THE PULSATILITY INDEX AND THE RESISTIVE INDEX IN RENAL-ARTERIES - ASSOCIATIONS WITH LONG-TERM PROGRESSION IN CHRONIC-RENAL-FAILURE

Background. The pulsatility index (PI) and the resistive index (RI) ar e used as pulsed-wave Doppler measurements of downstream renal artery resistance. PI and RI have been found to correlate with renal vascular resistance, filtration fraction and effective renal plasma how in chr onic renal failure. The aim of the present study was to evalute the po tential relationship between these indices and the rate of decline in renal function, as reflected by changes in different parameters of ren al function in patients with chronic renal failure. Methods. Twenty-on e patients (8 females, 13 males, mean age 58 years (36-75)) with chron ic renal failure were enrolled in the study. Doppler examinations were performed in the segmental arteries by an Acuson 128XP. The PI and th e RI was calculated from the blood flow velocities. Parameters of rena l function were measured every 3 1/2 months, and all patients were fol lowed for 18-21 months. Progression of renal dysfunction was estimated by linear regression of parameters of renal function versus time. Res ults. In a multiple regression analysis both PI and RI correlated sign ificantly to the rate of decline in reciprocal serum creatinine (PI: r = -0.48, P = 0.03; RI: r = -0.52, P = 0.02). Furthermore, when separa ting the patients in two groups by the median RI value, there was a si gnificant difference between the groups in rate of decline in reciproc al serum creatinine (P = 0.02). For PI this distinction was also prese nt (P = 0.04). Conclusion. PI and RI correlated to the severity of the renal disease, as reflected by the rate of decline in reciprocal seru m creatinine during antihypertensive treatment. The median RI or PI va lue could separate the patients into groups one of slow and another of fast progression.