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Query: UMLS:C0002962 (angina)
 21,142 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In man a close interrelationship exists between hyperadrenergic states, myocardial ischemia, necrosis, infarction and sudden cardiac death. Persistent high catecholamine levels may also be associated with increased vascular endothelial turnover and permeability to calcium and lipoproteins, increased blood velocity, abnormal blood flow patterns and atheroma formation. There are thus good reasons to predict a cardiovascular protective effect of beta-blockers. Animal data indicate that in spite of apparently adverse plasma lipoprotein changes beta-blockers retard atheromatous plaque formation under conditions of high cholesterol diet with or without stress. A slow heart rate, as well as a reduction in calcium influx and inhibition of both esterification of arterial wall cholesterol (by ACAT) and endothelial permeability to lipoproteins, may be central to this process. Beta-blockers benefit a spectrum of conditions related to the atheromatous process and myocardial necrosis. These are silent ischemia; stable (including mixed), unstable and preinfarction angina; periinfarction events (including myocardial rupture and dissection of the ascending aorta); and myocardial necrosis associated with stress conditions such as head injuries and subarachnoid hemorrhage. In one study coronary deaths in hypertensive men, particularly in smokers, were significantly reduced by metoprolol (a beta 1-selective blocker) compared to a diuretic. In contrast in the MRC study of mild hypertension only nonsmoking men with mild to moderate hypertension who received a nonselective beta-blocker appeared to experience fewer myocardial infarctions. Recent clinical data showed that moderate-severe hypertensives who were optimally controlled by atenolol-based treatment over a 10-year period were less likely to die from myocardial infarction than those suboptimally controlled, irrespective of a rise in serum triglyceride levels. Thus the net effect of acute beta-blockade in hyperadrenergic states, including myocardial infarction, is to limit cardiovascular damage. Chronic beta-blockade inhibits atheroma formation (in animals) and beneficially modifies the incidence of stroke and myocardial infarction, which in man are the long-term consequences of hypertension.
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PMID:The beta-receptor, atheroma and cardiovascular damage. 257 Apr 26

Beta-blockers have been considered for decades as effective agents in preventing coronary events in hypertensive patients. Actually, the scrutiny of the available data arises some doubts over the real value of this pharmacological class. In primary prevention, the clinical benefits of beta-blockers are poorly documented: the studies conducted against placebo (MRC, IPPPSH...) did not show any significant differences regarding the rate of coronary events (except within non smokers); moreover, the beneficial effect of propranolol in preventing sudden deaths and silent myocardial infarctions has been reported byjust one retrospective analysis. Likewise in HAPPHY study, the comparison with diuretics did not emphasize a clear superiority of one of both classes; the better effect of metoprolol regarding overall mortality and fatal coronary events was shown in the pecular subset MAPHY, only. Furthermore, in elderly people, HEP, MRC OA and STOP studies did not find any significant effect of beta-blockers in preventing coronary events, as compared with placebo. However, SHEP study, which involved patients older than 60 years with isolated systolic hypertension receiving first a diuretic, then a beta-blocker(atenolol) in 1/4 of the cases, demonstrated a significant reduction versus placebo both in strokes and in coronary events. Finally, in UKPDS, CAPP, LIFE and CONVINCE studies, atenolol turned out to have a similar efficacy as captopril, losartan and verapamil, in preventing ischemic heart disease. Among the numerous published meta-analyses, that of Psaty pointed out the absence of a primary cardioprotective effect by beta-blockers; more recently, that of Carlberg, emphasized atenolol given alone as the first-line drug to fail in significantly reducing coronary events and strokes. In secondary prevention, some more convincing data may be found in the literature, regarding post myocardial infarction patients (meta-analyses of Staessen, 1982, Yusuf, 1985 and Soriano, 1997), as well as those with stable angina (BIP study in diabetics) or silent ischemia (ASIST study: significant reduction in number and duration of ischemic events by atenolol). Moreover, INVEST study recently showed atenolol and verapamil to have an equivalent efficacy in the hypertensive patients with stable coronary artery disease. Last, hypertension should be reminded as resulting in many cases of heart failure, a pathology where beta-blockers have clearly demonstrated their beneficial effects.
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PMID:[Do beta-blockers prevent coronary events in hypertensive patients?]. 1623 74