beta-blockers or calcium antagonists in silent ischaemia?

Unrecognized or silent myocardial ischaemia during daily life has generated considerable recent interest as it occurs in all forms of coronary artery disease, ranging from those who are totally asymptomatic to those who have had a myocardial infarction. A characteristic diurnal cycle of both frequency and duration of these ischaemic episodes occurs and is the same as the diurnal variation observed in frequency of acute myocardial infarction and out-of-hospital sudden death. These findings suggest common underlying triggering mechanisms which may couple transient ischaemia to these morbid events. The presence of daily-life silent ischaemia is associated with a two- to five-fold increase in risk of death and similar increases in risk of non-fatal infarction. Multivariate analysis suggests that silent ischaemia is the best independent predictor of outcome (e.g. death, or myocardial infarction) among a number of factors that include coronary angiography and exercise test results. Anti-anginal agents (e.g. nitrates, beta-blockers, calcium antagonists) also reduce or prevent daily-life silent ischaemia. While anti-anginal treatment can control both symptomatic and silent ischaemic episodes, therapy directed towards symptom control alone may be insufficient to control recurrent silent ischaemia in many individuals. A recent report suggests that suppression of painless ischaemia by anti-ischaemic treatment is associated with a reduced risk of adverse outcome. Additional advances in this area will require the results of large, well-controlled multicentre clinical trials, several of which are currently in progress.(ABSTRACT TRUNCATED AT 250 WORDS)