Usefulness of the Left Anterior Descending Artery Wrapping Around the Left Ventricular Apex to Predict Adverse Clinical Outcomes in Patients With Anterior Wall ST-Segment Elevation Myocardial Infarction (an INFUSE-AMI Substudy)

Abstract

The relation between left anterior descending coronary artery (LAD) anatomic features and clinical outcomes in patients with anterior ST-segment elevation myocardial infarction has not been fully investigated. The Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction (INFUSE-AMI) trial randomized 452 patients with anterior ST-segment elevation myocardial infarctions who underwent mechanical revascularization to intralesional abciximab versus no abciximab and to manual thrombus aspiration versus no aspiration. The primary end point was infarct size (percentage left ventricular mass) on contrast magnetic resonance imaging at 30 days. "Wraparound LAD" was defined as an LAD reaching the apex and supplying the apical inferior aspect of the heart. Among complete data available in 338 patients, 258 (76.3%) had wraparound LADs. Global infarct size (17.4% vs 16.1%, p = 0.64) and the left ventricular ejection fraction (49.7% vs 48.7%, p = 0.98) by contrast magnetic resonance imaging at 30 days were comparable between patients with and those without wraparound LADs. Regional apical anterior infarct size was comparable (59.5% vs 55.8%, p = 0.559) between the groups; however, apical septal (61.3% vs 48.9%, p = 0.005), apical inferior (19.0% vs 3.7%, p <0.0001), and apical lateral (12.2% vs 4.8%, p = 0.0584) infarct sizes were larger in patients with wraparound LADs compared with those with nonwraparound LADs. The incidence of new-onset severe heart failure at 1 year was significantly higher in patients with compared with those without wraparound LADs (6.3% vs 0%, p = 0.02). In conclusion, in patients with anterior ST-segment elevation myocardial infarctions, as compared with the LAD not supplying the inferior aspect of the heart, a wraparound LAD was associated with a larger left ventricular apex infarct size, resulting in worse adverse events at 1 year.