Coumarin Users at Higher Risk For Cerebral Microbleeds Interview Invitation
S. Akoudad, MD Msc PhD candidate
Dep. Epidemiology, Radiology, Neurology
Erasmus MC, Rotterdam , the Netherlands

Medical Research: What are the main findings of the study?

Dr.  Vernooij: We found that compared to never users, coumarin users had a higher prevalence of deep or infratentorial microbleeds and probably also a higher incidence of any microbleeds. A higher maximum international normalized ratio (INR) was associated with deep or infratentorial microbleeds, and among coumarin users, a greater variability in INR was associated with a higher prevalence of microbleeds.

Medical Research: What was most surprising about the results?

Dr.  Vernooij: In the cross-sectional results of our study we only found an association between coumarin use and deep or infratentorial microbleeds. However, when we used a longitudinal design we also found strong estimates (non-significant, probably due to lack of statistical power) for microbleeds in lobar brain locations. This is especially interesting because microbleeds in various brain locations are thought to represent different underlying etiologies, with lobar microbleeds probably reflecting amyloid angiopathy and deep microbleeds resulting from hypertensive arteriolosclerosis. Our results suggest that coumarin use may relate to microbleeds in both types of pathologies.

Medical Research: What should clinicians and patients take away from your report?

Dr. Vernooij: Microbleeds mark the presence of fragile small vessel in the brain. Use of coumarin anticoagulants may aggravate the leakage of blood products from these vessels, especially when persons’ hypercoagulable state is poorly controlled (overshooting INR values, and high variability in INR).

Medical Research: What recommendations do you have for future research as a result of this study?

Dr.  Vernooij: Clinical trials should investigate whether first-ever ICH are more frequent in persons using anticoagulant drugs (including new anticoagulant agents) with microbleeds compared to those without microbleeds.


Use of Coumarin Anticoagulants and Cerebral Microbleeds in the General Population

Saloua Akoudad, Sirwan K.L. Darweesh, Maarten J.G. Leening, Peter J. Koudstaal, Albert Hofman, Aad van der Lugt, Bruno H. Stricker, M. Arfan Ikram, and Meike W. Vernooij

Stroke. 2014;STROKEAHA.114.007112published online before print October 14 2014, doi:10.1161/STROKEAHA.114.007112

Last Updated on January 2, 2015 by Marie Benz MD FAAD