Association of a negative residual stenosis following rescue/adjunctive percutaneous coronary intervention with impaired myocardial perfusion and adverse outcomes among ST-segment elevation myocardial infarction patients.

Abstract

We hypothesized that <0% residual stenosis (RS) after rescue/adjunctive percutaneous coronary intervention (PCI) following fibrinolytic administration in ST-segment elevation myocardial infarction (STEMI) would be associated with improved outcomes. Prior studies have associated larger lumen diameters after PCI with reduced rates of restenosis and target vessel revascularization. Data were drawn from 748 patients with open epicardial arteries and with optimal luminal results (RS <20%) following rescue/adjunctive PCI after fibrinolytic administration in six STEMI trials. Patients were divided into two groups: 1) <0% RS and 2) 0% to 20% RS. A RS <0% was associated with greater gains in lumen diameter and smaller reference diameters after PCI (p < 0.001 for each), with a trend toward less frequent Thrombolysis In Myocardial Infarction flow grade (TFG) 3. A RS <0% was associated with a greater incidence of abnormal post-PCI Thrombolysis In Myocardial Infarction myocardial perfusion grades (TMPGs) (odds ratio 2.6 [1.2 to 5.9] for TMPG 0/1/2, p = 0.02), even when the analysis was restricted to patients with post-PCI TFG 3. A RS <0% following rescue/adjunctive PCI after fibrinolytic therapy for STEMI was independently associated with a reduction in the frequency of normal myocardial perfusion. Potential mechanisms of this finding include greater downstream embolization, increased stimulation of arterial stretch receptors with resultant coronary vasoconstriction, and increased vessel-wall injury after PCI. These findings suggest that additional prospective studies are needed to assess optimal RS that minimizes long-term restenosis without adverse effects.