Prediction of Hypertension Improvement After Stenting of Renal Artery Stenosis: Comparative Accuracy of Translesional Pressure Gradients, Intravascular Ultrasound, and Angiography

Abstract

We investigated the comparative accuracy of renal translesional pressure gradients (TPG), intravascular ultrasound (IVUS), and angiographic parameters in predicting hypertension improvement after stenting of renal artery stenosis (RAS). The degree of RAS that justifies stenting is unknown. In 62 patients with RAS, TPG (resting and hyperemic systolic gradient [HSG], fractional flow reserve, and mean gradient) were measured by a pressure guidewire; IVUS and angiographic parameters (minimum lumen area and diameter, area stenosis, and diameter stenosis) were measured by quantitative analyses. The HSG had a larger area under the curve than most other parameters and an HSG >or=21 mm Hg had the highest sensitivity, specificity, and accuracy (82%, 84%, and 84%, respectively) in predicting hypertension improvement after stenting of RAS. The average IVUS area stenosis was markedly greater in RAS with an HSG >or=21 mm Hg versus <21 mm Hg (78% vs. 38%, respectively; p < 0.001). After stenting, hypertension improved in 84% of patients with an HSG >or=21 mm Hg (n = 36) versus 36% of patients with an HSG <21 mm Hg (n = 26) at 12 months, p < 0.01; the number of antihypertensive medications was significantly lower in patients with an HSG >or=21 mm Hg versus <21 mm Hg (2.30 +/- 0.90 vs. 3.40 +/- 0.50, respectively; p < 0.01). By multivariable analysis, HSG was the only independent predictor of hypertension improvement (odds ratio: 1.39; 95% confidence interval: 1.05 to 1.65; p = 0.013). An HSG >or=21 mm Hg provided the highest accuracy in predicting hypertension improvement after stenting of RAS, suggesting that an HSG >or=21 mm Hg is indicative of significant RAS.