Samir Arnaout

Switching patients from warfarin to dabigatran therapy: To RE-LY or not to rely☆

The RE-LY study showed that dabigatran, given at 110 mg twice daily, is non-inferior to warfarin for preventing stroke in patients with atrial fibrillation [1]. Previous vitamin K antagonist exposure was also shown not to influence the benefits of dabigatran in this setting [2]. We herein present an unfavorable outcome after shifting an eligible patient from warfarin to dabigatran therapy; thus challenging some existing comfort zones. A 78-year-old, 80-kg patient with controlled hypertension underwent angioplasty and Cypher stent implantation in the proximal Ramus artery five years ago; and has been free of coronary events since then. One year after stent placement, the patient underwent laparoscopic cholecystectomy at which time he was noted to be in sinus rhythm. One year later and on routine evaluation, he was found to be in atrial fibrillation. Transesophageal echocardiogram showed a left atrial thrombus (Fig. 1A) and the patient was started on warfarin therapy with close follow-up of prothrombin time being in the therapeutic range. Repeat echocardiogram one year later showed the left atrium to be free of thrombus (Fig. 1B). Following data from the

The interaction of gender and clinical risk profile in patients referred for exercise nuclear imaging versus exercise echocardiography

BACKGROUND Exercise myocardial perfusion imaging (E-MPI) and exercise echocardiography (E-Echo) are thought to be compatible for the non-invasive evaluation of patients with suspected coronary artery disease (CAD). The interaction of gender and clinical risk profile in the referral of patients to either of these two imaging modalities has not been well studied. METHODS AND RESULTS This was a prospective study of 922 consecutive patients who were referred for either E-MPI (331 patients) or E-Echo (591 patients) at the American University of Beirut Medical Center in the year of 2008. Men undergoing E-MPI had a higher risk profile than those undergoing E-Echo. They were older (58±12 years versus 55±12 years, p=0.002) and had a higher prevalence of multiple (>2) CAD risk factors (55% versus 37%, p<0.001) as well as a higher prevalence of prior PCI (22% versus 15%, p=0.017) or CABG (12% versus 7%, p=0.016). Furthermore, they achieved lower METS in their exercise (9.4±2.0 versus 10.4±2.3, p<0.001) and had a higher incidence of ischemia and on their scans (16% versus 9.1%, p=0.008). In contrast, women undergoing E-MPI had a similar profile to those undergoing E-Echo in terms of prevalence of risk factors, prior history of coronary events and the prevalence of ischemia or impaired ejection fraction on their scans. CONCLUSION There is an important interaction between gender and clinical risk profile in patients undergoing E-MPI versus E-Echo. In men, E-MPI seems to be the preferred test for the higher risk profile patients, whereas in women the two tests are interchangeable.