Survival of Kidney Transplantation Patients in the United States After Cardiac Valve Replacement

Abstract

Background— Few published studies address the survival of kidney transplantation patients after valve surgery, and none address relative outcomes related to tissue versus nontissue prosthesis. This study aimed to assess survival of US kidney transplantation patients after cardiac valve replacement and to compare associations of valve selection. Methods and Results— Of 1 698 706 patients in the US Renal Data System database, we identified 1335 kidney transplantation patients hospitalized in 1991 to 2004 for cardiac valve replacement. Survival was estimated by the Kaplan-Meier method; independent predictors of death were examined in a comorbidity-adjusted (by Charlson and propensity score) Cox model. Of the cohort, 17% were 0 to 44 years of age, 50% were 45 to 64 years of age, 28% were 65 to 74 years of age, and 5% were ≥75 years of age; 78% were white; 63% were men; and 20% had kidney failure caused by diabetes mellitus. Of 369 patients (28%) who received tissue valves, 75% had aortic valve replacement, 20% had mitral valve replacement, and 5% had both. Use of tissue valves increased from 13% in 1991 to 1995 to 38% in 2000 to 2004. Age, diabetes mellitus, and combined aortic and mitral valve replacement were the strongest predictors of all-cause mortality. In-hospital mortality was 14.0% overall, 11.4% for tissue-valve patients, and 15.0% for nontissue-valve patients ( P =0.09). Two-year survival estimates were 61.5% for tissue-valve and 59.5% for nontissue-valve patients ( P =0.30). The adjusted hazard ratio of death for tissue- versus nontissue-valve patients was 0.83 (95% confidence interval, 0.70 to 0.99). Conclusions— Renal transplantation patients requiring valve replacement have high mortality rates (≈20%/y). These data suggest minimally reduced mortality risk for patients receiving tissue versus nontissue valves.