Short-term pacemaker dependency after transcatheter aortic valve implantation.

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a less invasive technique for the treatment of severe aortic stenosis in high-risk patients. Occurrence of conduction disturbances requiring permanent pacemaker (PPM) implantation after TAVI is frequently observed.

METHODS

The retrospective analysis comprised 153 patients (96 women, aged from 65 to 97 years) who underwent TAVI due to high-grade aortic stenosis. The aim was to evaluate the incidence of high-grade atrioventricular (AV) block after TAVI and the percentage of ventricular pacing and pacemaker (PM)-dependency at the first follow-up 6-8 weeks after implantation.

RESULTS

Out of the 153 patients (age 81 ± 6 years) who underwent TAVI, 144 (94 %) had a transfemoral and 9 (6 %) patients a transapical approach. A PPM was implanted in 31 (20 %) patients, 24 (16 %) were implanted with the Medtronic CoreValve® and 7 (5 %) with the Edwards Sapien® valve (p = n.s.). Complete AV block was the indication in 21 patients (68 %), second-degree AV block in 1 patient (3 %), slow atrial fibrillation in 3 patients (10 %), new left bundle branch block (LBBB) plus sustained ventricular tachycardia (VT) in 1 patient (3 %), sick sinus syndrome in 2 patients (7 %), whereas in 3 patients (10 %) a PPM was inserted for safety reasons because of new LBBB and first-grade AV block. All of the nine patients (6 %) with a preexisting bundle branch block developed total AV block after TAVI. At follow-up PM-dependency (intrinsic rhythm < 30 bpm) occurred in 11/30 patients (37 %), whereas an intrinsic rhythm > 50 bpm was seen in 17 patients (57 %). At nominal device programming the percentage of ventricular stimulation (VP) during the short-term observation period was 60 ± 44 % in dual-chamber devices (N = 18), and 70 ± 36 % in single-chamber PPM (N = 5).

CONCLUSION

The PPM implantation rate of about 20 % after TAVI is comparable to previously published data. The need for permanent pacing is linked to the valve type and preexistence of a right bundle branch block. At short-term more than half of the patients implanted with a device were not strictly PM-dependent, but presented an underlying intrinsic rhythm, indicating that temporary AV conduction disturbances may recover over time. This might justify a more conservative approach in some patients under watchful waiting. From another point of view, ventricular pacing at a regular or sensor-modulated rate may provide rhythm stability and chronotropy during the short-term period post-TAVI.