The Association Between Renin-Angiotensin System Blockade and Long-term Outcomes in Renal Transplant Recipients

In Brief Background Renin-angiotensin system (RAS) blockade reduces mortality in the general population and among non-dialysis–dependent patients with chronic kidney disease. The RAS blockade also decreases proteinuria and protects renal function in non-transplant patients with chronic kidney disease. It remains controversial, however, whether this translates to improved patient or graft survival among transplant recipients. Methods We analyzed 2684 primary kidney transplant recipients at the University of Wisconsin in 1994 to 2010 who had a functioning graft at 6 months after transplantation. We assessed the association of RAS blockade with patient and graft survival using time-dependent Cox and marginal structural models. Results Three hundred seventy-seven deaths and 329 graft failures before death (638 total graft losses) occurred during a median of 5.4 years of follow-up. The RAS blockade was associated with an adjusted-hazard ratio of 0.63 (95% confidence interval, 0.53-0.75) for total graft loss, 0.69 (0.55-0.86) for death, and 0.62 (0.49-0.78) for death-censored graft failure. The associations of RAS blockade with a lower risk of total graft loss and mortality were stronger with more severe proteinuria. The RAS blockade was associated with a 2-fold higher risk of hyperkalemia. Conclusions Our findings suggest RAS blockade is associated with better patient and graft survival in renal transplant recipients. This large, single center, retrospective study conducted over 16 years was adjusted for several important variables, and shows that renin-angiotensin system blockade is highly associated with decreases in renal allograft failure and recipient death. Use of these drugs may be indicated in a high percentage of kidney transplant recipients.