Background Unlike antiphospholipid antibody (aPL) profile or arterial hypertension and hypercholesterolemia, age has not been identified as a risk factor for thrombosis by previous scores and studies on antiphospholipid syndrome (APS).1-3 However, age increases the thrombotic risk of patients in other settings (i.e. atrial fibrillation).4
Objectives To investigate the impact of multiple factors including the age on the risk of thrombosis in aPL carriers.
Methods Retrospective study of a historical cohort of patients with medium-high titres of aPL according to current recommendations on APS, recruited in the outpatient clinic of a tertiary care hospital. Association between occurrence of thrombosis and several variables such as age, gender, arterial hypertension, hypercholesterolemia, diabetes mellitus, tobacco use, oral contraceptive therapy, mean platelet volume, lupus anticoagulant (LA), anticardiolipin antibodies (aCL), anti-β2-glycoprotein I antibodies, APS score and Global APS score was assessed by univariate analysis followed by multivariate logistic regression. Diagnostic accuracy of the independent variables was evaluated by receiver operating characteristic (ROC) curve analysis.
Results Fifty patients (38 women, 12 men; baseline age 49±18 years), of which 27 fulfilled definite classification criteria for APS (18 primary APS, 9 secondary APS), were followed for 4.95±5.48 years. At baseline, 26 patients had ≥1 cardiovascular risk factors (15 tobacco use, 13 arterial hypertension, 8 hypercholesterolemia and 4 diabetes mellitus). Twenty-three patients developed 27 thrombotic events (14 in venous bed, 13 in arterial bed) including 4 thrombotic recurrences. Compared with patients without thrombosis, patients with thrombosis were older (57±18 vs 42±14 years, p<0.01), had more frequently ≥1 cardiovascular risk factors (17/23 vs 9/27, p<0.01) and were more frequently positive to LA+aCL (9/23 vs 4/27, p=0.05). The logistic regression model confirmed the age (OR=1.05, 95%CI=1.01-1.10, p=0.02), the cardiovascular risk factors (OR=4.61, 95%CI=1.10-19.32, p=0.03) and the double positivity to LA+aCL (OR=7.71, 95%CI=1.19-49.80, p=0.03) as independent predictors of thrombosis. For this set of three variables, the area under the ROC value was 0.85 (graph).
Conclusions As with traditional cardiovascular risk factors and coexistence of LA+aCL, advanced age is also associated with a higher risk of thrombosis in aPL carriers. The type and intensity of thromboprophylaxis should be based on a thorough risk-benefit balance, especially in the elderly patients.
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Disclosure of Interest None declared