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.

OBJECTIVES: 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.
BACKGROUND: Prior studies have associated larger lumen diameters after PCI with reduced rates of restenosis and target vessel revascularization.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.