1001-30 Comparison of Different Vasodilators on Coronary Flow Reserve In Patients with Documented Coronary Artery Disease

No-reflow phenomenon after angioplasty or atherectomy may result in important ischemic complications. No-reflow phenomenon is related to distal embolization of microparticulate material and/or spasm in the microcirculation. Maximal vasodilatation of the coronary microcirculation may prevent or terminate episodes of no-reflow phenomenon. In this preliminary study, we evaluated the vasodilatory capacities of agents commonly used during coronary procedures, The coronary flow reserve (CFR=hyperemic/basal flow velocity) was measured with 0.018” Doppler FloWire in coronary arteries with <50% diameter stenoses (6 RCA, 4 LAD, and 10 LCX) in 20 patients (mean age=64±7 years; 15 men) undergoing angiography (n=6) or angioplasty (n=14) in another coronary artery. Random paired CFR measurements in the same artery were obtained with intracoronary adenosine, nitroglycerin (NTG), verapamil, and contrast agents (Hypaque, Hexabrix, and Optiray), with blood injection as a control. After each measurement, basal flow conditions were restored before subsequent test injections. At the doses chosen, there were no hemodynamic or conduction abnormalities, which could influence coronary flow responses.adenosine (6 or 12μg)verapamil (100μg)verapamil (200μg)NTG (50μg)NTG (200μg)Hypaque (6ml)Blood (6ml)CFR*2.2±0.9**14±0.31.5±031.7±0.41.8±0.52.1±0 81.2±0 1Duration*29±9***58±6377±5721±722±935±109±5*p<0.001 by ANOVA and multiple pairwise comparisons with Bonferroni correction, using adenosine as the comparison group**p<0,001 vs. all others except Hypaque***p<0.05 vs. all others except verapamil (100μg) and Hypaque: Duration of hyperemic response in secondsAmong different contrast agents, there was no difference in CFR, although duration of hyperemia was significantly longer with Hypaque vs. other contrast agents (p<0.001 by ANOVA). We conclude that adenosine and Hypaque had the highest vasodilatory effect among the agents tested. These agents should be further studied for a potential benefit in the prevention or treatment of no-reflow phenomenon during angioplasty and atherectomy procedures