"Previous studies have shown a causal and dose-response relation between alcohol and AF. Our study found that alcohol is an independent risk factor for stroke in patients with AF. Alcohol might induce AF, leading to embolic stroke, or there could be a specific alcohol effect that causes systemic or cerebral thromboembolism. Using alcohol-related hospitalization as a proxy for alcohol abuse likely underestimates the extent of the problem and does not allow grading of the amount of alcohol consumed.
"Doctors should ask their AF patients about alcohol use and advise patients to cut down if they are drinking more than is recommended. The beneficial link between oral anticoagulant use and ischemic stroke in this low-risk population without a recognized indication for these drugs needs further investigation, including the benefit to harm (bleeding) ratio," Dr. Al-Khalili concluded.
New Oral Anticoagulants Provide Same Stroke Prevention as Warfarin But Cause Less Bleeding
The new oral anticoagulants provide the same stroke prevention as warfarin, but cause less intracranial bleeding, according to research presented by Laila Staerk, PhD, a research fellow at Herlev and Gentofte University Hospital in Hellerup, Denmark.
"Atrial fibrillation is the most common cardiac rhythm disorder and currently affects more than 10 million Europeans," said Dr. Staerk. "Atrial fibrillation is associated with a fivefold risk of stroke, potentially leading to disability and death. In the next four decades, the number of patients with atrial fibrillation is expected to triple, so the number of Europeans diagnosed could rise to a staggering 25 to 30 million."
Patients with atrial fibrillation are treated life-long with oral anticoagulation to reduce their risk of stroke. But treatment with non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (eg, warfarin) lowers the risk of stroke at the cost of increased bleeding risk.
Several treatment options are available, and physicians may be unsure about which one to use. "There has been a need to investigate the safety and effectiveness of NOACs versus warfarin in a real-world population, and our Danish registries provide this opportunity," said Dr. Staerk.
The current study compared the risk of stroke and intracranial bleeding associated with NOACs (ie, dabigatran, rivaroxaban, and apixaban) versus that associated with warfarin in a real-world setting. The study was conducted at the Cardiovascular Research Centre at Herlev and Gentofte University Hospital. It included 43,299 patients with atrial fibrillation who were recruited from Danish nationwide administrative registries.
Approximately 42% of patients were taking warfarin, while 29%, 16%, and 13% were taking dabigatran, apixaban, and rivaroxaban, respectively. During follow-up, stroke occurred in 1,054 patients, and there were 261 intracranial bleedings.
The risk of having a stroke within one year was similar between the NOAC and warfarin groups and ranged from 2.0% to 2.5%. At one year, the risk of intracranial bleeding was significantly lower in patients treated with dabigatran and apixaban (0.3% to 0.4%), compared with that in those treated with warfarin (0.6%).
"The inclusion and exclusion criteria in our study were broadly similar for patients initiating NOACs or warfarin, and this gave a straightforward opportunity to directly compare the treatment regimens, which is in contrast to the randomized trials. The results suggest that although they have similar effects in preventing stroke, dabigatran and apixaban were associated with a safer use regarding the absolute one-year risk of intracranial bleeding," said Dr Staerk. "Our results complement the large randomized phase III trials by providing real-world data on stroke and intracranial bleeding with NOACs versus warfarin, since fragile patients were not excluded from our nationwide cohort. For example, patients with increased risk of bleeding, liver disease, and chronic kidney disease are less represented in trials."