OBJECTIVES : Currently, national level research on mortality and medical resource utilization of surgical mitral valve replacement (SMVR) are lacking in Taiwan. This study uses a national database to compare the clinical outcomes and costs associated with three different types of prosthetic valves used to treat mitral valve disease.

METHODS : Taiwan’s National Health Insurance Research Database (NHIRD) was queried from 2000 to 2017 for clinical and cost data in 10,406 patients undergoing isolated SMVR. Patients undergoing isolated aortic valve replacement were excluded. This database contains hospital cost and coding data from all open-heart surgical programs in Taiwan. Patients with International Classification of Diseases (ICD) diagnosis codes associated with mitral valve disorders and replacement procedures and the type of valve used in the procedure; bovine (BV), porcine (PV), and mechanical (MV), were included in this analysis. We built Kaplan-Meier curves for each group and compared unadjusted survival statistics using Log-rank test.

RESULTS : Mechanical valve (MV) use was most prevalent during the study period but decreased, from 78% in 2000 to 25% in 2017. Patients receiving a BV and MV showed lower all-cause mortality rate than PV (p<0.001). Patients in age ≦50 and 51-70 groups who received a BV had a lower all-cause mortality rate than patients with PV and MV replacement (p<0.001). From 2014 to 2017 length of stay in patients with PV replacement were higher than MV and BV (26.7, 22.5 and 23.8 days respectively, p<0.001). Mean hospital costs were also higher in patients receiving a PV compared to an MV or BV ($19,972, $17,613 and $18,234 USD respectively, p<0.001).

CONCLUSIONS : These findings indicate that there are differences in clinical outcomes and cost for SMVR based on the type of prosthetic valve implanted. Further studies are needed to understand which valve types optimize outcomes and reduce costs.