Pacemakers implanted following TAVR may increase mortality risk

Patients who were implanted with a pacemaker after undergoing transcatheter aortic valve replacement (TAVR) had a 31 percent higher one-year mortality rate compared with patients who did not receive a pacemaker following TAVR, according to a retrospective cohort study.

The registry analysis also found that patients who received a pacemaker had a 33 percent higher one-year composite of mortality or heart failure admission.

Lead researcher Opeyemi Fadahunsi, MBBS, MPH, of Dalhousie University in Halifax, Nova Scotia, Canada, and colleagues published their results online Nov. 7 in the Journal of the American College of Cardiology: Cardiovascular Interventions.

The researchers evaluated data on 9,785 patients who underwent TAVR for severe aortic stenosis at 229 sites in the U.S. between November 2011 and September 2014. They obtained the information from the Society of Thoracic Surgeons (STS)/American College of Cardiology TVT registry and the Centers for Medicare and Medicaid Services database.

During the study, two FDA-approved valve systems were used in most TAVR procedures: the balloon-expandable Sapien valve (Edwards Lifesciences) and the CoreValve revalving system (Medtronic). The FDA approved the Sapien valve in 2011 and the CoreValve in 2014. The CoreValve was used in 11.2 percent of the procedures in this study.

Of the patients, 6.7 percent were implanted with a pacemaker within 30 days of TAVR, including 25.1 percent of patients who received the CoreValve and 4.3 percent of patients who received the Sapien valve. In addition, the 30-day incidence of pacemaker implantation was 7.3 percent for patients undergoing transfemoral TAVR and 5.1 percent of patients undergoing transapical TAVR. The median time from TAVR to pacemaker implantation was 3 days.

Patients who had pacemakers were more likely to be men and have a higher STS-predicted risk of operative mortality score and less likely to have undergone prior aortic valve procedures and require home oxygen. They were also more likely to have larger prostheses implanted and higher proxies of valve oversizing and less likely to be considered inoperable or at extreme risk.

After adjusting for multiple variables, the significant predictors of 30-day pacemaker implantation were increasing age, prior conduction defect, aortic valve area of 0.75 cm2 or less and use of the CoreValve. Negative predictors were prior aortic valve procedure, home oxygen use and longer procedure time.

The median length of hospital stay was seven days in patients who received pacemakers and six days in patients who did not receive pacemakers. The median length of stay in the intensive care unit was 56.7 hours and 45.0 hours, respectively. The differences were similar after multivariable adjustment.

At one-year, the incidence of heart failure admission was 16.5 percent in patients who received a pacemaker and 12.9 percent in patients who did not receive a pacemaker. The one-year mortality rates were 24.1 percent and 19.1 percent, respectively, while the one-year composite rates of mortality or heart failure were 37.3 percent and 28.5 percent, respectively.

The researchers mentioned a few limitations of the study, including the possibility of selection bias. The patients and physicians were also not blinded to the interventions. In addition, the researchers did not have information on the cause of death, the indication for pacemaker placement and the type of pacemaker implanted.

“[Pacemaker] placement may be associated with negative long-term outcomes, such as mortality and a composite of mortality or heart failure,” the researchers wrote. “As TAVR indications expand to include lower risk patients with aortic stenosis, interventions to curtail the need for [pacemaker] placement are needed, as well as further studies to confirm or refute its association with adverse outcomes reported in this study.”