Long-term outcomes of surgical aortic valve replacement in patients receiving chronic dialysis

BACKGROUND: Surgical aortic valve replacement (SAVR) has been the standard treatment for symptomatic severe aortic stenosis, which is common among patients receiving long-term dialysis. The aim of this study was to report the long-term outcomes of SAVR in patients receiving chronic dialysis and to identify independent risk factors for early and late mortality. METHODS: Every consecutive patient with SAVR with or without concomitant cardiac procedures in British Columbia between January 2000 and December 2015 was identified from the provincial cardiac registry. The Kaplan-Meier method was used to estimate survival. Univariate and multivariable models were conducted to determine independent risk factors for short-term mortality and reduced long-term survival. RESULTS: Between 2000 and 2015, 654 patients receiving dialysis underwent SAVR with or without concomitant procedures. The mean follow-up was 2.3 (standard deviation 2.4) years (median 2.5 yr). The overall 30-day mortality was 12.8%. The 5-year and 10-year survival rates were 45.6% and 23.5%, respectively. Twelve patients (1.8%) had redo aortic valve surgery. There was no difference in 30-day mortality or long-term survival between 2 age groups (> 65 yr v. ≤ 65 yr). Anemia and cardiopulmonary bypass (CPB) were independent risk factors for both longer hospital stay and reduced long-term survival. The impact of CPB pump time on mortality occurred mainly within the first 30 days after surgery. When CPB pump time extended beyond 170 minutes, there was a significant increase in 30-day mortality with further prolongation of CPB pump time, and the relationship between 30-day mortality and CPB pump time became approximately linear. CONCLUSION: Patients receiving dialysis have poor long-term survival with a very low rate of redo aortic valve surgery following SAVR with or without concomitant procedures. Older age (> 65 yr) is not an independent risk factor for either 30-day mortality or reduced long-term survival. Using alternative strategies to limit CPB pump time is an important way to reduce 30-day mortality.