Treatment and prevention of heparin-induced thrombocytopenia: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.
BACKGROUND
Heparin-induced thrombocytopenia (HIT) is an antibody-mediated adverse drug reaction that can lead to devastating thromboembolic complications, including pulmonary embolism, ischemic limb necrosis necessitating limb amputation, acute myocardial infarction, and stroke.


METHODS
The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.


RESULTS
Among the key recommendations for this article are the following: For patients receiving heparin in whom clinicians consider the risk of HIT to be > 1%, we suggest that platelet count monitoring be performed every 2 or 3 days from day 4 to day 14 (or until heparin is stopped, whichever occurs first) (Grade 2C). For patients receiving heparin in whom clinicians consider the risk of HIT to be < 1%, we suggest that platelet counts not be monitored (Grade 2C). In patients with HIT with thrombosis (HITT) or isolated HIT who have normal renal function, we suggest the use of argatroban or lepirudin or danaparoid over other nonheparin anticoagulants (Grade 2C). In patients with HITT and renal insufficiency, we suggest the use of argatroban over other nonheparin anticoagulants (Grade 2C). In patients with acute HIT or subacute HIT who require urgent cardiac surgery, we suggest the use of bivalirudin over other nonheparin anticoagulants or heparin plus antiplatelet agents (Grade 2C).


CONCLUSIONS
Further studies evaluating the role of fondaparinux and the new oral anticoagulants in the treatment of HIT are needed.
Department of Medicine, McMaster University, Hamilton, ON, Canada. Electronic address: linkinla@mcmaster.ca.
Lori-Ann
LA
Linkins
College of Medicine, University of the Philippines Manila, Manila, Philippines.
Antonio L
AL
Dans
The Uniformed Services, University of Health Sciences, Bethesda, MD.
Lisa K
LK
Moores
School of Medicine, Quinnipiac University, North Haven, CT.
Robert
R
Bona
University of Washington School of Medicine, Seattle, WA.
Bruce L
BL
Davidson
Department of Medicine, McMaster University, Hamilton, ON, Canada.
Sam
S
Schulman
Department of Medicine, McMaster University, Hamilton, ON, Canada.
Mark
M
Crowther
D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D019317:Evidence-Based Medicine; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D006493:Heparin / Q000009:adverse effects* / Q000627:therapeutic use*; D006801:Humans; D019934:International Normalized Ratio; D010976:Platelet Count; D012307:Risk Factors; D012955:Societies, Medical; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis / Q000188:drug therapy*; D013923:Thromboembolism / Q000097:blood / Q000139:chemically induced / Q000628:therapy; D013927:Thrombosis / Q000097:blood / Q000188:drug therapy*; D014481:United States; D014812:Vitamin K / Q000037:antagonists & inhibitors
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D014812:Vitamin K; D006493:Heparin