A Study on the Prevalence of Heparin-Induced Thrombocytopenia in Cardiovascular Patients

A Multicenter, Prospective Cohort Study to Determine the Prevalence and Profile of Heparin-Induced Thrombocytopenia in Patients Undergoing Cardiovascular Surgery or Percutaneous Coronary Intervention

Several clinical studies in Western countries have revealed that the prevalence of HIT is 0.5 to 5%, varying depending on the clinical setting. Thirty to 50% of HIT patients suffer from thromboembolic events, and the mortality of HIT is 10 to 20%. In contrast, many physicians in Japan report no experience in treating HIT, although approximately 200,000 patients per year receive heparin. This raises the possibility that the prevalence of HIT might be much lower in Japan than in Western countries. In fact, neither the drug for HIT treatment nor the laboratory test for HIT diagnosis has been approved by the Pharmaceutical Affairs Law in Japan. We have therefore conducted a multi-center, prospective cohort study to determine the prevalence and profile of HIT in patients undergoing cardiovascular surgery or percutaneous coronary intervention. Approximately 1,500 patients will be enrolled in this study.

Study Overview

• Status: Unknown
• Conditions: Heparin-Induced Thrombocytopenia

Detailed Description

Heparin is an important anticoagulation treatment, especially for cardiovascular patients. Recently, heparin-induced thrombocytopenia type II (HIT) has been shown to be an immune-mediated, life-threatening side effect of heparin therapy. Antibodies against heparin-platelet factor 4 (HIT antibodies), induced by heparin administration, are the major cause of HIT. HIT antibodies can stimulate platelets and endothelial cells, resulting in an excess production of thrombin, inducing thrombocytopenia and thromboembolic events. HIT typically occurs 5 to 14 days after the initial administration of heparin (typical-onset). HIT antibodies are transient but can be detected for about 100 days after the cessation of heparin treatment. Thus, some patients develop HIT either days after discontinuing heparin (delayed-onset) or soon after the re-administration of heparin (rapid-onset). HIT is clinically diagnosed by a drop in platelet count to less than 100,000/μL or a 50% decrease in platelets after the initiation of heparin therapy with no apparent explanation other than HIT. A positive laboratory test for HIT antibodies supports the clinical diagnosis.

Several clinical studies in Western countries have revealed that the prevalence of HIT is 0.5 to 5%, varying depending on the clinical setting. Thirty to 50% of HIT patients suffer from thromboembolic events, and the mortality of HIT is 10 to 20%. In contrast, many physicians in Japan report no experience in treating HIT, although approximately 200,000 patients per year receive heparin. This raises the possibility that the prevalence of HIT might be much lower in Japan than in Western countries. In fact, neither the drug for HIT treatment nor the laboratory test for HIT diagnosis has been approved by the Pharmaceutical Affairs Law in Japan. We have therefore conducted a multi-center, prospective cohort study to determine the prevalence and profile of HIT in patients undergoing cardiovascular surgery or percutaneous coronary intervention. Approximately 1,500 patients will be enrolled in this study.

• Study Type: Observational
• Enrollment: 1500

Contacts and Locations

Study Locations

• Japan
  • Kumamoto, Japan
    • National Hospital Organization Kumamoto Medical Center
  • Aichi
    • Nagoya, Aichi, Japan
      • National Hospital Organization Nagoya Medical Center
    • Nagoya, Aichi, Japan
      • Nagoya University Hospital
    • Nagoya, Aichi, Japan
      • Nagoya Daini Red Cross Hospital
  • Hokkaido
    • Hakodate, Hokkaido, Japan
      • National Hospital Organization Hakodate National Hospital
  • Hukuoka
    • Kurume, Hukuoka, Japan
      • Kurume University Hospital
  • Hyogo
    • Kobe, Hyogo, Japan
      • Kobe University Hospital
    • Kobe, Hyogo, Japan
      • Kobe City General Hospital
  • Iwate
    • Morioka, Iwate, Japan
      • Iwate Medical University Hospital
  • Kanagawa
    • Isehara, Kanagawa, Japan
      • Tokai University Hospital
  • Osaka
    • Suita, Osaka, Japan, 565-8565
      • National Cardiovascular Center
  • Tokyo
    • Fuchu, Tokyo, Japan
      • Sakakibara Memorial Hospital
  • Yamaguchi
    • Iwakuni, Yamaguchi, Japan
      • National Hospital Organization Iwakuni Clinical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Adult males or females who meet the criteria listed below:

  1. Patients who are >=20 years of age
  2. Patients scheduled to undergo cardiovascular surgery or patients with acute coronary syndrome scheduled to undergo percutaneous coronary intervention
  3. Patients willing and able to give informed consent

Exclusion Criteria:

1. Patients who have a documented history of heparin-induced thrombocytopenia
2. Chronic thrombocytopenia (<100,000/μL)
3. Hematopoietic malignancy
4. Patients who receive an anticancer drug

Study Plan

How is the study designed?

Collaborators and Investigators

• Sponsor: Ministry of Health, Labour and Welfare, Japan
• Investigators: Study Chair: Shigeki Miyata, MD, PhD, National Cerebral and Cardiovascular Center

Study record dates

Study Major Dates

• Study Start: November 1, 2004
• Study Completion: March 1, 2006

Study Registration Dates

• First Submitted: September 12, 2005
• First Submitted That Met QC Criteria: September 12, 2005
• First Posted (Estimate): September 20, 2005

Study Record Updates

• Last Update Posted (Estimate): February 16, 2006
• Last Update Submitted That Met QC Criteria: February 15, 2006
• Last Verified: February 1, 2006

More Information

Terms related to this study

• Keywords: percutaneous coronary intervention; heparin-induced thrombocytopenia; cardiovascular surgery
• Additional Relevant MeSH Terms: Hematologic Diseases; Blood Platelet Disorders; Thrombocytopenia
• Other Study ID Numbers: 15C-1-3