Fractional Flow Reserve-Guided Renal Artery Stenting in Renovascular Hypertension: 1-Year Results of the FAIR Study

Whether fractional flow reserve (FFR)-guided revascularization improves outcomes in atherosclerotic renal artery stenosis (ARAS) remains uncertain.

This study will evaluate whether the benefit of FFR-guided stenting sustained at 1 year including renal outcomes.

FAIR pilot is an investigator-initiated, multicentre, open-label trial with blinded endpoint adjudication. Adults with ARAS were randomized 1:1 to FFR-guided vs angiography-guided groups. Stenting was performed in the FFR-guided group when FFR <0.80, and it was performed for all in the angiography-guided group regardless of FFR. The percentage changes in ambulatory daytime mean systolic blood pressure (DMSBP), composite index of antihypertensive medicines (CIAHM), and renal outcomes were analyzed for 1 year.

Among all 107 randomized patients, 1-year follow-up was achieved in 50 (93%) in the FFR-guided group and 51 (96%) in the angiography-guided group. At 1 year, DMSBP, CIAHM, and renal outcomes were similar between the groups, while stenting rate was lower with FFR guidance (46% vs 100%, P < 0.01). Patients with FFR <0.80 who underwent stenting experienced the greatest blood pressure reductions (median [IQR] ΔDMSBP: 13 [4, 21] mm Hg at 3 months; 8 [3, 16] mm Hg at 6 months, 7 [0, 16] mm Hg at 12 months; all paired P < 0.05) and sustained declines in CIAHM (2 [0, 5] at 3, 6, and 12 months; all paired P < 0.05). Significant 12-month estimated glomerular filtration rate improvement after stenting was only observed when FFR <0.80, with greater percentage eGFR improvement under quantile regression analysis.

At the 1-year follow-up, FFR-guided renal artery stenting reduced stent use without loss of blood pressure control or renal safety compared with angiography guidance.