Treatment of no-reflow and impaired flow with the nitric oxide donor nitroprusside following percutaneous coronary interventions: Initial human clinical experience

OBJECTIVES The objective of this study was to test the hypothesis that the intracoronary administration of a direct donor of nitric oxide is a safe an d effective method to treat impaired blood flow (no-reflow phenomenon) that occurs during percutaneous transluminal coronary interventions (PTCI). BACKGROUND The absence of blood flow or decreased blood how in a coronary a rtery following PTCI despite the presence of a patent epicardial vessel or graft is designated "no-reflow" or "impaired flow." This alteration in bloo d flow is a serious complication of percutaneous revascularization strategi es that results in an increased incidence of morbidity, myocardial infarcti on and mortality. METHODS Nineteen consecutive patients undergoing standard percutaneous reva scularization procedures complicated bq either no-reflow or impaired flow t hat received intracoronary nitroprusside treatment were studied. One patien t had two procedures performed on two separate grafts on two successive day s. Interventions were performed on either saphenous vein grafts or native v essels and utilized angioplasty, stent deployment or rotational atherectomy strategies. Following interventions that were associated with impaired flo w, varying total doses (of nitroprusside 50 to 1,000 mug) were administered into the coronary artery or saphenous vein graft. The angiographic archive s before and after intracoronary administration of nitroprusside were analy zed for TIMI grade flow and a frame count method was used to quantitate blo od flow velocity. RESULTS Following a PTCI that resulted in either no-reflow or impaired flow , nitroprusside (median dose 200 mug) was found to lead to a highly signifi cant and rapid improvement in both angiographic flow (p < 0.01 compared wit h pretreatment angiogram) and blood flow velocity (p < 0.01 compared with p retreatment angiogram). No significant hypotension or other adverse clinica l events were associated with nitroprusside administration. CONCLUSIONS The direct nitric oxide donor nitroprusside is an effective, sa fe treatment of impaired blood flow and no-reflow associated. with PTCI. Th e use of nitroprusside to treat syndromes secondary to microvascular dysfun ction may provide a novel therapeutic strategy for treating no-reflow or im paired blood flow following percutaneous interventions. (J Am Cell Cardiol 2001;37:1335-43) (C) 2001 by the American College of Cardiology.