Value of basal HV Interval prior TAVR as predictor of permanent pacemaker implantation

Transfemoral aortic valve replacement (TAVR) is an effective and safe treatment for severe aortic stenosis (SAoS) even in low risk patients (1,2). As population ages, the volume of TAVR procedure increases and although improvements in technology and technique, new onset persistent disturbances in the electrocardiogram (ECG) are present up to 34,8% of patients at hospital discharge(3) and the secondary need of permanent pacemaker implantation (PPM) remains high, being of 4-24% with balloon-expanding valves (BEV) and 14.7-26.7% with self-expanding valves (SEV)(3). According to ESC guidelines, an electrophyisiologic study (EPS) centered in HV interval measure with a cutoff of ≥70ms is a useful tool to assess the risk of progression to high auriculoventricular block (HAVB) in specific groups with persistent ECG abnormalities to consider PPM(4-5), but this only applies in post TAVR scenario. Measuring HV interval at the intervention day prior procedure could help optimize and assess risk for PPM post TAVR.

To measure basal HV interval prior TAVR and correlate it to risk of PPM implantation before discharge and 30 days after discharge.

Single-center prospective cohort study, patients with SAoS scheduled for TAVR, sinus rhythm at intervention day, without PPM or history of PPM indication were included. At time of TAVR, a tetrapolar catheter was placed at the septal aspect of tricuspid valve. A mobile polygraph was used to measure ECG parameters and HV interval before TAVR. Then, tetrapolar catheter was advanced to ventricle to perform rapid stimulation as part of habitual valve implantation protocol. After procedure, a rhythm monitorization for >48-72 hrs, was made to decide, PPM, HV interval measure or clinical daily ECG vigilance with posterior discharge was performed. A 30-day post discharge follow up was expected.

38 patients were enrolled, median age 83.5 ± 5.5 years, 23 females (60,5%). 37 patients had SEV implanted and 1 patient had BEV implanted. Median HV interval was 54.4ms. 18 patients (47.4%) had a mild abnormal HV interval, of whom 11 had a narrow QRS. Post TAVR procedure, 15 patients (39.5%) persisted with "de novo" LBB at discharge. 5 women and 7 men, had PPM implanted before discharge. 1 woman was implanted 6 days after discharge due to HAVB (66ms HV interval prior TAVR). In a multivariate analysis including sex, age, PR, QRS and HV interval >55ms, the RR (IC 95% 1.9-70.3) risk of PPM was 13.42 folds higher (p=0.008). At a bivariate quantitative HV analysis, a higher HV period persisted significantly related to PPM outcome (p=0.001).

In our study population, a pre-existing mild to moderate prolongation of HV interval prior TAVR substantially elevates the risk of requiring PPM before discharge.

61.1% of these basal mild prolongation HV interval patients had a narrow QRS prior TAVR.

HV measure prior TAVR in narrow QRS