Angiotensin converting enzyme inhibition in the prevention of restenosis: the MERCATOR and MARCATOR trials

Abstract

Angiotensin II is recognized to result in hypertrophy, migration and proliferation of vascular smooth muscle cells. Recently it has been shown that the angiotensin converting enzyme inhibitor (ACE) cilazipril, inhibits myointimal proliferation following balloon injury in the rat. Confirmatory studies suggest that ACE inhibitors may prevent restenosis experimentally. Two large multicenter trials are now being conducted to evaluate the efficacy of cilazipril in the prevention of restenosis following angiography. The European study (the MERCATOR study) involves 27 centers. 736 patients have been randomized to placebo plus aspirin or cilazipril 5 mg bid. The primary endpoint is the change in minimal lumen diameter as assessed by quantitative angiography (CAAS system) at a core laboratory in Rotterdam. Other endpoints include death, non-fatal MI, function status, angina relief, and exercise stress testing. The final results will be presented in August 1991. The North American Study (MARCATOR) is a parallel study including 42 centers in the United States and Canada. It utilizes similar entry criteria and endpoints but differs in that patients are randomized into 4 groups (placebo, 1 mg, 5 mg or 10 mg of cilazipril bid plus aspirin). 1,428 patients have been enrolled and the study will conclude in December of 1991. Presentation of the results are expected in the spring of 1992. Together these studies will be the largest restenosis trial utilizing detailed angiographic endpoints.