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Having to get a permanent pacemaker after transcatheter aortic valve replacement (TAVR) was associated with longer hospital stays and more adverse events at 1 year, a Medicare-linked registry study suggested.

One year after TAVR, pacemaker recipients had spent longer in the hospital (median 7 versus 6 days, P<0.001) and in the intensive care unit (56.7 versus 45.0 hours, P<0.001), , of Reading Health System in West Reading, Pa., and colleagues reported online in .

Permanent pacemakers were also tied to increased odds of mortality (24.1% versus 19.6%, HR 1.31, 95% CI 1.09-1.58) and a higher combined rate of death or heart failure readmission (37.3% versus 28.5%, HR 1.33, 95% CI 1.13-1.56).

Conduction abnormalities led to permanent pacemaker implantation in 6.7% of patients within 30 days of TAVR (25.1% with self-expanding CoreValves and 4.3% with balloon-expandable Sapien valves)

Based on a multivariable analysis of the national TVT Registry -- a joint effort by the Society of Thoracic Surgeons and American College of Cardiology -- patients were more likely to get a permanent pacemaker if they:

• Were older (OR 1.07 per 5-year increment, 95% CI 1.01-1.15)
• Had a prior conduction defect (OR 1.93, 95% CI 1.63-2.29)
• Received the self-expanding Medtronic CoreValve (OR 7.56, 95% CI 5.98-9.56)
• Got TAVR via transapical (OR 1.36, 95% CI 1.10-1.68) or transaortic (OR 1.52, 95% CI 1.09-2.11) versus transfemoral access

Having had a previous aortic valve procedure was associated with fewer permanent pacemakers implanted after TAVR (OR 0.74, 95% CI 0.57-0.95), as was home oxygen use (OR 0.67, 95% CI 0.49-0.91).

However, heart failure readmission was not more likely after device implantation (16.5% versus 12.9%, HR 1.23, 95% CI 0.92-1.63).

"As TAVR indications expand to include lower risk patients with aortic stenosis, interventions to curtail the need for permanent pacemaker placement are needed, as well as further studies to confirm or refute its association with adverse outcomes reported in this study," the investigators urged.

Furthermore, they suggested, reducing the number of permanent pacemakers needed after TAVR may help with controlling medical costs.

Fadahunsi and colleagues linked TVT Registry data with records from Centers for Medicare and Medicaid Services. They collected information on 9,785 patients who underwent TAVR in the U.S. at 229 sites between 2011 and 2014.

Pacemakers were implanted within 3o days of transfemoral TAVR in 7.3% of cases; that figure reached a peak of 18.8% for axillary/subclavian access.

"Conduction abnormalities usually occur either during or immediately after the TAVR procedure. Most studies reported a median time of 3 days from TAVR to permanent pacemaker implantation, and almost 90% of permanent pacemakers were implanted within 7 days of TAVR. The timing of pacemaker implantation found in our study was similar," Fadahunsi and colleagues noted.

"It should be noted that conduction abnormalities can occur at a later time, and these are believed to be due to edema and late expansion of the prosthesis."

The data from the study, although adjusted for during multivariate analysis, left room for selection bias, the authors acknowledged.

"As this was a registry, the granularity of the data limited further analysis to explore other potential associations. For example, there was no information on indication for permanent pacemaker placement post-TAVR as well as the type of permanent pacemaker implanted. Similarly, there was no information on cause of death that may have allowed us explore the reasons for a potential increase in mortality following permanent pacemaker implantation in TAVR patients."

"Finally, the question of pacing dependency and its relation to later adverse left ventricular function remains a potential unmeasured confounder in our study cohort, as these data were not available to us," Fadahunsi's group wrote.

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