A randomized trial comparing the impact of a nonionic (iomeprol) versus anionic (ioxaglate) low osmolar contrast medium on abrupt vessel closure andischemic complications after coronary angioplasty

OBJECTIVES To assess the effect of nonionic versus ionic contrast media on abrupt vessel closure and major ischemic complications after coronary angio plasty. BACKGROUND There is a continuous debate about the "thrombogenic potential" of nonionic contrast media. The results of both in vitro and in vivo invest igations are incongruent. METHODS We prospectively evaluated the outcomes of 2,000 patients undergoin g percutaneous transluminal coronary angioplasty (PTCA). According to a ran domized, double-blind protocol, they received either iomeprol (nonionic; n = 1,001) or ioxaglate (ionic; n = 999). Intracoronary thrombus before PTCA was found more often in the iomeprol group (4.2% vs 2.7%, p = 0.04). No oth er significant differences between both groups were observed with regard to pre-PTCA clinical and angiographic characteristics. RESULTS The frequency of reocclusions necessitating repeat angioplasty occu rring either in laboratory (2.9% with iomeprol and 3.0% with ioxaglate) or out of laboratory (3.1% vs 4.1%) was not significantly different. The rate of major ischemic complications was also comparable aft er both contrast me dia (emergency bypass surgery: 0.8% vs 0.7%, myocardial infarction: 1.8 vs 2.0%, cardiac death during hospital stay: 0.2% vs 0.2%). In the iomeprol gr oup, more patients had dissections post-PTCA (30.2% vs 25.0%, p = 0.01) and more patients received intracoronary stents (31.6% vs 25.7%, p = 0.004). A llergic reactions requiring treatment occurred only in the ioxaglate group (0.0% vs 0.9%, p = 0.002). CONCLUSIONS The nonionic contrast medium was not associated with a higher r ate of abrupt vessel closure requiring repeat angioplasty, or major ischemi c events. These data suggest that nonionic contrast media do not increase t he risk of thrombotic complications in patients undergoing coronary interve ntions. (C) 1999 by the American College of Cardiology.