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Need for a pacemaker after transfemoral transcatheter aortic valve replacement (TAVR) with a self-expanding device was both common and impactful for mortality, but the risk appeared to be modifiable, international registry data showed.

Of patients treated with an Acurate neo/neo2 (approved outside the U.S.) or Evolut PRO/PRO+ valve, 11.3% needed new permanent pacemaker implantation (PPI) in the 30 days after the procedure, reported Antonio Mangieri, MD, of Humanitas University in Milan, and colleagues in .

New PPI recipients had a mortality rate of 16.9% at 1 year compared with a rate of 10.8% among other patients, which was a significant 66% elevated relative risk even after adjustment for other factors. This risk was particularly concentrated in patients with baseline left ventricular (LV) ejection fraction under 40% (P=0.049 for interaction).

The verdict on prognostic significance of PPI has been mixed in prior studies, noted Hasan Jilaihawi, MD, of Cedars-Sinai Medical Center in Los Angeles, in an .

"Many of the earlier TAVR studies that did not find a prognostic association with PPI may have either excluded patients with LV dysfunction or may have had a lower threshold to implant PPI, thus resulting in lower frequencies of right ventricular pacing in less significant conduction disturbances, potentially accounting for the disparities seen," he wrote.

The researchers concluded that "careful THV [transcatheter heart valve] selection and implantation seem crucial in patients at risk for new PPI, and alternative therapeutic options such as cardiac resynchronization therapy may be relevant in patients with LV dysfunction needing PPI after TAVR."

Their study utilized the retrospective NEOPRO registry of real-world use of the Acurate neo or Evolut PRO devices at 24 centers internationally from January 2012 to March 2018, as well as the NEOPRO-2 registry that expanded the included devices to the latest-generation Acurate neo2 and Evolut PRO or PRO+ devices at 20 international centers from August 2017 to December 2021. All were consecutive cases done via transfemoral access for symptomatic severe aortic stenosis in a native aortic valve.

Altogether, there were 3,211 patients without a prior pacemaker or implantable cardioverter-defibrillator who underwent TAVR with Acurate neo (n=1,090), Acurate neo2 (n=665), Evolut PRO (n=1,312), or Evolut PRO+ (n=144).

PPI rates were 8.8%, 7.7%, 15.2%, and 10.4%, respectively, for the four valve types.

Jilaihawi highlighted that the rates with the latest-generation self-expanding TAVR were "either close to or even <10%, achieving 'Sapien-like' rates of this complication, while still affording the putative hemodynamic benefits of a supra-annular design."

He also pointed to implications for market share.

"In a global TAVR landscape thus far heavily dominated by balloon-expandable TAVR, namely Sapien 3 (Edwards Lifesciences), valued by many operators for its ease of use and consistently favorable outcomes, such iterative advances in anatomically directed procedural planning, procedural optimization, and device design, represent healthy advances to strive for a minimization of complications, continually driving even better outcomes in the field," Jilaihawi wrote.

"It is unclear how the anticipated imminent U.S. commercial approval of the Acurate neo platform will impact operator choice of TAVR devices overall," he continued. "However, with ease of deployment and relatively easy coronary access, as well as favorable hemodynamics and clinical outcomes, including the low rates of PPI demonstrated in this important paper, it will contribute with others to a meaningful end to a monopoly/duopoly in the TAVR landscape."

Competition could "allay stagnation, drive ongoing innovation to minimize important complications such as PPI, improve efficiencies, and limit overall costs," he added.

Significant independent predictors of PPI were similar with both devices:

• Baseline right bundle branch block: OR 5.81 for Acurate neo/neo2 and 5.26 for Evolut PRO/PRO+
• Depth of valve implantation: OR 1.19 and 1.13, respectively
• STS-PROM score: adjusted OR 1.12 and 1.10, respectively

The rate of PPI was lower in patients with implantation depth of less than 3 mm versus at least 3 mm in both Acurate neo/neo2 (4.4% vs 8.8%, P=0.024) and Evolut PRO/PRO+ groups (7.8% vs 16.3%, P=0.003).

Optimal implantation depth thresholds estimated in the study to avoid a new PPI were 5.9 mm and 4.3 mm with Acurate neo/neo2 and Evolut PRO/PRO+, respectively, the researchers said, although they called for studies to explore strategies like higher implantation depth or lower prosthesis oversizing and to clearly identify which higher-risk patients might benefit from extended rhythm monitoring.

"Interestingly, and given neither Acurate neo or Sapien 3 are repositionable, it appears that -- for all designs -- accuracy in procedural planning and implantation technique impacts PPI more than retrievability or device design per se," Jilaihawi wrote. "The long-term prognostic impact of PPI in these patients needs to be further evaluated."

He noted, though, that the registry didn't have data on membranous septum length, which "has emerged in many studies as an important predictor for PPI with TAVR and offers the potential for a patient-specific, anatomically directed depth of implantation."

Other study limitations were the observational retrospective design, with no core laboratory analysis or independent adjudication of clinical events.

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