Women are far more susceptible to dangerous risk factors and mortality following aortic valve replacement (AVR) procedures, according to a study newly published in the Journal of the American Heart Association.

In a large-scale study of sex differences in AVR surgeries and related outcomes, lead researcher Mohamad Alkhouli, MD, and colleagues found that of 166,809 patients who underwent AVR for severe aortic stenosis (AS) between 2003 and 2013, women were older, more likely to have existing nonatherosclerotic comorbid conditions and showed higher in-hospital mortality rates following their surgeries.

AVR has long been the gold standard treatment for calcific AS, Alkhouli and co-authors wrote, and the outcomes of AVR have improved greatly in the past 10 years. Prior studies comparing the outcomes of the procedure in men versus women have yielded conflicting results, and this study is the first published account that resulted in clear differences between the sexes.

The researchers pulled thousands of patients’ data from the Nationwide Inpatient Sample, which collects and records information about patient discharges from more than 1,000 nonfederal hospitals across 45 states, from between 2003 and 2014. All individuals enrolled in Alkhouli’s study had received a discharge diagnosis of aortic valve stenosis and were set to undergo AVR within the next several years.

Off the bat, demographics varied widely. Women accepted for the study were markedly older than men, with an average age of 70 years old versus 67 years old in men. Women also had significantly higher rates of medical comorbidities prior to their AVR procedure, which included hypertension, diabetes, chronic obstructive lung disease and anemia. Coronary and peripheral artery disease, as well as a history of prior sternotomy, were more prevalent in male patients.

Following AVR surgery, which was mostly performed at teaching hospitals, Alkhouli and colleagues noticed it was far more likely that women would die in-hospital than men, at a rate of 5.6 percent compared to men’s 4 percent. Women also saw higher rates of vascular complications, permanent pacemaker implantations and blood transfusions, which led to higher rates of admission in nursing homes or immediate care centers than in men. Stroke rates were similar between both groups.

Alkhouli and co-authors wrote in their study that interest in the gender gap in relation to AVR was renewed when transcatheter AVR (TAVR) procedures started to become more common after 2011. A report from the American College of Cardiology, the authors wrote, signified a greater success rate of TAVR in women than in men, and women have indeed been referred more often for TAVR procedures than men.

The researchers suggested in their study it could possibly be beneficial to offer women the option of TAVR rather than surgical AVR, since TAVR is associated with better outcomes and safety than AVR procedures in female patients.

“Women have worse in-hospital mortality following AVR compared with men,” the authors wrote. “Coupled with the accumulating evidence suggesting higher magnitude of benefit of transcatheter AVR over AVR in women, women should perhaps be offered transcatheter AVR over AVR at a lower threshold than men.”