Calcium Channel Antagonists Should Be Among the First-line Drugs in the Management of Cardiovascular Disease

There are a number of cardiovascular conditions in which calcium channel antagonists (CCAs) are accepted as first-line therapy, including Prinzmetal's angina and Raynaud's phenomenon. The real issue is whether symptomatic relief of angina or effective reduction of blood pressure (BP) is matched by a good safety record. In effort angina, verapamil is as safe as metoprolol, and nifedipine (tablet form) is as safe as atenolol. In unstable angina, intravenous diltiazem is better than intravenous nitroglycerin; there are no similar data on beta-blockade. Short-acting nifedipine is contraindicated in unstable angina. There is no place for CCAs in acute phase myocardial infarction and short-acting nifedipine is contraindicated. In the post-MI phase, two specific groups of patients benefit from diltiazem or verapamil: (1) those who had non-Q-wave infarcts and (2) those who are hypertensive. The DAVIT studies argue for the safety and efficacy of verapamil but do not allow comparisons with standard beta-blocker therapy. In the treatment of hypertension, the recommendation often made that a low-dose diuretic should be first-line therapy holds for the elderly with systolic hypertension but is not based on prospective studies in the case of younger patients. High-dose diuretics may have adverse effects, as reported in two case-controlled studies. Prospective outcome data favoring beta-blocker monotherapy as first-line therapy are limited, especially in the elderly, while case-control studies suggest an increased incidence of cardiac death in those treated by beta-blockers. CCAs may be the preferred first-line antihypertensive treatment for those groups in whom low-dose diuretics are unlikely to work as monotherapy.