Non-vitamin K antagonist oral anticoagulants versus warfarin in AF patients ≥ 85 years.

BACKGROUND: Atrial fibrillation (AF) prevalence and its risk of stroke rise with ageing. We aimed to investigate the outcomes of NOAC and warfarin in AF patients aged ≥ 85 years. METHODS: This is a retrospective study using Taiwan National Health Insurance Research Database. A total of 15,361 patients aged ≥ 85 years with AF on oral anticoagulants were identified. The end points included ischaemic stroke, intracranial haemorrhage (ICH), major bleeding, all-cause mortality and composite adverse events (ICH or major bleeding or all-cause mortality). Clinical outcomes were compared between each NOAC and warfarin after propensity matching. RESULTS: Before propensity matching, patients taking warfarin were older, more female with more comorbidities than NOACs users. After propensity matching, baseline characteristics did not differ significantly between matched subjects receiving warfarin and each NOAC. Compared to warfarin, dabigatran was associated with a lower risk of ICH (hazard ratio [HR] 0.496), mortality (HR 0.558) and adverse events (HR 0.628), while rivaroxaban was associated with a lower risk of ischaemic stroke (HR 0.781), ICH (HR 0.453), mortality (HR 0.558) and adverse events (HR 0.636). Apixaban was associated with a lower risk of mortality (HR 0.488) and adverse events (HR 0.557) compared to warfarin. (all P < .05). CONCLUSION: For the efficacy, NOACs were associated with a comparable or lower risk of ischaemic stroke compared to warfarin. For adverse events, NOACs were associated with a lower risk of all-cause mortality and composite adverse events. In the elderly AF population, NOACs could be a more favourable choice for stroke prevention.

Level set contouring for breast tumor in sonography.

The echogenicity, echotexture, shape, and contour of a lesion are revealed to be effective sonographic features for physicians to identify a tumor as either benign or malignant. Automatic contouring for breast tumors in sonography may assist physicians without relevant experience, in making correct diagnoses. This study develops an efficient method for automatically detecting contours of breast tumors in sonography. First, a sophisticated preprocessing filter reduces the noise, but preserves the shape and contrast of the breast tumor. An adaptive initial contouring method is then performed to obtain an approximate circular contour of the tumor. Finally, the deformation-based level set segmentation automatically extracts the precise contours of breast tumors from ultrasound (US) images. The proposed contouring method evaluates US images from 118 patients with breast tumors. The contouring results, obtained with computer simulation, reveal that the proposed method always identifies similar contours to those obtained with manual sketching. The proposed method provides robust and fast automatic contouring for breast US images. The potential role of this approach might save much of the time required to sketch a precise contour with very high stability.