Prognostic Value of Segmental Strain After ST‐Elevation Myocardial Infarction: Insights From the EARLY Assessment of MYOcardial Tissue Characteristics by Cardiac Magnetic Resonance (EARLY‐MYO‐CMR) Study

Abstract

BackgroundThe prognostic value of left ventricular segmental strain (SS) in ST‐elevation myocardial infarction (STEMI) remains unclear.HypothesisTo assess the prognostic value and application of SS.Study TypeRetrospective analysis of a prospective registry.PopulationFive hundred and forty‐four patients after STEMI (500 in Cohort 1, 44 in Cohort 2).Field Strength/Sequence3 T, balanced steady‐state free precession, gradient echo, and gradient echo contrast‐enhanced images.AssessmentParticipants underwent cardiac MR during the acute phase after STEMI. Infarct‐related artery (IRA) strain was determined based on SS obtained from cine images. The primary endpoint was the composite of major adverse cardiovascular events (MACEs) after 8 years of follow‐up. In Cohort 2, SS stability was assessed by MR twice within 8 days. Contrast and non‐contrast risk models based on SS were established, leading to the development of an algorithm.Statistical TestStudent's t‐test, Mann–Whitney U‐test, Cox and logistic regression, Kaplan–Meier analysis, net reclassification index (NRI). P < 0.05 was considered significant.ResultsDuring a median follow‐up of 5.2 years, 83 patients from Cohort 1 experienced a MACE. Among SS, IRA peak circumferential strain (IRA‐CS) was an independent factor for MACEs (adjusted hazard ratio 1.099), providing incremental prognostic value (NRI 0.180, P = 0.10). Patients with worse IRA‐CS (>−8.64%) demonstrated a heightened susceptibility to MACE. Additionally, IRA‐CS was significantly associated with microvascular obstruction (MVO) (adjusted odds ratio 1.084) and infarct size (r = 0.395). IRA‐CS showed comparable prognostic effectiveness to global peak circumferential strain (NRI 0.100, P = 0.39), also counterbalancing contrast and non‐contrast risk models (NRI 0.205, P = 0.05). In Cohort 2, IRA‐CS demonstrated stability between two time points (P = 0.10). Based on risk models incorporating IRA‐CS, algorithm “HJKL” was preliminarily proposed for stratification.Data ConclusionsIRA‐CS is an important prognostic factor, and an algorithm based on it is proposed for stratification.Level of Evidence4Technical EfficacyStage 2