Primary renal artery stenting: Characteristics and outcomes after 363 procedures

Background Stenting improves the acute results of percutaneous balloon angi oplasty for atherosclerotic renal artery stenosis. Predictors of benefit an d angiographic restenosis are not well understood. We describe the technica l and clinical success of renal artery stenting in a large consecutive seri es of patients with hypertension or renal insufficiency. We identify clinic al, procedural, and anatomic factors that might influence outcome, restenos is, and survival. Methods Primary renal artery stenting was performed in 300 consecutive pati ents who underwent 363 stent procedures in 358 arteries. Angiograms were an alyzed quantitatively. Clinical and angiographic follow-up data are availab le after a median of 16.0 months. Results At baseline, 87% of patients had hypertension, and 37% had chronic renal insufficiency. The mean age was 70 years (interquartile range 63.1-74 .6) years. The stenosis was unilateral in 49% and bilateral in 48% and invo lved a solitary functioning kidney in 3.6%. The stenting procedure was succ essful in all attempts. There were no procedural deaths or emergency renal surgical procedures. Postprocedure azotemia was seen in 45 of 363 (12%) pro cedures but persisted in only 6 patients (2%), all of whom had baseline ren al insufficiency. Systolic and diastolic blood pressures were significantly reduced (systolic blood pressure from 164.0 +/- 28.7 to 142.4 +/- 19.1 mm Hg, P <.001). At follow-up, 70% of patients had improved blood pressure con trol regardless of renal function. In patients with baseline renal insuffic iency, 19% had improvement in serum creatinine levels at follow-up, 54% had stabilization, and 27% had deterioration. Follow-up mortality was 10% and was predicted by baseline creatinine levels (odds ratio 1.72 for each 1 mg/ dL creatinine increment, 95% confidence interval 1. 13-2.49) and extent of coronary artery disease (odds ratio 1.66 for each diseased coronary artery, 95% confidence interval 1.03-2.67). Angiographic restenosis was found in 2 1% of 102 patients overall and was less common (12%) in arteries with a ref erence caliber >4.5 mm (P<.01 vs caliber <4.5 mm). Neither poststenotic dil ation nor severity of angiographic stenosis predicted clinical outcome. Conclusions Primary renal artery stenting can be performed safely with near ly uniform technical success. The majority of patients with hypertension or renal insufficiency derive benefit. Follow-up mortality is 5-fold higher i n patients with baseline renal insufficiency. Clinical and angiographic fea tures did not predict blood pressure or renal functional outcome. Restenosi s is more common in renal arteries with a reference caliber less than 4.5 m m.