Randomized Comparison of Vasodilator Effects of Iloprost versus Diltiazem on Flow and Pathologic Changes in Radial Arteries: Mid-term Angiographic Control Study of the Comparison of Vasodilators on Radial Artery Vasospasm

Abstract

The increasing prevalence of routine radial artery (RA) use in coronary artery bypass grafting (CABG) has rendered the pharmacologic prevention of spasm of this artery a critical consideration in the early postoperative period and in the long-term outcome. In this study, we compared the effects of iloprost and diltiazem on vasospasm. Seventy patients who underwent CABG with the RA were randomized into 2 groups, and the vasodilator effects of iloprost and diltiazem were studied prospectively. RA flow was measured with Doppler ultrasonography. Following harvesting, a 5-mm piece was removed from the RA distally for pathologic examination. In group B, diltiazem was infused before removing the RA, whereas in group A, iloprost infusion was initiated 5 days before surgery. At the end of a 2-year follow-up, each patient underwent coronary angiography. Doppler flow measurements made during harvesting revealed a statistically significant reduction in flow, and a pathologic examination of the RAs revealed significant luminal narrowing in group B. A 2-year angiographic follow-up revealed all of the RA grafts in group A to be patent. Our evaluation of the results revealed the superior efficacy of iloprost over diltiazem in preventing RA spasm in the early period, and the 2-year angiographic findings showed that the use of iloprost produced superior mid-term patency.