Impact of Central Venous Pressure on Cardiorenal Interactions in Adult Patients with Congenital Heart Disease after Biventricular Repair

Abstract

Cardiorenal interactions adversely impact the prognosis in heart failure patients an effect which crucially involves increased central venous pressure (CVP). However, it is unclear whether the same pathophysiology operates in adults with congenital heart disease (CHD). The present study was designed to assess cardiorenal interactions in adults with CHD after biventricular repair. We measured the kidney length (KL, cm/m) and renal resistive index (RI) in 77 consecutive patients and 30 controls. We also measured hemodynamics, plasma B-type natriuretic peptide level, 24-hour creatinine clearance, and peak oxygen uptake in each patient. The CVP correlated with the KL (r = 0.44, P <.001) and the RI was greater in the patients (P <.0001). The high RI was independently determined by the CVP, aortic pressure, and cardiac index (P <.05-.001), and correlated with the 24-hour creatinine clearance (r = -0.30, P <.05). The RI correlated closely with the neurohumoral activations and peak oxygen uptake (|r| = 0.45-0.50, P <.0001), and the patients with a traditional criteria of high RI (≥0.70) had a higher incidence of cardiovascular events that required unscheduled hospitalization (hazard ratio = 2.78, 95% confidence interval 1.26-6.10, P <.05). Multivariate Cox model with the cutoff values of KL ≥68 cm/m and RI ≥0.74 revealed that a greater KL (hazard ratio = 4.03, 95% confidence interval 1.46-11.1, P <.01) as well as B-type natriuretic peptide (P <.001) independently predicted the events. Hemodynamics, especially a high CVP, independently predicted the enlarged kidney and abnormal intrarenal flow dynamics that are closely associated with heart failure severity and cardiovascular events in adults with CHD after biventricular repair.