Background: The type of cardiac valve replacement associated with the lowest health risks for young women who may undergo pregnancies is unknown. We investigated which valve type was associated with greatest patient and valve survival and the effect of pregnancy on valve loss.
Methods and results: In this retrospective study, all women 12 to 35 years old who underwent valve replacements between 1972 and 1992 at Greenlane Hospital were identified, and follow-up was available in 93%. The 232 women were followed up for 1499 patient-years. Ten-year survival of women with mechanical (n=178), bioprosthetic (n=73), and homograft (n=72) valves was 70% (95% CI, 59% to 83%), 84% (95% CI, 72% to 99%), and 96% (95% CI, 91% to 100%), P=0.002. After adjustment for confounding variables, the relative risk (RR) of death with mechanical compared with bioprosthetic valves was 2.17 (95% CI, 0.78 to 5.88). Thromboembolic events occurred in 45% of women with mechanical valves within 5 years, compared with 13% with bioprosthetic valves, P=0.0001. Valve loss at 10 years was higher in bioprosthetic valves [82% (95% CI, 62% to 92%)] than in mechanical [29% (95% CI, 17% to 39%)] or homograft [28% (95% CI, 12% to 41%)] valves, P=0.0001. Pregnancy was not associated with increased bioprosthetic (RR, 0.96; 95% CI, 0.68 to 1. 35), homograft (RR, 0.65; 95% CI, 0.37 to 1.13), or mechanical (RR, 0.54; 95% CI, 0.27 to 1.08) valve loss.
Conclusions: Although 10-year valve survival was greater with mechanical than bioprosthetic valves, mechanical valves may be associated with reduced patient survival in young women. Thromboembolic complications, often with long-term sequelae, were common with mechanical valves. Pregnancy did not increase structural deterioration or reduce survival of bioprosthetic valves.