Morphologic and Functional Changes after LVAD Implantation in Patients with Preoperative Severe Mitral Regurgitation

Abstract

Examined cardiac changes after continuous flow left ventricular assist device (cfLVAD) implantation in patients with preop severe mitral regurgitation (MR). From 2003-2017, 134 patients with severe MR had cfVLAD implant without mitral valve (MV) intervention. We assessed echocardiographic (echo) features pre-cfLVAD, early post-cfLVAD, and the last available echo. Ventricular and atrial volumes were calculated from established area-length formulas. Volumes were normalized to predicted volume given sex, body habitus and age. Values were compared using paired or independent t-test or Wilcoxon analysis. Two step cluster analysis based on preop normalized left ventricular and atrial volumes and MV height identified 3 groups with a silhouette measure of 0.4 (table). Median echo follow up for early and late times were 0.92 months (IQR=0.90) and 15.16 months (IQR=33.00) respectively. MR improved early after cfLVAD by 2.10+1.16 grades (P<0.01). However, MR worsened over time where greater than mild MR was present in 26% in early and 76% in late follow up (P<0.01). Neither pre-cfLVAD MV height (P=0.29) nor left ventricular volume (P=0.56) alone predicted MR resolution on regression analysis. However preoperative left atrial volume was predictive of MR improvement post-cfLVAD (P=0.02). Morphologically, Cluster 1 with smaller left sided chambers and MV height was predictive of MR improvement at early (P=0.03) and late (P<0.01) echo follow up. Right heart function worsened over time. Moderate or severe tricuspid regurgitation in the early and late echo were 15% and 25% respectively (P=0.01). Severe right ventricular dysfunction in the early and late echo were 15% and 38% respectively (P<0.01). Smaller overall cardiac dimension predicts improvement in severe MR after cfLVAD. Larger left atrial size is independently predictive of MR improvement perhaps reflecting MR chronicity. Despite cfLVAD, right heart function continues to decline over time.