A Restrospective Review Of Thrombophilia Evaluation At a Single Academic Institution

There is no consensus exists regarding which patients should be evaluated for thrombophilia. Also there is no clear role for hypercoagulobility screening (HS) in patients with unprovoked thrombosis. However if decision to test is made there are disorders that may significantly increase the risk for recurrent thrombosis. An important application of this knowledge is a possible change in the length of anticoagulation. Nevertheless reports from investigators in Europe indicated that few institutions adhere to evidence based testing.

We conducted a retrospective review of tests used in our institution by different services to investigate for hypercoagulobility in 100 consecutive patients with acute pulmonary embolism (PE) between 2008 and 2012. Age, provoking factors and recurrence, thrombophilia tests and its timing in respect to acute thrombosis and anticoagulation were reviewed. The source of data was an electronic medical record system used by all providers in our institution.

Of 100 cases 50 had provoking factors and 30 of them had HS. Of 50 patients with unprovoked PE 16 had no HS and 2 of them had recurrent PE. There was no consistent pattern in ordering HS, neither in regards of time from acute thrombosis nor panel components. 26 patients had protein C and S testing and 28 had antithrombin (AT) done at the time of the diagnosis of an acute PE. In nearly all cases these tests were not repeated later. While screening for antiphospholipid antibodies syndrome (APLAS) 34 patients were tested for lupus anticoagulant, 32 for anticardiolipin antibodies (ACA) and 24 for anti-beta2-glycoprotein antibodies. Only 12 patients had tests for all three groups of antiphospholipid antibodies. Notably all patients tested for ACA had IgM, IgG and IgA measured, even though IgA is not included in Sapporo criteria. In 2 cases when one of these antibodies was positive the test was not repeated 12 weeks later. Regarding common inherited thrombophilias 52 patients underwent both factor V Leiden and prothrombin G20210 mutations screens. Only 20 of them had prior evaluation for activated protein C resistance. The least relevant tests, such as homocysteine level, PAI-1, factor VIII and vWF were performed in 24, 4, 14 and 4 cases, respectively. Interestingly, out of 18 patients tested for MTHFR mutations only 12 had prior homocysteine measurement and 4 cases were reflected to MTHFR screening with normal homocysteine level.

In conclusion our review revealed significant variability in HS that appeared to be greater if tests were ordered by non hematology providers. Although there are no universally accepted guidelines for HS most high risk thrombophilias are well recognized and should be screened for appropriately. Our results are similar to those reported by investigators in Europe. The problem of HS variability and poor efficacy will persist as long as guidelines are not available. Our institution is planning to improve quality of service by creating a battery of tests that will be available to all services when decision to screen is made.