Is Permanent Pacing Indicated in Patients who Develop LBBB and Long PR Following TAVI?

Background:
Conduction disorders post trans-catheter aortic valve implantation (TAVI) are relatively frequent, some of which require implantation of permanent pacemaker (PPM). Post procedural electrocardiogram (ECG) with left bundle branch block (LBBB) and long PR interval (1DAVB) is still a controversial indication for pacemaker implantation.

Objective:
We sought to evaluate electrocardiographic progression and outcome of LBBB &1AVB over time.

Methods:
All patients (n=554) underwent ECG evaluation prior to and immediately after TAVI, and daily thereafter until discharge. Those who have had PPMs implanted were followed at the pacemaker clinic and checked for pacemaker dependency by inhibition for 10 seconds at least once yearly. We reviewed their records for ECG dynamics and survival status. Mean follow up duration was 914 days±682 days.

Results:
Of 554 patients undergoing TAVI, 58 (10.4%) had LBBB and 1AVB on their first post TAVI ECG. Baseline ECG was normal in 26 patients. The rest had LBBB (N=4), 1DAVB (N=20) or LBBB with 1DAVB (N=8).

Of the 58, 8 (14%) progressed to high degree AVB (mean 1.6 days±1.8) and received PPM. Fourteen other patients underwent PPM implantation (mean 5±3) just for LBBB & 1AVB at their physicians` discretion. During follow-up, none of them developed pacemaker dependency. KM curves demonstrated significantly lower survival in patients paced for LBBB&1DAVB compared to non-paced patients (p=0.012).

Conclusions:
Patients with LBBB&1AVB post-TAVI may develop high degree AVB within 6 days following TAVI. Those implanted with PPM for LBBB&1AVB without evidence of high degree AVB had higher mortality over time. These data question the rationale behind PPM implantation for new LBBB&1AVB without evidence of advanced AVB.