Effect of oral anticoagulant therapy on mortality in end-stage renal disease patients with atrial fibrillation : a prospective study

Background The aim of this study was to evaluate, in a cohort of haemodialysis patients with atrial fibrillation (AF), the relationship between oral anticoagulant therapy (OAT) and mortality, thromboembolic events and haemorrhage. Methods Two hundred and ninety patients with AF were prospectively followed for 4 years. Warfarin and antiplatelet intake, age, dialytic age, comorbidities, CHA2DS2-VASc and HAS-BLED scores were considered as predictors of risk of death, thromboembolism and bleeding events. In patients taking OAT, the international normalized ratio (INR) was assessed and the percentage time in the target therapeutic range (TTR) was calculated. Results At recruitment, 134/290 patients were taking warfarin. During follow-up there were 170 deaths, 28 thromboembolic events and 95 bleedings. After balancing for treatment propensity, intention-to-treat analysis on OAT intake at recruitment did not show differences in total mortality, thromboembolic events and bleedings, while the as-treated analysis, accounting for treatment switch, showed that patients taking OAT at recruitment had a significantly lower mortality than those not taking it [hazard ratio, HR 0.53 (95% confidence interval 0.28\u20130.90), p\u2009=\u20090.04], with a decrease of thromboembolic events [HR 0.36 (0.13\u20131.05), p\u2009=\u20090.06], and an increase of bleedings [HR 1.79 (0.72\u20134.39), p\u2009=\u20090.20], both non-significant. Among patients taking OAT at recruitment, those continuing to take warfarin had a significant reduction in the risk of total [HR 0.28 (0.14\u20130.53), p\u2009<\u20090.001] and cardiovascular [HR 0.21 (0.11\u20130.40), p\u2009<\u20090.001] mortality compared to patients stopping OAT. Conclusions In haemodialysis patients with AF, continuously taking warfarin is associated with a reduction of the risk of total and cardiovascular mortality

Warfarin use, mortality, bleeding and stroke in haemodialysis patients with atrial fibrillation

OBACKGROUND: Oral anticoagulation therapy (OAT) is the choice treatment for thromboembolism prevention in atrial fibrillation (AF), although data about OAT use in haemodialysis (HD) patients with AF are contradictory. METHODS: The effect of OAT on the risk of mortality, stroke and bleeding was prospectively evaluated in a population of HD patients with AF. All the patients of 10 HD Italian centres alive on 31 October 2010 with documented AF episode(s) were recruited and followed-up for 2 years. OAT and antiplatelet intake, age, dialytic age, comorbidities and percentage time in the target international normalized ratio (INR) range (target therapeutic range; TTR) were considered as predictors of hazard of death, thromboembolic and bleeding events. RESULTS: At recruitment, 134 patients out of 290 were taking OAT. During the follow-up, 115 patients died (4 strokes, 3 haemorrhagic and 1 thromboembolic). Antiplatelet therapy, but not OAT, was associated with increased mortality (HR 1.71, CI 1.10-2.64, P = 0.02). The estimated survival of patients always taking OAT tended to be higher than that of patients who stopped taking (68.6 versus 49.6%, P = 0.07). OAT was not correlated to a significant decreased risk of thromboembolic events (HR 0.12, CI 0.00-3.59, P = 0.20), while it was associated with an increased risk of bleeding (HR 3.96, CI 1.15-13.68, P = 0.03). Higher TTR was associated with a reduced bleeding risk (HR 0.09, CI 0.01-0.76, P = 0.03), while previous haemorrhagic events were associated with higher haemorrhagic risk (HR 2.17, CI 1.09-4.35, P = 0.03). CONCLUSIONS: In our population of HD patients with AF, the mortality is very high. OAT is not associated with increased mortality, while antiplatelet drugs are. OAT seems, on the contrary, associated with a better survival; however, it does not decrease the incidence of ischaemic stroke, whereas it increases the incidence of bleeding. Bleeding risk is lower in subjects in whom the INR is kept within the therapeutic range

Collaborative research on the ecology and management of the 'Wulo' monsoon rainforest in Wunambal Gaambera Country, North Kimberley, Australia

Indigenous groups are increasingly combining traditional ecological knowledge and Western scientific approaches to inform the management of their lands. We report the outcomes of a collaborative research project focused on key ecological questions associated with monsoon vine thickets in Wunambal Gaambera country (Kimberley region, Western Australia). The study mapped monsoon rainforests and analysed the environmental correlates of their current distribution, as well as the historical drivers of patch dynamics since 1949. Remote sensing was used to chart the effectiveness of an intervention designed to re-instate Aboriginal fire regimes according to customary principles. We identified the most vulnerable patches based on size, distance from neighbouring patches, and fire frequency. More than 6000 rainforest patches were mapped. Most were small (<1 ha), occurring predominantly on nutrient-rich substrates (e.g., basalt) and fire-sheltered topographic settings (e.g., slopes and valleys). Rainforests with low fire frequency and no cattle were more likely to expand into surrounding long-unburnt savannas. Frequent fires and cattle did not cause substantial contraction, although the latter affected rainforest understories through trampling. Fire management performed by Aboriginal rangers effectively shifted fire regimes from high-intensity late dry season fires to early dry season fires, particularly in areas with clusters of vulnerable rainforests. The remote sensing methods developed in this project are applicable to the long-term monitoring of rainforest patches on Aboriginal-managed land in North Kimberley, providing tools to evaluate the impacts of fire management, feral animal control, and climate change. The study confirmed the importance of the cattle-free and rarely burnt Bougainville Peninsula as one of the most important rainforest areas in Western Australia