Chronic kidney disease after heart transplantation: a single-centre retrospective study at Skåne University Hospital in Lund 1988-2010

We aimed to study the incidence, predictors and outcome of chronic kidney disease (CKD) after heart transplantation (HT). All our HT patients 1988-2010 were considered for inclusion. Of these, 134 came for annual follow-ups including evaluation of glomerular filtration rate (GFR) using iohexol clearance measurements, and the CKD-EPI (adults) or Schwartz (children) formulae. Median GFR (Q1-Q3) (ml/min/1.73 m(2) ) declined from 67.0 (50.0-82.0) during transplant assessment (TA) to 56.0 (45.0-69.0) at year 1, 53.0 (41.0-68.0) at year 5 and 44.5 (25.0-57.3) at year 10. The cumulative incidence of CKD ≥ stage 4 was 25% at 5 years and 41% at 10 years after transplantation. Proteinuria the first year post-HT was the only predictor related (P < 0.05) to a higher rate of GFR decline (HR 5.15, 95% CI 1.23-21.55). GFR ≥60 as compared to <60 before HT, or a first-year GFR decline <30% as compared to >30%, was moreover associated (P < 0.05) with a lower risk of death (HR 0.30, 95% CI 0.12-0.76 and HR 0.35, 95% CI 0.13-0.90, respectively). Notably, the CKD-EPI and Schwartz formulae overestimated GFR by 28 ± 29% and 26 ± 33%, respectively. In conclusion, CKD in HT patients is common and associated with worse outcome. To avoid diagnostic delay, GFR estimating equations' validity in HT patients needs further study.