Aortic valve and left ventricular outflow tract calcium volume and distribution in transcatheter aortic valve replacement: Influence on the risk of significant paravalvular regurgitation

Abstract

ObjectivesWe sought to determine the impact of aortic root calcium on the risk of significant paravalvular regurgitation (sPAR) in transcatheter aortic valve replacement (TAVR). MethodsIn 302 consecutive patients from 3 centers, aortic root calcium was quantified volumetrically on pre-TAVR multidetector computed tomography (MDCT) in three regions: 1) the aortic valve region, 2) the overall left ventricular outflow tract (LVOT) and 3) the upper LVOT. Transcathether heart valve (THV) oversizing was calculated as (THV nominal area/MDCT annular area−1) × 100. The study endpoint sPAR was a composite of post-dilatation (PD) and PAR > mild. ResultssPAR occurred in 15% (46/302) of patients. Upper LVOT calcium volume was more predictive of sPAR than overall LVOT calcium volume, with an area under the receiver operating curve (AUC) (95% confidence interval [CI]) of 0.80 (0.67–0.89) vs. 0.60 (0.51–0.70); p = 0.0001. The optimal cut-off calcium volume thresholds determined from receiver operating curves were 21 mm3 and 30 mm3 for upper LVOT and overall LVOT calcium, respectively. Upper LVOT calcium ≥ 21 mm3, but not overall LVOT calcium ≥ 30 mm3, independently predicted sPAR, odds ratio (95%CI): 9.5 (4.1–22.3) vs 1.6 (0.6–2.7). Upper LVOT calcium was more predictive of sPAR in patients with THV oversizing ≥ 13% compared to patients with THV oversizing <13%, AUC (95% CI): 0.83 (0.72–0.93) vs. 0.67 (0.51–0.74); p < 0.0001. ConclusionsUpper LVOT calcium predicts more-than-mild paravalvular regurgitation following TAVR or the need for postdilatation. Upper LVOT calcium is most predictive of paravalvular regurgitation in the event of THV oversizing ≥ 13%.