Meeting highlights: nitric oxide donors.

D irect nitric oxide (NO) donors are a novel class of pharmacological agents that have vasodilatory properties as well as antiplatelet effects in animal angioplasty models. Two studies of NO donors were presented at the 43rd Annual Scientific Session of the American College of Cardiology: an unstable angina trial and a percutaneous transluminal coronary angioplasty (PTCA) trial. Dr Thierry Giraud of Paris, France, on behalf of the French Multicentric Group in Unstable Angina, presented the results of a randomized parallel-group study of the efficacy and tolerability of a continuous intravenous infusion of linsidomine (SIN-1, an NO donor) in comparison to isosorbide dinitrate (ISDN). A total of 568 patients with angina at rest and recent ECG changes were randomized at 48 clinical centers in France to receive a 3-day infusion of either intravenous SIN-1 (1 mg/h up to 1.6 mg/h) or ISDN (2.5 mg/h up to 5.5 mg/h). All patients received intravenous heparin, oral aspirin, a-blockers (80%), and/or calcium blockers (40%). End points of the study included recurrent pain, Holter ischemic episodes, and clinical events (death, myocardial infarction, urgent revascularization). There were no significant differences in the frequency of symptomatic episodes, Holter ischemia, or major clinical events (5% total with SIN-1 versus 8% total with ISDN). Dr Giraud concluded that SIN-1 was as effective as (but not more effective than) ISDN for the treatment of severe (class IIIb) unstable angina. Dr Jean-Marc Lablanche, from the University of Lille in France, on behalf of the ACCORD Study Investigators,