Post-TAVR conduction disorders are common and lead to frequent permanent pacemaker (PPM) implantation. They limit the spread of indications of TAVR from high risk to intermediate risk patients. The computed tomography (CT) measurement of membranous septum (MS) length seems to be an efficient predictive factor of PPM implantation. We hypothesized that MS could be used in daily practice to predict accurately post-TAVR PPM implantation.

The present study is a monocentric cohort trial. We developed a score to determine the impact of MS length on the PPM implantation rate. We have identified 604consecutive patients, who underwent TAVR from January 2016 to May 2018. Among them, 406patients met the inclusion criteria (no previous PPM, no previous aortic-valve replacement, CT available for measurement). We assessed the relevance of the score developed based on multivariate analysis regression.

In our cohort, Corevalve and Sapien devices were both equally implanted and femoral access was used in 90% of the cases. 111 patients (27.3%) received PPM. After adjustment on pre and post-procedural parameters, multivariate analysis revealed three independent predictive factors: pre-existing right bundle branch block (OR: 5.85; CI [2.26; 15.12]; P<0.001), Landing zone calcifications (for low degree of calcification OR: 7.39; IC [2.90; 18.82]; P<0.001; for high degree of calcification OR: 29.6; IC [11.95; 73.40]; P<0,001), difference between MS length and implantation depth (OR: 2.48; IC [2.01; 3.06]; P<0.001). The c-statistic of the model of PPM showed an area under the curve of 0.0.937 (Fig. 1).

Our results confirm that MS seems to be an important factor that could help predicting post-TAVR PPM implantation. Our score could be easily implemented in the daily practice, as a routine tool for cardiologist.