During the last two decades several large clinical trials have documented beneficial effects of different pharmacological interventions on morbidity and mortality in various cardiovascular conditions. Based on the results of these trials physicians in general feel convinced that there is a considerable reduction of mortality and morbidity as a result of treatment with: (a) β receptor blockers in patients with acute myocardial infarction as well as in the postinfarction period; (b) acetylsalicylic acid (ASA; aspirin) and thrombolytic drugs in patients with acute myocardial infarction; (c) angiotensin converting enzyme (ACE) inhibitors in patients with left ventricular systolic dysfunction irrespective of symptoms of heart failure and, as recently shown in the HOPE study, in patients with high cardiovascular risk but without heart failure or obvious left ventricular systolic dysfunction; (d) β receptor blockers and spironolactone in addition to an ACE inhibitor in patients with chronic heart failure; (e) diuretics, β receptor blockers, calcium channel blockers, and ACE inhibitors in hypertension; and (f) statins in secondary prevention.

However, trials not showing benefit of the intervention have conveyed important messages also. Thus, based on trials showing lack of benefit or even harm from the intervention, most cardiologists do not use class I (and perhaps class III) antiarrhythmic drugs to treat supraventricular or ventricular arrhythmias, as well as (most) calcium channel blockers and positive inotropic drugs in the treatment of heart failure. Furthermore, the role of digitalis in the treatment of heart failure has been clarified since digitalis has been shown not to affect mortality in these patients. The message about lack of effect or harm is not clear, however. As regards antiarrhythmic drugs some studies show benefit of amiodarone, and benefit from calcium channel blocking agents has been indicated in heart failure patients with preserved left ventricular systolic function. Furthermore, preliminary mortality data on …