Abstract 2535: Diagnostic Accuracy of Renal Pressure Measurements to Assess the Significance of Renal Artery Stenosis: Comparison with Intravascular Ultrasound, Quantitative Angiography, and Duplex Ultrasound.
Background: Renal artery stenosis (RAS) remains a diagnostic and therapeutic dilemma. The physiological significance of RAS measured by a pressure guidewire has not been investigated.
Methods: In 51 RAS (40 patients), duplex ultrasound, quantitative renal angiography (QRA), and intravascular ultrasound (IVUS) were performed. Hyperemic systolic pressure gradient (HSPG) was measured by a pressure guidewire after intrarenal injection of papaverine.
Results: Strong correlations were found comparing HSPG with IVUS minimum lumen area (MLA) and area stenosis (r = 0.73 and r = 0.67, respectively; p <0.0001). The correlations comparing HSPG with minimum lumen diameter (MLD) by QRA and duplex ultrasound were poor. The diagnostic accuracy of HSPG compared with IVUS MLA and area stenosis was the highest when HSPG was >20 mm Hg (sensitivity, 100%; specificity, 100%; and predictive accuracy, 100%). The mean IVUS area stenosis and MLA, in RAS with an HSPG >20 mm Hg compared with an HSPG ≤20 mm Hg, were 77% versus 35% and 4.82 mm2 versus 14.0 mm2, respectively; P<0.001. By QRA, the highest sensitivity and specificity between HSPG >20 mm Hg and MLD were 78% and 56%, respectively. By duplex ultrasound, the highest sensitivity and specificity between HSPG >20 mm Hg and peak systolic velocity were 65% and 53%, respectively.
Conclusion: An HSPG >20 mm Hg is indicative of significant RAS and is a more powerful predictor of significant RAS than QRA or duplex ultrasound. An HSPG >20 mm Hg, in patients with RAS, might lead to better patient selection for renal artery stenting than QRA or duplex ultrasound.