Predicting blood pressure response after renal artery stenting

Abstract

Background: Although technical success of renal artery stenting (RAS) is high and adverse events are infrequent, clinical success (improved blood pressure and renal function) and durability have been less predictable. Identifying those patients who will respond to RAS could improve overall outcomes of the procedure.

Methods: This was a retrospective analysis of all patients who underwent RAS for treatment of renovascular hypertension (RVH) between 2001 and 2007 at Dartmouth-Hitchcock Medical Center. The primary outcome measure was blood pressure improvement or cure as judged by American Heart Association criteria. Estimated glomerular filtration rate (eGFR), number of antihypertensive medications, and survival were evaluated as secondary outcomes. Univariate and multivariate analyses were performed to identify factors associated with blood pressure improvement at the last follow-up.

Results: During the 6-year period, 129 patients (179 renal arteries) underwent stent placement for RVH. Procedural complications occurred nine patients (7.0%). Average length follow-up was 1.5 years. Follow-up data were obtained in 122 patients (95%). At last follow-up, there were significant improvements in systolic blood pressure (161 vs 144 mm Hg, P < .001), diastolic blood pressure (80 vs 73 mm Hg, P < .001), and number of antihypertensive medications (3.1 vs 2.8, P = .034). The eGFR was improved in 16% of patients, stable in 60%, and worse in 24%. By multivariate analysis, a baseline eGFR <40 mL/min/1.73 m2 (odds ratio, 1.6; 95% confidence interval [CI], 1.0-2.9; P = .02) and female gender (OR, 1.3; 95% CI, 1.0-2.1; P = .04) were independent predictors of failure to achieve blood pressure improvement. By 2 and 4 years of follow-up, sustained blood pressure improvement was present in 67% of patients with a baseline eGFR of > or = 40 mL/min/1.73 m2 and in 31% of patients with a baseline eGFR <40 mL/min/1.73 m2. During 2 years of follow-up, survival was similar between patients with sustained blood pressure response and those without.

Conclusion: Patients treated for RVH who have a baseline eGFR of > or = 40 mL/min/1.73 m2 demonstrate a better response to RAS at each follow-up interval, with a significant difference at 2 to 4 years, compared with patients with an eGFR <40 mL/min/1.73 m2.