Renal resistance index independently predicts worsening of renal function after coronary angiography

Abstract

The renal resistance index (RRI) has been demonstrated to be a useful parameter that can detect patients at a high risk of worsening of renal function (WRF). This study was designed to evaluate the role of the RRI in predicting WRF mediated by the intravascular administration of contrast media. We enrolled patients who were referred for coronary angiography. Renal arterial echo-color Doppler was performed to calculate the RRI. WRF was defined as an increase of > 0.3 mg/dL and at least 25% of the baseline value in creatinine concentration 24–48 h after coronary angiography. Among the 148 patients enrolled in this study, 18 (12%) had WRF. In the multivariate logistic analysis, the RRI was independently associated with WRF (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.09–1.36; p = 0.001). After angiography, the RRI significantly increased in both patients with and without WRF. In the receiver operating characteristic curve analyses for WRF, the RRI at baseline and after angiography showed similar accuracy, and the best cutoff value for predicting WRF was 70%. In patients undergoing coronary angiography, the RRI is independently associated with WRF, probably because it provides more accurate information about cardiorenal pathophysiological factors and reflects kidney hemodynamic status and flow reserve.

Current Insights into Renal Resistive Index Significance in Kidney and Cardiovascular Disease

“…Thus, in acute coronary syndromes, renal RI and pulsatility index (PI) are independent predictors of elevated SYNTAX score [98]. Moreover, RRI is superior to glomerular filtration rate (GFR) for predicting worsening of renal function after coronary angiography, because it provides a comprehensive characterization of hemodynamic and neuro-hormonal factors of cardiorenal syndrome [99]. RRI higher than 0.7 predicts with good accuracy renal dysfunction after invasive coronary evaluation [99].…”

“…Moreover, RRI is superior to glomerular filtration rate (GFR) for predicting worsening of renal function after coronary angiography, because it provides a comprehensive characterization of hemodynamic and neuro-hormonal factors of cardiorenal syndrome [99]. RRI higher than 0.7 predicts with good accuracy renal dysfunction after invasive coronary evaluation [99]. Several mechanisms of worsening renal function due to contrast media are incriminated [99,100].…”

“…RRI higher than 0.7 predicts with good accuracy renal dysfunction after invasive coronary evaluation [99]. Several mechanisms of worsening renal function due to contrast media are incriminated [99,100]. Increased RRI and renal vascular resistance favor the occurrence of endothelial dysfunction, cytokine secretion, ischemia and fibrosis and determine renal vascular rarefaction with worsening of renal function [99].…”

“…Several mechanisms of worsening renal function due to contrast media are incriminated [99,100]. Increased RRI and renal vascular resistance favor the occurrence of endothelial dysfunction, cytokine secretion, ischemia and fibrosis and determine renal vascular rarefaction with worsening of renal function [99]. Furthermore, contrast media may facilitate an imbalance between vasodilating and vasoconstrictive substances, with inhibition of nitric oxide synthesis due to increased free radicals and reactive oxygen species [99,100].…”

“…Increased RRI and renal vascular resistance favor the occurrence of endothelial dysfunction, cytokine secretion, ischemia and fibrosis and determine renal vascular rarefaction with worsening of renal function [99]. Furthermore, contrast media may facilitate an imbalance between vasodilating and vasoconstrictive substances, with inhibition of nitric oxide synthesis due to increased free radicals and reactive oxygen species [99,100]. Whereas viscous contrast media induces direct tubular injury, water-soluble contrast media leads to renal dysfunction secondary to osmolarity difference between arterioles and the interstitial tissue [99,100].…”