Changes of renal vein renin activity in patients with unilateral atherosclerotic renal artery stenosis

Objective: To assess plasma renin activity (PRA) of renal veins in patients with unilateral renal artery atherosclerotic stenosis and its relationship with blood pressure changes after renal artery stenting.

Methods: Fifty patients with significantly unilateral renal artery stenosis (lumen loss > or = 70%) and coronary artery stenosis were included. Bilateral renal vein and peripheral PRA and angiotensin II were determined and their relations with blood pressure changes after stenting were analyzed.

Results: All patients were revascularized successfully for both coronary and renal artery stenosis. PRA in the ischemic kidney was significantly higher than that in the contralateral kidney (1.44 +/- 1.73 ng.ml(-1).h(-1) vs 1.27 +/- 1.57 ng.ml(-1).h(-1), P = 0.04). Ischemic and contralateral renal vein renin ratio (RVRR) was > or = 1.5 in 14 patients (28%) (renal vascular hypertension, RVH group). During follow-up (12 +/- 9 months), blood pressure returned to normal in 9 patients after revascularization, 7 were of RVH group (50%) and 2 were in control group (6%) (P < 0.001). Multivariate logistic analysis indicated RVRR > or = 1.5 was significantly related to the decrease of hypertension after renal artery stenting (OR = 3.15, 95% CI = 1.49 approximately 5.97, P = 0.02).

Conclusions: PRA was significantly increased in the ischemic kidney in about one-third of patients with unilateral renal artery stenosis. Hypertension could be controlled easily to normal value after renal artery stenting in half of the patients with RVRR > or = 1.5. Measurement of renal vein renin activity in patients with renal artery stenosis is very useful in evaluating the effects of renal artery stenting on hypertension.