Quantitative estimation of myocardial salvage after primary percutaneous transluminal coronary angioplasty in patients with angiographic no reflow

Angiographic Thrombolysis in Myocardial Infarction (TIMI) flow grade less than or equal to2 after primary percutaneous transluminal coronary angioplasty (PTCA), defined as angiographic no reflow, predicts poor left ventricular functional recovery and survival in patients with acute myocardial infarction (MI). To determine the relation between angiographic coronary flow and myocardial salvage in the acute phase of MI, serial technetium-99m tetrofosmin imaging was performed before, immediately after and I month after PTCA in 117 patients. Angiographic no reflow was observed in 23 patients (20%; group 1), while 94 patients did not have angiographic no reflow (group 2). Although there was no significant difference in the defect score before PTCA between the two groups (group 1, 14.4 +/- 5.7; group 2, 13.5 +/- 4.6), the defect score immediately after PTCA in group I was significantly higher than that in group 2 (group 1, 12.8 +/- 5.1, group 2, 8.9 +/- 4.6; P < 0.0001). A significantly smaller change in the defect score after PTCA (before minus immediately after PTCA) was observed in group I as compared with group 2 (group 1, 1.7 +/- 2.0; group 2, 4.5 +/- 2.9; P < 0.0001). Twenty patients in group 1 (87%) had impaired myocardial reperfusion (<4 change in the defect score immediately after PTCA), as compared with 36 patients (38%) in group 2; this difference was significant (chi(2)=17.5, P < 0.0001). The sensitivity, specificity and accuracy of angiographic no reflow in estimating impaired myocardial reperfusion were 36%, 95% and 67%, respectively. Thus, angiographic no reflow is a highly specific, although not sensitive, marker of impaired myocardial reperfusion immediately after primary PTCA.