MRI Investigation of the Differential Impact of Left Ventricular Ejection Fraction After Myocardial Infarction in Elderly vs. Nonelderly Patients to Predict Readmission for Heart Failure

Abstract

BackgroundPatients with ST‐segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF).PurposeTo study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI.Study TypeProspective.PopulationMulticenter registry of 759 reperfused STEMI patients (23.3% elderly).Field Strength/Sequence1.5‐T. Balanced steady‐state free precession (cine imaging) and segmented inversion recovery steady‐state free precession (late gadolinium enhancement) sequences.AssessmentOne‐week MRI‐derived LVEF (%) was quantified. Sequential MRI data were recorded in 579 patients. Patients were categorized according to their MRI‐derived LVEF as preserved (p‐LVEF, ≥50%), mildly reduced (mr‐LVEF, 41%–49%), or reduced (r‐LVEF, ≤40%). Median follow‐up was 5 [2.33–7.54] years.Statistical TestsUnivariable (Student's t, Mann–Whitney U, chi‐square, and Fisher's exact tests) and multivariable (Cox proportional hazard regression) comparisons and continuous‐time multistate Markov model to analyze transitions between LVEF categories and to AHF. Hazard ratios (HR) with 95% confidence intervals (CIs) were computed. P < 0.05 was considered statistically significant.ResultsOver the follow‐up period, 79 (10.4%) patients presented AHF. MRI‐LVEF was the most robust predictor in nonelderly (HR 0.94 [0.91–0.98]) and elderly patients (HR 0.94 [0.91–0.97]). Elderly patients had an increased AHF risk across the LVEF spectrum. An excess of risk (compared to p‐LVEF) was noted in patients with r‐LVEF both in nonelderly (HR 11.25 [5.67–22.32]) and elderly patients (HR 7.55 [3.29–17.34]). However, the mr‐LVEF category was associated with increased AHF risk only in elderly patients (HR 3.66 [1.54–8.68]). Less transitions to higher LVEF states (n = 19, 30.2% vs. n = 98, 53%) and more transitions to AHF state (n = 34, 53.9% vs. n = 45, 24.3%) were observed in elderly than nonelderly patients.Data ConclusionMRI‐derived p‐LVEF confers a favorable prognosis and r‐LVEF identifies individuals at the highest risk of AHF in both elderly and nonelderly patients. Nevertheless, an excess of risk was also found in the mr‐LVEF category in the elderly group.Evidence Level2.Technical EfficacyStage 2.