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TAVR Studies 'Systematically Underestimate' New Pacemaker Rates?

— Failure to exclude patients not at risk has meant 'major bias'

Ƶ MedicalToday

Need for new permanent pacemaker implantation tends to be underreported in transcatheter aortic valve replacement (TAVR) studies, investigators suggested.

Among the studies that included both balloon-expandable and self-expanding valves, new pacemaker placement was reported in 15.0% of patients.

, of Quebec Heart and Lung Institute in Canada, and colleagues determined that the real incidence of new permanent pacemakers lay somewhere , though, after accounting for the fact that some patients who died within 30 days of TAVR probably already had pacemakers implanted and that people who already had one before the procedure weren't at risk.

In TAVR studies, "the inclusion of patients who are not at risk for this specific complication may have translated into a significant underestimation of the real incidence of permanent pacemaker following TAVR, and introduces a major bias when informing patients about the real risks of permanent pacemaker following the TAVR procedure," the authors argued in the Nov. 29 issue of the Journal of the American College of Cardiology.

A review of the literature on self-expanding valves showed an average permanent pacemaker implantation rate of 23.1%. When recalculated excluding all patients with prior permanent pacemakers as well as those who were deceased at 30 days post-TAVR, that rate was actually between 27.4% and 29.9%.

Similarly, balloon-expandable valves were reported as having a pacemaker incidence of 6.8%; but the real rate of new pacemaker placement fell in the 7.8% to 8.4% range, according to Rodés-Cabau's group.

The authors performed a pooled analysis of 28 large multicenter registries and six randomized trials.

"The chief finding of this analysis is that TAVR studies tend to systematically underestimate the real incidence of new permanent pacemaker rates by failing to consider patients with prior permanent pacemakers," they wrote.

"Controversy still exists regarding the long-term impact of new permanent pacemaker post-TAVR, but the short- and long-term risks and morbidity associated with permanent pacemaker are well known. Therefore, it would be important to consider these results in future TAVR studies especially with the shift towards implanting newer generation devices within lower-risk patients. Also, these results should be taken into account when advising TAVR candidates without prior permanent pacemaker about the risks of the procedure."

  • author['full_name']

    Nicole Lou is a reporter for Ƶ, where she covers cardiology news and other developments in medicine.

Disclosures

Rodés-Cabau declared receiving research grants from Edwards Lifesciences and Medtronic.

Primary Source

Journal of the American College of Cardiology

Chamandi C, et al "Reported versus 'real' incidence of new pacemaker implantation post-transcatheter aortic valve replacement" J Am Coll Cardiol 2016; DOI: 10.1016/j.jacc.2016.08.065.