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Non-vitamin K antagonist oral anticoagulants (NOACs) have changed the landscape for stroke prevention in atrial fibrillation (AF). Given the huge burden of AF in Asians, more attention to stroke prevention is clearly needed. Aiming to provide an overview and reappraisal of stroke prevention in Asians with AF, we searched MEDLINE for information on NOACs in Asians. In addition, abstracts from national and international cardiovascular meetings were studied to identify unpublished studies. In the 4 recent Phase 3 trials comparing NOACs to warfarin, a consistent pattern is evident. For efficacy endpoints in the comparison of NOACs vs warfarin, a significant reduction in stroke/systemic embolization was seen for dabigatran 150 mg [HR 0.45 (0.28-0.72)], with non-significant trends seen for lower stroke/systemic embolization with other NOACs, except edoxaban 30 mg. A similar pattern was seen for ischaemic stroke, with a significant reduction for dabigatran 150 mg [HR 0.55 (0.32-0.950]. For haemorrhagic stroke, all NOAC regimes, except rivaroxaban 20 mg, had significantly lower hazard ratios. No evidence of increased myocardial infarction was found for NOACs. All-cause mortality was significantly lowered amongst Asian patients on edoxaban 60 mg compared to warfarin [HR 0.63 (0.40-0.98)] with non-significant trends to lower mortality with dabigatran 150 mg, rivaroxaban and edoxaban 30 mg. For safety endpoints, all the NOAC regimes, except rivaroxaban 20 mg, significantly reduced major bleeding and 'all bleeding' events. Intracranial haemorrhage was consistently lowered by all NOACs. None of NOACs increased gastrointestinal bleeding. These information suggested that NOACs should be preferentially indicated for stroke prevention in Asians with AF. [ABSTRACT FROM AUTHOR]

Background Current clinical guidelines recommend that risk stratification for ischaemic stroke in patients with nonvalvular AF (NVAF) should be performed using the CHA2DS2-VASc score (Congestive heart failure, Hypertension, Age ≥ 75 years [double], Diabetes mellitus, previous thromboembolism [double], Vascular disease, Age 65-74 years, and female gender) to aid decision making for antithrombotic treatment, with a preference for Non-Vitamin K Oral Anticoagulants (NOACs) in those with CHA2DS2-VASc score ≥ 1. However, CHA2DS2-VASc score is not recommended in the 2014 Japanese Circulation Society (JCS) guidelines for patients with NVAF. Methods To assess the impact of the JCS approach to stroke prevention in AF, and model the impact of using a CHA2DS2-VASc based 2-step decision making strategy, we calculated the incidence of ischaemic stroke in NVAF patients without OAC on basis of the CHADS2 and CHA2DS2-VASc scores using published Japanese data, and estimated the preventable number of stroke events. Results Using a CHA2DS2-VASc-based approach, the potential annual stroke events based on the estimated total number of NVAF patients in Japan was 889,000, as follows: 4369 for dabigatran 150 mg, 6049 for dabigatran 110 mg, 5918 for rivaroxaban (intention-to-treat; ITT), 5302 for apixaban, 5843 for edoxaban 60 mg (ITT), and 7598 for edoxaban 30 mg (ITT), respectively. Using a CHADS2 score-based approach, the number of potential stroke events was much greater for each agent. Conclusion Our modelling analysis has shown that when considering antithrombotic treatment for Japanese NVAF patients, using a CHA2DS2-VASc-based approach would allow greater opportunities for stroke prevention. [ABSTRACT FROM AUTHOR]

Background: Cerebral microbleeds are a potential neuroimaging biomarker of cerebral small vessel diseases that are prone to intracranial bleeding. We aimed to determine whether presence of cerebral microbleeds can identify patients at high risk of symptomatic intracranial haemorrhage when anticoagulated for atrial fibrillation after recent ischaemic stroke or transient ischaemic attack.Methods: Our observational, multicentre, prospective inception cohort study recruited adults aged 18 years or older from 79 hospitals in the UK and one in the Netherlands with atrial fibrillation and recent acute ischaemic stroke or transient ischaemic attack, treated with a vitamin K antagonist or direct oral anticoagulant, and followed up for 24 months using general practitioner and patient postal questionnaires, telephone interviews, hospital visits, and National Health Service digital data on hospital admissions or death. We excluded patients if they could not undergo MRI, had a definite contraindication to anticoagulation, or had previously received therapeutic anticoagulation. The primary outcome was symptomatic intracranial haemorrhage occurring at any time before the final follow-up at 24 months. The log-rank test was used to compare rates of intracranial haemorrhage between those with and without cerebral microbleeds. We developed two prediction models using Cox regression: first, including all predictors associated with intracranial haemorrhage at the 20% level in univariable analysis; and second, including cerebral microbleed presence and HAS-BLED score. We then compared these with the HAS-BLED score alone. This study is registered with ClinicalTrials.gov, number NCT02513316.Findings: Between Aug 4, 2011, and July 31, 2015, we recruited 1490 participants of whom follow-up data were available for 1447 (97%), over a mean period of 850 days (SD 373; 3366 patient-years). The symptomatic intracranial haemorrhage rate in patients with cerebral microbleeds was 9·8 per 1000 patient-years (95% CI 4·0-20·3) compared with 2·6 per 1000 patient-years (95% CI 1·1-5·4) in those without cerebral microbleeds (adjusted hazard ratio 3·67, 95% CI 1·27-10·60). Compared with the HAS-BLED score alone (C-index 0·41, 95% CI 0·29-0·53), models including cerebral microbleeds and HAS-BLED (0·66, 0·53-0·80) and cerebral microbleeds, diabetes, anticoagulant type, and HAS-BLED (0·74, 0·60-0·88) predicted symptomatic intracranial haemorrhage significantly better (difference in C-index 0·25, 95% CI 0·07-0·43, p=0·0065; and 0·33, 0·14-0·51, p=0·00059, respectively).Interpretation: In patients with atrial fibrillation anticoagulated after recent ischaemic stroke or transient ischaemic attack, cerebral microbleed presence is independently associated with symptomatic intracranial haemorrhage risk and could be used to inform anticoagulation decisions. Large-scale collaborative observational cohort analyses are needed to refine and validate intracranial haemorrhage risk scores incorporating cerebral microbleeds to identify patients at risk of net harm from oral anticoagulation.Funding: The Stroke Association and the British Heart Foundation. [ABSTRACT FROM AUTHOR]