INCIDENCE AND TREATMENT OF NO-REFLOW AFTER PERCUTANEOUS CORONARY INTERVENTION

Background Profound reduction in antegrade epicardial coronary flow wi th concomitant ischemia is seen occasionally during percutaneous coron ary intervention despite the absence of evident vessel dissection, obs truction, or distal vessel embolic cutoff. In a prior small series of cases, this ''no-reflow'' phenomenon appeared to be promptly reversed by the intracoronary administration of verapamil. Methods and Results To further understand the prevalence of this syndrome and its responsi veness to the proposed therapy, we reviewed 1919 percutaneous interven tions performed between January 1991 and April 1993. During the study period, 39 patients (2.0%) met our criteria for no reflow, 37 of whom were treated with intracoronary nitroglycerin followed by intracoronar y verapamil and 2 of whom received intracoronary nitroglycerin alone. An additional 16 patients (0.8%) were given verapamil as part of the m anagement of a flow-limiting dissection or distal embolus (mechanical obstruction). Intracoronary verapamil (50 to 900 mu g, total dose) imp roved TIMI flow grade in 89% of no-reflow patients and markedly reduce d the number of cineframes between contrast injection and opacificatio n of a selected distal landmark (from 91+/-56 to 38+/-21 frames, P<.00 1). By contrast, only 19% of patients with epicardial mechanical obstr uction showed improvement in TIMI flow grade after verapamil, with min imal reduction in frames to opacification (from 107+/-42 to 101+/-69, P=.73). Conclusions The no-reflow phenomenon-reduction in distal flow without apparent dissection or distal embolization-occurs in 2% of cor onary interventions. It generally responds promptly to intracoronary v erapamil administration, suggesting that distal microvascular spasm ma y be its etiology.