Abstract 17124: Aortic Valve Calcification as a Predictor of Post-TAVR Pacemaker Dependence

Abstract

Introduction: Atrioventricular block requiring permanent pacemaker (PPM) implantation is a common complication of TAVR. Our group has previously reported that a significant number of patients receiving PPM immediately post-TAVR do not require right ventricular (RV) pacing at 30 days. The mechanism of AV block during TAVR is not fully understood, but is thought to partly be due to the mechanical stress of TAVR deployment and resultant tissue edema, resulting in possible injury to the nearby compact AV node. Aortic valve calcification (AVC) may worsen this condition and has been associated with an increased risk for post-TAVR PPM implantation. We performed a retrospective analysis to determine if AVC is predictive for long-term RV pacing in post-TAVR pacemaker patients at 30 days. Methods: Prospectively collected data of 262 consecutive patients who underwent TAVR with placement of a balloon-expandable valve at Rhode Island Hospital from March 2012 to October 2016 were analyzed. AVC data were derived from contrast-enhanced computed tomography and characterized by leaflet sector and region. Results: A total of 25 patients (11.1%) required post-TAVR PPM implantation. Seventeen patients did not require RV pacing at 30 days. Nine of these 17 patients had no RV pacing requirement within 10 days. Non-coronary leaflet (NCL) calcium volume was significantly higher in patients who were pacemaker dependent at 30 days ( p =0.01) and a calcium volume of >200mm 3 in the NCL was significantly associated with pacemaker dependence at 30 days (OR 51.9, 2.3-1170.2, p = 0.01). Pre-existing RBBB (OR 105.4, 4.52-2458.5, p=0.0002), bifascicular block (OR 12.50, 1.60-97.65, p=0.02), intra-procedural complete heart block (OR 12.83, 1.26-130.52, p =0.03), and QRS duration >120ms (OR 70.43, 3.23-1535.22, p=0.0002) were also significantly associated with pacemaker dependence at 30 days. Conclusions: Quantification of AVC by non-coronary leaflet calcium volume was found to be a novel predictor for RV pacing dependence at 30 days. The association of NCL calcification and pacemaker dependence may be related to the proximity of the conduction bundle to the non-coronary leaflet. Further studies are necessary to improve risk prediction for long-term RV pacing requirements following TAVR.