Despite encountering more short-term complications after transcatheter aortic valve replacement (TAVR), women have better long-term survival rates than men, according to a meta-analysis of 47,188 patients. However, they remain at greater risk for stroke.

At one year, 16 percent of women had died compared to 19.4 percent of men—a 15 percent risk reduction. When only studies with at least three years of follow-up were included—cutting the patient group to about 6,000—women were at a 14 percent reduced risk of all-cause mortality.

Marwan Saad, MD, PhD, with the University of Arkansas for Medical Sciences in Little Rock, and colleagues published these findings online Oct. 18 in JACC: Cardiovascular Interventions. They offered three potential explanations for why women derived better long-term survival than men:

• Women had a lower risk of moderate to severe aortic insufficiency (AI) following TAVR. “More-than-mild AI after TAVR is a well-known risk factor for cardiovascular mortality,” the authors wrote. “Smaller annular size in women reduces the incidence of prosthesis undersizing compared with men who tend to receive undersized valves and hence experience more paravalvular leaks.”
• Men had more comorbidities despite being, on average, a year younger than female patients.
• Finally, “compared with men, women’s hearts tend to exhibit more favorable remodeling to hemodynamic stress caused by (aortic stenosis), mainly through less fibrosis and collagen deposition, thus allowing a faster and better reversal of cardiac remodeling after TAVR,” Saad et al. wrote.

The researchers noted women had greater incidence of bleeding, vascular complications and stroke/transient ischemic attack (TIA) at 30 days. However, unlike results from a previous study, female sex wasn’t associated with a significant increase in short-term mortality. The 30-day death rates in Saad and colleagues’ analysis were 6.5 percent for women and 6.2 percent for men.

Even though women demonstrated better survival than men over time, they remained at a 23 percent increased risk of stroke at one year. The researchers speculated this could be tied to the greater likelihood that women receive balloon-expandable versus self-expanding valves compared to men, but said further research is necessary to determine the reasons for increased stroke risk in females.

“It remains unclear why women are at higher risk of stroke after TAVR, especially since male sex in most of these studies, including ours, was associated with worse baseline vascular comorbidities,” they wrote.

Saad et al. also suggested additional investigation into whether women may benefit from the use of embolic protection devices during TAVR.