Similar Safety, Efficacy With Leadless vs Transvenous Pacemakers at 2 Years Post-TAVI

Patients who require a new permanent pacemaker after TAVI do just as well with leadless devices out to 2 years as they do with transvenous pacemakers, according to an analysis of real-world data from the US Medicare population.

Leadless pacing, which has increased in popularity over time, also was associated with fewer complications, investigators report, and did not increase total healthcare expenditures.

“The main finding of our study is that leadless pacemakers appear to be safe and efficacious in patients who undergo a pacemaker after TAVR,” lead author Hiroki A. Ueyama, MD (Emory University School of Medicine, Atlanta, GA), told TCTMD. “There is a growing interest of using it in this population, . . . and future studies should focus on identifying which patient population would benefit from this approach.”

Ueyama said that despite the uptick in leadless devices used over the course of the study, they are still “not widespread.” The current findings could lead to “broader usage,” he noted, adding that they cannot be generalized to non-Medicare patients, especially those younger than 65 years old.

“There's no question that leadless pacing is an option for patients who have the bradycardia AV block potentially associated with TAVR,” Fred Kusumoto, MD (Mayo Clinic, Jacksonville, FL), who was not involved in the study, commented to TCTMD. “I'm not surprised that it's increasing in use. I'm also happy to note that the requirement for pacing over time continues to decrease.”

Good Safety, Efficacy

Conduction disturbances after TAVI have remained a stubborn problem despite improvements in the procedure over the past 20 years. Unlike transvenous pacemakers, which can cause complications related to their leads or pockets becoming dislodged or infected, the newer leadless pacemakers have shown potential with minimal rates of infection out to 6 years.

For the study, published online last week in JACC: Cardiovascular Interventions, Ueyama and colleagues included 10,338 Medicare beneficiaries (mean age 82 years; 56.4% male) who received leadless (n = 730) or transvenous (n = 9,608) pacemakers at a median of 1 day after TAVI between 2017 and 2020.

The proportion of leadless pacemakers increased 3.5-fold from 4.3% in the first quarter of 2017 to 15.2% in the last quarter of 2020. Those who received leadless devices had a higher prevalence of comorbidities than those implanted with transvenous pacemakers, and they were less likely to have complete heart block (59.3% vs 77.5%; P < 0.001). Additionally, atrial fibrillation (AF; adjusted OR 2.42) and end-stage renal disease (adjusted OR 3.71) were independent predictors of leadless pacemaker use.

In a weighted analysis, in-hospital complications were less common following leadless versus transvenous pacemaker implantation (7.2% vs 10.1%; P = 0.014). Device-related complications (0.7% vs 2.1%; P = 0.015) and other complications (3.0% vs 5.1%; P = 0.014), including hematoma and vascular complications, were the biggest drivers of this difference. Also, after adjustment, leadless pacemakers were associated with longer hospital lengths of stay by a mean of 0.8 days (P = 0.005), but the strategies were associated with similar total healthcare spending amounts of just over $3,500.

Over a median follow-up period of 17.3 months, the weighted analysis showed no differences in all-cause death (adjusted HR 1.13; 95% CI 0.96-1.32), heart failure hospitalization (subdistribution HR 0.89; 95% CI 0.74-1.08), and infective endocarditis (subdistribution HR 0.98; 95% CI 0.44-2.17).

Additionally, the risk of device-related complications was lower for those who received leadless pacemakers (subdistribution HR 0.37; 95% CI 0.21-0.64).

Sensitivity analyses showed similar findings when looking only at patients with AF who received VVI leadless pacemakers or single-chamber transvenous pacemakers as well as when VVI leadless pacemakers were compared to dual-chamber pacemakers in patients without AF. However, the researchers did note a lower complication rate for those without AF who received VVI leadless pacemakers compared with dual-chamber transvenous devices (1.2% vs 6.3%; P = 0.017).

Ueyama said none of their results were unexpected. It was reassuring, he said, not to see worse outcomes with leadless pacemakers, especially since most included in the study were VVI devices that don’t have an AV synchrony function. “Hemodynamically, AV synchrony is thought to be beneficial, and [it was thought] the lack of AV synchrony with older generation VVI pacemakers may lead to worse heart failure hospitalization or all-cause mortality,” he explained. “But that wasn't shown.”

Who Should Get These?

Kusumoto pointed out that the patients getting leadless pacemakers in the study are different than the transvenous population, specifically that they more often had AF and didn’t need AV synchrony. “It was a lot of people who are on dialysis, where there would be challenges in getting vascular access in one of the upper extremity large venous systems,” he said. “And also, too, [there were] fewer people with AV block and a lot of this ‘unknown’ reason for pacemaker implant, presumably some transient bradycardia or whatever the case may be.”

Even so, the complication rates “are essentially the same,” Kusumoto added. “As the authors appropriately point out, that was almost completely due to the atrial lead, because the atrial lead dislodged or became nonfunctional or whatever the case may be.”

Kusumoto said there are two populations for whom he would not currently recommend leadless pacing: “Number one, those people who absolutely need AV synchrony, and number two, those people whose ejection fractions are not normal.”

Ueyama agreed. “For patients who are young who would require pacing for long-term, leadless pacemakers as of now only provide RV pacing, which in the long term may cause issues with dyssynchrony and cardiomyopathy related to that,” he said. “So those patients may require cardiac resynchronization therapy, which as of now, is better with transvenous pacemakers.”

In an accompanying editorial, Amit N. Vora, MD, James V. Freeman, MD, and Alan D. Enriquez, MD (all Yale University School of Medicine, New Haven, CT), write that “the investigators make a compelling point in suggesting that leadless pacemakers are a safe and effective alternative to transvenous pacemakers following TAVR.” However, whether these data will change practice remains to be seen, they say, especially with the current evolution of leadless pacemakers taking place.

“Although transvenous pacemaker technology is largely mature at this point, future iterations of leadless platforms are likely to be even more sophisticated,” the predict. “The first-generation platform was VVI only, whereas current platforms allow for AV synchrony. The current technology allows for only RV pacing, whereas cardiac resynchronization therapy and conduction system pacing platforms are currently under development. However, these platforms are likely to be even more costly and challenging to implement immediately post-TAVR given the financial pressures associated with the procedure.”

Nevertheless, because of the known risks associated with transvenous pacing, the editorialists foresee a “niche for reimagining currently available leadless technologies to be useful as a simpler, more temporary pacing solution post-TAVR in selected patients.”