Renal Decline Following Heart Transplant

Abstract

<h3>Purpose</h3> Renal decline is common after organ transplantation and is often attributed to nephrotoxic immunosuppressive regimens. There are limited data on the impact of renal decline and survival following heart transplant (HTx). We assessed the association of renal decline following HTx and 3-year mortality. <h3>Methods</h3> This was a retrospective review of our institutional HTx database from 2012-2019. Multi organ transplants were excluded. Glomerular filtration rate (eGFR) was estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Postoperative acute kidney injury (AKI) and chronic kidney disease (CKD) were calculated by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and CKD Staging System, respectively. The primary outcome was renal decline within 3 years of transplantation. For those without baseline CKD, renal decline was defined as the development of stage 3+ CKD. For those with baseline CKD, renal decline was defined as progression in CKD stages or ≥20% decrease in eGFR. Those that died within 30 days were excluded from the renal decline analysis. <h3>Results</h3> 232 patients met study entry criteria with 106 (45.7%) having baseline CKD. The overall 30-day mortality rate was 1.7% (n=4). A total of 91/232 (39.2%) patients experienced an AKI within 7 post-operative days. The rate of renal decline within 3 years post-operatively was 43.4% (n=99). Permanent dialysis was required in 13/232 (5.6%) of patients. There were no differences in progression of renal decline in those that did and did not experience an AKI (44.9% versus 42.4%, P=.784). There were no differences in 3-year mortality between those that did and did not experience renal decline (7.1% versus 9.3%, P=.633). On binary logistic regression, the following variables were associated with renal decline: age (OR 1.043, 95% CI 1.02-1.07, P=.002), diabetes mellitus (OR 2.40, 95% CI 1.28-4.50, P=.006), and baseline CKD (OR .31, 95% CI .17-.59, P<.001). <h3>Conclusion</h3> Renal decline is common after heart transplantation but does not increase mortality risk over a 3-year period.