Literature review of apixaban or dabigatran for probable acute HIT (including new patients reported in this article): primary or secondary treatment (groups A1, A2, and B)
| Study author . | Reference . | No. of patients . | Group . | Median platelet count at DOAC start . | HIT-associated thrombosis* . | Outcome . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thrombosis . | Bleed . | |||||||||||
| A1 . | A2 . | B . | No. . | % . | No. . | % . | No. . | % . | ||||
| Apixaban | ||||||||||||
| Sharifi et al† | 30 | 5 | 0 | 0 | 5 | 90‡ | 1 | 0 | 0 | |||
| Larsen et al | 37 | 1 | 1 | 0 | 0 | 112 | 0 | 0 | 0 | |||
| Delgado-García et al§ | 38, 39 | 1 | 1 | 0 | 0 | 25 | 1 | 0 | 0 | |||
| Kunk et al | 40 | 5 | 0 | 0 | 5 | 111 | 3 | 0 | 0 | |||
| Total | 12 | 2 | 0 | 10 | 90‡ | 5/12|| | 41.7 | 0/12 | 0 | 0/12 | 0 | |
| Dabigatran | ||||||||||||
| Sharifi et al† | 30 | 6 | 0 | 0 | 6 | 90‡ | 2 | 0 | 0 | |||
| Anniccherico et al | 41, 42 | 1 | 0 | 0 | 1 | 120 | 1 | 0 | 0 | |||
| Mirdamadi§ | 43 | 1 | 1 | 0 | 0 | 32 | 1 | 0 | 0 | |||
| Tardy-Poncet et al | 44 | 1 | 0 | 0 | 1 | 56 | 0 | 0 | 0 | |||
| Noel et al | 45 | 1 | 0 | 1 | 0 | 216 | 1 | 1¶ | 0 | |||
| Bircan and Alanoglu§ | 46 | 1 | 1 | 0 | 0 | 52 | 1 | 0 | 0 | |||
| Total | 11 | 2 | 1 | 8 | 58 | 6/11|| | 54.5 | 1/11 | 9.1 | 0/11 | 0 | |
| Study author . | Reference . | No. of patients . | Group . | Median platelet count at DOAC start . | HIT-associated thrombosis* . | Outcome . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thrombosis . | Bleed . | |||||||||||
| A1 . | A2 . | B . | No. . | % . | No. . | % . | No. . | % . | ||||
| Apixaban | ||||||||||||
| Sharifi et al† | 30 | 5 | 0 | 0 | 5 | 90‡ | 1 | 0 | 0 | |||
| Larsen et al | 37 | 1 | 1 | 0 | 0 | 112 | 0 | 0 | 0 | |||
| Delgado-García et al§ | 38, 39 | 1 | 1 | 0 | 0 | 25 | 1 | 0 | 0 | |||
| Kunk et al | 40 | 5 | 0 | 0 | 5 | 111 | 3 | 0 | 0 | |||
| Total | 12 | 2 | 0 | 10 | 90‡ | 5/12|| | 41.7 | 0/12 | 0 | 0/12 | 0 | |
| Dabigatran | ||||||||||||
| Sharifi et al† | 30 | 6 | 0 | 0 | 6 | 90‡ | 2 | 0 | 0 | |||
| Anniccherico et al | 41, 42 | 1 | 0 | 0 | 1 | 120 | 1 | 0 | 0 | |||
| Mirdamadi§ | 43 | 1 | 1 | 0 | 0 | 32 | 1 | 0 | 0 | |||
| Tardy-Poncet et al | 44 | 1 | 0 | 0 | 1 | 56 | 0 | 0 | 0 | |||
| Noel et al | 45 | 1 | 0 | 1 | 0 | 216 | 1 | 1¶ | 0 | |||
| Bircan and Alanoglu§ | 46 | 1 | 1 | 0 | 0 | 52 | 1 | 0 | 0 | |||
| Total | 11 | 2 | 1 | 8 | 58 | 6/11|| | 54.5 | 1/11 | 9.1 | 0/11 | 0 | |
Information on clinical setting was available for 12 patients (ie, all but 11 patients from 1 of the studies30 ): post–cardiac surgery/post–vascular surgery (n = 1), treatment of venous thromboembolism (n = 5), post–orthopedic surgery (n = 3), hemodialysis (n = 1), medical thromboprophylaxis (n = 1), and periprocedural thromboprophylaxis (n = 1). No patients had limb amputation.
Thrombus that occurred in association with HIT, not thrombosis present before HIT.
Aggregate data only, rather than data for individual patients presented in this article.
Platelet count at start of DOAC estimated to be 90 (Mohsen Sharifi, Arizona Cardiovascular Consultants & Vein Clinic and A.T. Still University, e-mail, 5 February 2017).
No laboratory testing for HIT antibodies was available; however, the patient was included because sufficient clinical information was provided to make a diagnosis of HIT (with associated HIT-related thrombosis) highly probable.
Most of the HIT-associated thrombotic events were venous (predominantly DVT and PE); however, 1 patient had HIT-associated non-ST-elevation myocardial infarction.45
Patient with essential thrombocythemia developed HIT with platelet count fall from 750 to 216 × 109/L; dabigatran was given for atrial fibrillation, as the clinicians initially deemed HIT to be unlikely; however, signs of stroke became evident shortly thereafter with computed tomography imaging confirming multiple cerebral infarcts; when the serotonin-release assay returned positive for HIT antibodies, dabigatran was switched to lepirudin.