An Audit of Thrombophilia Testing in Patients with Ischemic Stroke or Transient Ischemic Attack: The Futility of Testing

Objectives

Many patients admitted with an ischemic stroke or transient ischemic attack (TIA) undergo thrombophilia testing. There is limited evidence to support this practice. We examined the effect of thrombophilia testing on management of patients admitted with an ischemic stroke or TIA.

Materials and Methods

In this retrospective observational single-center study, we identified patients who were admitted with stroke or TIA and underwent thrombophilia testing over a 45-month period. We reviewed their electronic medical records to assess whether testing affected clinical management, defined as anticoagulation treatment by the time of discharge due to a positive test result. Secondary endpoints included potential misdiagnosis due to false positive results and cost of testing.

Results

Testing was performed in 143 patients with a stroke or TIA. Forty-four patients (31%) had at least 1 positive test result. The most common positive tests were an elevated factor VIII activity (18% of patients tested) and decreased protein S activity (11% of patients tested). Both of these tests are subject to acute phase effects. Testing altered clinical management in only 1 patient (1% of total patients tested). Thirty-three patients (75%) have the potential for carrying a misdiagnosis due to a positive test that was never repeated for confirmation or repeated too soon after the initial positive test. The annual cost of testing was approximately $62,000.

Conclusions

Thrombophilia testing in the acute inpatient setting rarely impacted the clinical management of patients admitted with a stroke or TIA. By avoiding thrombophilia testing, both the potential for misdiagnosis and health care costs can be reduced. Therefore, we have discontinued thrombophilia testing in in-patients with a diagnosis of stroke.