Supplementary Material for: Abnormal Right Ventricular to Pulmonary Artery Coupling in Patients with End-Stage Kidney Disease and Normalization After Renal Transplantation: An Observational Study

Background: Pulmonary hypertension and right ventricular (RV) dysfunction are associated with an increase in mortality and worse prognosis in patients with end-stage kidney disease (ESKD), but pathophysiologic mechanisms underlying the progression of RV dysfunction remains incompletely understood. Present study aimed to understand right ventricular to pulmonary artery (RV-PA) coupling, which is an early indicator of transition to RV dysfunction, to better characterize adaptive RV response to increased afterload in ESKD patients and changes in RV-PA coupling following renal transplantation. Methods: 111 patients with ESKD, including 49 patients scheduled for renal transplantation, underwent a detailed echocardiographic examination and measurement of tricuspid annular plane excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio, and a repeat examination was performed 6 months after the baseline examination. Results: Patients with ESKD had significantly lower TAPSE/PASP ratio at baseline (1.02 (0.71 - 1.63) vs. 1.29 (1.09 - 1.96), p<0.001). In 40 patients that underwent transplantation, TAPSE/PASP ratio increase significantly from 0.97 (0.72 - 1.42) to 1.30 (1.01 - 1.82) (p=0.03), while in 27 patients remained on dialysis there was a non-significant reduction in TAPSE/PASP ratio (1.21 (0.71 - 1.62) vs. 0.84 (0.61 - 1.38), p=0.44). The change in TAPSE/PASP ratio correlated significantly with the change in pulmonary vascular resistance (OR:0.61,95%CI:0.51-0.72, p<0.001) and left ventricular mass index (OR:0.97, 95%CI:0.96-0.99, p=0.001) after adjustment. Conclusions: Patients with ESKD had abnormal RV-PA coupling, as indicated by a reduced TAPSE/PASP ratio, which normalizes 6 months after renal transplantation.