1270Early systolic lengthening in patients with ST-segment elevation myocardial infarction: a novel predictor of cardiovascular events

Abstract

Abstract Background Early systolic lengthening (ESL) may occur in ischemic myocardial segments with reduced contractile force. We sought to evaluate the prognostic potential of ESL in patients with ST-segment elevated myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). Methods We prospectively enrolled 372 patients with STEMI who were treated with primary PCI. All patients underwent a speckle tracking echocardiographic examination with a median of 2 days (interquartile range 1, 3 days) after the PCI. We assessed a novel viability index, the ESL index, defined as: (100 x [peak positive systolic strain/peak negative global strain]), obtained as the average value from all 18 segments. We also calculated ESL duration from 18 segments, defined as time from onset of QRS complex on the electrocardiogram to time to peak of positive systolic strain. Results During a median follow-up time of 5.3 years (interquartile range 2.5, 6.0), 145 (39%) experienced major adverse cardiovascular events (MACEs), which was a composite of incident heart failure, new myocardial infarction and all-cause mortality. The ESL index and ESL duration were significantly increased in culprit lesion areas (6.7±6.2% vs. 5.0±4.1% and 43±33ms vs. 33±24ms, P<0.001 for both). In Cox proportional hazards models the ESL index (HR 1.27 per 1% increase, 95% CI 1.13–1.43, P<0.001, Fig A) and ESL duration (HR 1.49 per 1ms increase, 95% CI 1.15–1.92, P=0.002, Fig B) yielded prognostic information on MACE. Both associations remained significant after adjusting for clinical (age, sex, hypertension, heart rate), echocardiographic (LVMI, E/e', WMSI, LVEF, postsystolic index) and invasive (postprocedural TIMI flow, TnI) confounders. Additionally, tertiles of the ESL index and ESL duration yielded significant prognostic information on MACE (Fig C-D). ESL index and ESL duration and MACE Conclusions Assessment of ESL following primary PCI in patients with STEMI yields independent and significant prognostic information on the future risk of cardiovascular events.