Incidence of oral anticoagulant interruption among stroke patients with atrial fibrillation and subsequent stroke.

BACKGROUND AND PURPOSE: We analyzed the incidence and causes of oral anticoagulant (OAC) cessation and subsequent stroke after OAC withdrawal in a cohort of Korean stroke patients with atrial fibrillation. METHODS: The Korean Atrial Fibrillation Evaluation Registry in Ischemic Stroke patients (K-ATTENTION) is a multicenter cohort study, merging stroke registries from 11 tertiary centers in Korea. The number of OAC interruption episodes and the reasons were reviewed from hospital records. Stroke after OAC withdrawal was defined when a patient experienced ischaemic stroke within 31 days after OAC withdrawal. Clinical variables were compared between patients who experienced stroke recurrence during OAC interruption and those who did not experience recurrence. RESULTS: Among 3213 stroke patients with atrial fibrillation, a total of 329 episodes of OAC interruption were detected in 229 patients after index stroke (mean age 72.9 ± 8.3 years, 113 female patients). The most frequent reason for OAC withdrawal was poor compliance [103 episodes (31.3%)] followed by extracranial bleeding [96 episodes (29.2%)]. Stroke after OAC withdrawal was noted in 13 patients. Mean age, vascular risk factor profile and mean CHA2 DS2 -VASc score were not significantly different between patients with and without recurrent stroke. CONCLUSIONS: A considerable number of stroke patients with atrial fibrillation experienced temporary interruption of OAC after index stroke, which was associated with stroke recurrence of 4.0 cases per 100 interruption episodes.

Comparison of white blood cell counts by WNR, WDF, and WPC channels in Sysmex XN hematology analyzer.

INTRODUCTION: The Sysmex XN modular system (Sysmex, Kobe, Japan) uses a novel technology for white blood cell (WBC) count and differential, using separate channels: white cell nucleated (WNR), WBC differential (WDF), and white progenitor cell (WPC) channels. We questioned how concordant WBC counts would be between them. METHODS: In a total of 6327 consecutive specimens, WBC counts were compared between WNR and WDF channels. They were also compared in three groups of WBC counts and two groups of chemotherapy status. In 508 specimens from the 4361 specimens that were run on the XN-20 module, the WPC channel was used for reflex test. Data were compared using Pearson's correlation, absolute difference, and percent difference (%D). RESULTS: WBC counts between WNR and WDF channels showed very high correlations in total specimens (r = 0.9976) and in the groups of WBC counts and chemotherapy. As WBC count increased, absolute difference increased, while %D decreased (P < 0.0001, both). Percent difference was 1.55% in total specimens and showed the highest value in the severe leukopenia group (<1.0 × 10(9)/L, 6.18%). CONCLUSIONS: This is the first large-scale study on novel channel technology for WBC counts in the Sysmex XN. WBC counts by WNR, WDF, and WPC channels are highly correlated, and they are overall interchangeable and reliable.

Training environment for inferior vena caval filter placement.

This paper describes a Virtual Environment system designed to aid in training interventional radiologists in inferior vena cava filter placement. It is being developed as part of a VE simulator for a number of surgical and interventional radiology procedures at the Laboratory for Advanced Computer Applications in Medicine at the George Washington University. In this procedure a filter is placed in the inferior vena cava to prevent blood clots from the lower portion of the body from reaching the lungs and causing a pulmonary embolus. The simulation is designed to provide both tutorial and testing modes for the filter placement procedure.