Researcher Examines Impact of Valve Type on Mortality in Women


Joy Hughes, MD

Surgeons often have friends who ask for medical advice. When two female friends asked Joy Hughes, MD about whether they should replace their bioprosthetic valves with the same valve type or a mechanical valve, she went well beyond sharing her opinion.

The fourth-year resident in general surgery and critical care fellow at the Mayo Clinic in Rochester, Minn., and her colleagues conducted a retrospective analysis and found that valve type did not influence survival. The researchers looked at 606 women aged 13-45 years (mean = 33 years) who underwent cardiac valve replacement between January 1967 and December 2012.

Dr. Hughes will present her research on long-term survival and valve durability after bioprosthetic and mechanical valve replacement in young women at 2:15 p.m. Tuesday during the Adult Cardiac Session: Mitral Valve in Room 120D from 1:00 p.m. to 3:00 p.m.

“I had several conversations with these friends and also female patients who were approaching the time when they needed to have their valves replaced,” Dr. Hughes said. “When women are in their 30s and looking to have children, it is a complicated issue. A tissue valve pretty much guarantees reoperation, and a mechanical valve requires anticoagulation therapy.

“Although there have been many successful and uneventful pregnancies for women on anticoagulation, pregnant women with mechanical valves have an increased risk of hemorrhage, complications in childbirth, and potentially could be teratogenic. Those are issues we cannot change, but we can reassure patients.”

The researchers concluded that initial selection of a bioprosthesis did not increase late mortality, and survival of patients with bioprosthetic valves replaced with mechanical valves was excellent.

Ninety-five patients had complex congenital heart disease; nine patients had prior valve replacements at other institutions. Of the 318 patients who underwent aortic valve replacement, 97 were bioprosthetic and 221 were mechanical. Of the 261 patients who underwent mitral valve replacement, 55 were bioprosthetic and 206 were mechanical. Follow-up averaged 15 years. Survival for all patients at 10, 20, and 30 years was 81%, 66%, and 41%, respectively. Reoperation at 10, 20, and 30 years for all valves was 8%, 43%, and 56%.

“We weren’t sure what we were going to find, but the results were reassuring,” Dr. Hughes said. “For a woman, this can be about what she is comfortable with, rather than whether she has to accept a mortality risk on top of other issues in choosing one valve over the other.”

Probability of reoperation increased in younger patients, valve replacement after year 2000, and with bioprosthetic valves. There were 65 patients who initially underwent valve replacement with bioprosthesis and subsequently had mechanical valves implanted during reoperation (82%), and their survival was 94%, 91%, 76%, and 68% at 5, 10, 15, and 20 years, respectively.

“This confirms that young patients who choose a tissue valve are going to need a reoperation,” Dr. Hughes said. “The procedures have advanced to the point that mortality risk doesn’t necessarily increase, which is a great credit to cardiac surgeons and health care teams who have worked to improve cardiac surgery outcomes.”