Echocardiographic Pulmonary Hypertension Predicts Post-transplantation Renal Allograft Failure

Abstract

Background: Pulmonary hypertension in the setting of renal transplantation has been associated with early allograft dysfunction and increased mortality, but this relationship has not been extensively studied.

Methods: We performed a retrospective cohort study of adult patients who underwent their first renal transplantation in the years 2003-2009 and had pre-transplantation echocardiograms. Pulmonary hypertension was defined as right ventricular systolic pressure ≥40 mm Hg in the absence of left-sided valvular disease and/or left ventricular ejection fraction ≤50%. Eighty-two of 205 patients (40%) met the inclusion criteria. The relationship between pulmonary hypertension and death-censored allograft failure (hemodialysis dependence or retransplantation) and serum creatinine was assessed with the use of Cox hazard regression and generalized mixed models.

Results: The presence of pulmonary hypertension was associated with a 3-fold increase in the risk of death-censored allograft failure (95% confidence interval, 1.20-7.32; P = .02). Failure rates were 19% at 24 months and 51% at 96 months for those with pulmonary hypertension versus 7% at 24 months and 20% at 86 months for those without pulmonary hypertension (P = .01). Among those without graft failure, there was an increase in creatinine levels after transplantation (P = .01). Effect estimates were unchanged by adjustment for multiple covariates and when pulmonary hypertension was defined as right ventricular systolic pressure ≥36 mm Hg.

Conclusions: Pulmonary hypertension before renal transplantation carries a 3-fold increased risk of death-censored allograft failure. The relationship between the pulmonary circulation and renal allograft failure warrants further study.

Figure 1

Study flow

Figure 2

Kaplan Meier curves demonstrating death-censored allograft failure, 19% at 24 months, 51% at 96 months for those with PH vs. 7% at 24 months, 20% at 86 months for those without PH (p=0.01). PH=pulmonary hypertension.

Figure 3

Mixed modeling displayed as least squares means showing creatinine levels at 90 days, 1 year, and 3 years after transplantation. P-value refers to overall F-test for total follow-up time. PH=pulmonary hypertension.