Renal arterial resistive index is associated with severe histological changes and poor renal outcome during chronic kidney disease

Abstract

BackgroundChronic kidney disease (CKD) is a growing public health problem and end stage renal disease (ESRD) represents a large human and economic burden. It is important to identify patients at high risk of ESRD. In order to determine whether renal Doppler resistive index (RI) may discriminate those patients, we analyzed whether RI was associated with identified prognosis factors of CKD, in particular histological findings, and with renal outcome.MethodsRI was measured in the 48 hours before renal biopsy in 58 CKD patients. Clinical and biological data were collected prospectively at inclusion. Arteriosclerosis, interstitial fibrosis and glomerulosclerosis were quantitatively assessed on renal biopsy in a blinded fashion. MDRD eGFR at 18 months was collected for 35 (60%) patients. Renal function decline was defined as a decrease in eGFR from baseline of at least 5 mL/min/ 1.73 m2/year or need for chronic renal replacement therapy. Pearson’s correlation, Mann–Whitney and Chi-square tests were used for analysis of quantitative and qualitative variables respectively. Kaplan Meier analysis was realized to determine renal survival according to RI value using the log-rank test. Multiple logistic regression was performed including variables with p < 0.20 in univariate analysis.ResultsMost patients had glomerulonephritis (82%). Median age was 46 years [21–87], eGFR 59 mL/min/ 1.73m2 [5–130], percentage of interstitial fibrosis 10% [0–90], glomerulosclerosis 13% [0–96] and RI 0.63 [0.31-1.00]. RI increased with age (r = 0.435, p = 0.0063), pulse pressure (r = 0.303, p = 0.022), renal atrophy (r = −0.275, p = 0.038) and renal dysfunction (r = −0.402, p = 0.0018). Patients with arterial intima/media ratio ≥ 1 (p = 0.032), interstitial fibrosis > 20% (p = 0.014) and renal function decline (p = 0.0023) had higher RI. Patients with baseline RI ≥ 0.65 had a poorer renal outcome than those with baseline RI < 0.65 (p = 0.0005). In multiple logistic regression, RI≥0.65 was associated with accelerated renal function decline independently of baseline eGFR and proteinuria/creatininuria ratio (OR=13.04 [1.984-85.727], p = 0.0075). Sensitivity, specificity, predictive positive and predictive negative values of RI ≥ 0.65 for renal function decline at 18 months were respectively 77%, 86%, 71% and 82%.ConclusionsOur results suggest that RI ≥ 0.65 is associated with severe interstitial fibrosis and arteriosclerosis and renal function decline. Thus, RI may contribute to identify patients at high risk of ESRD who may benefit from nephroprotective treatments.

Renal Resistive Index Predicts Postoperative Blood Pressure Outcome in Primary Aldosteronism

“…were significantly higher than those of the patients in the remission and responded-residual hypertension groups ( Figure S1). Thus, high RI may indicate the presence of established renal parenchymal damage [9][10][11] or arteriosclerotic changes that would contribute to intractable or residual hypertension after adrenalectomy. Indeed, it was reported that in patients with untreated PA, the kidneys presented histopathologic changes, such as sclerosis of glomeruli, atrophy of the tubules, and interstitial fibrosis.…”

“…[9][10][11][12][13][14][15] Color Doppler ultrasonography was performed by 2 well-trained ultrasonographers who were not informed of the details of the study to avoid any potential bias. The tracing findings were examined by an experienced reader who was blinded to the patients' clinical information.…”

“…Of particular importance may be baseline renal function because the estimated glomerular filtration rate (eGFR) in the study by Wu et al 8 was substantially lower than that in the study by Sechi et al 7 The RI, which is calculated based on systolic and diastolic flow velocity, has been shown to correlate significantly with histological findings, such as arteriosclerosis and tubulointerstitial changes. [9][10][11] In addition, increased renal RI was reported to be significantly associated with the incidence of cardiovascular and renal organ damage 12,13 and to serve as a predictor of worsening renal function in patients with chronic kidney disease. 14,15 In patients with APA, plasma aldosterone levels decrease drastically after adrenalectomy.…”

Lesão Renal Tubular Aguda Em Cães E Gatos: Fisiopatogenia E Diagnóstico Ultrassonográfico

“…Esses índices comparam o fluxo durante a sístole e a diástole, sendo razões das velocidades obtidas do espectro Doppler. Por isso, ao contrário da análise isolada da velocidade, os índices têm como vantagem a independência da correção do ângulo, sendo usados para avaliação de vasos muito pequenos e tortuosos em que é difícil a correção do ângulo, como no caso das artérias intrarrenais (CARVALHO, 2009;BIGÉ et al, 2012).…”

External Validation of the Kidney Failure Risk Equation and Re-Calibration with Addition of Ultrasound Parameters

“…However, although elevated RRI predicted adverse renal outcome in several cohort studies (10)(11)(12)(13)(14)(15)(16)(17)(18), these were mostly small-sized, and RRI was not compared against established models for CKD progression. Moreover, there is concern that RRI may not provide organ-specific information on structural or functional abnormalities within the kidneys, but rather reflects systemic vascular disease.…”