Antihypertensive drugs and cardioprotection.
Cardioprotection is a broad term; this short review deals with six aspects: 1. Secondary prevention of myocardial infarction (MI) has been shown for beta-blockers in both early and late intervention studies. Dihydropyridine calcium antagonists are associated with an excess incidence of coronary events, whereas non-dihydropyridines prevent reinfarction provided left ventricular (LV) function is adequate; dihydropyridines tend to increase heart rate and stimulate the sympathetic and renin-angiotensin systems. 2. Primary prevention of MI has been shown for beta-blockers in younger/middle-aged hypertensives but not in the elderly. Diuretics, by contrast, possibly increase the risk of coronary events in younger/middle-aged hypertensives but significantly reduce coronary events in older hypertensives. These results might be explained by the larger, noncompliant left ventricle of the elderly hypertensive, which, in the absence of overt ischemia, responds poorly to beta-blockade (further enlargement with increased wall stress and impaired coronary reserve), while diuretics have the opposite effect. Primary prevention of coronary events in patients with chronic angina is likely to occur with beta-blockers, while studies with calcium antagonists have shown a significant excess of coronary events. 3. Ischemic events occurring during the "vulnerable" period between 7 and 10 AM (when sympathetic activity is maximal) are significantly reduced by beta-blockers but not by calcium antagonists. 4. Stress-induced myocardial necrosis in humans is markedly reduced by beta-blockers. 5. Coronary risk factors, such as elevated blood lipids, hyperglycemia, and insulin resistance, are possibly adversely affected by diuretics and beta-blockers, with the former also increasing heart rate, plasma renin activity, and plasma catecholamine levels.(ABSTRACT TRUNCATED AT 250 WORDS)
Royal Brompton and National Heart-Chest Hospital, London, UK.
J M
JM
Cruickshank
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D006331:Heart Diseases / Q000517:prevention & control*; D006801:Humans; D009203:Myocardial Infarction / Q000517:prevention & control*
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents