Chronic kidney disease in prevalent orthotopic heart transplant recipients using a new CKD-EPI formula.

Background: Heart transplantation is an established treatment for advanced heart failure. However, chronic kidney disease (CKD) is an important long-term complication of all forms of organ transplantation other than renal. It has been shown that a GFR <60 ml/min is predictive of premature cardiovascular death.

Methods: The aim of this study was to assess the prevalence of kidney dysfunction in heart transplant recipients using a new CKD-EPI formula in a cohort of 169 prevalent patients (mean age 53.30+/-13.80 years).

Results: Mean serum creatinine in this population was 1.71+/-1.10 mg/dl, Serum creatinine was normal (<1.4 mg/dL in males and <1.2 mg/dL in females) in 45.4% of the patients. According to the Cockcroft-Gault formula, stage 2 CKD (i.e.GFR 60-89 ml/min) was demonstrated in 79 patients (46.75%), stage 3 CKD (i.e. GFR 30-59 ml/min) in 49 patients (29.00%) and stage 4 CKD (i.e. GFR 15-29 ml/min) in 15 patients (8.88%). According to MDRD formula stage 2 CKD was found in 36 patients (21.30%), stage 3 CKD was found in 79 patients (46.75%) and stage 4 in 27 patients (15.98%). According to new CKD-EPI formula, stage 2 CKD was found in 35 patients (20.71%), stage 3 CKD in 79 patients (46.75%) and stage 4 in 28 patients (16.57%). According to the creatinine clearance stage 2 CKD was found in 61 patients (36.09%), stage 3 CKD in 63 patients (37.28%) and stage 4 in 19 (11.24%) patients. Clinically significant CKD (GFR <60 ml/min) was found in 37.88-63.91% depending on the formula used to estimate the GFR. Normal kidney function was found in 27 patients (15.98%) according to MDRD formula, in 27 patients (15.98%) according to new CKD-EPI formula, in 26 patients (15.38%) according Cockcroft-Gault formula and 26 patients (15.38%) on the basis of 24-hours creatinine clearance.

Conclusions: We conclude that the prevalence of CKD is high in heart transplant recipients. Evaluation of renal function is important in order to select the appropriate strategy to reduce the cardiovascular risk. New CKD-EPI formula seems to more accurate in assessment kidney function that previously used, however, it merits further studied and validation against gold standard of isotope GFR measurement.