TRAINING and EDUCATION
You Make the Call
Each month in “You Make the Call,” we’ll pick a challenging clinical question
submitted through the Consult-a-Colleague program and post the expert’s
response. But, what would YOU do? We’ll also pose a submitted question
and ask you to send your responses. See how your answer matches up to the
experts’ in the next print issue.
This month, Michael H. Kroll, MD, advises on switching a patient with a history
of deep-vein thrombosis (DVT) from warfarin to an oral thrombin inhibitor.
Clinical Dilemma:
A 50-year-old patient who is currently on warfarin for a second DVT in his leg was referred to me for consultation. At
age 26, he had extensive right knee surgery to repair a torn meniscus; subsequently, at age 42, he was found to have
unprovoked right-extremity DVT and treated with warfarin for five years. The patient had a heterozygous factor V
Leiden abnormality and was also found to have a lupus anticoagulant. He was off anticoagulation for three years and
subsequently developed an unprovoked DVT on the left side below the knee. He restarted anticoagulation but wishes
to switch from warfarin to an oral thrombin inhibitor, such as dabigatran.
Should I have concerns about using an oral thrombin inhibitor – possibly for another 35 years – in this patient?
Experts Make the Call
• Anemias
• Hematopoietic cell
transplantation
• Hemoglobinopathies
• Hemostasis/thrombosis
• Lymphomas
• Lymphoproliferative disorders
• Leukemias
• Multiple myeloma & Waldenström
macgroglobulinemia
• Myeloproliferative Disorders
• Myelodysplastic Syndromes
• Thrombocytopenias
Michael H. Kroll, MD
Professor of Medicine
Chief of the Section of Benign
Hematology
University of Texas MD Anderson
Cancer Center
The information about this patient
indicates that he needs to be on
indefinite anticoagulation. This approach is unequivocally valid if he has a persistent lupus
anticoagulant, anti-phospholipid antibody, or anti–beta
2 glycoprotein 1 antibody.
From the point of view of bleeding risk – particularly
risk identified in the large atrial fibrillation trials – dabigatran (the oral direct thrombin inhibitor you allude to)
and apixaban present the best options in comparison
with warfarin and rivaroxaban. Studies conducted with
patients with venous thromboembolism corroborate
these conclusions about safety with newer agents versus
warfarin.
So, I do not share your concern about long-term anticoagulation and would encourage you to switch – with
Consult a Colleague is a service for ASH
members that helps facilitate the exchange of information between hematologists and their peers. ASH members
can seek consultation on clinical cases
from qualified experts in 11 categories:
Assigned volunteer (“colleagues”) will
respond to inquiries within two business
days (either by email or phone).
Thrombin blood-clotting enzyme: Human alpha-thrombin molecule.
confidence! – to either dabigatran or apixaban. Both drugs
are approved for use in a patient like yours and their
therapeutic index is likely to be most favorable over the
next 35 years!
Have a puzzling clinical dilemma?
Submit a question, and read more
about Consult-aColleague volunteers
at hematology.org/
Clinicians/Consult.
aspx or scan the QR
code.
*If you have a request related to a
hematologic disorder not listed here, please
email your recommendation to ashconsult@
hematology.org so it can be considered for addition in the future.
Next Month’s Clinical Dilemma:
I have a 90-year-old female patient with relatively poor
performance status and newly diagnosed bulky, symptomatic Hodgkin lymphoma. What treatment options
does she have – chemotherapy with ABVD (doxorubicin
[Adriamycin], bleomycin, vinblastine, and dacarbazine),
28
ASH Clinical News
gemcitabine as a single agent, brentuximab vedotin,
others? I worry that she won’t be able to tolerate ABVD.
How would you respond? Email us at ashclinicalnews@
hematology.org, or tweet us @ASHClinicalNews.
DISCLAIMER: ASH does not recommend
or endorse any specific tests, physicians,
products, procedures, or opinions, and
disclaims any representation, warranty, or
guaranty as to the same. Reliance on any
information provided in this article is solely
at your own risk.
February 2015