Dual Antiplatelet Therapy and the Severity Risk of Lower Intestinal Bleeding.

BACKGROUND

Dual antiplatelet (Plt) therapy with aspirin and clopidogrel is recommended for up to 1 year following acute coronary syndrome. Many of these cardiac patients are also on anithrombotic therapy like warfarin. Lower gastrointestinal bleeding (LGIB) is the main adverse event of this treatment.

AIMS

The main purpose of this study was to analyze the relationship of dual anti-Plt therapy and the risk of LGIB.

METHODS

Patients' electronic charts were reviewed to include a total of 19 variables, which included age, sex, ethnicity, daily use aspirin of any dose, daily use of clopidogrel, use of nonsteroidal anti-inflammatory drugs (NSAIDs) at least twice in the last week prior to admission and the daily use of anticoagulants (warfarin, heparin), and were obtained from history and physical examination reports, lab transcripts and procedural reports.

SETTINGS/DESIGN: A retrospective cohort study of the records of 3436 patients admitted to our hospital from January 1, 2009, to December 31, 2011, was evaluated. All the patients included were admitted through the emergency department with complaints of or relating to LGIB. The primary outcome studied was severe LGIB as defined by the requirement of at least two units of packed red blood cells and/or a decrease in the hematocrit of 20% or more or recurrent bleeding after 24 h of clinical stability with additional transfusions required. Other outcomes included surgical intervention.

STATISTICAL METHODS/ANALYSIS: Univariate analysis using -test on continuous variables and Chi-square test on categorical variables were done before carrying out logistic regression analysis. Logistic regression analyses were conducted to measures of association between the variables and LGIB. Logistic regression analysis was not carried for surgical intervention and death because none of the variables was significant from univariate tests.

RESULTS

A total of 511 patients were found to have true LGIB. Among these subjects, 61 were shown to be on dual or multiple antithrombotic therapies. Further exploration revealed that while the use of multiple blood thinning agents may, in fact, pose a significant risk to overall LGIB, it did not significantly increase the risk for severe bleeding as outlined above.

CONCLUSION

The use of multiple blood thinning agents does not significantly increase the risk for severe LGIB.