Transcatheter aortic valve replacement and cardiac conduction

ABSTRACT

Introduction: Conduction abnormalities after transcatheter aortic valve replacement (TAVR) account for a high percentage of post-TAVR complications.

Areas covered: The etiology of conduction abnormalities is closely tied to cardiac anatomy (length of membranous septum, degree of calcification, location of left bundle within the membranous septum), baseline conduction abnormalities (preprocedure right bundle branch block), and procedural variables (type of valve, depth of implant). Management of new high-grade AV block and new left bundle branch block varies by institution in the absence of consensus guidelines.

Expert opinion: Authors describe the incidence, etiology, outcomes, and management of conduction abnormalities related to aortic stenosis and TAVR.

KEYWORDS:

• TAVR
• pacemaker
• high-grade atrioventricular block
• complete heart block
• left bundle branch block
• right bundle branch block

Article highlights

• The incidence of baseline conduction abnormalities is high in elderly patients who have aortic stenosis. Even in medically managed aortic stenosis patients, the yearly incidence of new PPM is 3–5%.

• TAVR is associated with higher rates of new PPM implantation compared to SAVR and the rates of PPM are higher with mechanically expanding and self-expanding valves (versus balloon-expandable). The newer iterations of balloon expandable valves have increased rates of post-TAVR conduction abnormalities compared to the first generation balloon expandable valves, likely due to the addition of a perivalve cuff to prevent perivalve leak.

• The conflicting survival results with PPM might be secondary to the prevention of HAVB associated complications after the index hospitalization and/or the failure to exclude patients with pacemakers prior to TAVR from the ‘new’ pacemaker analyses. Early analysis of conduction abnormalities in the general population show that patients with valvular disease and conduction abnormalities have the highest mortality compared to patients with conduction abnormalities associated with coronary or hypertensive heart disease. Electrophysiology studies of severe AS patients also show a delayed HV interval, possibly secondary to myocardial fibrosis.

• While the risk of sudden cardiac death with symptomatic AS was previously thought to be largely secondary to obstruction caused by the stenotic valve, after fixing the stenosis, we have recognized yet another problem—the risk associated with native conduction abnormalities that these patients now survive to experience. Further studies of post-TAVR conduction abnormalities are key to continued improvement in long term TAVR outcomes.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.