Meta-analysis finds 2.5-fold higher pacemaker risk with CoreValve

A meta-analysis of predictors of permanent pacemaker implantation after transcatheter aortic valve replacement (TAVR) reinforced findings that patients treated with the CoreValve device were at increased risk compared with patients receiving the Sapien device. The predictors may help physicians avoid atrioventricular block-related complications, regardless of device type.

The need for a new, permanent pacemaker after TAVR in inoperable and surgically high-risk patients with severe aortic stenosis is a recognized complication. Writing in the July 15 issue of the Journal of the American College of Cardiology, George C. M. Siontis, MD, of Bern University Hospital in Switzerland, and colleagues noted that both surgical and percutaneous interventions at the valve level can result in conduction disturbances that then require a permanent pacemaker.

A number of studies have suggested potential predictors based on patient and procedural characteristics, but the studies generally have been small and inconsistent, they claimed. To overcome this, the authors conducted a meta-analysis of 41 studies that assessed atrioventricular conduction or cardiac rhythm disturbances and the need for pacemakers. For the meta-analysis, they focused on previously proposed predictors.

The studies, all observational, enrolled a total of 11,201 patients between 2005 and 2011. Of those patients, 17 percent needed a permanent pacemaker after TAVR, with a median 6 percent for Sapien (Edwards Lifesciences) recipients and 28 percent for CoreValve (Medtronic) recipients.

The most common indication for a permanent pacemaker was complete atrioventricular block. Male sex, evidence preprocedurally of abnormal atrioventricular conduction and intraprocedural atrioventricular block were significant predictors of permanent pacemaker implantation, regardless of valve type. But the risk of needing a permanent pacemaker was 2.5-fold higher for CoreValve recipients.

Siontis et al proposed that identifying patients at increased risk may help prevent complications such as syncope, exercise intolerance, heart failure and sudden death, and may avoid the costs of an extended hospitalization and the use of hospital resources.

They noted that previous studies found the need for permanent pacemaker implantation more frequently with CoreValve than with Sapien. “The increased risk of AV [atrioventricular] block with MCRS [CoreValve] has been attributed to the valve design (self-expanding vs. balloon-expandable) and the potential of a deeper implantation into the left ventricular outflow tract. This may result in more injury to the AV node and left bundle branches, which may be delayed because of the self-expanding nature of the prosthesis and tissue edema.”

The studies they assessed for the meta-analysis lacked long-term follow-up and adjustment. They recommended more research to validate predictors to help clinicians better risk stratify patients and large studies track long-term outcomes for TAVR devices.