Risk factors for ischemic antiphospholipid syndrome: a case-control study

Abstract Objective The objective of this study was to identify clinical and laboratory risk factors for ischemic stroke (IS) in primary antiphospholipid syndrome (APS) patients. Materials and Methods We performed a case-control study with consecutive primary APS patients divided into two groups, those who presented with IS, vs. those with no history of stroke. Demographics, vascular risk factors, therapeutic approaches, laboratory, imaging and functional outcomes were recorded. Results Fifty-three confirmed primary APS patients with IS and sixty-six non-stroke primary APS controls were recruited. Most patients were female (65.5%), with a median age of 33 years. The main vascular risk factors for primary APS-associated stroke were hypertension (11.3%), diabetes (11.3%) and hypercholesterolemia (9.4%). Among patients with stroke, median NIHSS score was 6; 15.1% of these patients presented a recurrent stroke, and 88.8% had a good functional outcome at the final follow-up. Positive lupus anticoagulant (OR = 6.1, 95%CI 2.7-13.5), anti-β2 glycoprotein IgG (OR = 3.6, 95%CI 1.7-7.9), and anticardiolipin IgG (OR = 2.8, 95%CI 1.3-5.9) were more prevalent in non-stroke primary APS, with a triple-positive antibody presence in 46.4% of controls vs. 22.2% of patients with stroke (OR = 3.0, 95%CI 1.3-6.7). At the time of the index event (arterial or venous), 14 known primary APS patients were using vitamin K antagonists, but only 35.7% of them had achieved therapeutic INR. Conclusion Patients with primary APS and IS have similar vascular risk factors and lower antibody positivity than those with extracranial thrombosis.