透析患者における機械弁対生体弁

Appropriate valve selection in hemodialysis patients requiring valve replacement is a highly contentious issue due to their short life expectancy and accelerated deterioration of bioprosthetic valves. This study aims to analyze clinical outcomes based on the types of prosthetic valves, and to estimate life expectancy and valve durability in this cohort.

765 hemodialysis patients undergoing first-time valve replacement were extracted from the Korean National Health Insurance Sharing Service database. Clinical outcomes were compared between the bioprosthetic (BP; N=421) and mechanical valve (MP; N=344) groups. An age-dependent subgroup analysis was conducted, and the median survival time was calculated. A competing risk analysis for late clinical events was also performed.

After adjustment, the early clinical outcomes and late mortality were comparable between the two groups. Redo aortic valve replacements occurred more frequently in the BP group (1.3%/patient-year vs 0.3%/patient-year; P=0.002), whereas gastrointestinal bleeding was more common in the MP group (7.0%/patient-year vs 4.8%/patient-year; P=0.010). The two groups did not show significant survival differences in all age-dependent subgroups. The estimated median survival times were 6.6, 4.0, and 2.1 years for patients aged <50, 50-64, and ≥65 years, respectively. Competing risk analysis showed a lower prevalence of valve durability-related events and a higher prevalence of major bleeding events with MP use (adjusted subdistribution hazard ratio, 0.45(0.25-0.80); P=0.006 and 1.46(1.13-1.89); P=0.004).

Given the considerably short lifespan of hemodialysis patients, bioprosthetic valves may be a reasonable option for younger patients, except for those with hypercalcemia or potential candidates for kidney transplantation.