Prognostic Role of Hypertension Remission in Kidney Transplant Recipients with Pretransplant Hypertension

Background: Hypertension is commonly associated with advanced chronic kidney disease and end-stage kidney disease. Kidney transplantation (KT) in patients with pre-transplant hypertension has the potential to lead to remission of hypertension. However, the remission rate of hypertension after KT and its prognostic impact on KT outcomes remain unknown. Methods: KT recipients (2006–2015) who had pre-transplant hypertension were identified and categorized into two groups based on their post-KT hypertension status: “persistent hypertension” and “hypertension remission”, using data from the Health Insurance Review & Assessment Service and Korean National Health Insurance System. Cox proportional hazard analyses were performed for death-censored graft failure and all-cause mortality. Results: A total of 3,109 (27%) among 11,342 KT recipients with pre-transplant hypertension experienced hypertension remission after KT. The patients who experienced hypertension remission had lower prevalences of delayed graft function and major comorbidities including diabetes, ischemic heart disease, and stroke, compared to those with persistent hypertension. Graft failure (incident rate [IR], 6.8 vs 12.0) and mortality rates (IR 5.5 vs 11.1) were both lower in the hypertension remission group (per 1,000 person-years, log-rank P <0.001 for both) than the persistent hypertension group. Hypertension remission was associated with 0.58-fold (95% confidence interval 0.48–0.72) and 0.50-fold (0.40–0.62) lower risks for graft failure and all-cause mortality, respectively, in unadjusted analyses. The adjusted hazard ratio of hypertension remission was 0.59 (0.49–0.73) for graft failure and 0.59 (0.48–0.73) for mortality compared to the persistent hypertension group after adjusting multiple covariates. There were significant interactions with sex for graft failure (stronger protection in females, P for interaction=0.045) and with diabetes status for mortality (weaker protection in recipients with diabetes, P for interaction=0.033). Conclusion: Kidney transplantation can lead to hypertension remission in a substantial number of patients. Remission of pre-transplant hypertension was associated with better graft survival as well as overall patient survival. We suggest that hypertension remission can be used as an indicator of favorable outcomes in KT recipients.