Mitral valve prosthesis choice in patients <70 years: A systematic review and meta-analysis of 20 219 patients

The optimal mitral prosthesis in young patients is unclear. This systematic review and meta-analysis were performed to compare outcomes between bileaflet mechanical mitral valve replacement (mMVR) and bioprosthesis mitral valve replacement (bioMVR) for MVR patients aged less than 70 years.

We searched MEDLINE and EMBASE databases from inception to July 2018 for studies comparing surgical outcomes of mMVR vs bioMVR.

There were 14 observational studies with 20 219 patients (n = 14 658 mMVR and n = 5561 bioMVR). Patients receiving an mMVR were younger with fewer comorbidities including renal failure, dialysis, and less-infective endocarditis (P < .001). The estimated 10-year mortality ranged from 19% to 49% for mMVR and 22% to 58% for bioMVR among studies. Comparing matched or adjusted data, mMVR was associated with lower operative (risk ratio [RR]: 0.61; 95% confidence interval [CI]: 0.39, 0.94; P = .03) and long-term (HR: 0.81; 95% CI: 0.71, 0.92; P = .002) mortality at a median follow-up of 8 years (IQR: 6-10 years). Estimated 10-year risk for mitral valve reoperation ranged from 0% to 8% for mMVR and 8% to 22% for bioMVR among matched/adjusted studies. mMVR was associated with lower matched/adjusted risk of reoperation (HR: 0.35; 95% CI: 0.19, 0.65; P = .001) but with greater risk of bleeding (HR: 1.59; 95% CI: 1.19, 2.13; P = .002) and a trend to greater risk of stroke and embolism (HR: 1.70; 95% CI: 0.92, 3.15; P = .09).

Mechanical MVR in patients aged less than 70 years is associated with a lower risk of operative mortality as well as a 20% lower risk of long-term death and 65% lower risk of mitral valve reoperation but 60% greater risk of bleeding compared with bioMVR in matched or adjusted data.