Conduction Disturbance After TAVR Tied to Worse Outcomes

By Will Boggs MD

January 21, 2020

NEW YORK (Reuters Health) - Conduction disturbances after transcatheter aortic-valve replacement (TAVR) are associated with increased mortality and other adverse outcomes, according to a systematic review and meta-analysis.

"This meta-analysis provided further evidence of the negative impact of conduction disturbances post-TAVR, including new-onset left bundle branch block and permanent pacemaker implantation, with increased risk of death and heart failure hospitalization at 1-year follow-up," Dr. Josep Rodes-Cabau from Quebec Heart and Lung Institute, Laval University, in Quebec City, Canada, told Reuters Health by email.

New-onset persistent left bundle branch block (NOP-LBBB), high-degree atrioventricular block leading to permanent pacemaker implantation and other conduction disturbances are the most frequent complications of TAVR. But the clinical impact of these disturbances remains controversial.

Dr. Rodes-Cabau and colleagues investigated the impact of NOP-LBBB and PPI post-TAVR on all-cause death, cardiac death and hospitalization for heart failure in their systematic review and meta-analysis of 30 studies involving more than 50,000 patients.

Overall, the rate of NOP-LBBB at discharge was 22.7%, and the one-year all-cause mortality rates ranged from 6.3% to 27.8% in patients with NOP-LBBB and from 4.9% to 28.4% in patients without it.

NOP-LBBB was associated with a 32% higher risk of all-cause death (P<0.001), a 46% higher risk of cardiac death (P<0.001), a 35% higher risk of heart-failure hospitalization (P=0.02) and an 89% higher risk of pacemaker implantation (P<0.001) at one year.

The overall rate of pacemaker implantation at discharge ranged from 5.9% to 32.0%, the researchers report in European Heart Journal. Pacemaker implantation was associated with a 15% higher risk of all-cause death (P=0.002) and an 18% higher risk of heart-failure hospitalization (P=0.02) at one year, but it had no apparent effect on cardiac death.

"Patients with conduction disturbances post-TAVR would require a closer follow-up, particularly those with low left ventricular ejection fraction," Dr. Rodes-Cabau said. "Also, patients with new-onset persistent left bundle branch block may benefit from prolonged continuous ECG monitoring in order to early detect and treat potentially life-threatening bradyarrhythmias."

"The occurrence of conduction disturbances post-TAVR has an important negative clinical impact," he said. "This highlights the relevance of preventive measures, particularly regarding modifiable factors such as valve implantation depth."

"Future studies need to identify, among those patients with conduction disturbances post-TAVR, those at highest risk of major cardiovascular events and death," Dr. Rodes-Cabau added. "This would allow us to implement optimized and more uniform treatment strategies in order to improve clinical outcomes."

Dr. Scott Lilly of Ohio State University Wexner Medical Center, in Columbus, who has also reviewed conduction disturbances after TAVR but was not involved in the new work, told Reuters Health by email, "Whether or not left bundle branch block progresses to complete heart block, and in some cases sudden cardiac death, is a concern of all physicians involved in these procedures. The relationship between persistent LBBB in this study and the risk of cardiac death at 12 months deepens this concern."

"Patients with new-onset and persistent LBBB after TAVR warrant additional observation," he said.

"Reliable outpatient monitoring has been adopted in many centers to detect potentially dangerous heart rhythms before the onset of heart failure or syncope," Dr. Lilly said. "It is possible that these strategies represent a safe alternative to preemptive placement of pacemakers, electrophysiological studies, or prolonged inpatient hospitalization."

SOURCE: European Heart Journal, online January 3, 2020.