Cardiovascular magnetic resonance-derived intramyocardial hemorrhage after STEMI: Influence on long-term prognosis, adverse left ventricular remodeling and relationship with microvascular obstruction.

BACKGROUND: T2 weighted cardiovascular magnetic resonance (CMR) can detect intramyocardial hemorrhage (IMH) after ST-elevation myocardial infarction (STEMI). The long-term prognostic value of IMH beyond a comprehensive CMR assessment with late enhancement (LE) imaging including microvascular obstruction (MVO) is unclear. The value of CMR-derived IMH for predicting major adverse cardiac events (MACE) and adverse cardiac remodeling after STEMI and its relationship with MVO was analyzed.
METHODS: CMR including LE and T2 sequences was performed in 304 patients 1 week after STEMI. Adverse remodeling was defined as dilated left ventricular end-systolic volume indexes (dLVESV) at 6 months CMR.
RESULTS: During a median follow-up of 140 weeks, 47 MACE (10 cardiac deaths, 16 myocardial infarctions, 21 heart failure episodes) occurred. Predictors of MACE were ejection fraction (HR .95 95% CI [.93-.97], p=.001, per %) and IMH (HR 1.17 95% CI [1.03-1.33], p=.01, per segment). The extent of MVO and IMH significantly correlated (r=.951, p<.0001). dLVESV was present in 40% of patients. CMR predictors of dLVESV were: LVESV (OR 1.11 95% CI [1.07-1.15], p<.0001, per ml/m(2)), infarct size (OR 1.05 95% CI [1.01-1.09], p=.02, per %) and IMH (OR 1.54 95% CI [1.15-2.07], p=.004, per segment). Addition of T2 information did not improve the LE and cine CMR-model for predicting MACE (.744 95% CI [.659-.829] vs. .734 95% CI [.650-.818], p=.6) or dLVESV (.914 95% CI [.875-.952] vs. .913 95% CI [.875-.952], p=.9).
CONCLUSIONS: IMH after STEMI predicts MACE and adverse remodeling. Nevertheless, with a strong interrelation with MVO, the addition of T2 imaging does not improve the predictive value of LE-CMR.