Assessment of hemodynamic significance of renal artery stenoses in endovascular treatment of resistant vasorenal arterial hypertension

Objective . To determine the significance of renal artery stenosis according to different methods of assessing the functional significance of stenosis and to evaluate the safety and efficacy of stenting of unilateral renal artery stenosis after 6 months and 1 year according to office BP and ABPM. Materials and methods. The study included 44 patients with resistant arterial hypertension and renal artery stenosis (mean age 69 ± 11 years), while receiving multicomponent antihypertensive therapy, including diuretic. After assessing the degree of RA stenosis according to selective angiography and additional methods of assessing the functional significance of RA stenosis (iFR, Pd/Pa, translesional gradient and FFR) the patients underwent RA stenting. The safety of the procedure was assessed by creatinine and glomerular filtration rate dynamics (MDRD equation). The effectiveness of the procedure was study according to office blood pressure (BP) and ambulatory BP monitoring (ABPM). Results. According to the results of angiography, the patients were divided into two groups: group A – patients with subtotal PA stenosis (> 90%) and group B – patients with moderate stenosis (60-90%), who underwent additional assessment of the functional significance of stenosis. The immediate angiographic result in both groups was optimal (the degree of residual stenosis was less than 5%). In group B, after stent implantation in the PA, there was a decrease of the translesional gradient by 38 ± 10 mm Hg (p < 0,0001), FFR > 0,8(p < 0.0001). iFR > 0.89, Pd/Pa>0.9 (p = 0,093). In both groups, there was a significantly significant reduction in arterial blood pressure at distant times, according to clinical BP measurement and ABPM. Conclusion. The measurement of such parameters as translesional gradient and fractional reserve is the most reliable in assessing the hemodynamic significance of PA stenosis in comparison with iFR and Pd/Pa measurements in patients with moderate PA stenosis. PA stenting in patients with uncontrolled resistant AH and severe renal artery lesions, as well as moderate stenosis confirmed by additional methods of stenosis functional significance assessment is reasonable to consider in order to enhance the antihypertensive effect.