Calcium antagonist drugs in hypertensive patients with angina pectoris

Abstract

Arterial hypertension frequently occurs in association with myocardial ischaemia and is an independent and significant risk factor for the development of coronary artery disease (CAD), as is left ventricular hypertrophy due to arterial hypertension. The prevalence of CAD in patients with hypertension is high, while hypertension occurs in approximately 60% of patients with CAD. Myocardial ischaemia occurs both in the presence and absence of CAD, probably as the result of limitation of coronary vasodilator capacity and reduction in coronary flow. This may occur in hypertension due to increased transmural coronary artery resistance, alterations in the vascular wall and endothelial dysfunction. Furthermore, left ventricular hypertrophy itself predisposes the heart towards ischaemia due to an increased diffusion distance between capillaries. When myocardial ischaemia occurs in hypertensive patients, 90% of all episodes are aysmptomatic. The highest incidence of ischaemic episodes appears to occur in treated elderly hypertensive men with inadequate blood pressure control (40%). Calcium antagonists exert a range of beneficial effects in hypertensive patients, including reduction of blood pressure, improvement in myocardial blood flow, regression of left ventricular hypertrophy and cardioprotection in reperfused organs. However, while vasoprotective effects have been demonstrated in animal models, beneficial effects in man are uncertain. Thus, in established coronary atherosclerosis, calcium antagonist treatment has produced only a mild reduction in the appearance of new atherosclerotic lesions.