Role of ischemia in postinfarction heart failure: hypothetical considerations based on use of verapamil in the DAVIT II Study. Danish Study Group on Verapamil in Myocardial Infarction

Calcium antagonists in the elderly. A risk-benefit analysis

Calcium antagonists are effective in lowering blood pressure, relieving anginal symptoms and improving exercise tolerance in older and younger patients with coronary artery disease. Verapamil and diltiazem are effective in slowing ventricular response rates to supraventricular arrhythmias in both older and younger patients. Although they belong to at least 3 distinct chemical classes, a moderate decrease in the clearance of all calcium antagonists occurs with aging. Most clinical trials of these drugs have used the same dosages in older and younger patients, confounding analyses of sensitivity in older compared with younger patients. Greater reductions in blood pressure usually occur in older compared with younger patients receiving the same dosages of calcium antagonists; similarly, the dosage required to reduce blood pressure to a certain level is usually lower in older compared with younger patients. Drug acquisition costs are generally higher for calcium antagonists than for beta-blockers or diuretics. Compared with younger patients, greater heart rate suppression may be seen in older patients treated with verapamil and diltiazem; conversely, heart rate increases are usually seen with dihydropyridines. Calcium antagonists have not been shown to provide long-term benefits or decreased morbidity or mortality in elderly patients with hypertension. Verapamil, but not dihydropyridines, decreases mortality after myocardial infarction in patients without congestive heart failure. Calcium antagonists have not been shown to be beneficial in the treatment of acute stroke. Adverse effects, such as a postural hypotension, may be more frequent in elderly compared with younger patients. In addition, the elderly are at greater risk for drug interactions with calcium antagonists due to the higher likelihood that they are receiving other drugs.

Anti-ischemic intervention as prognosis improvement in patients with coronary artery disease, with special focus on verapamil

Angina pectoris is a significant risk predictor in patients with atherosclerotic heart disease. The major complications are myocardial infarction, heart failure, and arrhythmias. Plaque rupture turns stable angina pectoris into acute coronary syndrome by provoking platelet aggregation and thereby thrombus formation. Verapamil significantly inhibits platelet aggregation and thrombus formation, which may be one of several reasons for the protective effect of verapamil on reinfarction in patients recovering from myocardial infarction. Ischemia may lead to left ventricular dilation and diastolic dysfunction, and thereby heart failure. In postinfarction patients intervention with verapamil significantly reduced the use of diuretics compared with placebo, indicating that anti-ischemic intervention may prevent heart failure. Ventricular arrhythmias are significantly associated with arrhythmic as well as non-arrhythmic death. The lack of preferential association of ventricular arrhythmias with arrhythmic death rather than nonarrhythmic death may imply that arrhythmias are provoked by ischemia. Antiarrhythmic intervention in postinfarction patients significantly increases death and arrhythmic events compared with placebo, especially in patients with residual ischemia. This may be due to a significant slowing of conduction during ischemia in patients treated with antiarrhythmic agents. In animal studies anti-ischemic agents prevent or suppress ventricular arrhythmias during ischemia, whereas traditional antiarrhythmic drugs have no effect or even worsen the arrhythmias, especially during episodes with elevated sympathetic activity. Verapamil significantly reduces plasma norepinephrine levels and the norepinephrine release during ischemia, whereby ventricular arrhythmias may be prevented. Also, supraventricular arrhythmias are significantly associated with myocardial ischemia and are prevented by verapamil. In patients with atherosclerotic heart diseases, angina pectoris is a significant risk predictor, but anti-ischemic intervention should be considered even in patients in whom the major problem is heart failure or arrhythmias.

ACE inhibitors and calcium antagonists in the treatment of congestive heart failure

The increased mortality after myocardial infarction is related to the risk of reinfarction, sudden death, and the development and progression of heart failure; in congestive heart failure it is due to the progression of heart failure and sudden death. ACE inhibitors have been proven to prevent cardiovascular events, especially the progression of heart failure, in postinfarct patients with reduced ejection fraction and heart failure in the SAVE and AIRE trials. In patients with congestive heart failure, ACE inhibitor treatment has prevented cardiovascular death and reduced morbidity due to progressive heart failure in the SOLVD trials. In post-myocardial infarction patients, the calcium antagonist nifedipine did not affect mortality or morbidity; diltiazem improved prognosis in patients without congestive heart failure and in patients with non-Q-wave infarction; and verapamil improved prognosis by prevention of reinfarction and sudden death. Combination treatment with both verapamil, which has pronounced antiischemic properties and prevents sudden death and reinfarction, and an ACE inhibitor, which prevents the progression of heart failure, is a possibility for future cardiovascular therapy that should be evaluated.