Prevention of restenosis after PTCA: role of calcium antagonists

Abstract

The recurrence of coronary obstruction after initially successful percutaneous transluminal coronary angioplasty (PTCA) represents a major problem of this interventional procedure at present. In the pathogenesis of restenosis the growth factor-dependent proliferation and migration of medial smooth muscle cells into the intima of the vessel wall may play a very important role. In experimental studies this process could be inhibited by calcium antagonists. However, the first two placebo-controlled clinical trials showed disappointing results: the restenosis rate was not decreased by the treatment with 10 mg of nifedipine four times daily or by the treatment with 90 mg of diltiazem three times daily. The influence of high-dose verapamil treatment [Isoptin RR (240 mg) twice daily] on the recurrence of coronary stenosis has been investigated by a recently completed double-blind, placebo-controlled trial, the verapamil angioplasty study (VAS). The VAS included 196 consecutive patients with at least one risk factor for restenosis after successful PTCA for stable angina pectoris (n = 75) or unstable angina pectoris/non-Q-wave infarction (n = 97). Eighty-eight percent of the patients underwent follow-up angiography at 4.3 +/- 2.3 months. The publication of detailed data of the VAS including restenosis rates in both clinical subgroups is being prepared.