Prognostic significance of LGE by CMR in aortic stenosis patients undergoing valve replacement

Abstract

Background: Prior studies have shown that late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) can detect focal fibrosis in aortic stenosis (AS), suggesting that it might predict higher mortality risk.

Objectives: This study was conducted to evaluate whether LGE-CMR can predict post-operative survival in patients with severe AS undergoing aortic valve replacement (AVR).

Methods: We prospectively evaluated survival (all-cause and cardiovascular disease related) according to LGE-CMR status in 154 consecutive AS patients (96 men; mean age: 74 ± 6 years) without a history of myocardial infarction undergoing surgical AVR and in 40 AS patients undergoing transcatheter aortic valve replacement (TAVR).

Results: LGE was present in 29% of patients undergoing surgical AVR and in 50% undergoing TAVR. During a median follow-up of 2.9 years, 21 patients undergoing surgical AVR and 20 undergoing TAVR died. In surgical AVR, the presence of LGE predicted higher post-operative mortality (odds ratio: 10.9; 95% confidence interval [CI]: 1.2 to 100.0; p = 0.02) and worse all-cause survival (73% vs. 88%; p = 0.02 by log-rank test) and cardiovascular disease related survival (85% vs. 95%; p = 0.03 by log-rank test) on 5-year Kaplan-Meier estimates of survival after surgical AVR. Multivariate Cox analysis identified the presence of LGE (hazard ratio: 2.8; 95% CI: 1.3 to 6.9; p = 0.025) and New York Heart Association functional class III/IV (hazard ratio: 3.2; 95% CI: 1.1 to 8.1; p < 0.01) as the sole independent predictors of all-cause mortality after surgical AVR. The presence of LGE also predicted higher all-cause mortality (p = 0.05) and cardiovascular disease related mortality (p = 0.03) in the subgroup of patients without angiographic coronary artery disease (n = 110) and higher cardiovascular disease related mortality in 25 patients undergoing transfemoral TAVR.

Conclusions: The presence of LGE indicating focal fibrosis or unrecognized infarct by CMR is an independent predictor of mortality in patients with AS undergoing AVR and could provide additional information in the pre-operative evaluation of risk in these patients.

Keywords: aortic stenosis; aortic valve replacement; late gadolinium enhanced cardiac magnetic resonance.