Cardiovascular Magnetic Resonance Studied to Evaluate Aortic Regurgitation After TAVR

August 8, 2016—A study of cardiovascular magnetic resonance (CMR) to evaluate aortic regurgitation (AR) after transcatheter aortic valve replacement (TAVR) was published by Henrique B. Ribeiro, MD, PhD, et al in the Journal of the American College of Cardiology (JACC; 2016;68:577–585).

Residual AR after TAVR is associated with greater mortality, but determining the severity of AR using Doppler echocardiography remains challenging. CMR is reported to be more accurate in quantifying AR; however, no data exist regarding the prognostic value of AR as assessed by CMR after TAVR.

As summarized in JACC, the study included 135 patients from three centers. AR was quantified using regurgitant fraction (RF) measured by phase-contrast velocity mapping CMR at a median of 40 days post-TAVR and Doppler echocardiography at a median of 6 days post-TAVR. Median follow-up was 26 months. Clinical outcomes included mortality and rehospitalization for heart failure.

The investigators reported that moderate-severe AR occurred in 17.1% and 12.8% of patients as measured by echocardiography and CMR, respectively. Higher RF after TAVR was associated with increased mortality (hazard ratio [HR], 1.18 for each 5% increase in RF; 95% confidence interval [CI], 1.08–1.3; P < .001) and the combined endpoint of mortality and rehospitalization for heart failure (HR, 1.19 for each 5% increase in RF; 95% CI, 1.15–1.23; P < .001).

According to the investigators, prediction models yielded significant incremental predictive value. CMR performed a median of 40 days after TAVR had a greater association with post-TAVR clinical events compared with early echocardiography (P < .01). Poorer clinical outcomes were best predicted by an RF ≥ 30% (P < .001 for either mortality or the combined endpoint of mortality and heart failure rehospitalization). 

The investigators concluded that worse AR as quantified by CMR was associated with increased mortality and poorer clinical outcomes after TAVR. Quantifying AR with CMR may identify patients with AR who could benefit from additional treatment measures, advised the investigators in JACC.