The Relationship of Renal Augmented Velocity Index With Ventricular–Arterial Coupling in Comparison to Renal Resistive Index

Abstract

ObjectiveIt's a well‐known scientific statement that the heart and kidney functions are frequently tied together and the impairment of one directly alters the other. However, there exist knowledge gaps about this intricate pathophysiologic link and the exact unifying mechanism is not established. Herein, we aimed to investigate the presence of cardiorenal interaction at subclinical level while the conventional cardiac and renal clinical parameters are not disrupted yet in patients with hypertension.MethodsWe chose a novel renal Doppler ultrasonographic parameter—augmented velocity index (Avi)—and an echocardiographic measure—ventriculoarterial coupling—which is complex to analyze but increasingly used after its acceptance about being a key determinant of cardiovascular efficiency. We recruited 137 patients without a previous history of antihypertensive medication use (47.4% women; median age, 49 years). Renal Avi, renal resistive index (RI), arterial elastance (Ea), ventricular elastance (Ees) and Ea/Ees (ventriculoarterial coupling) parameters were all examined.ResultsRenal Avi, Ea, and Ea/Ees values were higher in females. Correlation analysis revealed that renal Avi was correlated with many hemodynamic variables including Ea and Ea/Ees. On multiple linear regression analysis, Ea and Ea/Ees remained as significant independent predictors of renal Avi but not of renal RI after adjustments for co‐variables (β = 0.488, P < .001 for Ea; β = 0.380, P < .001 for Ea/Ees).ConclusionsIn comparison to renal RI, we suggest that renal Avi is a more reliable and promising index that can even measure subclinical changes in the cardiorenal circulation which needs to be elucidated.