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Drug-drug interactions between direct oral anticoagulants (DOAC) and antiseizure medications via the cytochrome P450 (CYP) or the P-glycoprotein (P-gp) systems may lead to under-anticoagulation. The clinical relevance of these interactions is unclear. We aimed to elucidate the risk of thromboembolism with concurrent DOAC and CYP/P-gp modulating antiseizure medications.In this propensity score-weighted population-based retrospective cohort study, we used competing risk regression analyses to determine the risks of ischemic stroke, venous thromboembolism, and death in DOAC recipients taking CYP/P-gp-modulating antiseizure medications (phenytoin, valproate, levetiracetam, carbamazepine, or phenobarbital) versus those taking CYP/P-gp-neutral antiseizure medications (pregabalin, gabapentin, or clobazam). We also performed secondary analyses for the epilepsy and atrial fibrillation subgroups.Among DOAC users, CYP/P-gp-modulating antiseizure medications were collectively associated with an increased risk of ischemic stroke (adjusted hazard ratio 1.28, 95% confidence interval 1.05-1.57, p = 0.017). In addition, phenytoin (adjusted hazard ratio 1.34, 95% confidence interval 1.07-1.68, p = 0.011) and valproate (adjusted hazard ratio 1.38, 95% confidence interval 1.10-1.74, p = 0.006) were associated with increased mortality. In the epilepsy subgroup, the risk of ischemic stroke and venous thromboembolism did not differ between CYP/P-gp-modulating and CYP/P-gp-neutral antiseizure medications.Although CYP/P-gp-modulating antiseizure medications were associated with an increased risk of ischemic stroke when paired with DOAC in the primary analysis, such a phenomenon was not found among patients with epilepsy who took phenytoin, valproate, or levetiracetam with DOAC. Therefore, these antiseizure medication options among patients with epilepsy with concurrent DOAC should not be restricted solely based on their potential drug-drug interactions. Yet, the increased mortality during concurrent use of DOAC with phenytoin or valproate might call for caution.

Introduction: We compared the morphology of intracranial atherosclerotic plaques in the anterior versus posterior circulation, using three-dimensional rotational angiography (3DRA). Methods: We prospectively recruited adult patients with acute ischemic stroke or transient ischemic attack attributed to high-grade (60-99%), atherosclerotic intracranial stenosis as confirmed by 3DRA. We assessed the plaque morphology in 3DRA, including the percentage of luminal stenosis, smooth/irregular/ulcerative plaque surface contour, plaque thickness, length, eccentricity, upstream plaque shoulder angulation, longitudinal distribution of the maximal stenosis, and adjoining branch atheromatous disease (BAD). We compared characteristics of patients with middle cerebral artery-M1 (MCA-M1) and basilar artery (BA) plaques, and the plaque morphology in the two subgroups. Results: Overall, 164 and 17 patients respectively with MCA-M1 and BA plaques were analyzed, with similar age (medians 60 versus 62 years), sex (male 64.6 versus 52.9%) and history of common vascular risk factors. The percentage of luminal stenosis (medians 77 versus 81%), proportion of smooth/irregular/ulcerative plaque surface contour, upstream plaque shoulder angulation (32.1 versus 25.8 °), longitudinal distribution of the maximal stenosis, and presence of adjoining BAD (56.7 versus 64.7%) were similar between MCA-M1 and BA plaques. However, BA plaques were thicker (1.5 versus 1.3mm; p=0.03) and longer (16.4 versus 8.4mm; p Conclusions: There were differences in the morphology of symptomatic atherosclerotic plaques in anterior and posterior circulations, independent of demographics and common vascular risk factors. Different artery geometry and the hemodynamics may underlie such differences.

ObjectivesThe predisposition of intracranial atherosclerotic disease (ICAD) to East Asians over Caucasians infers a genetic basis which, however, remains largely unknown. Higher prevalence of vascular risk factors (VRFs) in Chinese over Caucasian patients who had a stroke, and shared risk factors of ICAD with other stroke subtypes indicate genes related to VRFs and/or other stroke subtypes may also contribute to ICAD.MethodsUnrelated symptomatic patients with ICAD were recruited for genome sequencing (GS, 60-fold). Rare and potentially deleterious single-nucleotide variants (SNVs) and small insertions/deletions (InDels) were detected in genome-wide and correlated to genes related to VRFs and/or other stroke subtypes. Rare aneuploidies, copy number variants (CNVs) and chromosomal structural rearrangements were also investigated. Lastly, candidate genes were used for pathway and gene ontology enrichment analysis.ResultsAmong 92 patients (mean age at stroke onset 61.0±9.3 years), GS identified likely ICAD-associated rare genomic variants in 54.3% (50/92) of patients. Forty-eight patients (52.2%, 48/92) had 59 rare SNVs/InDels reported or predicted to be deleterious in genes related to VRFs and/or other stroke subtypes. None of the 59 rare variants were identified in local subjects without ICAD (n=126). 31 SNVs/InDels were related to conventional VRFs, and 28 were discovered in genes related to other stroke subtypes. Our study also showed that rare CNVs (n=7) and structural rearrangement (a balanced translocation) were potentially related to ICAD in 8.7% (8/92) of patients. Lastly, candidate genes were significantly enriched in pathways related to lipoprotein metabolism and cellular lipid catabolic process.ConclusionsOur GS study suggests a role of rare genomic variants with various variant types contributing to the development of ICAD in Chinese patients.