ASSESSMENT OF RENAL RESISTIVE INDEX IN HYPERTENSIVE PATIENTS: A DOPPLER ULTRASOUND STUDY

Abstract

Background: Renal resistive index (RI), measured via Doppler ultrasound, is a non-invasive marker used to assess intrarenal hemodynamics and vascular resistance. Elevated RI has been linked to hypertension-related target organ damage (TOD), including microalbuminuria and left ventricular hypertrophy (LVH). This study aims to evaluate RI in hypertensive individuals, those with a family history of hypertension, and normotensive individuals, and to assess its association with early markers of TOD.
Methods: This prospective, single-center study was conducted at Sree Balaji Medical College & Hospital, Chennai, over six months. A total of 60 patients were enrolled, divided into hypertensive (n=20), normotensive (n=20), and individuals with a family history of hypertension (n=20). Doppler ultrasound was performed to measure RI in interlobar arteries. Additional investigations included albumin-to-creatinine ratio (ACR), renal function tests, electrocardiography (ECG), and echocardiography (ECHO) to evaluate TOD. Multiple regression analysis was used to determine independent predictors of RI.

Results: The prevalence of microalbuminuria and LVH was 14% and 5%, respectively. Hypertensive patients exhibited significantly higher RI values compared to normotensive individuals (P < 0.001). Elevated RI correlated positively with systolic blood pressure (r = 0.50, P = 0.05) and ACR (r = 0.22, P = 0.01), and negatively with renal volume and diastolic blood pressure. Multiple regression analysis identified age, systolic blood pressure, and ACR as independent predictors of RI.
Conclusion: Renal RI serves as a valuable, non-invasive marker for early detection of hypertensive TOD. Hypertensive patients with increased RI are at greater risk for renal impairment and cardiac remodeling. Incorporating. RI measurements into routine hypertension management may aid in early risk stratification and intervention.