ASSOCIATION BETWEEN PERIOPERATIVE RENAL FUNCTION AND TIME TO CHRONIC RENAL INSUFFICIENCY FOLLOWING ORTHOTOPIC HEART TRANSPLANTATION

Abstract

630 Objective. Risk factors for developing chronic renal insufficiency (CRI) following heart transplantation remain unclear. The objective of this study was to determine the effects of perioperative renal function changes on the development of CRI. Methods. We conducted a five-year retrospective cohort study of all patients (n=163) aged > 10 years who had orthotopic heart transplantation at OHSU from 1985-1992. CRI was defined as a serum creatinine≥2.0 on ≥2 occasions more than one year post-transplantation. Subjects were classified into 3 groups based on perioperative renal function: 1) patients with a preoperative creatinine >1.5 (n=38); 2) patients with a preoperative creatinine ≤1.5 but a postoperative (first 4 days) creatinine ≥2.0 (n=47); and 3) patients with a preoperative creatinine≤1.5 and a postoperative creatinine <2.0 (n=78). Association between time to CRI and perioperative renal dysfunction was examined by the Cox Proportional Hazard model, allowing us to control for confounding factors. Results. The mean age of the patients was 49.1 ±13.2; 138(84.7%) were male. A total of 47 (28.8%) patients developed CRI during the first 5 years post-transplantation. 6/47 of these patients developed end-stage renal failure requiring dialysis. The mean preoperative serum creatinine was higher in patients who developed CRI than those who did not (1.6 vs 1.3, P<0.01). The mean serum creatinine was 2.0 on post transplant day 3 in patients who developed CRI and 1.7 in those who did not (P=0.07). The mean cyclosporine loading dose was 6.3 mg/kg in patients who developed CRI and 5.9 in those who did not (P=0.41). The proportion of patients who developed CRI was highest in group 1 (55.3%), lower in group 2 (25.5%), and lowest in group 3 (17.9%) (P<0.01). After adjusting for age, sex, hypertension, diabetes, and cardiopulmonary bypass time, the relative risk of CRI for patients in group 1 was 2.5 times higher than those in group 2 (95% CI= 1.2-5.2, P<0.01), 3.1 times higher than patients in group 3 (95% CI= 1.5-6.2, P=0.01), 1.7 times higher than a combined groups 2 and 3 (95% CI=1.3-2.3, P<0.01). The risk of CRI was 22% higher in group 2 compared to group 3 but the difference was not statistically significant (P=0.61). Controlling for the cyclosporine loading dose did not alter these associations. Conclusions. We conclude that preoperative renal dysfunction predicts the development of CRI. This association was unchanged by controlling for the initial cyclosporine dose.