Hemodynamics and Renin Profiles of Renal Artery Variations in Hypertensive CKD.

BACKGROUND: The functional implications of renal artery variations-including accessory renal artery (ARA) and early branching-in hypertensive chronic kidney disease remain poorly understood. METHODS: This prospective cohort study enrolled 38 patients with hypertensive chronic kidney disease with unilateral solitary renal artery variation (24 ARA, 14 early branching) undergoing pressure wire-based hemodynamic evaluation and selective segmental renal vein renin sampling; 35 patients completed 2-year follow-up. RESULTS: Mean pressure gradient was higher in variant artery than in ipsilateral main (1.10±3.39 versus -0.15±2.21 mm Hg, P=0.04) and contralateral renal artery (versus -0.10±1.56 mm Hg, P=0.04) in the overall cohort, a difference limited to the ARA subgroup. Plasma renin activity was elevated in ARA-supplied segments compared with the ipsilateral main trunk (1.77±1.86 versus 1.24±1.40 ng/(mL·h), P=0.004) and contralateral artery-supplied segments (versus 1.24±1.37, P=0.002), whereas no significant difference was observed in the early branching subgroup. After multivariable adjustment, variant artery systolic pressure gradient was positively associated with variant-supplied segmental (β=0.41, P=0.02) and peripheral (β=0.37, P=0.04) plasma renin activity, angiotensin II, and nighttime mean arterial pressure. Peripheral aldosterone was associated with lower estimated glomerular filtration rate and higher urinary protein. All adjusted associations represent exploratory signals given limited sample size. Over 2 years, an intragroup estimated glomerular filtration rate decline was observed within the ARA subgroup (-5.2 mL/[min·1.73 m2]; P=0.02) while the early branching subgroup remained stable (P=0.47); however, the group-by-time interaction was not significant (P=0.06), indicating these preliminary trends require larger validation cohorts. CONCLUSIONS: Renal artery variations may alter intrarenal hemodynamics, with functional impairment and segmental renin hypersecretion observed primarily in ARA. This suggests a potential role for functional evaluation.