The effects of calcium antagonists after PTCA

Experiments have shown that calcium antagonists can prevent restenosis after coronary angioplasty. The first controlled clinical trials, however, failed to show such a benefit after PCTA: the recurrence rate was not significantly influenced by either nifedipine (10 mg q.i.d.) or diltiazem (90 mg t.i.d.). Another trial used a higher dose of diltiazem (mean 329 mg per day) in a larger number of patients, but again the result was negative. In contrast, diltiazem 180 mg per day was reported more recently to significantly reduce restenosis, and high-dose verapamil treatment was similarly successful in a subgroup of patients with stable angina pectoris at the time of primary successful PCTA. Despite some important limitations of the five monocentre trials, the combined analysis of the results shows that calcium antagonists have a beneficial effect on restenosis rate after PTCA. Whether this effect is limited to heart rate slowing substances and to special subgroups of lesions has to be clarified by further studies in sufficiently large patient populations.