Effect of non-vitamin-K oral anticoagulants on stroke severity compared to warfarin: a meta-analysis of randomized controlled trials.

BACKGROUND AND PURPOSE: In addition to lowering stroke risk, warfarin use is also associated with reduced stroke severity in patients with atrial fibrillation and acute ischaemic stroke. It was sought to determine whether the effect of non-vitamin-K oral anticoagulants (NOACs), compared to warfarin, differed by stroke severity. METHODS: Phase III randomized controlled trials with participants who were randomized to receive NOACs or warfarin for stroke prevention in the setting of non-valvular atrial fibrillation were identified. Stroke was classified into two categories, fatal or disabling stroke and non-disabling stroke, and meta-analyses were completed for both outcomes and for comparative case fatality of stroke amongst trials. RESULTS: Five randomized controlled trials met our inclusion criteria. In clinical trials evaluating the NOACs usually prescribed in clinical practice (four trials), acute stroke was reported in 1403 (1.86%) participants, 787 (1.04%) in the NOAC group [386 (0.51%) fatal or disabling, 401 (0.53%) non-disabling] and 616 (0.82%) in the warfarin group [367 (0.49%) fatal or disabling, 249 (0.33%) non-disabling]. On meta-analysis NOACs were significantly superior to warfarin for fatal or disabling stroke (odds ratio [OR] 0.77; 95% confidence interval [CI] 0.66-0.89, I2  = 21%) and non-disabling stroke (OR 0.85; 95% CI 0.73-0.98, I2  = 2%). The case fatality of stroke was no different between groups (OR 0.90, 95% CI 0.75-1.13, I2  = 0%), but the point estimate favoured NOACs. CONCLUSION: In phase III trials of NOACs, for prevention of stroke in atrial fibrillation, NOACs are associated with a lower risk of both fatal/disabling and non-disabling stroke compared to warfarin.

A review of vitamin D insufficiency and its management: a lack of evidence and consensus persists.

Vitamin D deficiency is the most common nutritional deficiency worldwide, however uncertainty persists regarding the benefits of vitamin D supplementation. Vitamin D is essential for calcium homeostasis, and has been linked to falls and fractures in older people. There are numerous risk factors for vitamin D deficiency, chief among them old age. Studies of vitamin D supplementation have given mixed signals, but over all there is evidence of benefit for those with risk factors for deficiency. International guidelines recommend vitamin D target levels of >25 to >80 nmol/l, best achieved by a daily dose of 800-1000 IU. Large bolus doses should be avoided. There are still unanswered questions regarding vitamin D supplementation and target levels. There is need for well designed and powered trials to achieve consensus.