Noninvasive Myocardial Work Indices 3 Months after ST-Segment Elevation Myocardial Infarction: Prevalence and Characteristics of Patients with Postinfarction Cardiac Remodeling

Abstract

Assessment of left ventricular (LV) remodeling after ST-segment elevation myocardial infarction (STEMI) is pivotal for patient management. Noninvasive myocardial work indices obtained from echocardiography-derived strain-pressure loops provide a new tool that permits characterization of LV mechanics. We aimed at characterizing myocardial work indices in patients with LV remodeling after STEMI versus patients without remodeling. Six-hundred STEMI patients were retrospectively analyzed (456 men, mean age: 61±11years) and divided according to the presence of LV remodeling 3months after the index admission (≥20% increase in LV end-diastolic volume). Noninvasive myocardial work indices were measured at 3months after STEMI. LV remodeling was observed in 150 patients (25%) who showed more impaired global myocardial work indices compared with their counterparts: work index (1,708±522mm Hg% vs 1,979±450mm Hg%; P<.001), constructive work (1,941±598mm Hg% vs 2,272±519mm Hg%; P<.001), and work efficiency (92% [range 88%-96%] vs 95% [range 93%-96%]; P<.001). In addition, patients with LV remodeling had significantly increased wasted work (116mm Hg% [range 73-184mm Hg%] vs 91mm Hg% [range 61-132mm Hg%]; P<.001). The frequency of impaired global work index, constructive and work efficiency, and increased wasted work was significantly higher among patients with LV remodeling compared with theircounterparts: 21.3%, 34.7%, 34.7%, and 14.0%, respectively, versus 5.3%, 9.6%, 8.9%, and 4.9%, respectively (P<.001). At 3-month follow-up after STEMI, patients with LV remodeling revealed more impaired myocardial work indices compared with patients without LV remodeling. The prevalence of impaired myocardial work indices was higher among patients with LV remodeling compared with patients without.