Prognostic significance of infarct core pathology revealed by quantitative non-contrast in comparison with contrast cardiac magnetic resonance imaging in reperfused ST-elevation myocardial infarction survivors

Abstract

AimsTo assess the prognostic significance of infarct core tissue characteristics using cardiac magnetic resonance (CMR) imaging in survivors of acute ST-elevation myocardial infarction (STEMI).Methods and resultsWe performed an observational prospective single centre cohort study in 300 reperfused STEMI patients (mean ± SD age 59 ± 12 years, 74% male) who underwent CMR 2 days and 6 months post-myocardial infarction (n = 267). Native T1 was measured in myocardial regions of interest (n = 288). Adverse remodelling was defined as an increase in left ventricular (LV) end-diastolic volume ≥20% at 6 months. All-cause death or first heart failure hospitalization was a pre-specified outcome that was assessed during follow-up (median duration 845 days). One hundred and sixty (56%) patients had a hypo-intense infarct core disclosed by native T1. In multivariable regression, infarct core native T1 was inversely associated with adverse remodelling [odds ratio (95% confidence interval (CI)] per 10 ms reduction in native T1: 0.91 (0.82, 0.00); P = 0.061). Thirty (10.4%) of 288 patients died or experienced a heart failure event and 13 of these events occurred post-discharge. Native T1 values (ms) within the hypo-intense infarct core (n = 160 STEMI patients) were inversely associated with the risk of all-cause death or first hospitalization for heart failure post-discharge (for a 10 ms increase in native T1: hazard ratio 0.730, 95% CI 0.617, 0.863; P < 0.001) including after adjustment for left ventricular ejection fraction, infarct core T2 and myocardial haemorrhage. The prognostic results for microvascular obstruction were similar.ConclusionInfarct core native T1 represents a novel non-contrast CMR biomarker with potential for infarct characterization and prognostication in STEMI survivors. Confirmatory studies are warranted.ClinicalTrials.gov identifierNCT02072850.

Automated Extracellular Volume Fraction Mapping Provides Insights Into the Pathophysiology of Left Ventricular Remodeling Post–Reperfused ST‐Elevation Myocardial Infarction

“…Although the sample size was smaller in our study, our findings may also differ from the studies by Carrick et al.,14, 31 given that we used mean segmental values for T1, T2, and ECV rather than manual ROI (the ICC for reliability of remote T1 in Carrick et al 14. was 0.92 and had quite a wide 95% CI [0.80, 0.97]).…”

The Prognostic Role of T1 Mapping Sequences: Can T1 Mapping Parameters Have a Role in Risk Stratification?

“…In ST elevation myocardial infarction patients, higher core native T1 was related to all-cause death or first hospitalization for HF post-discharge [23]. Although a sub-study of the Surgical Treatment for Ischemic Heart Failure trial failed to demonstrate the utility of pre-procedural viability assessment with dobutamine stress echocardiography or single-photon-emission computed tomography to guide revascularization in patients with ischemic cardiomyopathy [24,25], other studies support the identification of myocardial fibrosis as carrying important prognostic information [26].…”

Coronary Thermodilution Waveforms After Acute Reperfused ST‐Segment–Elevation Myocardial Infarction: Relation to Microvascular Obstruction and Prognosis

“…However, failed myocardial reperfusion, depicted by microvascular obstruction on contrast‐enhanced cardiac magnetic resonance (CMR) imaging, occurs in more than half of these patients,3, 4 implicating an adverse long‐term prognosis 5, 6…”

“…Standard measures of myocardial reperfusion, including TIMI (Thrombolysis in Myocardial Infarction) Myocardial Perfusion Grade and corrected frame count, or ST‐segment resolution on the ECG, lack sensitivity and reproducibility 6, 7, 8, 9. CMR is the reference noninvasive technique for detection of microvascular pathology3, 5, 10; however, CMR is neither feasible acutely nor widely available1 and is not routinely recommended in contemporary practice guidelines 1, 11…”