Predictors for clinical success at one year following renal artery stent placement

To determine pretreatment variables that may predict 1-year clinical outcome of stent placement for renal artery stenosis.

In a prospective study, 40 consecutive patients (29 men; mean age 60 +/- 9.1 years) with angiographically proven atherosclerotic renal artery stenosis were treated with stent placement because of drug resistant hypertension (n=14), renal function impairment (n=14), or both (n=12). Clinical success at 1 year was defined as a decrease of diastolic blood pressure > or = 10 mmHg or a decrease in serum creatinine > or = 20%, depending on the indication for treatment. Regression analysis was performed using anatomical parameters from angiography and intravascular ultrasound, estimates of renal blood flow from renal scintigraphy, and single-kidney renal function measurements.

Patients treated for hypertension had better outcome than those treated for renal function impairment, with clinical success rates of 85% and 35%, respectively. Preserved renal function, with low serum creatinine and high 2-kidney glomerular filtration rate at baseline, was associated with clinical success in the entire patient group at follow-up (p=0.02 and p=0.03, respectively). An elevated vein-to-artery renin ratio on the affected side was borderline predictive (p=0.06). In patients treated for renal impairment, lateralization to the affected kidney (affected kidney-to-2-kidney count ratio < or = 0.45) on the scintigram emerged as a significant predictor for clinical success, with an odds ratio of 15 (p=0.048).

Clinical success of renal artery stent placement is better for the treatment of hypertension than for preserving renal function. In patients with renal function impairment, lateralization to the affected kidney on the scintigram appears to be a predictor of clinical success.