MedicalResearch.com Interview with: Christopher D. Anderson, MD, MMSc Neurocritical Care | Acute Stroke Center for Human Genetic Research Massachusetts General Hospital Harvard Medical School Broad Institute of Harvard and MIT Medical Research: What are the main findings of the study? Dr. Anderson: Previous studies have linked Apolipoprotein E (APOE) epsilon variants with spontaneous intracerebral hemorrhage (ICH) particularly in the lobar (cortical and subcortical) regions of the brain, but it was not known whether this association would extend to warfarin-related ICH, or whether the risk of intracerebral hemorrhage on warfarin would be multiplicatively compounded by APOE epsilon allele status.  Our results demonstrate that APOE e2 and e4 variants are associated with more than a two-fold risk of lobar ICH for patients on warfarin, in comparison to warfarin-exposed individuals without ICH.  This observed association was strongest when analyzing subjects with definite or probable Cerebral Amyloid Angiopathy (CAA), as defined by the Boston Criteria.  No association between APOE e2 or e4 and non-lobar ICH was identified following our replication phase.  Furthermore, we did not detect an interaction between APOE status and warfarin status in ICH subjects using a case-only design. (more…)