Identification of patients at risk from ischaemic complications

Several risk factors for cardiovascular disease are discussed, including blood pressure, left ventricular hypertrophy, stress and smoking. Beta-blockers have a modest effect in reversing increased left ventricular mass, compared with angiotensin converting enzyme (ACE) inhibitors, although beta-blockers are as effective as ACE inhibitors in reducing posterior wall and interventricular septal thickness. Coronary events and many risk factors show a circadian rhythm. Beta-blockers can reduce the mid-morning (0700-1000 h) risk of ischaemic events and myocardial infarction. Catecholamine levels peak at 0700-1000 h, and catecholamine-induced myocardial necrosis can be significantly reduced by beta-blockade. Beta-blockers appear to be more effective than calcium antagonists in modifying the mid-morning vulnerable period and reducing the duration of ischaemia. However, the problems of using surrogate endpoints are discussed. In young to middle-aged hypertensives, beta-blockers are more effective in primary prevention of myocardial events than diuretics, though this is not the case for the elderly. Beta-blockers are also more effective than calcium antagonists in reducing morbidity and mortality after a myocardial infarction (i.e. secondary prevention). Patients with hypertension associated with ischaemic heart disease are most likely to get maximal benefit from treatment with beta-blockers.