Prognostic value of renal fractional fl ow reserve in blood pressure response after renal artery stenting (PREFER study)

Abstrakt

Background: The aim of our study was to determine a potential relationship between resting translesional pressures ratio (Pd/Pa ratio), renal fractional fl ow reserve (rFFR) and blood pressure response after renal artery stenting.

Methods: Thirty fi ve hypertensive patients (49% males, mean age 64 years) with at least 60% stenosis in angiography, underwent renal artery stenting. Translesional systolic pressure gradient (TSPG), Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR — after intrarenal administration of papaverine — were measured before stent implantation. Ambulatory blood pressure measurements (ABPM) were recorded before the procedure and after 6 months. The ABPM results were presented as blood pressure changes in subgroups of patients with normal (≥ 0.9) vs. abnormal (< 0.9) Pd/Pa ratio and normal (≥ 0.8) vs. abnormal (< 0.8) rFFR.

Results: Median Pd/Pa ratio was 0.84 (interquartile range 0.79–0.91) and strongly correlated with TSPG (r = –0.89, p < 0.001), minimal lumen diameter (MLD; r = 0.53, p < 0.005) and diameter stenosis (DS; r = –0.51, p < 0.005). Median rFFR was 0.78 (0.72–0.82). Similarly, signifi cant correlation between rFFR and TSPG (r = –0.86, p < 0.0001), as well as with MLD (r = 0.50, p < 0.005) and DS (r = –0.51, p < 0.005) was observed. Procedural success was obtained in all patients. Baseline Pd/Pa ratio and rFFR did not predict hypertension response after renal artery stenting. Median changes of 24-h systolic/diastolic blood pressure were comparable in patients with abnormal vs. normal Pd/Pa ratio (–4/–3 vs. 0/2 mm Hg; p = NS) and with abnormal vs. normal rFFR (–2/–1 vs. –2/–0.5 mm Hg, respectively).

Conclusions: Physiological assessment of renal artery stenosis using Pd/Pa ratio and papaverine-induced renal fractional fl ow reserve did not predict hypertension response after renal artery stenting.