Background

Detection and adequate therapy of new-onset conduction disturbances after transcatheter aortic valve replacement (TAVR) remain one of the most frequent complications in modern therapy of aortic stenosis. Recent studies reported pacemaker implantation rates between 4 to 27.7% and new onset of left bundle branch block (LBBB) up to 19.2% depending on the valve system used. The aim of this study was to analyze ECG changes and pacemaker implantation rates in a large study population using contemporary valves.

Methods and Results

From January 2019 till December 2020, 1056 patients underwent TAVR at Charité Universitätsmedizin, Berlin (mean age 82 ± 6.1 years, 45% female). In this retrospective analysis, we reviewed 933 ECGs before and 1015 ECGs within 48 hours after TAVR. Mean left ventricular ejection fraction (LVEF) was 54.7 ± 11%, mean STS Score was 4.5 ± 3.6%. 51% of the implanted valves were self-expandable (11.4% Evolut R/PRO, 42.5% Portico), 46.1% balloon-expandable (Edwards Sapien 3).

Following current guidelines, we analyzed six different groups regarding ECG changes after TAVR: Patients developing new first-degree atrioventricular block (AV block I°, n = 80; 11.8%), new LBBB (n = 230; 23.3%), new PR-time > 240ms (n = 29; 2.9%), prolongation of PR-time by >20ms (n = 181; 21.5%), prolongation of QRS duration by >20ms (n = 299; 32.9%) and patients with pacemaker implantation (n = 123; 15.6%).

After multivariate analysis, new first-degree AV Block was associated with a larger valve size (OR 1.18, CI 95% 1.01-1.3; p=0.02). PR-time >240ms after TAVR was associated with pre-existing AV block I° (OR 1.1, CI 95% 1.05-1.1; p<0.001). New LBBB after TAVR was more frequently observed after the implantation of Portico valve (OR 2.1; CI 95% 1.2-3.4; p<0.004) and with deeper implantation (OR 1.1, CI 95% 1.04-1.2; p<0.003). Independent risk factor for a prolongation of QRS duration >20ms was the implantation depth (OR 1.1, CI 95% 1.03-1.22; p=0.008). Prolongation of QRS and PR-time by >20ms was less frequent after implantation of a balloon-expandable valve (OR 0.4 CI 95% 0.22-0.75; p=0.004 and OR 0.54 CI 95% 0.28-1.015; p=0.04). Permanent pacemaker implantation was associated with the implantation of a Portico valve (p=0.02). However, after multivariate analysis, only pre-existing first-degree AV block (OR 1.8, CI 95% 1.1-3.2; p=0.02), pre-existing right bundle branch block (RBBB, OR 5.1, CI 95% 2.7-9.4; p<0.01) and implantation depth (OR 1.1, CI 95% 1.01-1.28; p=0.02) remained independent risk factors for pacemaker implantation after TAVR.

Conclusion:

In this large, contemporary study population we observed a relevant increase in new LBBB and unspecific prolongation of the QRS-duration post TAVR. New onset LBBB was associated with the implantation of a Portico valve. In contrast, implantation of a balloon-expandable valve was associated with the lowest risk for changes in PQ and QRS time. 15.6% of patients needed post-procedural pacemaker implantation after TAVR. As shown with older valve generations, pre-existing RBBB, first-degree AV block and the implantation depth remain the most important risk factors.