Clinical and kidney morphologic predictors of outcome for renal artery stenting: data to inform patient selection.

Abstract

The purpose of the current study was to identify clinical and kidney morphologic features that predict a favorable blood pressure (BP) response to renal artery stenting (RAS). The study cohort consisted of 149 patients who underwent primary RAS over 9 years. Patients were categorized as "responders" based on modified American Heart Association guidelines: BP <160/90 mm Hg on fewer antihypertensive medications or diastolic BP <90 mm Hg on the same medications. All other patients were deemed "nonresponders." Renal volume was estimated as kidney length × width × depth/2 based on preoperative computed tomography or magnetic resonance scans. Median follow-up was 19 months (interquartile range [IQR] 10.0-29.5 months). The median age of the cohort was 68 years (IQR, 60-74 years). A favorable BP response was observed in 50 of 149 patients (34%). Multivariate analysis identified three independent predictors of a positive BP response: (1) requirement for four or more medications (odds ratio, 29.9; P = .0001), (2) preoperative diastolic BP >90 mm Hg (OR, 31.4; P = .0011), and (3) preoperative clonidine use (OR, 7.3; P = .029). The BP response rate varied significantly based on the number of predictors present per patient (P < .0001). Among patients with three-drug hypertension, a larger ipsilateral kidney (volume ≥150 cm(3)) increased the BP response rate more than threefold compared with patients with smaller kidneys (63% vs 18% BP response rate; P = .018). The current study demonstrated that three clinical predictors (≥4 antihypertensive medications, diastolic BP ≥90 mm Hg, and clonidine use) are preoperative predictors of BP response to RAS. Kidney volume may help in discriminating responders from nonresponders among those patients with three-drug hypertension. These parameters may assist clinicians in patient selection and provide more concrete data with which to counsel patients on the likely outcomes for RAS.