Late Gadolinium Enhancement Predicts Adverse Clinical Events in Heart Transplant Patients

Abstract

Introduction Late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) is a well-studied predictor of adverse clinical outcomes in many cardiac conditions. While the presence of LGE in heart transplant (HTx) patients has been previously demonstrated, these studies were limited by sample size and short follow-up. Therefore, we sought to examine the presence and extent of myocardial LGE at two time points and its association with long-term outcomes following HTx. Hypothesis Myocardial LGE persists over time and portends worse prognosis in HTx patients. Methods This was a single-center, prospective, longitudinal study of HTx patients who underwent CMR imaging at baseline (median of 5.1 years post-HTx; IQR 2.1, 8.0) and follow-up imaging (median of 12 month from baseline scan; IQR 6,22). Quantification of LGE was performed using Circle Cardiovascular Imaging. The primary endpoint was pre-defined as a composite of death, nonfatal myocardial infarction, coronary revascularization and hospitalization. Survival by LGE status (absence/presence) was assessed using Kaplan-Meier-curve. Differences in event-free survival curves between patients with and without LGE were compared using log-rank test. Univariate and multivariate Cox regression analysis was performed to examine the association of myocardial LGE on clinical outcomes adjusted for demographic and clinical characteristics. Results Of the 92 patients enrolled, mean age was 50±16 years, 72% were male, and 80 % had a history of cellular rejection. Median follow-up after the baseline scans was 2.4 years (IQR 1.5, 3.5). LGE was present in 35% (n=32) of patients at baseline and follow-up. Among patients with LGE, the extent of LGE in the baseline and follow-up was 3% (median; IQR 2.3, 6.8) and 3% (median; IQR 2.3, 6.0) of the LV myocardium respectively. All patients with LGE had a non-coronary pattern. No incident or resolution of LGE was observed. Patients with a higher prevalence of baseline LGE were at increased risk of major clinical events (52% vs 25%; p=0.012). Furthermore, the presence of baseline LGE independently predicted adverse clinical events even after adjustment for clinical characteristics in a multivariate model (HR 2.25; 95% CI 1.10, 4.60, p=0.027, FIGURE). Conclusions Presence and extent of myocardial LGE was stable over a median follow-up of 24 months and was independently associated with adverse prognosis in HTx patients.