IgG Anticardiolipin Antibody Titer >40 GPL and the Risk of Subsequent Thrombo-occlusive Events and Death

Abstract

Background Anticardiolipin antibodies (aCL) have been associated with an increased risk of stroke and thrombo-occlusive events. Little is known about the influence of aCL on recurrent thrombo-occlusive events. Methods Consecutively identified patients (n=132) with focal cerebral ischemia [stroke=112, transient ischemic attack (TIA)=20] harboring aCL of at least 10 GPL units at the time of their index event were prospectively followed to estimate the effect of aCL titer on time to and risk of subsequent thrombo-occlusive events (stroke, TIA, deep venous thrombosis, pulmonary embolism, myocardial infarction) and death. On the basis of prior literature, we divided patients into those with aCL ≤40 GPL (n=111; mean age, 63±14 years; mean follow-up, 1.95 years) and those with aCL >40 GPL (n=21; mean age, 54±20 years; mean follow-up, 1.50 years). Results There was no difference between groups for prevalence of hypertension, diabetes mellitus, cigarette smoking, atrial fibrillation, prior TIA, or sex. The GPL >40 group was younger (54±20 versus 63±14 years; P =.055), had more prior strokes [9/21 (48%) versus 27/111 (20%); P =.030], more frequent subsequent thrombo-occlusive events and death [15/21 (71%) versus 51/111 (48%); P =.030], and a shorter median time (years) to event (0.15 versus 0.61, log rank P =.005). The risk ratio for recurrent event and death with GPL >40 obtained from Cox proportional hazards models, adjusted for prior strokes, prior TIAs, hypertension, diabetes mellitus, atrial fibrillation, and cigarette smoking was 1.9 (95% confidence interval, 1.0 to 3.5; P =.051). Conclusions Our data suggest that subsequent thrombo-occlusive events and death after focal cerebral ischemia associated with IgG aCL may occur sooner and more frequently with GPL >40.