Renal artery stenosis in hypertensive patients with antiphospholipid (Hughes) syndrome: outcome following anticoagulation

Objective. We have demonstrated a point prevalence of 26% renal artery stenosis in patients with antiphospholipid syndrome (APS) and uncontrolled hypertension. We describe the effect of anticoagulation on blood pressure control and renal function.Methods. We studied 23 patients retrospectively with renal artery stenosis (RAS). Fourteen received oral anticoagulation for more than 1 yr (target International Normalized Ratio (INR) of 3.0–4.5). Five patients had primary APS. Patients were divided into two groups based on their INR (<3.0 and ≥3.0). Nine patients had repeat magnetic resonance angiography (MRA) or an angiogram of the renal arteries after 2 yr.Results. Only 8/14 patients managed to maintain their INR ≥3.0 (median INR 3.1, range 2.8–3.7) while six had a INR <3.0 (median INR 1.9, range 1.2–2.4). Patients with a median INR <3.0 had poorly controlled blood pressure and there was significant deterioration in mean serum creatinine values (Wilcoxon's test, P<0.03). Nine patients underwent follow-up renal artery imaging. Three of nine patients with an INR <3.0 (median INR 1.9) had re-stenosis and a fourth developed bilateral renal artery stenosis. Five patients with INR ≥3.0 (median INR 3.1) did not show re-stenosis of the renal arteries; their renal function was stable and blood pressure was well controlled. One other patient with secondary APS (mixed connective tissue disorder) with INR >3.0 showed recanalization of the stenosed renal artery.Conclusion. Anticoagulation with INR maintained ≥3.0 helped to control the blood pressure and prevent the progression of renal disease.