RESUMO
BACKGROUND/AIM: The renal arterial resistance index (RRI) is a Doppler measure, which reflects abnormalities in the renal blood flow. The aim of this study was to verify the value of RRI as a predictor of worsening renal function (WRF) in a group of chronic heart failure (CHF) outpatients. METHODS: We enrolled 266 patients in stable clinical conditions and on conventional therapy. Peak systolic velocity and end diastolic velocity of a segmental renal artery were obtained by pulsed Doppler flow, and RRI was calculated. Creatinine serum levels were evaluated at baseline and at 1 year, and the changes were used to assess WRF occurrence. RESULTS: During follow-up, 34 (13%) patients showed WRF. RRI was associated with WRF at univariate (OR: 1.13; 95% CI: 1.07-1.20) as well as at a forward stepwise multivariate logistic regression analysis (OR: 1.09; 95% CI: 1.03-1.16; p = 0.005) including the other univariate predictors. CONCLUSIONS: Quantification of arterial renal perfusion provides a new parameter that independently predicts the WRF in CHF outpatients. Its possible role in current clinical practice to better define the risk of cardiorenal syndrome progression is strengthened.
RESUMO
BACKGROUND: In chronic heart failure (CHF) patients there is a wide variability in the minimal effective diuretic dose. The aim of this study is to evaluate whether renal resistance index (RRI) is associated to baseline diuretic dose and the changes at one year. METHODS AND RESULTS: 250 outpatients in a stable condition and in conventional therapy were enrolled. Baseline RRI was calculated by renal arterial Doppler. The total daily dose of loop diuretics was assessed at baseline and after one year. High diuretic dose (HDD) was defined as a daily furosemide equivalent dose > 100 mg. RRI was independently associated with baseline HDD at univariate (OR 1.39; 95% CI: 1.233-1.58; p < 0.001) and multivariate analysis (OR 1.27; 95% CI: 1.09-1.49; p: 0.002) after correction for other univariate predictors (age, NYHA class, left ventricular ejection fraction, tricuspid annulus peak of systolic excursion, NT-proBNP, glomerular filtration rate by EPI formula and central venous pressure). Moreover, baseline RRI was independently associated to one year stable increase in loop diuretic dose at univariate and multivariate regression analyses. CONCLUSIONS: RRI is independently associated with high dose loop diuretics and their increase during a mid-term follow-up thus suggesting its usefulness in detecting an altered diuretic response in CHF outpatients.
RESUMO
AIMS: The renal arterial resistance index (RRI) is a measure of renal blood flow obtained by Doppler ultrasonography, which has been demonstrated to reflect both vascular and parenchymal renal abnormalities. The aim of the study was to evaluate clinical correlates and the prognostic relevance of RRI in a group of patients affected by chronic heart failure (CHF). METHODS AND RESULTS: We enrolled 250 CHF outpatients in a stable clinical condition and receiving conventional therapy. Peak systolic velocity and end-diastolic velocity of a segmental renal artery were obtained by pulsed Doppler flow. Then the RRI was calculated. Standard renal function assessment was obtained by the measurement of creatinine serum levels and the estimation of the glomerular filtration rate (GFR). During follow-up (21.4 ± 11.3 months), 41 patients experienced heart failure progression (hospitalization and/or heart transplantation and/or death due to worsening heart failure). Considered as a continuous variable, RRI was associated with events at univariate [hazard ratio (HR) 1.14; 95% confidence interval (CI) 1.09-1.19; P < 0.001] as well as at multivariate Cox regression analysis (HR 1.08; 95% CI 1.02-1.13; P = 0.004) after correction for independent predictors of the reference model. When the RRI was added to the reference model including GFR, a significant improvement of reclassification according to both category-free net reclassification improvement (NRI, 47%; 95% CI 13-80%; P = 0.006) and integrated discrimination improvement (IDI, 0.034; 95% CI 0.006-0.061; P = 0.016) was observed. CONCLUSIONS: Quantification of arterial renal perfusion provides a new parameter that independently predicts CHF patient outcome, thus strengthening its possible role in current clinical practice in order to better characterize renal function and stratify patients' prognosis.
