Does the new angiotensin converting enzyme inhibitor cilazapril prevent restenosis after percutaneous transluminal coronary angioplasty? Results of the MERCATOR study: a multicenter, randomized, double-blind placebo-controlled trial. Multicenter European Research Trial with Cilazapril after Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MERCATOR) Study Group.

BACKGROUND: Cilazapril is a novel angiotensin converting enzyme inhibitor with antiproliferative effects in the rat model after balloon injury. METHODS AND RESULTS: We conducted a randomized, double-blind placebo-controlled trial to assess the effect of cilazapril in angiographic restenosis prevention after percutaneous transluminal coronary angioplasty (PTCA). Patients received cilazapril 2.5 mg in the evening after successful PTCA and 5 mg b.i.d. for 6 months or matched placebo. In addition, all patients received aspirin for 6 months. Coronary angiograms before PTCA, after PTCA, and at 6-month follow-up were quantitatively analyzed. In 94% of 735 recruited patients, PTCA was successful and all inclusion and exclusion criteria were met. For the per-protocol analysis, quantitative angiography after PTCA and at follow-up was available in 595 patients who complied with the treatment regimen (309 control, 286 cilazapril). The mean difference in minimal coronary lumen diameter between post-PTCA and follow-up angiogram (primary end point) was -0.29 +/- 0.49 mm in the control group and -0.27 +/- 0.51 mm in the cilazapril group. Clinical events during 6-month follow-up, analyzed on an intention-to-treat basis, were ranked according to the most serious clinical event ranging from death (control, two; cilazapril, three), nonfatal myocardial infarction (control, eight; cilazapril, 5), coronary revascularization (control, 51; cilazapril, 53), or recurrent angina requiring medical therapy (control, 67; cilazapril, 68) to none of the above (control, 224; cilazapril, 212). There were no significant differences in ranking. CONCLUSIONS: Long-term angiotensin converting enzyme inhibition with cilazapril in a dose of 5 mg b.i.d. does not prevent restenosis and does not favorably influence the overall clinical outcome after PTCA.