Coronary flow reserve may predict myocardial recovery after myocardial infarction in patients with TIMI grade 3 flow

Background: The aim of the study was to determine whether the recovery of global and regional left ventricular function after successful percutaneous transluminal angioplasty (PTCA) could be predicted by measuring coronary flow reserve before performing the intervention. Methods and Results: Thirty-two patients underwent PTCA 6.9 ± 3.4 days after a recent myocardial infarction. Coronary flow reserve was determined in the infarct- related artery before PTCA by using an intracoronary Doppler tipped wire. Global and regional wall motion were determined by 2-dimensional echocardiography before the Flowire study and again 7 weeks after the angioplasty. Whereas the global and regional wall motion score indices improved in 20 patients (recovery group), they deteriorated or did not change in 9 patients (nonrecovery group). Coronary flow reserve distal to the lesion in the infarct-related artery was significantly higher in the recovery group (1.43 ± 0.57 vs 0.98 ± 0.70, P = .0001). Coronary flow reserve distal to the lesion in the infarct-related artery was <1.1 in patients whose global or regional eft ventricular function did not improve at follow-up, whereas flow reserve ranged between 1.1. and 1.8 while patients in whom left ventricular function improved. Conclusions: These results suggest that the absence of inducible coronary flow reserve may predict failure of left ventricular systolic function to improve between the first and sixth week after infarction. Measurement of flow reserve with a Flowire at the time of diagnostic angiography after recent myocardial infarction may ultimately prove helpful in deciding whether to proceed with revascularization.