Introduction: Background: Previous studies showed that ankle-brachial index (ABI) is a marker of peripheral atherosclerosis in general population. Therefore, the majority of the guidelines included the measurement of ABI in the assessment of global cardiovascular risk. There are few studies regarding ABI in patients with antiphospholipid syndrome (APLS), a special clinical condition known to be associated with an increased cardiovascular risk. Objectives: The aim of this study was to evaluate the clinical and laboratory predictors of an abnormal ABI in patients with APLS. Methods: In 106 patients with APLS (primary and secondary) we performed the evaluation of the ABI according to standard recommendations. Traditional cardiovascular risk factors and a large spectrum of antiphospholipid antibodies (including the antiphosphatidylserine, antiphosphatidylethanolamine and antiprothrombine antibodies) were assessed. We divided the study group in two subgroups: A – patients with an abnormal ABI (defined by a value below 0.9); and B -patients with normal ABI. Results: 30 pts (28.3%) had a low ABI. Age (51.1 ± 13.2
in subgroup A vs 42.1 ± 11.0 yo in subgroup B, p = 0.001), arterial hypertension (63.3 vs 32.8%, p = 0.008), diabetes (23.3 vs 6.5%, p = 0.02), pulse pressure (53.8 ± 12.3 vs 48.6 ± 9.8 mmHg, p = 0.02), fasting glucose (95.2 ± 17.5 vs 84.6 ± 15.9 mg/dl, p = 0.004) and values of HDL-cholesterol in men (43.1 ± 7.9 vs 58.4 ± 10.1, p = 0.01) were associated with an abnormal ABI. Antibeta 2-glycoprotein I IgG antibodies [4.00 (1.00-79.00) vs 3.00 (0.00-29.00), p = 0.02] and anti-prothrombin IgM antibodies [4.50 (0.00-82.00) vs 3.00 (0.00-14.00), p = 0.05] were found to have higher values in patients with abnormal ABI. In multivariate analysis, only the titer of anti-beta 2-glycoprotein I IgG was significantly associated with an abnormal ABI (p = 0.04).
Conclusions: We found a high prevalence of an abnormal ABI in patients with APLS. The traditional cardiovascular risk factors are associated with peripheral atherosclerosis in these patients. However, only the titer of anti-beta 2-glycoprotein I IgG was independently associated with a low ABI in patients with APLS, reflecting the role of disease itself in the pathogenesis of atherosclerosis.