Calcium antagonists in myocardial infarction.

Area of Science:

• Cardiology
• Pharmacology

Background:

• Calcium antagonists are effective cardioprotective agents in experimental myocardial infarction models.
• Clinical trial results for calcium antagonists in acute myocardial infarction and secondary prevention have been conflicting due to trial size and drug-specific properties.

Purpose of the Study:

• To evaluate the efficacy of calcium antagonists, particularly diltiazem, in managing acute myocardial infarction (MI) and in post-MI secondary prevention.
• To differentiate the effects of calcium antagonists in Q-wave versus non-Q-wave myocardial infarction.

Main Methods:

• Review of existing clinical trials and subgroup analyses.
• Assessment of infarct size using thallium SPECT defect scores.
• Evaluation of left ventricular ejection fraction.
• Analysis of reinfarction rates, postinfarction angina, and long-term cardiac mortality.

Main Results:

• Diltiazem decreased infarct size and increased left ventricular ejection fraction in acute Q-wave infarctions compared to placebo.
• In non-Q-wave infarction, diltiazem significantly reduced early reinfarction rates, postinfarction angina, and 1-year cardiac mortality and nonfatal reinfarction rates.
• Q-wave patients did not appear to benefit, but early administration data is inconclusive.

Conclusions:

• Early administration of diltiazem shows encouraging results in acute Q-wave myocardial infarction.
• Diltiazem demonstrates strong beneficial effects in non-Q-wave infarction, including reduced reinfarction and mortality.
• Prophylactic diltiazem, alongside aspirin, is recommended for non-Q-wave infarction patients due to a lack of alternative treatments.