A RANDOMIZED TRIAL OF LOW-OSMOLAR IONIC VERSUS NONIONIC CONTRAST-MEDIA IN PATIENTS WITH MYOCARDIAL-INFARCTION OR UNSTABLE ANGINA UNDERGOINGPERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

Objectives. The purpose of this study was to determine prospectively w hether the differences in anticoagulant and antiplatelet effects of io nic and nonionic contrast media alter angiographic or clinical outcome s in patients with unstable ischemic syndromes undergoing percutaneous transluminal coronary angioplasty. Background. The interaction of pla telets and thrombin with the endothelium of injured vessels contribute s to thrombosis and restenosis after coronary angioplasty. Case report s and retrospective observations have reported an increased risk of th rombosis with the use of nonionic contrast media. Methods. A total of 211 patients with acute myocardial infarction or unstable angina under going coronary angioplasty were randomized to receive nonionic or ioni c low osmolar contrast media. Coronary angiograms were assessed by a t echnician blinded to the study contrast media, and clinical events wer e monitored by an independent nurse for 1 month. Results. Patients rec eiving the ionic media were significantly less likely to experience de creased blood flow during the procedure (8.1% vs. 17.8%, p = 0.04). Af ter the angioplasty, residual stenosis, vessel patency, the incidence of moderate to large thrombi and use of adjunctive thrombolytic therap y were similar between the two groups. However, patients receiving ion ic media had fewer recurrent ischemic events requiring repeat catheter ization (3.0% vs. 11.4%, p = 0.02) and repeat angioplasty during the i nitial hospital stay (1.0% vs. 5.8%, p = 0.06). One month after angiop lasty, patients receiving ionic contrast media reported significantly fewer symptoms of any angina (8.5 vs, 20.0%, p 0.04) or of angina at r est (1.4% vs. 11.8%, p = 0.01) and a reduced need for subsequent bypas s surgery (0% vs. 5.9%, p = 0.04), compared with patients receiving th e nonionic media. Con Conclusions. These findings demonstrate that in patients with unstable ischemic syndromes undergoing coronary angiopla sty, the use of ionic low osmolar contrast media reduces the risk of i schemic complications acutely and at 1 month after the procedure. Ther efore, low osmolar ionic contrast media should be strongly considered when performing interventions in patients with unstable angina or myoc ardial infarction.