Four major studies presented at AHA 2025 are reshaping strategies for managing atrial fibrillation (AFib) in complex clinical scenarios. OCEAN addresses whether ongoing anticoagulation is necessary after successful catheter ablation, offering fresh insights into stroke prevention and bleeding risk. ADAPT AF-DES and OPTIMA-AF explore optimal antithrombotic approaches after PCI, while CLOSURE-AF evaluates left atrial appendage closure (LAAC) vs. medical therapy in high-risk patients.

In OCEAN, simultaneously published in NEJM, rivaroxaban did not result in a significantly lower incidence of stroke, systemic embolism or new covert embolic stroke compared with aspirin among patients at high risk for stroke who had undergone a catheter ablation for atrial AFib at least one year prior.

Researchers randomized 1,284 patients to either aspirin (70-120 mg daily) or rivaroxaban (15 mg daily) with an average follow-up period of three years. The primary outcome was a composite of stroke, systemic embolism, or new covert embolic stroke.

Overall results showed a primary-outcome event occurred in five patients assigned to rivaroxaban compared with nine patients in the aspirin group. Researchers noted that new cerebral infarcts measuring less than 15 mm occurred in 3.9% of patients receiving rivaroxaban (n=22/568) and 4.4% receiving aspirin (n=26/590). However, fatal or major bleeding (the composite primary safety outcome) was higher in the rivaroxaban group compared with the aspirin group at 3 years (1.6% vs. 0.6%).

“In essence, catheter ablation for AFib reduced the recurrence of AFib and can also reduce the risk of stroke associated with this common heart rhythm condition,” said Atul Verma, MD, FACC, in presenting the findings. “With the notably increased bleeding risk associated with rivaroxaban, we concluded that the anticoagulant did not offer any advantages in comparison to aspirin for reducing what we found to be a low stroke risk in these individuals. Now, we can advise patients that it may be safe to stop blood thinners, even if they have a moderate stroke risk.”

In ADAPT AF-DES, also simultaneously published in NEJM, use of non–vitamin K antagonist oral anticoagulant (NOAC) monotherapy was noninferior to combination therapy for net adverse clinical events in patient with AFib who had undergone drug-eluting stent implantation at least one-year prior.

The trial randomly assigned 960 patients (mean age 71 years/21% women) from 32 centers in South Korea to either NOAC monotherapy or combination therapy (NOAC plus clopidogrel). The primary end point – a composite of death from any cause, myocardial infarction, stent thrombosis, stroke, systemic embolism, or major bleeding or clinically relevant nonmajor bleeding at 12 months – occurred in 46 patients in the monotherapy group compared with 82 patients in the combination therapy group.

In OPTIMA-AF, researchers in Japan compared one-month vs. 12-month dual antithrombotic therapy with a direct oral anticoagulant and a P2Y12 inhibitor, followed by the oral anticoagulant alone, with outcomes assessed at 12 months. Approximately 1,000 adults who had AFib and who had received a coronary stent took part in the trial.

Overall findings found that a one-month course of dual clot-preventing therapy followed by a single clot-prevention medication for the remainder of the standard 12-month regimen was as effective as one year of continuous dual therapy for preventing stroke, heart attack and death. Additionally, patients treated with the one-month regimen experienced fewer bleeding problems than those in the year-long dual-treatment group.

“These results may help doctors feel more confident in prescribing shorter durations of dual antithrombotic therapy after stenting among some patients with AFib,” said Yohei Sotomi, MD, FACC, in presenting the findings. “By reducing the length of time individuals are exposed to combination therapy, we can lower the risk of bleeding – a serious concern for many older adults – without increasing their risk of stroke or heart attack.”

In CLOSURE-AF, researchers in Germany found that physician-directed standard medical therapy, which included anticoagulation medications when applicable, was better than LAAC in patients with AFib and at high risk of stroke and major bleeding.

“We expected that catheter-based LAAC would be comparable to physician-directed standard medical care often using blood thinning anticoagulant medications,” said study lead researcher Ulf Landmesser, MD. “However, this was not the case in this trial of older patients at very high risk of bleeding and stroke.

Landmesser did note that the results of LAAC are different for lower-risk patients and that other studies are currently exploring whether standard care and LAAC are comparable in this patient group. Additionally, ongoing studies comparing LAAC in addition to blood thinning in very high-risk patients are also underway.

Clinical Topics: Acute Coronary Syndromes, Anticoagulation Management, Arrhythmias and Clinical EP, Anticoagulation Management and ACS, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: AHA Annual Scientific Sessions, AHA25, Arrhythmias, Cardiac, Anticoagulants, Acute Coronary Syndrome