Preventing Stroke in Patients with Atrial Fibrillation
A multi-part session titled “Stroke in Atrial Fibrillation: A Preventable Condition” was begun by Michael D. Ezekowitz, MB, ChB, DPhil, of the Lankenau Institute for Medical Research. In his presentation titled “All Novel Agents are Preferred to Warfarin,” he discussed the benefits of novel anticoagulant agents. They are short acting with rapid onset of action, require no routine monitoring, and have fewer drug-drug interactions. However, compliance will be a challenge with these medications, especially those with twice-daily dosing. The clinical indications are new onset atrial fibrillation (AF) with or without cardioversion, poor control on warfarin (although this is not well defined), treatment with aspirin for stroke prevention, and good control on warfarin (because the new agents confer a lower risk of hemorrhagic stroke). Dr Ezekowitz reviewed multiple studies that suggested a clear benefit of novel agents dabigatran, rivaroxaban, and apixaban when compared with warfarin. Both dabigatran and rivaroxaban have been associated with increased GI bleeding. Apixaban is the only novel agent to show reductions in all-cause mortality and major bleeding. Data on edoxaban are not yet available.
The next presentation was titled “Aspirin Dead, Warfarin Still Alive,” by Kristen Patton, MD, associate professor of cardiology at the University of Washington Medical Center. Dr Patton began by reviewing older data that showed a more favorable relative risk reduction of stroke from AF with warfarin when compared with aspirin. She also reviewed literature that supported the change in the European Society of Cardiology’s (ESC’s) guidelines for not recommending aspirin for many patients. Although the data indicate that warfarin is inferior to novel anticoagulant agents, some patients need to remain on warfarin due to cost or medical reasons (renal disease or valvular AF, for example). For this reason, clinicians still need to find a way to make warfarin safer. Overall, Dr Patton said, stroke prevention management depends on patient characteristics.
“Left Atrial Appendage Occlusion Devices: Techniques and Different Devices” was presented by Horst Sievert, MD, professor at the CardioVascular Center Frankfurt, Sankt Katharinen in Germany. Dr Sievert gave a review of left atrial appendage (LAA) devices, which are intended to reduce the risk of stroke, but are not currently approved in the United States. Many of the devices in development have high technical success rates, but there are risks of perioperative complications. Several devices are in development, mostly endocardial, but Dr Sievert also described a device with an epicardial approach, which eliminates the need for the device to be left in the heart. According to Dr Sievert, the PROTECT AF trial provided proof that LAA closure with the Watchman device is superior to anticoagulation with warfarin, and the Amulet and WaveCrest devices seem to have comparable results.
The last presentation of this session, “Left Atrial Appendage Occlusion: A Valid Option to Anticoagulation for Long-term Prevention of Stroke,” was presented by Saibal Kar, MD, director of the Cardiovascular Intervention Center Research at Cedars-Sinai Medical Center in Los Angeles. Review of the data on LAA occlusion devices (most of which come from the Watchman device), especially the PROTECT AF study, suggests that there is a clear mortality benefit (60% reduction in cardiac mortality at 4 years) with these devices. Complications appear to be procedure-related with few late events. LAA occlusion is a “very reasonable alternative to medical therapy,” according to Dr Kar.