Renal arterial resistance index is independently associate to high diuretic dose in chronic heart failure outpatients

Abstract

In chronic heart failure (CHF) patients, diuretic administration plays a key role in the control of congestion. However, high diuretic dose (HDD) has been also demonstrated to be associated to a worse prognosis. The aim of this study was to evaluate the factors independently associated to HDD and, in particular, the role of a marker of renal perfusion, the Renal arterial Resistance Index (RRI). We enrolled 250 outpatients (78% males, 64±13 years, NYHA class 2.2±0.6, left ventricular ejection fraction, LVEF, 34±10%) with CHF (ESC criteria) due to left ventricular systolic dysfunction, in stable clinical conditions (> 1 month) and in conventional therapy. All patients underwent: A clinical evaluation to assess NYHA class; a routine chemistry to evaluate NT-proBNP and glomerular filtration rate (GFR) by creatinine (MDRD formula); an echocardiogram to evaluate LVEF and to estimate central venous pressure (CVP); a renal echo-Doppler in order to evaluate RRI. Peak systolic velocity and end diastolic velocity of segmental renal artery was obtained by pulsed Doppler flow and RRI was then calculated. RRI was positively and significantly correlated with furosemide equivalent dose (r: 0.33; p<0.001) and with HDD (r: 0.36; p<0.001). As shown in the table, RRI remained significantly associated with HDD in a multivariate logistic regression analysis including the other factors significantly correlated at univariate analysis. (Table presented) In conclusion, our findings help to better understand the wide variability of diuretic dosage, by demonstrating the independent influence of RRI, a parameter reflecting renal arterial resistance. These data could also represent the basis of future studies aimed to optimise therapeutic strategies by improving renal flow and, as a consequence, diuretic response.