Abstract 14929: Sex Based Differences in Excess Dosing of Antithrombotic and Antiplatelet Agents in Young Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention: The VIRGO Study
Background: Among patients treated for acute myocardial infarction (AMI), excess dosing of antithrombotic and antiplatelet agents is associated with worse outcomes, particularly in women. However, the prevalence and predictors of excess dosing among young patients with AMI are not well understood.
Methods: We analyzed data from the prospective observational Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients (VIRGO) study. Among 2992 patients enrolled in the VIRGO study, we identified 1507 AMI patients 18-55 years of age who underwent percutaneous coronary intervention (PCI) at 104 hospitals between August 2008 and January 2012. We abstracted doses of unfractionated heparin (UFH), bivalirudin and glycoprotein IIb/IIIa inhibitors (GPIs) administered during PCI from the medical records. We defined doses as excessive if they exceeded the recommended range by more than 10%. We determined patient characteristics associated with excess dosing using hierarchical logistic regression to adjust for patient demographics, co-morbidities and clustering within sites.
Results: Among 1507 patients, a total of 268 patients (17.8%) received at least one dose in excess of the recommended range, and 27 patients (1.8%) received excess doses of more than one drug. An excess dose was administered to 14.7% patients treated with GPIs, 12.3% treated with UFH and 4.7% treated with bivalirudin. Women were only slightly more likely to receive excess doses of antithrombotics than men overall (19.0% versus 15.5%, P= 0.08). Compared with men, women were significantly more likely to receive excess dose of UFH (14.9% versus 7.7%, P<0.001), but equally likely to receive an excess dose of GPI (14.0% versus 15.9%, P=0.4) and bivalirudin (4.78% versus 4.76%, P= 0.9). In multivariable analysis, low body weight was the only predictor of excess dosing (adjusted odds ratio, 0.9 per 5 Kg increase; 95% CI 0.87-0.94, P<0.0001).
Conclusions: Among young AMI patients undergoing PCI, antithrombotic and antiplatelet agents are often administered in excess of the recommended range, but this did not vary by sex. Excess dosing was more common in lower weight patients, underscoring the importance of obtaining accurate body weight in both sexes when dosing these agents.
- © 2012 by American Heart Association, Inc.