Background: Patients with ST-segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF).
Purpose: To study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI.
Study type: Prospective.
Population: Multicenter registry of 759 reperfused STEMI patients (23.3% elderly).
Field strength/sequence: 1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences.
Assessment: One-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 tests: Univariable (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.
Results: Over 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 conclusion: MRI-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 level: 2.
Technical efficacy: Stage 2.
Keywords: acute heart failure; acute myocardial infarction; elderly; left ventricular ejection fraction.
© 2023 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.