Key Updates in Thrombosis
Table of Contents
There’s been a lot going on in the world of thrombosis, especially during ESC! We saw interesting results from factor XIa inhibitor phase II trials (AXIOMATIC-SSP, PACIFIC AMI, PACIFIC stroke), APOLLO (prophylactic apixaban in stable patients with COVID-19), and COVID-PACT (anticoagulation intensity and use of clopidogrel in ICU patients with COVID-19).
The four studies that particularly caught my attention this month:
People used to think of VTE and arterial thrombotic events as two distinct diseases with different therapies. Yet, aspirin gained some interest for VTE prophylaxis in orthopedic surgeries after results of the PEP trial (aspirin 160 mg/d vs. placebo). Secondary prevention trials such as WARFASA and ASPIRE (100 mg vs. placebo in both trials) strengthened the idea. However, results from the recently published CRISTAL study showed that aspirin (100 mg/d), compared with enoxaparin (40 mg/d) failed to meet noninferiority and was, indeed, inferior with respect to the 90-day rate of symptomatic VTE. A double-blind double-dummy design may have been more difficult but more desirable than a cluster-randomized trial. Learn more.
The CHEST guidelines are very helpful and replete with practical tables and figures. One of the recommendations that became heated was that about patients receiving vitamin-K antagonists for mechanical heart valves, where the panel recommended against perioperative bridging with heparin. On a closer look, however, the guidelines do make exceptions for patients with high risk of thromboembolic events (which is not far from recommendations in the 2020 AHA/ACC valve guidelines). The expert panel was multidisciplinary with representation from many specialties. On my read, cardiologists were conspicuously absent, which could be an area for improvement in the next iteration. Learn more.
DOACs are far more convenient for patients, and let’s face it, also for clinicians and health systems! So, it came as a great disappointment for many to observe that rivaroxaban failed to meet noninferiority criteria in the INVICTUS trial of patients with AF and rheumatic heart disease. In fact, warfarin came out as the winner with lower risk of the primary composite efficacy outcome, lower risk of stroke, and lower risk of death. INVICTUS is not alone in that finding. Previously, DOACs (dabigatran) failed compared with vitamin-K antagonists in patients with mechanical valves (RE-ALING), and there is growing concern in patients with antiphospholipid syndrome. Stay tuned for more data! Learn more.
Analyses from the national data from the Centers for Disease Control and Prevention indicate that there was a 24% increase in deaths attributable to pulmonary embolism in the United States in 2020, compared with the 2018-2019 period. The difference was only partially related to COVID-19-associated PE deaths. The findings highlight the direct as well as indirect impact of COVID-19 on cardiovascular care and outcomes. Learn more.
Behnood Bikdeli, MD, MS
Cardiologist, Section of Vascular Medicine, Division of Cardiovascular Medicine, Brigham and Women’s Hospital
Investigator, Thrombosis Research Group, Division of Cardiovascular Medicine, Brigham and Women’s Hospital
Instructor, Harvard Medical School
Investigator, Yale/ YNHH Center for Outcomes Research and Evaluation, Yale School of Medicine
Investigator, Cardiovascular Research Foundation
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