Thromboembolic events around the time of cardioversion for atrial fibrillation in patients receiving antiplatelet treatment in the ACTIVE trials.

AIMS: It is unknown whether cardioversion of atrial fibrillation causes thromboembolic events or is a risk marker. To assess causality, we examined the temporal pattern of thromboembolism in patients having cardioversion. METHODS AND RESULTS: We studied patients randomized to aspirin or aspirin plus clopidogrel in the ACTIVE trials, comparing the thromboembolic rate in the peri-cardioversion period (30 days before until 30 days after) to the rate during follow-up, remote from cardioversion. Among 962 patients, the 30-day thromboembolic rate remote from cardioversion was 0.16%; while it was 0.73% in the peri-cardioversion period [hazard ratio (HR) 4.1, 95% confidence interval (CI) 2.1-7.9]. The 30-day thromboembolic rates in the periods immediately before and after cardioversion were 0.47% and 0.96%, respectively (HR 2.2, 95% CI 0.7-7.1). Heart failure (HF) hospitalization increased in the peri-cardioversion period (HR 11.5, 95% CI 6.8-19.4). Compared to baseline, the thromboembolic rate in the 30 days following cardioversion was increased both in patients who received oral anticoagulation or a transoesophageal echocardiogram prior to cardioversion (HR 7.9, 95% CI 2.8-22.4) and in those who did not (HR 4.8, 95% CI 1.6-14.9) (interaction P = 0.2); the risk was also increased with successful (HR 4.5; 95% CI 2.0-10.5) and unsuccessful (HR 10.2; 95% CI 2.3-44.9) cardioversion. CONCLUSIONS: Thromboembolic risk increased in the 30 days before cardioversion and persisted until 30 days post-cardioversion, in a pattern similar to HF hospitalization. These data suggest that the increased thromboembolic risk around the time of cardioversion may not be entirely causal, but confounded by the overall clinical deterioration of patients requiring cardioversion.

Rationale and design of the Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation (ARTESiA) trial.

BACKGROUND: Device-detected subclinical atrial fibrillation (AF) refers to infrequent, short-lasting, asymptomatic AF that is detected only with long-term continuous monitoring. Subclinical AF is common and associated with an increased risk of stroke; however, the risk of stroke with subclinical AF is lower than for clinical AF, and very few patients with subclinical AF alone have been included in large AF anticoagulation trials. The net benefit of anticoagulation in patients with subclinical AF is unknown. DESIGN: ARTESiA is a prospective, multicenter, double-blind, randomized controlled trial, recruiting patients with subclinical AF detected by an implanted pacemaker, defibrillator, or cardiac monitor, and who have additional risk factors for stroke. Patients with clinical AF documented by surface electrocardiogram will be excluded from the study. Participants will be randomized to receive either apixaban (according to standard AF dosing) or aspirin 81mg daily. The primary outcome is the composite of stroke, transient ischemic attack with diffusion-weighted magnetic resonance imaging evidence of cerebral infarction, and systemic embolism. Approximately 4,000 patients will be enrolled from around 230 clinical sites, with an anticipated mean follow-up of 36months until 248 adjudicated primary outcome events have occurred. SUMMARY: ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with subclinical AF and additional risk factors.

Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of paroxysmal atrial fibrillation (RAAFT-2): a randomized trial.

IMPORTANCE: Atrial fibrillation (AF) is the most common rhythm disorder seen in clinical practice. Antiarrhythmic drugs are effective for reduction of recurrence in patients with symptomatic paroxysmal AF. Radiofrequency ablation is an accepted therapy in patients for whom antiarrhythmic drugs have failed; however, its role as a first-line therapy needs further investigation. OBJECTIVE: To compare radiofrequency ablation with antiarrhythmic drugs (standard therapy) in treating patients with paroxysmal AF as a first-line therapy. DESIGN, SETTING, AND PATIENTS: A randomized clinical trial involving 127 treatment-naive patients with paroxysmal AF were randomized at 16 centers in Europe and North America to received either antiarrhythmic therapy or ablation. The first patient was enrolled July 27, 2006; the last patient, January 29, 2010. The last follow-up was February 16, 2012. INTERVENTIONS: Sixty-one patients in the antiarrhythmic drug group and 66 in the radiofrequency ablation group were followed up for 24 months. MAIN OUTCOMES AND MEASURES: The time to the first documented atrial tachyarrhythmia of more than 30 seconds (symptomatic or asymptomatic AF, atrial flutter, or atrial tachycardia), detected by either scheduled or unscheduled electrocardiogram, Holter, transtelephonic monitor, or rhythm strip, was the primary outcome. Secondary outcomes included symptomatic recurrences of atrial tachyarrhythmias and quality of life measures assessed by the EQ-5D tool. RESULTS: Forty-four patients (72.1%) in the antiarrhythmic group and in 36 patients (54.5%) in the ablation group experienced the primary efficacy outcome (hazard ratio [HR], 0.56 [95% CI, 0.35-0.90]; P = .02). For the secondary outcomes, 59% in the drug group and 47% in the ablation group experienced the first recurrence of symptomatic AF, atrial flutter, atrial tachycardia (HR, 0.56 [95% CI, 0.33-0.95]; P = .03). No deaths or strokes were reported in either group; 4 cases of cardiac tamponade were reported in the ablation group. In the standard treatment group, 26 patients (43%) underwent ablation after 1-year. Quality of life was moderately impaired at baseline in both groups and improved at the 1 year follow-up. However, improvement was not significantly different among groups. CONCLUSIONS AND RELEVANCE: Among patients with paroxysmal AF without previous antiarrhythmic drug treatment, radiofrequency ablation compared with antiarrhythmic drugs resulted in a lower rate of recurrent atrial tachyarrhythmias at 2 years. However, recurrence was frequent in both groups. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00392054.

The Anti-Coronavirus Therapies (ACT) Trials: Design, Baseline Characteristics, and Challenges.

Background: Effective treatments for COVID-19 are urgently needed, but conducting randomized trials during the pandemic has been challenging. Methods: The Anti-Coronavirus Therapy (ACT) trials are parallel factorial international trials that aimed to enroll 3500 outpatients and 2500 inpatients with symptomatic COVID-19. The outpatient trial is evaluating colchicine vs usual care, and aspirin vs usual care. The primary outcome for the colchicine randomization is hospitalization or death, and for the aspirin randomization, it is major thrombosis, hospitalization, or death. The inpatient trial is evaluating colchicine vs usual care, and the combination of rivaroxaban 2.5 mg twice daily and aspirin 100 mg once daily vs usual care. The primary outcome for the colchicine randomization is need for high-flow oxygen, need for mechanical ventilation, or death, and for the rivaroxaban plus aspirin randomization, it is major thrombotic events, need for high-flow oxygen, need for mechanical ventilation, or death. Results: At the completion of enrollment on February 10, 2022, the outpatient trial had enrolled 3917 patients, and the inpatient trial had enrolled 2611 patients. Challenges encountered included lack of preliminary data about the interventions under evaluation, uncertainties related to the expected event rates, delays in regulatory and ethics approvals, and in obtaining study interventions, as well as the changing pattern of the COVID-19 pandemic. Conclusions: The ACT trials will determine the efficacy of anti-inflammatory therapy with colchicine, and antithrombotic therapy with aspirin given alone or in combination with rivaroxaban, across the spectrum of mild, moderate, and severe COVID-19. Lessons learned from the conduct of these trials will inform planning of future trials.

Contexte: Il est urgent de mettre au point des traitements efficaces contre la COVID-19, mais il n'est pas facile de réaliser des essais à répartition aléatoire dans un contexte pandémique. Méthodologie: Les essais internationaux factoriels ACT (Anti-Coronavirus Therapy) avaient un objectif d'inscription de 3 500 patients externes et de 2 500 patients hospitalisés présentant une COVID-19 symptomatique. L'essai mené auprès de patients externes visait à évaluer la colchicine par rapport aux soins habituels, et l'aspirine par rapport aux soins habituels. Le paramètre d'évaluation principal au terme de la répartition aléatoire des patients était l'hospitalisation ou le décès dans le groupe traité par la colchicine, et la thrombose majeure, l'hospitalisation ou le décès dans le groupe traité par l'aspirine. L'essai mené auprès de patients hospitalisés visant à évaluer la colchicine par rapport aux soins habituels, et un traitement associant le rivaroxaban à 2,5 mg deux fois par jour et l'aspirine à 100 mg une fois par jour par rapport aux soins habituels. Le paramètre d'évaluation principal au terme de la répartition aléatoire des patients était le recours à l'oxygénothérapie à haut débit ou à la ventilation mécanique ou le décès dans le groupe traité par la colchicine, et la survenue de manifestations thrombotiques majeures, le recours à l'oxygénothérapie à haut débit ou à la ventilation mécanique ou le décès dans le groupe traité par l'association rivaroxaban-aspirine. Résultats: À la fin de la période d'inscription, le 10 février 2022, 3 917 patients externes et 2 611 patients hospitalisés formaient la population des essais. Certains aspects se sont révélés problématiques, notamment le manque de données préliminaires sur les interventions à évaluer, les incertitudes liées aux taux d'événements prévus, les retards touchant les approbations réglementaires et éthiques et les interventions de recherche, de même que l'évolution de la pandémie de COVID-19. Conclusions: Les essais ACT détermineront l'efficacité du traitement anti-inflammatoire par la colchicine et du traitement antithrombotique par l'aspirine, administrée seule ou en association avec le rivaroxaban, contre la COVID-19 légère, modérée ou sévère. Les leçons tirées de ces essais orienteront la planification d'essais ultérieurs.

Long-Term Treatment with Apixaban in Patients with Atrial Fibrillation: Outcomes during the Open-Label Extension following AVERROES.

BACKGROUND: AVERROES, a randomized controlled trial in high-risk patients with atrial fibrillation, unsuitable for vitamin K antagonist therapy, demonstrated efficacy and safety of apixaban compared with aspirin. At the conclusion of the double-blind phase, an open-label extension was initiated to allow study participants to receive apixaban until it became locally available. This study reports outcomes of patients on apixaban during the open-label extension. METHODS: Rates of stroke or systemic embolism, hemorrhagic stroke, major bleeding, and other outcomes during the open-label extension are reported. RESULTS: Of the 5,599 participants enrolled in AVERROES, 3,275 (58.5%) received apixaban during the open-label extension. Median (interquartile range) follow-up in the open-label extension was 3.0 (2.5-3.5) years. The rate of stroke or systemic embolism during the open-label extension was 1.0% per year, and the annual rates of hemorrhagic stroke and major bleeding were 0.3 and 1.2%, respectively. After adjustment for imbalances in patient variables, event rates in patients on apixaban during the open-label extension were similar to those of patients receiving apixaban during AVERROES. Additional analyses in all patients who received apixaban, at any time from the start of AVERROES to the end of the open-label extension, were performed. This cohort (n = 4,414) showed annual event rates of 1.1% for stroke or systemic embolism, 0.3% for hemorrhagic stroke, and 1.2% for major bleeding. CONCLUSION: During the open-label extension, annual rates of stroke or systemic embolism, hemorrhagic stroke, and major bleeding remained as low as those observed during apixaban treatment in AVERROES. These data support the long-term efficacy and safety of apixaban in patients with atrial fibrillation.