atrial fibrillation

Background: The optimal long-term antithrombotic strategy in patients with atrial fibrillation (AF) and stable coronary artery disease (CAD) remains uncertain. Individual randomized controlled trials (RCTs) had variations in their reported results and were not powered for effectiveness outcomes.

Objectives: This study aimed to pool the results of RCTs comparing the effectiveness and safety of oral anticoagulation (OAC) monotherapy vs OAC plus single antiplatelet therapy (SAPT) in patients with AF and stable CAD.

Methods: We systematically searched PubMed, Embase, and ClinicalTrials.gov until September 09, 2024. The primary effectiveness outcome was a composite of myocardial infarction, ischemic stroke, systemic embolism, or death. The primary safety outcome was major bleeding. We obtained unpublished results from principal investigators of the included RCTs, as needed, to calculate pooled HRs and 95% CIs and to perform prespecified subgroup analyses.

Results: Among 690 screened records, 4 RCTs with 4,092 randomized patients were included (2 using edoxaban, 1 using rivaroxaban, and 1 using any oral anticoagulant; mean age 73.9 years, 20.1% women). The median follow-up durations ranged from 12 to 30 months (overall estimated weighted mean follow-up of 21.9 months). There were no statistically significant differences between OAC monotherapy vs OAC plus SAPT in the primary effectiveness outcome (7.3% vs 8.2%; HR: 0.90; 95% CI: 0.72-1.12), myocardial infarction (1.0% vs 0.7%; HR: 1.51; 95% CI: 0.75-3.04), ischemic stroke (1.9% vs 2.1%; HR: 0.89; 95% CI: 0.57-1.37), all-cause death (4.2% vs 5.3%; HR: 0.94; 95% CI: 0.49-1.80), or cardiovascular death (2.4% vs 3.0%; HR: 0.79; 95% CI: 0.54-1.15). OAC monotherapy was associated with a lower risk of major bleeding than OAC plus SAPT (3.3% vs 5.7%; HR: 0.59; 95% CI: 0.44-0.79). Subgroup analyses did not show significant interactions for effectiveness but suggested that the magnitude of bleeding reduction may be greater among men (Pinteraction = 0.03) and among patients with diabetes mellitus (Pinteraction = 0.04).

Conclusions: In patients with AF and stable CAD, OAC monotherapy, compared with OAC plus SAPT, was not associated with a statistically significant increased risk of ischemic events but resulted in a significantly reduced risk of bleeding.

Importance: In the US, approximately 10.55 million adults have atrial fibrillation (AF). AF is associated with significantly increased risk of stroke, heart failure, myocardial infarction, dementia, chronic kidney disease, and mortality.

Observations: Symptoms of AF include palpitations, dyspnea, chest pain, presyncope, exertional intolerance, and fatigue, although approximately 10% to 40% of people with AF are asymptomatic. AF can be detected incidentally during clinical encounters, with wearable devices, or through interrogation of cardiac implanted electronic devices. In patients presenting with ischemic stroke without diagnosed AF, an implantable loop recorder (ie, subcutaneous telemetry device) can evaluate patients for intermittent AF. The 2023 American College of Cardiology (ACC)/American Heart Association (AHA)/American College of Clinical Pharmacy (ACCP)/Heart Rhythm Society (HRS) Guideline writing group proposed 4 stages of AF evolution: stage 1, at risk, defined as patients with AF-associated risk factors (eg, obesity, hypertension); stage 2, pre-AF, signs of atrial pathology on electrocardiogram or imaging without AF; stage 3, the presence of paroxysmal (recurrent AF episodes lasting ≤7 days) or persistent (continuous AF episode lasting >7 days) AF subtypes; and stage 4, permanent AF. Lifestyle and risk factor modification, including weight loss and exercise, to prevent AF onset, recurrence, and complications are recommended for all stages. In patients with estimated risk of stroke and thromboembolic events of 2% or greater per year, anticoagulation with a vitamin K antagonist or direct oral anticoagulant reduces stroke risk by 60% to 80% compared with placebo. In most patients, a direct oral anticoagulant, such as apixaban, rivaroxaban, or edoxaban, is recommended over warfarin because of lower bleeding risks. Compared with anticoagulation, aspirin is associated with poorer efficacy and is not recommended for stroke prevention. Early rhythm control with antiarrhythmic drugs or catheter ablation to restore and maintain sinus rhythm is recommended by the 2023 ACC/AHA/ACCP/HRS Guideline for some patients with AF. Catheter ablation is first-line therapy in patients with symptomatic paroxysmal AF to improve symptoms and slow progression to persistent AF. Catheter ablation is also recommended for patients with AF who have heart failure with reduced ejection fraction (HFrEF) to improve quality of life, left ventricular systolic function, and cardiovascular outcomes, such as rates of mortality and heart failure hospitalization.

Conclusions and relevance: AF is associated with increased rates of stroke, heart failure, and mortality. Lifestyle and risk factor modification are recommended to prevent AF onset, recurrence, and complications, and oral anticoagulants are recommended for those with an estimated risk of stroke or thromboembolic events of 2% or greater per year. Early rhythm control using antiarrhythmic drugs or catheter ablation is recommended in select patients with AF experiencing symptomatic paroxysmal AF or HFrEF.

Background: Atrial fibrillation (AF) has consistently been associated with a higher risk of incident dementia. Observational evidence has suggested catheter ablation may be associated with a lower risk of dementia in patients with AF, but further research is needed. The objectives of this study were to use a global health research network to examine associations between catheter ablation, incident dementia and mortality in older adults with AF, and amongst subgroups by age, sex, co-morbidity status, and oral anticoagulant use.

Methods: The research network primarily included healthcare organizations in the United States. This network was searched on 28th September 2022 for patients aged ≥65 years with a diagnosis of AF received at least 5 years prior to the search date. Cox proportional hazard models were run on propensity-score matched cohorts.

Results: After propensity score matching, 20,746 participants (mean age 68 years; 59% male) were included in each cohort with and without catheter ablation. The cohorts were well balanced for age, sex, ethnicity, co-morbidities, and cardiovascular medications received. The risk of dementia was significantly lower in the catheter ablation cohort (Hazard Ratio 0.52, 95% confidence interval: 0.45-0.61). The catheter ablation cohort also had a lower risk of all-cause mortality (Hazard Ratio 0.58, 95% confidence interval: 0.55-0.61). These associations remained in subgroup analyses in individuals aged 65-79 years, ≥80 years, males, females, participants who received OACs during follow-up, participants with paroxysmal and non-paroxysmal AF, and participants with and without hypertension, diabetes mellitus, ischemic stroke, chronic kidney disease and heart failure, including heart failure with preserved ejection fraction and heart failure with reduced ejection fraction.

Conclusion: The observed lower risk of dementia and mortality with catheter ablation could be an important consideration when determining appropriate patient-centered rhythm control strategies for patients with AF. Further studies including data on the success of ablation are required.

Patients with suspected cerebral ischemia should be urgently assessed to distinguish between transient ischemic attack (TIA), minor stroke or mimics such as migraine, seizure, vertigo or syncope.

The Canadian TIA Score can be used to determine risk for early subsequent stroke in patients with a suspected TIA or minor stroke.

All patients with TIA or minor stroke should undergo urgent electrocardiography and computed tomography of the head.

Clinicians should order early vascular imaging for patients at moderate or high risk of subsequent stroke; urgent revascularization should be considered if there is more than 50% arterial stenosis congruent with symptom presentation.

Clinicians should prescribe dual antiplatelet drugs for high-risk patients, single antiplatelet agents for low-risk patients or direct oral anticoagulants for patients with atrial fibrillation.

All patients with TIA or minor stroke should be counselled about modifiable lifestyle factors (including smoking cessation), be treated with statins and take steps toward optimizing blood pressure, including treatment with antihypertensive drugs, if necessary.