Acute hemorrhage risk ‘clinically significant’ for dual antiplatelet therapy
MedWire News: US researchers have identified a clinically significant risk for acute hemorrhage among patients using dual antiplatelet therapy (DAT) with clopidogrel plus aspirin.
The estimated rate of emergency department (ED) visits involving acute hemorrhages from DAT was 1.2 per 1000 outpatient visits at which clopidogrel plus aspirin was prescribed, report Nadine Shehab (Centers for Disease Control and Prevention, Atlanta, Georgia) and colleagues.
This compares with 2.5 ED visits for acute hemorrhage per 1000 outpatient prescription visits at which warfarin was prescribed, they add.
The researchers note that "although data on adverse events (AEs) from DAT are available from clinical trials, the clinical management of and patient risks for AEs in the real-world use of antithrombotic agents are known to differ."
They therefore used nationally representative surveillance data from the US to describe the frequency, rates, and nature of ED visits for hemorrhagic and other related AEs attributed to clopidogrel plus aspirin therapy. To put their findings into context, they compared them with similar data for warfarin.
Based on 384 hemorrhage-related AEs identified in a sample of 58 US hospitals, the team estimated that were 7654 ED visits in the US annually for hemorrhage-related AEs due to DAT compared with 2926 cases and an estimated 60,575 ED visits due to warfarin.
The researchers found that 59.4% of ED visits for DAT-related acute hemorrhages involved epistaxis, skin, or other minor hemorrhages (eg, bleeding from the mouth, small cuts, and bruising) compared with 54.3% for warfarin.
"Although the immediate harm from these types of hemorrhages may not be severe, this finding is concerning because these 'nuisance' bleedings have been linked to early discontinuation of clopidogrel therapy, which, in turn, has been associated with in-stent thrombosis and poor clinical outcomes in patients who have undergone coronary stenting," remark Shehab et al.
However, 29.4% of DAT-related ED visits for acute hemorrhages were serious enough to require hospitalization compared with 40.1% for warfarin, although the difference was not statistically significant.
Gastrointestinal tract hemorrhages composed approximately 30.5% and 22.8% of ED visits for acute hemorrhages associated with DAT and warfarin, respectively, and almost 80% of these patients required hospitalization.
"These findings reinforce the importance of practitioners and patients recognizing and anticipating the acute hemorrhagic risk associated with DAT," Shehab and co-authors conclude in the Archives of Internal Medicine.
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By Laura Dean