Prothrombotic Factors Have Significant Association with Arterial and Venous Strokes in Indian Tamilians

Abstract

Background: Prothrombotic factors have been correlated with vascular events in young patients, with recurrent strokes, and with venous thromboembolisms. However, their prevalence in adult strokes, in healthy populations, and in specific ethnic groups is not well defined. We investigated the association of prothrombotic factors with strokes in a South Indian Tamil population. Methods: In this hospital-based cross-sectional study, plasma homocysteine (Hcys), protein C and protein S activity levels, activated protein C resistance (APCR) as a surrogate for factor V Leiden (FVL), fibrinogen, and antithrombin III (ATIII) were determined from 75 consecutive patients with ischemic stroke (IS), 25 with cortical venous thrombosis (CVT), and 75 healthy control participants. The Student t test or Mann-Whitney U test was used for comparing prothrombotic factor levels between the stroke and control groups. The χ2 or Fisher exact test was used for comparisons of proportions of thrombophilia and estimation of odds ratios. Mid-P correction was done for multiple estimations. Results: Hcys levels in patients with IS were significantly higher compared with those in healthy control participants (P = 0.02). Proportions of ATIII deficiency and hyperfibrinogenemia were significantly higher in the IS group, and no healthy control participants had hyperfibrinogenemia. Protein C deficiency was more frequent in those with IS (17%; P < 8 × 10-5) and CVT (P < 10-7) compared with healthy control participants, and protein C activity levels (P = 0.016) were also significantly lower in patients with CVT. Other parameters had no significant associations with IS and CVT. The frequency of protein S deficiency was high in healthy control participants (60%) and in both patients with IS (45%; P = 0.1) and patients with CVT (48%; P = 0.4). No patients or control participants had abnormal APCR. Conclusions: In Tamilian participants, several prothrombotic factors were associated with IS. Protein C deficiency alone was associated with CVT. Replication of the pattern in genetically linked populations around the world may affect management of stroke in those populations.