Retrospective Analysis Isolates Predictors of Late Pacemaker Need Post-TAVR

NATIONAL HARBOR, MD—A small percentage of patients discharged after TAVR without a permanent pacemaker will require one in the intervening months, but predicting who those patients are is challenging. New data from a small, retrospective study found that patients with baseline QRS width ≥ 120 ms and those implanted with a self-expanding valve were at increased risk for advanced conduction disturbance requiring pacing.

“We’ve learned a lot about what predicts pacemaker need in the hospital, but what actually happens when patients leave the hospital is not really clear,” said Alexis K. Okoh, MD (RWJBarnabas Health, NJ), during his presentation here at CRT 2020.

For the study, Okoh and colleagues prospectively reviewed data on patients treated with TAVR at their high-volume center. After excluding those had a history of pacemaker or who needed one before discharge, there were 883 patients available for analysis. Of those, 2.7% developed an advanced conduction disturbance at 30 days or beyond that required a late pacemaker implantation. According to Okoh, the time frame for development of the conduction disorder in most of those patients was between 60 and 180 days.

Compared with those not needing a late pacemaker, patients who did had a wider QRS (120 ± 31 vs 103 ± 25 ms; P = 0.001). They also had a wider PR interval (202 ± 25 vs 180 ± 29 ms; P = 0.018) and a higher prevalence of baseline left bundle branch block (16.6% vs 5.5%; P = 0.021). Okoh and colleagues also found that late pacemaker patients were much more likely to have received a self-expandable valve than a balloon-expandable valve (79.2% vs 20.8%; P = 0.002). In multivariable analysis, baseline QRS interval, self-expandable valve, and earlier procedure year (2015/2016 vs 2017/2018) all were independent predictors of late pacemaker. Okoh noted that none of the patients included in the study had bicuspid valves.

We’ve learned a lot about what predicts pacemaker need in the hospital, but what actually happens when patients leave the hospital is not really clear. Alexis K. Okoh

He also stressed that the small, single-center study was retrospective, lacks long-term follow up to better understand the impact of the conduction abnormalities on mortality, and did not include information on specific valves or follow-up data after the permanent pacemaker was implanted.

“Baseline QRS width and a self-expanding valve are independent predictors of advanced conduction disturbances requiring a late permanent pacemaker, and for that reason it’s strongly encouraged to perform meticulous follow-up in patients who have a widened QRS at baseline,” Okoh said.

In an interview with TCTMD, Okoh said that as TAVR becomes an option for more and more low-risk patients, the importance of having a multidisciplinary team at specialized TAVR centers follow them as opposed to returning them to their regular cardiologist after the procedure is increasingly important.

“Some of these patients go back to their community and they get lost to follow-up, unfortunately,” he noted. “Not only do we have to be following them in the short term, they clearly have to be closely monitored for at least a year or so.”

Co-existing Conduction Disturbance?

“This is a topic of intense debate,” noted session co-moderator Sahil Khera, MD (Icahn School of Medicine at Mount Sinai, New York, NY), asking the audience if they knew how many patients in the control arm of the PARTNER trial who had received medical or nonsurgical therapy ultimately needed a pacemaker.

“If you don’t treat them at all, 8% will have a pacemaker at 1 year,” he observed. “So, it is possible that aortic stenosis and this conduction system disturbance might be coexisting, and just by chance they require the pacemaker [after TAVR].”

Khera added that while the predictors in the study are reasonable, “it’s so hard to tease all of [the possibilities] out, and I’m not entirely sure that we’re doing a good job of it.” While implantable monitors can be used in the immediate postdischarge phase to detect conduction events, he said, the cost-effectiveness of using that as a widespread strategy is unclear.

“It’s just such a challenging topic,” Khera added, noting that post-TAVR issues like valve sizing problems and membranous septum length are still going to account for a portion of those who eventually will require a pacemaker.