Author + information
- Michel Le May, MD∗ (, )
- Jordan Bernick, MSc and
- George A. Wells, PhD
- ↵∗University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 1J7, Canada
We thank Drs. Potter and Bastiany (1) for their interest in our paper (2). We compared patients with anterior ST-segment myocardial infarction managed with primary percutaneous coronary intervention (PCI) who were subsequently prescribed warfarin to patients who were not. We excluded patients with left ventricular thrombus found on a transthoracic echocardiogram (TTE). The primary outcome was a composite of net adverse clinical events (NACE) consisting of all-cause mortality, stroke, reinfarction, or major bleeding at 180 days of the TTE.
The propensity score was derived by fitting a multivariable logistic regression model where treatment (warfarin vs. no warfarin) was used as the outcome. The derived propensity score was then used to derive the weights for the inverse probability weighting logistic regression model where NACE was used as the outcome and warfarin as the independent variable. In addition, a multivariable analysis using a logistic regression model was performed to determine the independent effect of adding warfarin therapy on NACE. The apical score, left ventricular ejection fraction, and the presence of cardiogenic shock were entered into the model.
In patients deemed not to require oral anticoagulants, heparin was discontinued immediately after the TTE; however, heparin was continued as bridging therapy in patients to be started on warfarin. The decision to start warfarin exposed patients to full-dose anticoagulation therapy during the hospital stay, and therefore, it is appropriate to count events that occurred during this interval.
By propensity score analysis, allocation to warfarin therapy was an independent predictor of NACE (odds ratio [OR]: 4.01, 95% confidence interval [CI]: 2.15 to 7.50, p < 0.0001). In a separate multivariable analysis, the odds of NACE remained significantly higher in comparison to patients who were not prescribed warfarin (OR: 3.13, 95% CI: 1.34 to 7.22, p = 0.007). In conclusion, our results do not support the addition of warfarin therapy following primary PCI in patients with apical akinesis or dyskinesis.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2015 American College of Cardiology Foundation
- Potter B.J.,
- Bastiany A.
- Le May M.R.,
- Acharya S.,
- Wells G.A.,
- et al.