Clinical Impact of Thrombophilia Screening in Young Adults with Ischemic Stroke

Abstract

Objective: We evaluated the ability of genetic and serological testing to diagnose clinically relevant thrombophilias in young adults with ischemic stroke.

Methods: We performed a retrospective cohort study of patients aged 18-65 years diagnosed with acute ischemic stroke at a comprehensive stroke center between 2011 and 2015 with laboratory testing for thrombophilia. The primary outcome was any positive thrombophilia screening test. The secondary outcome was a change in clinical management based on thrombophilia testing results. Logistic regression was used to assess whether the prespecified risk factors of age, sex, prior venous thromboembolism, family history of stroke, stroke subtype, and presence of patent foramen ovale were associated with outcomes.

Results: Among 196 young ischemic stroke patients, at least 1 positive thrombophilia test was identified in 85 patients (43%; 95% CI, 36%-51%) and 16 (8%; 95% CI, 5%-13%) had a resultant change in management. Among 111 patients with cryptogenic strokes, 49 (44%) had an abnormal thrombophilia test and 9 (8%) had a change in management. After excluding cases of isolated hyperhomocysteinemia or methylenetetrahydrofolate reductase or Factor V Leiden gene mutation heterozygosity, the proportion of patients with an abnormal thrombophilia screen decreased to 24%. Prespecified risk factors were not significantly associated with positive thrombophilia testing or a change in management.

Conclusions: Two-of-five young patients with ischemic stroke who underwent thrombophilia screening at our institution had at least 1 positive test but only one-in-twelve had a resultant change in clinical management. Neither cryptogenic stroke subtype nor other studied clinical factors were associated with a prothrombotic state.

Keywords: Ischemic stroke; hypercoagulable state; stroke in the young; thrombophilia.

Figure 1. Yield of Thrombophilia Testing in Young Adults with Ischemic Stroke.

Proportions represent the number of patients with a positive screening result (numerator) over the number of patients who underwent the specific screening test (denominator). MTHFR indicates Methylenetetrahydrofolate Reductase gene.

Figure 2. Percentage of Patients with a Change in Management due to an Abnormal Thrombophilia Screen.

Proportions represent the number of patients with a change in clinical management due to the results of the thrombophilia screening test (numerator) over the number of patients with that positive test result (denominator). Numbers do not sum to group total, as some patients had more than one positive screening test leading to a change in management. MTHFR indicates Methylenetetrahydrofolate Reductase gene.