Why Does Renal Resistive Index Predict Mortality in Chronic Kidney Disease?

To evaluate the significance of the renal resistive index (RI) as a noninvasive marker of renal histological damage and a prognostic indicator, we examined RI by Doppler ultrasonography in 202 chronic kidney disease (CKD) patients who underwent renal biopsy. RI increased as the CKD stage progressed and correlated with age, systolic blood pressure, estimated glomerular filtration rate (eGFR), and renal histological changes, including glomerulosclerosis, arteriolosclerosis, and tubulointerstitial damage. Prognostic evaluation with a median follow-up period of 38.5 months revealed that patients withRI≥0.7(high RI group,n=39) had significantly poorer renal survival than those withRI<0.65(normal RI group,n=120) and0.65≤RI<0.7(high-normal RI group,n=43). The patients in the high-normal RI group showed good response to steroids. However, in the high RI group, steroid therapy did not significantly improve renal survival. Of the clinical indices studied,RI≥0.7, hypertension, proteinuria, and low eGFR at diagnosis were independent risk factors for worsening renal dysfunction. In conclusion, RI in CKD patients was considered as a marker of renal function, histological damage, and renal prognosis, and a possible determinant of indication for steroids.

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Renal resistivity index is inversely proportional to estimated glomerular filtration rate in chronic kidney disease

International Journal of Advances in Medicine ◽

10.18203/2349-3933.ijam20183126 ◽

2018 ◽

Vol 5 (4) ◽

pp. 950

Author(s):

Animesh Gupta ◽

Piyush Saxena ◽

Upma Narain ◽

Seema Pandey ◽

Poonam Gupta ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Glomerular Filtration Rate ◽

Kidney Disease ◽

Glomerular Filtration ◽

Filtration Rate ◽

Estimated Glomerular Filtration Rate ◽

Rank Order ◽

Resistive Index ◽

Renal Resistive Index ◽

Resistivity Index

Background: Renal resistive index (RRI) measured by Doppler ultrasonography has been associated with severity, rate of progression and mortality in chronic renal failure. Parameters like renal vascular resistance, ﬁltration fraction and effective renal plasma ﬂow have been associated with renal resistivity index in chronic kidney disease patients.Methods: This hospital based cross-sectional study was conducted from April 2016 to August 2017. 100 patients with chronic kidney disease were enrolled. RRI was calculated from the blood ﬂow velocities observed during Doppler examinations of the segmental arteries and estimated glomerular ﬁltration rate (eGFR) was calculated using the chronic kidney disease epidemiology collaboration (CKD-EPI) equation. Spearman Rank-Order Correlation Coefficient was used.Results: A Significant inverse correlation was observed between RRI and eGFR (r= -0.347, p =0.0004). It was also observed that older age (r= 0.297), higher systolic blood pressure (r= 0.365), lower levels of hemoglobin (r= -0.34 for males and r= -0.353 for females) were observed to correlate with higher values of RRI in advanced CKD stages.Conclusions: RRI correlated inversely with eGFR in chronic kidney disease and hence was directly related to the severity of the disease.

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Low systolic blood pressure values, renal resistive index measurement and glomerular filtration rate in a non-dialysis dependent chronic kidney disease population

Archivio Italiano di Urologia e Andrologia ◽

10.4081/aiua.2018.4.288 ◽

2019 ◽

Vol 90 (4) ◽

pp. 288-292

Author(s):

Simone Brardi ◽

Gabriele Cevenini

Keyword(s):

Blood Pressure ◽

Chronic Kidney Disease ◽

Glomerular Filtration Rate ◽

Kidney Disease ◽

Serum Creatinine ◽

Systolic Blood Pressure ◽

Filtration Rate ◽

Left Kidney ◽

Resistive Index ◽

Renal Resistive Index

Objective: A longitudinal prospective case control study was organized to explore the relationships between glomerular filtration rate (GFR), renal resistive index (RRI) and blood pressure values in a non-dialysis dependent adult population affected by chronic kidney disease and exposed to low systolic blood pressure (SBP) values.Material and methods: The study sample (54 patients: 31 males and 23 females with an average age of 61.7 ± 19.2 years) was randomly selected from a population of adult non-dialysis dependent patients that scored a SBP < 100 mmHg at the medical examination. The patients were equally divided in two groups defined by the presence and absence of chronic kidney disease, (i.e. a GFR less or greater than 60 ml/min/1.73 m2, respectively). Patients were submitted to a full therapeutic and dietetic intervention to correct the hypotension until reaching a steady SBP > 100 mmHg. Results: In the group with chronic renal disease, the comparison between the data recorded with SBP < 100 mmHg (t0) and those detected with SBP ≥ 100 mmHg (t1) showed a statistically significant decrease of serum creatinine as well as an increase of GFR (mean serum creatinine t0 – serum creatinine t1: 0.194 ± 0.35, p < 0.01; mean GFR t0 – GFR t1: -4.615 ± 8.8, p < 0.013). There was also a statistically significant reduction of the RRI (mean right kidney RRI t0 – mean right kidney RRI t1: + 0.082 ± 0.03, p < 0; mean left kidney RRI t0 – mean left kidney RRI t1: 0.076 ± 0.03, p < 0). Conclusion: We concluded that, in CKD, when aorta is stiffed, a decrease of SBP can limit the renal perfusion that, in this condition, is mostly dependent by stroke volume, causing an increase of RRI and a decrease of GFR that we suppose as reversible with the restoration of SBP.

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