Acute myocardial ischaemia: what information can be expected in the near future from ongoing clinical trials with nifedipine?

Nifedipine is a calcium antagonist with established anti-vasospastic action in man and, possibly cardioprotective effects during ischaemia. Although it is regularly used in the treatment of acute myocardial ischaemia, few double-blind randomized trials have been performed in this area. Recently, one trial was published which showed that nifedipine, when added to conventional treatment (beta-blockers, nitrates) of patients hospitalized for unstable angina pectoris (UAP) prevents recurrent ischaemia. Several further trials are known to be under way. The American nifedipine angina-myocardial infarction study (NAMIS) comprises sub-protocols both for patients diagnosed as UAP and patients diagnosed as acute myocardial infarction (AMI). In the former, a comparison is made between a nifedipine and a propranolol based regimen. Recurrence of ischaemia is the end point. In the NAMIS-protocol for AMI; nifedipine is compared with placebo. Infarct-size and complications are the end points. The Holland Interuniversity Nifedipine/metoprolol Trial (HINT) is similar in design to the NAMIS UAP-study. However, it has a placebo group for comparison and also deals with the combination of nifedipine and beta-blockade. NAMIS and HINT may resolve several important questions in reference to the treatment of acute myocardial ischaemia but they are of insufficient size to study effects on total mortality. Finally, in the area of secondary prevention after MI, a major trial (secondary prevention reinfarction nifedipine trial: SPRINT) is known to be under way in Israel.