypertension are due to functional and structural alterations of the coronary microcirculation. Consequently, an antihypertensive therapy should not only aim at lowering blood pressure and reversing myocardial hypertrophy, but also to improve coronary microcirculation in order to avoid the consequences of chronic ischemia on the myocardium. Until now, only experimental studies have indicated that antihypertensive therapy can improve coronary flow reserve. To determine (also under clinical conditions) if coronary flow reserve can be improved, in 30 hypertensive patients maximal coronary blood flow, minimal coronary resistance, and coronary reserve (dipyridamol) were studied before and after a long-term antihypertensive treatment (9-12 months) with an ACE-inhibitor (enalapril 10-20 mg/d), a calcium channel blocker (diltiazem 120-180 mg/d) and a beta 1-selective beta-receptor-blocker (bisoprolol 5-10 mg/d). To assess the chronic effects rather than the acute effects of the antihypertensive pharmacon, coronary microcirculation was studied after intermission of medical therapy for a period of 1 week. Along with a comparable decrease in LV muscle mass, coronary reserve was improved after enalapril by 48%, after diltiazem by 48%, and after bisoprolol by 22%. It is possible that the observed increase in coronary reserve is related to the reversal of structural vascular abnormalities on the level of the coronary microcirculation.(ABSTRACT TRUNCATED AT 250 WORDS)