SP300
LONG-TERM CLINICAL OUTCOMES IN ATHEROSCLEROTIC RENOVASCULAR DISEASE: A SINGLE-CENTER OBSERVATIONAL STUDY

Introduction and Aims: Although recent large trials have shown that revascularization does not confer additional benefit to optimal medical therapy in patients with atherosclerotic renovascular disease (ARVD), there is evidence that it may improve clinical outcomes in a subgroup of patients who present with specific ‘high-risk’ clinical features: uncontrolled hypertension, rapidly declining renal function or flash pulmonary oedema. To date, accurate identification of these individuals and timely referral for revascularization remain difficult. We aimed to characterize the phenotype and risk factors of patients who reach clinical end-points and to assess the affect of revascularization.

Methods: Prospective data collection on patients with ARVD referred to our tertiary renal center started in 1986. Date of diagnostic imaging was considered time zero. Clinical end-points included data of death, date of reaching end-stage kidney disease (ESKD) or starting renal replacement therapy (RRT), date of first cardiovascular event (CVE) and the first of any of these events. Baseline characteristics of patients who reached these clinical end-points were compared to those who did not, using Chi-squared or Mann-Whitney U tests. Univariate and multivariate Cox models were constructed to determine hazard ratios (HR) for all four end-points, both in the whole group and in a selected sub-group representing potential candidates for revascularization (age &lt 85 years; angiographic diameter stenosis of at least 65% but less than 100% unilaterally or bilaterally).

Results: The median age for the whole group was 71.1 years (IQR 64.7-76.7). Over a median follow-up of 54.9 months (IQR 20.2-96.2), 73.5% patients died, 20.3% reached ESKD, 36.6% suffered a CVE while 81.4% experienced any of these events in the whole group. Multivariate analysis of the whole group showed that macrovascular disease (MVD), congestive heart failure (CHF), flash pulmonary oedema (FPE), impaired renal function and higher degrees of proteinuria at baseline were associated with increased risk for all four end-points. Statin use at baseline was associated with reduced risk for death (HR=0.78, p=0.0009) but not CVE, and other vasculoprotective therapies had no impact on outcomes. Revascularization was significantly associated with reduced risk of death (HR 0.71, p=0.006) and ESKD (HR=0.68, p=0.003). In the selected sub-group, the effect of revascularization was not evident whereas higher proteinuria at baseline was strongly associated with increased risk for all end-points (Death: HR 1.23, p=0.014; ESKD: HR 1.28, p=0.003; CVE: HR 1.32, p&lt0.0005; Any: HR 1.30, p=0.001).

Conclusions: Patients with ARVD are enriched with cardiovascular risk factors, hence as expected, adverse events are closely linked to co-existing cardiac comorbidities, impaired renal function and increased proteinuria at baseline. However, in a selected sub-group of patients with more haemodynamically-relevant stenosis, our results highlight the overriding importance of intra-parenchymal injury, manifest by proteinuria, in determining clinical outcomes. Selection bias and the lack of longitudinal drug administration data may affect interpretation of the effect of revascularization and vasculoprotective therapy on long-term clinical outcomes. Further studies are required to help characterize the sub-group of patients who may respond to revascularization.