Prognostic impact of remote myocardium changes using T1 mapping in patients with ST-segment elevation myocardial infarction.

Abstract

The aim of this study was to investigate the prognostic relevance of remote myocardium alterations assessed by cardiac magnetic resonance (CMR) T1 mapping (native T1 and extracellular volume (ECV)) in patients after ST-segment elevation myocardial infarction (STEMI). This retrospective study analyzed STEMI patients treated with primary percutaneous coronary intervention (PCI) who were included in the prospective MARINA-STEMI study. CMR images were analyzed for left ventricular (LV) function, standard infarct characteristics, as well as native remote T1 and remote ECV. The primary clinical endpoint was the composite of all-cause mortality, re-infarction and new congestive heart failure (Major adverse cardiac events (MACE)). Four hundred ninety-one patients (median age 58 [Interquartile range (IQR): 52-66 years], 91 (19%) female) patients underwent CMR imaging at 4 ([IQR: 3-5]) days after PCI. Over a median follow-up of 12 months ([IQR: 12-13]) after STEMI, 42 MACE outcomes occurred. Higher native remote T1-times (1018.5 [IQR: 997.0-1064.0] ms vs. 1007.0 [IQR: 977.0-1041.5] ms, p = 0.033) as well as higher remote ECV values (28.07 vs. 26.27%, p = 0.009) were observed in patients with MACE. Multivariable Cox-regression analysis demonstrated that remote ECV (hazard ratio (HR): 1.53 [confidence interval (CI): 1.07-2.19], p = 0.020) but not native remote T1 is independently associated with MACE. A comprehensive assessment of the remote myocardium with native T1 and ECV provides prognostic information in a contemporary cohort of low-risk STEMI patients. Remote ECV, but not remote native T1, was found to be an independent predictor of MACE. Question The prognostic implications of remote myocardium changes assessed by cardiac magnetic resonance (CMR) T1 mapping in patients after ST-segment elevation myocardial infarction (STEMI) are not fully understood. Findings After STEMI, for patients treated with primary percutaneous coronary intervention, remote extracellular volume (ECV) was found to be an independent predictor of major adverse cardiac events. Clinical relevance This study underlines the importance of remote myocardium characterization as a promising diagnostic tool. In particular, the quantification of ECV changes in the remote myocardium could be relevant for optimized CMR-imaging-based risk stratification in patients after STEMI.