Hypertension after kidney transplantation

Abstract

Background: Few studies have examined the possible role of blood pressure (BP), independent of acute rejection and graft function, on outcomes after kidney transplantation.

Methods: We investigated the prevalence, treatment, control, and clinical correlates of hypertension and its association with outcomes, using multivariate analyses with time-dependent covariates, in a retrospective cohort of 1,666 kidney transplant recipients.

Results: Hypertension was common, and its control was poor. For example, at 1 year, only 55.5% had a BP less than 140 mm Hg. Control improved only slightly in 1993-2002 compared to 1976-2002, even as patients administered 2 or more antihypertensive medications at 1 year increased from 43.5% to 54.6%. Independent correlates of higher BP included male sex, age, donor age, diabetes, body mass index, the presence of native kidneys, and delayed graft function. Previous acute rejection was associated with higher BP at virtually all times after transplantation, and these associations were independent of estimated creatinine clearance (C(Cr)). Conversely, an association between BP and subsequent acute rejection was not statistically significant when differences in C(Cr) were taken into account. After adjusting for the effects of acute rejection, C(Cr), and other variables, each 10 mm Hg of systolic BP was associated with an increased relative risk for graft failure (1.12; 95% confidence interval, 1.08 to 1.15; P < 0.0001), death-censored graft failure (1.17; 1.12 to 1.22; P < 0.0001), and death (1.18; 1.12 to 1.23; P < 0.0001).

Conclusion: High BP is closely tied to graft function, but nevertheless is an independent risk factor for graft failure and mortality. Better strategies are needed to control BP after kidney transplantation.