Renal impairment is considered a contra-indication for lung (LTX) or combined heart-lung (HLTX) transplantation due to increased mortality. We hypothesize that renal impairment is partly reversible in pulmonary arterial hypertension (PAH) due to reduced cardiac output. We aimed to investigate the evolution of renal function in PAH patients following LTX/HTLX. In addition predictors for eGFR decline, renal replacement therapy (RRT) and mortality were identified.

A retrospective analysis was performed of 67 consecutive PH patients (63 PAH, 4 CTEPH) who underwent LTX/HLTX in our centre. The evolution of eGFR in function of baseline renal function was assessed using a mixed model effect test. Predictors for renal deterioration, RRT and mortality were assessed by multivariate analysis.

Mean baseline eGFR was 77 ml/min/1,73m² (range 41-149 ml/min/1,73m²); 14 patients (21%) had a reduced baseline eGFR <60 ml/min/1,73m². 16 patients (24%) required RRT. Renal function appeared to improve during the first month after LTX/HLTX; this increase was more distinct in patients with worse baseline renal function. Renal impairment at baseline was not significantly associated with renal function decline at 1 and 2 years after LTX/HLTX; neither was there a significant association with mortality. Only older age was significantly associated with renal impairment after 1 and 2 years and increased mortality after 1 year according to multivariate analysis.

We conclude that renal impairment in PAH was not significantly associated with renal deterioration or increased mortality after LTX/HTLX. Mild to moderate renal impairment should not be considered as an absolute contraindication for transplantation in PAH patients.