Renal resistive index reflects Fontan pathophysiology and predicts mortality. Issue 20 (2nd May 2017) - Ohuchi, Hideo
Abstract : Objectives: The renal resistive index (RRI) reflects non-renal pathophysiology, such as great artery stiffness, haemodynamics and even end-organ damage in patients with hypertension. This study was conducted to clarify the clinical significance of the RRI in Fontan pathophysiology. Methods: We measured the RRI in 280 consecutive Fontan patients and 36 healthy controls. Results: The patients exhibited a higher RRI than the controls (0.71±0.07 vs 0.60±0.04, p<0.0001). A high central venous pressure, low arterial pressure, greater pulse pressure and low arterial oxygen saturation (SaO2 ) independently predicted a high RRI (p<0.05–0.0001). The RRI was inversely correlated with the peak oxygen uptake (PVO2 ) and 24-hour creatine clearance, and was positively correlated with the plasma levels of brain natriuretic peptide (BNP) (p<0.0001 for all). The high RRI was also associated with liver dysfunction and postprandial hyperglycaemia during the oral glucose tolerance test (p<0.001). During the follow-up period, 18 patients died. Age, RRI, SaO2, BNP, use of diuretics and antiarrhythmic drugs, and PVO2 predicted mortality. When PVO2 was excluded, RRI (HR: 1.13; 95% CI: 1.04 to 1.23; p<0.01) or RRI ≥0.81 (HR: 12.0; 95% CI: 3.4 to 50; p<0.0001) independently predicted mortality. Conclusions: The RRI reflected heart failure severity, hepatorenal function and glucose intolerance, and predicted all-cause mortality in Fontan patients. Therefore, the RRI may be a useful marker of Fontan-associated multiorgan pathophysiology.