Abstract P165: Incident and Associated Factors of Restenosis After Percutaneous Transluminal Renal Angioplasty in Renovascular Hypertensive Patients

Background: Percutaneous transluminal renal angioplasty (PTRA) is one of the standard treatments for renal artery stenosis (RAS). Restenosis after PTRA may influence disease prognosis, but little is unknown about the frequency or its associated factors. Methods: This study included 174 renovascular hypertensive patients (mean age= 59.5 years; 33.9% women) who underwent PTRA and were followed more than 12 months after PTRA. Data collection including blood pressure (BP), intensity of antihypertensive medication, and duplex ultrasonography (DUS) was performed before and 3, 6, and 12 months after PTRA. Cure of hypertension was defines as a BP below 140/90mmHg without antihypertensive medication. Diagnosis of restenosis was based on DUS, by applying a renal aortic ratio >3.5 in conjunction with a renal artery peak systolic velocity > 250cm/s. Results: At 12 months after PTRA, BP (156±25/82±15 to 133±16/75±13mmHg) as well as antihypertensive medications (2.5±1.2 to 2.1±1.3 types) decreased significantly (p<0.01, respectively), and the incident of restenosis was 34 (19.5%). Compared with patients without restenosis, baseline clinical characteristics in those with restenosis showed significantly younger (46.1±23.6 vs 62.8±16.3 years), higher prevalence of female (50.0 vs 30.0%), fibromuscular dysplasia (FMD) diagnosed by angiography (58.8 vs 23.6%), and balloon PTRA without stenting (44.1 vs 18.6%), and lower numbers of antiplatelet and/or anticoagulant agents administrated after PTRA (1.3±0.6 vs 1.7±0.6 types of drug) (p<0.05, respectively). Compared with atherosclerotic RAS patients (n=121), the rates of cured (25.9 vs 9.0%) and the cumulative incident rates of restenosis at 3 (20.8 vs 0 %), 6 (35.9 vs 6.6%), and 12 (37.7 vs 11.6%) months after PTRA were significantly higher in FMD (p<0.01, respectively). FMD without restenosis showed a significantly greater decrease in systolic BP than that with (159±21 to 131±17 vs 154±28 to 141±25 mmHg, p<0.05), whereas no significant difference was found in atherosclerotic RAS. Conclusions: Incident of restenosis after PTRA was higher in FMD than in atherosclerotic, and its incident pattern seemed to be different by causes. Especially for FMD, assessment of restenosis is important for treatment success.