This Article Full Text Free Full Text (PDF) Free All Versions of this Article: chest.06-2109v1 131/6/1644    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Smythe, M. A. Articles by Mattson, J. C. Search for Related Content PubMed PubMed Citation Articles by Smythe, M. A. Articles by Mattson, J. C. Related Content Related Editorial

The Incidence of Recognized Heparin-Induced Thrombocytopenia in a Large, Tertiary Care Teaching Hospital^*

^* From the Department of Pharmaceutical Services (Drs. Smythe and Koerber), and the Division of Hematopathology (Dr. Mattson), Department of Clinical Pathology, William Beaumont Hospital, Royal Oak, MI.

Correspondence to: Maureen A. Smythe, PharmD, FCCP, Department of Pharmacy Practice, Suite 2190, Wayne State University, 259 Mack Ave, Detroit, MI 48201; e-mail: msmythe{at}beaumont.edu

Abstract

Background: Heparin-induced thrombocytopenia (HIT) is estimated to occur in up to 5% of patients receiving unfractionated heparin. The goal was to determine the incidence of HIT within our 1,061-bed tertiary care institution.

Methods: A retrospective review of three hospital database systems (ie, admission, pharmacy, and laboratory) was undertaken for a 1-year period ending in March 2004. The pharmacy database was queried to identify patients who received heparin and those who received a direct thrombin inhibitor (DTI). The medical records of patients receiving a DTI were reviewed to categorize the indication for DTI therapy. The laboratory system database was queried to retrieve heparin platelet factor 4 immunoassay results.

Results: A total of 58,814 patient admissions occurred with an estimated 24,068 patients being exposed to unfractionated heparin. DTI therapy was administered to 133 patients. Of these, 49 new HIT cases and 15 cases of suspected HIT (unconfirmed) were identified. The overall incidence of recognized new HIT was 0.2%. New HIT occurred in 0.76% of patients receiving therapeutic-dose IV heparin and in < 0.1% of patients receiving antithrombotic prophylaxis (subcutaneous heparin). Forty-nine percent of all new HIT cases were in coronary artery bypass and/or valve replacement surgery patients, while no cases were identified in hip/knee arthroplasty patients.

Conclusions: The incidence of recognized HIT in a large teaching institution was 0.2%, with a 0.76% incidence in those patients receiving therapeutic-dose IV heparin. The low incidence likely reflects a brief duration of heparin exposure for many patients. Approximately half of all new HIT cases were recognized in the cardiovascular surgery population.

Key Words: anticoagulation • heparin • heparin-induced thrombocytopenia • thrombosis

Related Editorial

Who Is (Still) Getting HIT?

Theodore E. Warkentin and John W. Eikelboom
Chest 2007 131: 1620-1622. [Full Text] [PDF]

This article has been cited by other articles:

				T. E. Warkentin and A. Greinacher So, Does Low-Molecular-Weight Heparin Cause Less Heparin-Induced Thrombocytopenia Than Unfractionated Heparin or Not? Chest, October 1, 2007; 132(4): 1108 - 1110. [Full Text] [PDF]