UC Irvine

Background

Previous studies have indicated U-shaped associations between blood pressure (BP) and mortality in dialysis patients. We hypothesized that a similar association exists between pre-transplant BP and post-transplant outcomes in dialysis patients who undergo successful kidney transplantation.

Methods

Data from the Scientific Registry of Transplant Recipients were linked to the five-yr cohort of a large dialysis organization in the United States. We identified all dialysis patients who received a kidney transplant during this period. Unadjusted and multivariate adjusted predictors of transplant outcomes were examined.

Results

A total of 13 881 patients included in our study were 47 ± 14 yr old and included 42% women. There was no association between pre-transplant systolic BP and post-transplant mortality, although a decreased risk trend was observed in those with low post-dialysis systolic BP. Compared to patients with pre-dialysis diastolic BP 70 to <80 mmHg, patients with pre-dialysis diastolic BP <50 mmHg experienced lower risk of post-transplant death (hazard ratios [HR]: 0.74, 95% CI: 0.55-0.99). However, compared to patients with post-dialysis diastolic BP 70 to <80 mmHg, patients with post-dialysis diastolic BP ≥100 mmHg experienced higher risk of death (HR: 3.50, 95% CI: 1.57-7.84). In addition, very low (<50 mmHg for diastolic BP and <110 mmHg for systolic BP) pre-transplant BP was associated with lower risk of graft loss.

Conclusions

Low post-dialysis systolic BP and low pre-dialysis diastolic BP are associated with lower post-transplant risk of death, whereas very high post-dialysis diastolic BP is associated with higher mortality in kidney transplant recipients. BP variations in dialysis patients prior to kidney transplantation may have a bearing on post-transplant outcome, which warrants additional studies.