TCT-467 Clinical Outcomes after Anterior ST-Elevation Myocardial Infarction According to LAD Lesion Location: The INFUSE-AMI Trial

Abstract

Background: Prognosis of ST-elevation myocardial infarction (STEMI) is determined predominantly by the extent of myocardial damage and hemodynamic status. Thus, in previous studies patients with proximal LAD occlusion have had worse outcome than those with more distal LAD lesions. It is not known whether modern reperfusion therapy has altered this relationship. Methods: The INFUSE-AMI trial randomized patients with anterior STEMI due to proximal or mid LAD occlusion to intracoronary bolus abciximab delivered locally via the ClearWay RX catheter vs. no abciximab, and to manual thrombus aspiration with the Export catheter vs. no aspiration. The primary endpoint was core laboratory assessed MRI infarct size (IS, % of LV mass) at 30 days. Lesion location was assessed at a core laboratory blinded to randomization and outcomes and was defined as proximal (pLAD) if present before or at first significant septal perforator branch, or mid (mLAD) if beyond it. Results: The study enrolled 452 patients. The median age was 61y, 74% were men and 11% had diabetes. Intracoronary abciximab reduced IS (% LV mass): 15.1[6.8-22.7] vs. 17.9[10.3-25.4], P=0.03. Thrombectomy had no effect on IS. There were 292 (64.7%) patients with pLAD and 159 (35.3%) with mLAD occlusion. Patients with pLAD presented more often within 3h of symptom onset and had lower systolic blood pressure, but did not differ from mLAD patients with respect to heart rate, Killip class or extent of coronary disease. Thrombectomy was performed in 49.3% and 56.0% of the two groups, P=0.18 and intracoronary abciximab was used in 46.9% and 47.2%, respectively, P=0.79. Reperfusion succes, infarct size and major clinical outcomes are listed in Table. Conclusions: These data confirm the excess risk of death associated with pLAD infarcts even with contemporary reperfusion therapy. Reduced TIMI 3 flow rates and larger IS in pLAD infarcts translate into increased mortality.