Background Successful kidney transplantation is associated with reduced cardiovascular (CV) morbidity and mortality compared to patients who remain on dialysis but is higher than in the general population. Longitudinal data reporting changes in uremic cardiomyopathy after renal transplant are conflicting; studies with echo have reported regression of left ventricular (LV) hypertrophy and improved systolic function but have not been replicated using cardiac MRI which is volume independent and does not depend on geometric assumptions. The CV response early after transplant with restoration of normal renal function have not been reported. The aim of this study was to assess changes in LV structure and function before and acutely (<8 weeks) after renal transplantation in patients with end-stage kidney disease (ESKD).

Method All subjects were prospectively recruited prior to live-donor kidney transplantation. Patients had no history of CV disease or diabetes and underwent cardiac MRI pre-operatively and within eight weeks post-operatively. Stress echocardiography or a myocardial perfusion scan was performed to exclude ischaemic heart disease. Haemodialysis patients were scanned on the day after dialysis, and peritoneal dialysis patients were scanned at their dry weight. Cardiac MRI data were analysed using CVi42 (Calgary, Canada).

Results In total 10 patients were studied (male gender 70%, age 45 years [30-60], dialysis 40%). Cardiac MRI data is presented in Table 1. Pre-operative studies demonstrated; median left ventricular mass 82 g/m2 with 6 patients reaching criteria for LV hypertrophy. Increased segmental wall thickness >11 mm in 8 patients. Mean LV ejection fraction (LVEF) 66%±10, only 2 patients had mild LV impairment (LVEF 50%–55%). The mean estimated glomerular filtration rate (eGFR) increased from 11 ml/min/1.73 m² to 53 ml/min/1.73 m² after transplantation without a change in body weight. Left ventricular and atrial volumes decreased at follow up without a change in LV mass. The reduction in indexed left ventricular diastolic volume (LVEDVi) was associated with an increase in ejection fraction (EF) (r=−0.810, p<0.001), and with an increased MAPSE (r=−0.868, p=0.001).

Discussion A reduction in LV volumes acutely after renal transplantation is associated with improved prognostic markers of LV function and atrial size. Patients with ESKD are chronically fluid overloaded even at dry weigh. Cardiac MRI is the method of choice for longitudinal studies in defining the natural history of uremic cardiomyopathy after renal transplantation.

Values are expressed as mean±SD or median (interquartile range). P Value <0.05 demonstrates significance in change of variable following transplantation.

Values are expressed as mean SD or median (interquartile range). P Value >0.05 ?demonstrates significance in change of variable following transplantation.