Dive Brief:

• A large cohort study has linked permanent pacemaker implantation after surgical aortic valve replacement with increased risks of death and heart failure hospitalization.
• Ten years after surgery, the estimated survival rate in patients who needed a pacemaker was 52.8%, compared to 57.5% in their peers without a permanent implant. Risk of heart failure hospitalization was higher in the pacemaker group.
• The study looked at patients who underwent surgical, rather than transcatheter, procedures. Yet, the authors said the findings are likely to apply to TAVR and suggest the pacemaker risk is an important consideration as transcatheter procedures are performed in younger people.

Dive Insight:

Replacing the aortic valve can damage the conduction system and necessitate the implantation of a permanent pacemaker. TAVR was initially associated with a far higher rate of pacemaker implantation than surgical procedures but the difference has shrunk as newer valves such as Medtronic's Evolut R and Edwards Lifesciences' Sapien 3 have come to market.

Evidence on the long-term implications of permanent pacemaker implantation are mixed. A Mayo Clinic study of surgical aortic valve replacement patients linked pacemaker implantation to increased risk of long-term death, but another, albeit smaller analysis, found no effect on mortality. 

Researchers have added to the evidence with a paper published online Tuesday in JAMA Network Open. The paper describes an analysis of the outcomes of almost 25,000 patients who underwent surgical aortic valve replacement in Sweden at eight centers that performed cardiac procedures from 1997 to 2018.

Prior studies "are limited by their small patient numbers, short follow-up times, and single-center designs," wrote the authors, who emphasized that their research is a "nationwide, population-based cohort study to investigate long-term prognosis after primary surgical AVR among patients who underwent postoperative permanent pacemaker implantation."

In the JAMA study, around 3% of patients required a permanent pacemaker within 30 days, a figure that is in line with results from other assessments of surgical procedures and lower than the rate associated with TAVR. Estimated 10- and 20-year survival rates in the pacemaker arm were 52.8% and 18.0%, respectively. The figures are lower than the 57.5% and 19.6% survival rates in the non-pacemaker group.

All-cause mortality was significantly higher in the pacemaker group. The researchers also linked the permanent implantation of a pacemaker to a significant increase in risk of hospitalization with heart failure. 

The authors of the paper caution that the "results cannot be directly generalized to patients who underwent transcatheter AVR" but nonetheless think the findings are likely to be valid in TAVR. The applicability of the results to TAVR is important given the trend for surgeons to perform transcatheter procedures on patients who are younger and have lower surgical risk.  

"Younger patients have a longer life expectancy; therefore, the association of permanent pacemaker implantation with adverse outcomes becomes more relevant in this patient population. Thus, the risks associated with permanent pacemaker implantation after transcatheter AVR are becoming increasingly important," the authors wrote.

Researchers concluded that their findings further suggest that future studies should investigate how to avoid permanent pacemaker dependency after surgical and transcatheter AVR.