Calcium channel blockers in heart failure.

The rationale for the use of calcium channel blockers in patients with chronic heart failure lies in their vasodilator action, antiischemic effect, ability to lessen left ventricular diastolic dysfunction and data showing their effect in preventing progression of myocardial dysfunction in animals with cardiomyopathy. Despite initial studies reporting improvement of the hemodynamic profile with nifedipine, further evaluation showed variable results, with hemodynamic worsening seen in up to 29% of patients. Longer-term controlled studies evaluating symptoms and clinical status demonstrated worsening chronic heart failure in approximately 25% of patients within 8 weeks of nifedipine therapy. Although diltiazem has a lesser myocardial depressant effect and its short-term use was associated with less frequent hemodynamic and clinical worsening, long-term exposure to the drug in a large group of patients with chronic heart failure due to left ventricular systolic dysfunction after myocardial infarction resulted in an increased incidence of cardiac events, with worsening heart failure and death. The use of verapamil in a similar patient cohort showed the loss of its demonstrated protective effect in patients with clinical evidence of heart failure. In an attempt to improve the safety of calcium channel blockers, the following approaches were suggested: 1) use of second-generation drugs with less myocardial depressant effect; 2) concomitant use of angiotensin-converting enzyme inhibitors to prevent reported neurohormonal activation; and 3) development of drugs with favorable neurohormonal effects. These approaches led to mixed results.(ABSTRACT TRUNCATED AT 250 WORDS)