Atrial Fibrillation Ablation in Heart Failure With Reduced vs Preserved Ejection Fraction: A Systematic Review and Meta-Analysis.

Importance: Catheter ablation is associated with reduced heart failure (HF) hospitalization and death in select patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF). However, the benefit in patients with HF with preserved ejection fraction (HFpEF) is uncertain. Objective: To investigate whether catheter ablation for AF is associated with reduced HF-related outcomes according to HF phenotype. Data Source: A systematic search of MEDLINE, Embase, and Cochrane Central was conducted among studies published from inception to September 2023. Study Selection: Parallel-group randomized clinical trials (RCTs) comparing catheter ablation with conventional rate or rhythm control therapies in patients with HF, New York Heart Association functional class II or greater, and a history of paroxysmal or persistent AF were included. Pairs of independent reviewers screened 7531 titles and abstracts, of which 12 RCTs and 4 substudies met selection criteria. Data Extraction and Synthesis: Data were abstracted in duplicate according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Pooled effect estimates were calculated using random-effects Mantel-Haenszel models. Interaction P values were used to test for subgroup differences. Main Outcomes and Measures: The primary outcome was HF events, defined as HF hospitalization, clinically significant worsening of HF, or unscheduled visits to a clinician for treatment intensification. Secondary outcomes included cardiovascular and all-cause mortality. Results: A total of 12 RCTs with 2465 participants (mean [SD] age, 65.3 [9.7] years; 658 females [26.7%]) were included; there were 1552 participants with HFrEF and 913 participants with HFpEF. Compared with conventional rate or rhythm control, catheter ablation was associated with reduced risk of HF events in HFrEF (risk ratio [RR], 0.59; 95% CI, 0.48-0.72), while there was no benefit in patients with HFpEF (RR, 0.93; 95% CI, 0.65-1.32) (P for interaction = .03). Catheter ablation was associated with reduced risk of cardiovascular death compared with conventional therapies in HFrEF (RR, 0.49; 95% CI, 0.34-0.70) but a differential association was not detected in HFpEF (RR, 0.91; 95% CI, 0.46-1.79) (P for interaction = .12). Similarly, no difference in the association of catheter ablation with all-cause mortality was found between HFrEF (RR vs conventional therapies, 0.63; 95% CI, 0.47-0.86) and HFpEF (RR vs conventional therapies, 0.95; 95% CI, 0.39-2.30) groups (P for interaction = .39). Conclusions and Relevance: This study found that catheter ablation for AF was associated with reduced risk of HF events in patients with HFrEF but had limited or no benefit in HFpEF. Results from ongoing trials may further elucidate the role of catheter ablation for AF in HFpEF.

Estimating Vitamin K Antagonist Anticoagulation Benefit in People With Atrial Fibrillation Accounting for Competing Risks: Evidence From 12 Randomized Trials.

BACKGROUND: Patients with atrial fibrillation have a high mortality rate that is only partially attributable to vascular outcomes. The competing risk of death may affect the expected anticoagulant benefit. We determined if competing risks materially affect the guideline-endorsed estimate of anticoagulant benefit. METHODS: We conducted a secondary analysis of 12 randomized controlled trials that randomized patients with atrial fibrillation to vitamin K antagonists (VKAs) or either placebo or antiplatelets. For each participant, we estimated the absolute risk reduction (ARR) of VKAs to prevent stroke or systemic embolism using 2 methods-first using a guideline-endorsed model (CHA2DS2-VASc) and then again using a competing risk model that uses the same inputs as CHA2DS2-VASc but accounts for the competing risk of death and allows for nonlinear growth in benefit. We compared the absolute and relative differences in estimated benefit and whether the differences varied by life expectancy. RESULTS: A total of 7933 participants (median age, 73 years, 36% women) had a median life expectancy of 8 years (interquartile range, 6-12), determined by comorbidity-adjusted life tables and 43% were randomized to VKAs. The CHA2DS2-VASc model estimated a larger ARR than the competing risk model (median ARR at 3 years, 6.9% [interquartile range, 4.7%-10.0%] versus 5.2% [interquartile range, 3.5%-7.4%]; P<0.001). ARR differences varied by life expectancies: for those with life expectancies in the highest decile, 3-year ARR difference (CHA2DS2-VASc model - competing risk model 3-year risk) was -1.3% (95% CI, -1.3% to -1.2%); for those with life expectancies in the lowest decile, 3-year ARR difference was 4.7% (95% CI, 4.5%-5.0%). CONCLUSIONS: VKA anticoagulants were exceptionally effective at reducing stroke risk. However, VKA benefits were misestimated with CHA2DS2-VASc, which does not account for the competing risk of death nor decelerating treatment benefit over time. Overestimation was most pronounced when life expectancy was low and when the benefit was estimated over a multiyear horizon.

Bleeding Outcomes in Patients Treated With Asundexian in Phase II Trials.

BACKGROUND: Phase II trials of asundexian were underpowered to detect important differences in bleeding. OBJECTIVES: The goal of this study was to obtain best estimates of effects of asundexian vs active control/placebo on major and clinically relevant nonmajor (CRNM) and all bleeding, describe most common sites of bleeding, and explore association between asundexian exposure and bleeding. METHODS: We performed a pooled analysis of 3 phase II trials of asundexian in patients with atrial fibrillation (AF), recent acute myocardial infarction (AMI), or stroke. Bleeding was defined according to the International Society on Thrombosis and Hemostasis (ISTH) criteria. RESULTS: In patients with AF (n = 755), both asundexian 20 mg and 50 mg once daily vs apixaban had fewer major/CRNM events (3 of 249; incidence rate [IR] per 100 patient-years 5.47 vs 1 of 254 [IR: not calculable] vs 6 of 250 [IR: 11.10]) and all bleeding (12 of 249 [IR: 22.26] vs 10 of 254 [IR: 18.21] vs 26 of 250 [IR: 50.56]). In patients with recent AMI or stroke (n = 3,409), asundexian 10 mg, 20 mg, and 50 mg once daily compared with placebo had similar rates of major/CRNM events (44 of 840 [IR: 7.55] vs 42 of 843 [IR: 7.04] vs 56 of 845 [IR: 9.63] vs 41 of 851 [IR: 6.99]) and all bleeding (107 of 840 [IR: 19.57] vs 123 of 843 [IR: 22.45] vs 130 of 845 [IR: 24.19] vs 129 of 851 [IR: 23.84]). Most common sites of major/CRNM bleeding with asundexian were gastrointestinal, respiratory, urogenital, and skin. There was no significant association between asundexian exposure and major/CRNM bleeding. CONCLUSIONS: Analyses of phase II trials involving >500 bleeds highlight the potential for improved safety of asundexian compared with apixaban and similar safety compared with placebo. Further evidence on the efficacy of asundexian awaits the results of ongoing phase III trials.

Optimizing warfarin dosing for patients with atrial fibrillation using machine learning.

While novel oral anticoagulants are increasingly used to reduce risk of stroke in patients with atrial fibrillation, vitamin K antagonists such as warfarin continue to be used extensively for stroke prevention across the world. While effective in reducing the risk of strokes, the complex pharmacodynamics of warfarin make it difficult to use clinically, with many patients experiencing under- and/or over- anticoagulation. In this study we employed a novel implementation of deep reinforcement learning to provide clinical decision support to optimize time in therapeutic International Normalized Ratio (INR) range. We used a novel semi-Markov decision process formulation of the Batch-Constrained deep Q-learning algorithm to develop a reinforcement learning model to dynamically recommend optimal warfarin dosing to achieve INR of 2.0-3.0 for patients with atrial fibrillation. The model was developed using data from 22,502 patients in the warfarin treated groups of the pivotal randomized clinical trials of edoxaban (ENGAGE AF-TIMI 48), apixaban (ARISTOTLE) and rivaroxaban (ROCKET AF). The model was externally validated on data from 5730 warfarin-treated patients in a fourth trial of dabigatran (RE-LY) using multilevel regression models to estimate the relationship between center-level algorithm consistent dosing, time in therapeutic INR range (TTR), and a composite clinical outcome of stroke, systemic embolism or major hemorrhage. External validation showed a positive association between center-level algorithm-consistent dosing and TTR (R2 = 0.56). Each 10% increase in algorithm-consistent dosing at the center level independently predicted a 6.78% improvement in TTR (95% CI 6.29, 7.28; p < 0.001) and a 11% decrease in the composite clinical outcome (HR 0.89; 95% CI 0.81, 1.00; p = 0.015). These results were comparable to those of a rules-based clinical algorithm used for benchmarking, for which each 10% increase in algorithm-consistent dosing independently predicted a 6.10% increase in TTR (95% CI 5.67, 6.54, p < 0.001) and a 10% decrease in the composite outcome (HR 0.90; 95% CI 0.83, 0.98, p = 0.018). Our findings suggest that a deep reinforcement learning algorithm can optimize time in therapeutic range for patients taking warfarin. A digital clinical decision support system to promote algorithm-consistent warfarin dosing could optimize time in therapeutic range and improve clinical outcomes in atrial fibrillation globally.

Efficacy and Safety of Non-Vitamin-K Antagonist Oral Anticoagulants Versus Warfarin Across the Spectrum of Body Mass Index and Body Weight: An Individual Patient Data Meta-Analysis of 4 Randomized Clinical Trials of Patients With Atrial Fibrillation.

BACKGROUND: The efficacy and safety of non-vitamin-K antagonist oral anticoagulants (NOACs) across the spectrum of body mass index (BMI) and body weight (BW) remain uncertain. METHODS: We analyzed data from COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation), which pooled patient-level data from the 4 pivotal randomized trials of NOAC versus warfarin in patients with atrial fibrillation. The primary efficacy and safety outcomes were stroke or systemic embolic events (stroke/SEE) and major bleeding, respectively; secondary outcomes were ischemic stroke/SEE, intracranial hemorrhage, death, and the net clinical outcome (stroke/SEE, major bleeding, or death). Each outcome was examined across BMI and BW. Because few patients had a BMI <18.5 kg/m2 (n=598), the primary analyses were restricted to those with a BMI ≥18.5 kg/m2. RESULTS: Among 58 464 patients, the median BMI was 28.3 (interquartile range, 25.2-32.2) kg/m2, and the median BW was 81.0 (interquartile range, 70.0-94.3) kg. The event probability of stroke/SEE was lower at a higher BMI irrespective of treatment, whereas the probability of major bleeding was lower at a higher BMI with warfarin but relatively unchanged across BMI with NOACs. NOACs reduced stroke/SEE overall (adjusted hazard ratio [HRadj], 0.80 [95% CI, 0.73-0.88]; P<0.001), with a generally consistent effect across BMI (Ptrend across HRs, 0.48). NOACs also reduced major bleeding overall (HRadj, 0.88 [95% CI, 0.82-0.94]; P<0.001), but with attenuation of the benefit at a higher BMI (trend test across BMI [Ptrend], 0.003). The overall treatment effects of NOACs versus warfarin for secondary outcomes were consistent across BMI, with the exception of the net clinical outcome and death. While these outcomes were overall reduced with NOACs (net clinical outcome, HRadj, 0.91 [95% CI, 0.87-0.95]; P<0.001; death, HRadj, 0.91 [95% CI, 0.86-0.97]; P=0.003), these benefits were attenuated at higher BMI (Ptrend, 0.001 and 0.08, respectively). All findings were qualitatively similar when analyzed across BW. CONCLUSIONS: The treatment effect of NOACs versus warfarin in atrial fibrillation is generally consistent for stroke/SEE across the spectrum of BMI and BW, whereas the reduction in major bleeding is attenuated in those with higher BMI or BW. Death and the net clinical outcome are overall reduced with NOACs over warfarin, although there remain uncertainties for these outcomes at a very high BMI and BW.

Effect of the Factor XIa Inhibitor Asundexian According to Baseline Infarct Pattern and on MRI Covert Infarct Outcomes.

BACKGROUND: Exploratory analysis of the phase 2 PACIFIC-Stroke (Program of Anticoagulation via Inhibition of FXIa by the Oral Compound BAY 2433334-Non-Cardioembolic Stroke) randomized trial suggested that asundexian, an oral factor XIa inhibitor, prevents recurrent stroke and transient ischemic attacks in patients with atherosclerotic stroke. In this post hoc exploratory analysis, we hypothesized that asundexian would be more effective in patients enrolled with large, multiple, or cortical acute infarcts on magnetic resonance imaging than in patients enrolled with a single small subcortical acute infarct, and asundexian would prevent incident cortical covert infarcts. METHODS: In this placebo-controlled double-blinded randomized controlled trial, patients with mild-to-moderate noncardioembolic ischemic stroke were assigned to asundexian (10, 20, or 50 mg once daily) or placebo, in addition to antiplatelet therapy. Brain magnetic resonance imagings were required within 72 hours of randomization and repeated at 26 weeks or at discontinuation of the study drug. RESULTS: Of 1808 randomized patients, 1780 (98.5%) had interpretable baseline magnetic resonance imagings, of which 1628 (91.5%) had ≥1 diffusion-weighted imaging positive acute infarcts. Magnetic resonance imaging follow-up was obtained in 1439 patients, of whom 1358 had no symptomatic stroke during the trial period. Compared with placebo, asundexian 50 mg daily conferred a trend toward reduced risk of recurrent ischemic stroke or incident covert infarcts (hazard ratio, 0.71 [95% CI, 0.45-1.11]) and recurrent ischemic stroke or transient ischemic attack (secondary outcome; hazard ratio, 0.59 [95% CI, 0.33-1.06]) that was not evident in patients with single small subcortical infarcts (hazard ratios, 1.14 [95% CI, 0.62-2.10] and 0.93 [95% CI, 0.28-3.06]). Incident cortical covert infarcts were reduced in patients taking asundexian 50 mg, but the difference was not statistically significant (crude incidence ratio, 0.56 [95% CI, 0.28-1.12]). CONCLUSIONS: These exploratory, unconfirmed results suggest that asundexian may prevent new embolic infarcts but not small artery occlusion. The hypothesis that subtypes of covert brain infarcts respond differently to anticoagulant prevention should be tested in future trials. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT04304508.

Apixaban for Stroke Prevention in Subclinical Atrial Fibrillation.

BACKGROUND: Subclinical atrial fibrillation is short-lasting and asymptomatic and can usually be detected only by long-term continuous monitoring with pacemakers or defibrillators. Subclinical atrial fibrillation is associated with an increased risk of stroke by a factor of 2.5; however, treatment with oral anticoagulation is of uncertain benefit. METHODS: We conducted a trial involving patients with subclinical atrial fibrillation lasting 6 minutes to 24 hours. Patients were randomly assigned in a double-blind, double-dummy design to receive apixaban at a dose of 5 mg twice daily (2.5 mg twice daily when indicated) or aspirin at a dose of 81 mg daily. The trial medication was discontinued and anticoagulation started if subclinical atrial fibrillation lasting more than 24 hours or clinical atrial fibrillation developed. The primary efficacy outcome, stroke or systemic embolism, was assessed in the intention-to-treat population (all the patients who had undergone randomization); the primary safety outcome, major bleeding, was assessed in the on-treatment population (all the patients who had undergone randomization and received at least one dose of the assigned trial drug, with follow-up censored 5 days after permanent discontinuation of trial medication for any reason). RESULTS: We included 4012 patients with a mean (±SD) age of 76.8±7.6 years and a mean CHA2DS2-VASc score of 3.9±1.1 (scores range from 0 to 9, with higher scores indicating a higher risk of stroke); 36.1% of the patients were women. After a mean follow-up of 3.5±1.8 years, stroke or systemic embolism occurred in 55 patients in the apixaban group (0.78% per patient-year) and in 86 patients in the aspirin group (1.24% per patient-year) (hazard ratio, 0.63; 95% confidence interval [CI], 0.45 to 0.88; P = 0.007). In the on-treatment population, the rate of major bleeding was 1.71% per patient-year in the apixaban group and 0.94% per patient-year in the aspirin group (hazard ratio, 1.80; 95% CI, 1.26 to 2.57; P = 0.001). Fatal bleeding occurred in 5 patients in the apixaban group and 8 patients in the aspirin group. CONCLUSIONS: Among patients with subclinical atrial fibrillation, apixaban resulted in a lower risk of stroke or systemic embolism than aspirin but a higher risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; ARTESIA ClinicalTrials.gov number, NCT01938248.).

Colchicine to Prevent Atrial Fibrillation Recurrence After Catheter Ablation: A Randomized, Placebo-Controlled Trial.

BACKGROUND: Inflammation may promote atrial fibrillation (AF) recurrence after catheter ablation. This study aimed to evaluate a short-term anti-inflammatory treatment with colchicine following ablation of AF. METHODS: Patients scheduled for ablation were randomized to receive colchicine 0.6 mg twice daily or placebo for 10 days. The first dose of the study drug was administered within 4 hours before ablation. Atrial arrhythmia recurrence was defined as AF, atrial flutter, or atrial tachycardia >30 s on two 14-day Holters performed immediately and at 3 months following ablation. RESULTS: The modified intention-to-treat population included 199 patients (median age, 61 years; 22% female; 70% first procedure) who underwent radiofrequency (79%) or cryoballoon ablation (21%) of AF. Antiarrhythmic drugs were prescribed at discharge in 149 (75%) patients. Colchicine did not prevent atrial arrhythmia recurrence at 2 weeks (31% versus 32%; hazard ratio [HR], 0.98 [95% CI, 0.59-1.61]; P=0.92) or at 3 months following ablation (14% versus 15%; HR, 0.95 [95% CI, 0.45-2.02]; P=0.89). Postablation chest pain consistent with pericarditis was reduced with colchicine (4% versus 15%; HR, 0.26 [95% CI, 0.09-0.77]; P=0.02) and colchicine increased diarrhea (26% versus 7%; HR, 4.74 [95% CI, 1.95-11.53]; P<0.001). During a median follow-up of 1.3 years, colchicine did not reduce a composite of emergency department visit, cardiovascular hospitalization, cardioversion, or repeat ablation (29 versus 25 per 100 patient-years; HR, 1.18 [95% CI, 0.69-1.99]; P=0.55). CONCLUSIONS: Colchicine administered for 10 days following catheter ablation did not reduce atrial arrhythmia recurrence or AF-associated clinical events, but did reduce postablation chest pain and increase diarrhea.

Outcomes of Patients with a Mechanical Heart Valve and Poor Anticoagulation Control on Warfarin.

BACKGROUND: Patients with a mechanical heart valve (MHV) require oral anticoagulation. Poor anticoagulation control is thought to be associated with adverse outcomes, but data are limited. OBJECTIVE: To assess the risks of clinical outcomes in patients with a MHV and poor anticoagulation control on warfarin. PATIENTS/METHODS: We conducted a retrospective study of consecutive patients undergoing MHV implantation at a tertiary care center (2010-2019). Primary outcome was a composite of ischemic stroke, systemic embolism, or prosthetic valve thrombosis. Major bleeding and death were key secondary outcomes. We constructed multivariable regression models to assess the association between time in therapeutic range (TTR) on warfarin beyond 90 days after surgery with outcomes. RESULTS: We included 671 patients with a MHV (80.6% in aortic, 14.6% in mitral position; mean age 61 years, 30.3% female). Median follow-up was 4.9 years, mean TTR was 62.5% (14.5% TTR <40%, 24.6% TTR 40-60%, and 61.0% TTR >60%). Overall rates of the primary outcome, major bleeding, and death were 0.73, 1.41, and 1.44 per 100 patient-years. Corresponding rates for patients with TTR <40% were 1.31, 2.77, and 3.22 per 100 patient-years. In adjusted analyses, every 10% decrement in TTR was associated with a 31% increase in hazard for the primary outcome (hazard ratio [HR]: 1.31, 95% confidence interval [CI]: 1.13-1.52), 34% increase in major bleeding (HR: 1.34, 95% CI: 1.17-1.52), and 32% increase in death (HR: 1.32, 95% CI: 1.11-1.57). CONCLUSION: In contemporary patients with a MHV, poor anticoagulation control on warfarin was associated with increased risks of thrombotic events, bleeding, and death.

Direct Oral Anticoagulants for Stroke Prevention in Patients with Device-Detected Atrial Fibrillation: A Study-Level Meta-Analysis of the NOAH-AFNET 6 and ARTESiA Trials.

Background: Device-detected atrial fibrillation (AF) (also known as subclinical AF or atrial high-rate episodes) is a common finding in patients with an implanted cardiac rhythm device and is associated with an increased risk of ischemic stroke. Whether oral anticoagulation is effective and safe in this patient population is unclear. Methods: We performed a systematic review of MEDLINE and Embase for randomized trials comparing oral anticoagulation to antiplatelet or no antithrombotic therapy in adults with device-detected AF recorded by a pacemaker, implantable cardioverter-defibrillator, cardiac resynchronization therapy device or implanted cardiac monitor. We used random-effects models for meta-analysis and rated the quality of evidence using the GRADE framework. The review was pre-registered (PROSPERO CRD42023463212). Results: From 785 unique citations, we identified two randomized trials with relevant clinical outcome data; NOAH-AFNET 6 (2,536 participants) evaluated edoxaban and ARTESiA (4,012 participants) evaluated apixaban. Meta-analysis demonstrated that oral anticoagulation with these agents reduced ischemic stroke (relative risk [RR] 0.68, 95% confidence interval [CI] 0.50-0.92; high-quality evidence). The results from the two trials were consistent (I2 statistic for heterogeneity=0%). Oral anticoagulation also reduced a composite of cardiovascular death, all-cause stroke, peripheral arterial embolism, myocardial infarction or pulmonary embolism (RR 0.85, 95% CI 0.73-1.00, I2=0%; moderate-quality evidence). There was no reduction in cardiovascular death (RR 0.95, 95% CI 0.76-1.17, I2=0%; moderate-quality evidence) or all-cause mortality (RR 1.08, 95% CI 0.96-1.21 I2=0%; moderate-quality evidence). Oral anticoagulation increased major bleeding (RR 1.62, 95% CI 1.05-2.5 I²=61%; high-quality evidence). Conclusions: The results of the NOAH-AFNET 6 and ARTESiA trials are consistent with each other. Meta-analysis of these two large randomized trials provides high-quality evidence that oral anticoagulation with edoxaban or apixaban reduces the risk of stroke in patients with device-detected AF and increases the risk of major bleeding.

Cerebral microbleeds and asundexian in non-cardioembolic ischemic stroke: Secondary analyses of the PACIFIC-STROKE randomized trial.

BACKGROUND AND AIMS: Cerebral microbleeds are magnetic imaging resonance (MRI) markers of hemorrhage-prone cerebral small vessel disease that predict future risk of ischemic stroke and intracranial hemorrhage (ICrH). There exist concerns about the net benefit of antithrombotic therapy in patients with microbleeds. We aimed to investigate the effects of an oral factor-XIa inhibitor (asundexian), that is hypothesized to inhibit thrombosis without compromising hemostasis, on the development of new microbleeds over time and interactions between microbleeds and asundexian treatment on clinical outcomes. We additionally assessed associations between baseline microbleeds and the risks of clinical and neuroimaging outcomes in patients with non-cardioembolic ischemic stroke. METHODS: This is a secondary analysis of the PACIFIC-STROKE, international, multi-center Phase 2b double-blind, randomized clinical trial. PACIFIC-STROKE enrolled patients aged ⩾ 45 years with mild-to-moderate non-cardioembolic ischemic stroke who presented within 48 h of symptom onset for whom antiplatelet therapy was intended. Microbleeds were centrally adjudicated, and participants with an interpretable T2*-weighted sequence at their baseline MRI were included in this analysis. Patients were randomized to asundexian (10/20/50 mg daily) versus placebo plus standard antiplatelet treatment. Regression models were used to estimate the effects of (1) all pooled asundexian doses and (2) asundexian 50 mg daily on new microbleed formation on 26-week MRIs. Cox proportional hazards or regression models were additionally used to estimate interactions between treatment assignment and microbleeds for ischemic stroke/transient ischemic attack (TIA) (primary outcome), and ICrH, all-cause mortality, hemorrhagic transformation (HT), and new microbleeds (secondary outcomes). RESULTS: Of 1746 participants (mean age, 67.0 ± 10.0; 34% female) with baseline MRIs, 604 (35%) had microbleeds. During a median follow-up of 10.6 months, 7.0% (n = 122) had ischemic stroke/TIA, 0.5% (n = 8) ICrH, and 2.1% (n = 37) died. New microbleeds developed in 10.3% (n = 155) of participants with adequate follow-up MRIs and HT in 31.4% (n = 345). In the total sample of patients with adequate baseline and 26-week follow-up MRIs (n = 1507), new microbleeds occurred in 10.2% of patients assigned to any asundexian dose and 10.5% of patients assigned to placebo (OR, 0.96; 95% CI, 0.66-1.41). There were no interactions between microbleeds and treatment assignment for any of the outcomes (p for interaction > 0.05). The rates of new microbleeds, HT, and ICrH were numerically less in patients with microbleeds assigned to asundexian relative to placebo. The presence of microbleeds was associated with a higher risk of HT (aOR, 1.6; 95% CI, 1.2-2.1) and new microbleeds (aOR, 4.4; 95% CI, 3.0-6.3). CONCLUSION: Factor XIa inhibition with asundexian appears safe in patients with non-cardioembolic ischemic stroke and hemorrhage-prone cerebral small vessel disease marked by microbleeds on MRI. These preliminary findings will be confirmed in the ongoing OCEANIC-STROKE randomized trial. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04304508.

Atrial Fibrillation Recurrence in Patients With Transient New-Onset Atrial Fibrillation Detected During Hospitalization for Noncardiac Surgery or Medical Illness : A Matched Cohort Study.

BACKGROUND: Atrial fibrillation (AF) is often detected for the first time in patients who are hospitalized for another reason. Long-term risks for AF recurrence in these patients are unclear. OBJECTIVE: To estimate risk for AF recurrence in patients with new-onset AF during a hospitalization for noncardiac surgery or medical illness compared with a matched population without AF. DESIGN: Matched cohort study. (ClinicalTrials.gov: NCT03221777). SETTING: Three academic hospitals in Hamilton, Ontario, Canada. PARTICIPANTS: The study enrolled patients hospitalized for noncardiac surgery or medical illness who had transient new-onset AF. For each participant, an age- and sex-matched control participant with no history of AF from the same hospital ward was recruited. All participants left the hospital in sinus rhythm. MEASUREMENTS: 14-day electrocardiographic (ECG) monitor at 1 and 6 months and telephone assessment at 1, 6, and 12 months. The primary outcome was AF lasting at least 30 seconds on the monitor or captured by ECG 12-lead during routine care at 12 months. RESULTS: Among 139 participants with transient new-onset AF (70 patients with medical illness and 69 surgical patients) and 139 matched control participants, the mean age was 71 years (SD, 10), the mean CHA2DS2-VASc score was 3.0 (SD, 1.5), and 59% were male. The median duration of AF during the index hospitalization was 15.8 hours (IQR, 6.4 to 49.6 hours). After 1 year, recurrent AF was detected in 33.1% (95% CI, 25.3% to 40.9%) of participants in the transient new-onset AF group and 5.0% (CI, 1.4% to 8.7%) of matched control participants; after adjustment for the number of ECG monitors worn and for baseline clinical differences, the adjusted relative risk was 6.6 (CI, 3.2 to 13.7). After exclusion of participants who had electrical or pharmacologic cardioversion during the index hospitalization (n = 40) and their matched control participants and limiting to AF events detected by the patch ECG monitor, recurrent AF was detected in 32.3% (CI, 23.1% to 41.5%) of participants with transient new-onset AF and 3.0% (CI, 0% to 6.4%) of matched control participants. LIMITATIONS: Generalizability is limited, and the study was underpowered to evaluate subgroups and clinical predictors. CONCLUSION: Among patients who have transient new-onset AF during a hospitalization for noncardiac surgery or medical illness, approximately 1 in 3 will have recurrent AF within 1 year. PRIMARY FUNDING SOURCE: Peer-reviewed grants.

Small-Volume Blood Collection Tubes to Reduce Transfusions in Intensive Care: The STRATUS Randomized Clinical Trial.

Importance: Blood collection for laboratory testing in intensive care unit (ICU) patients is a modifiable contributor to anemia and red blood cell (RBC) transfusion. Most blood withdrawn is not required for analysis and is discarded. Objective: To determine whether transitioning from standard-volume to small-volume vacuum tubes for blood collection in ICUs reduces RBC transfusion without compromising laboratory testing procedures. Design, Setting, and Participants: Stepped-wedge cluster randomized trial in 25 adult medical-surgical ICUs in Canada (February 5, 2019 to January 21, 2021). Interventions: ICUs were randomized to transition from standard-volume (n = 10 940) to small-volume tubes (n = 10 261) for laboratory testing. Main Outcomes and Measures: The primary outcome was RBC transfusion (units per patient per ICU stay). Secondary outcomes were patients receiving at least 1 RBC transfusion, hemoglobin decrease during ICU stay (adjusted for RBC transfusion), specimens with insufficient volume for testing, length of stay in the ICU and hospital, and mortality in the ICU and hospital. The primary analysis included patients admitted for 48 hours or more, excluding those admitted during a 5.5-month COVID-19-related trial hiatus. Results: In the primary analysis of 21 201 patients (mean age, 63.5 years; 39.9% female), which excluded 6210 patients admitted during the early COVID-19 pandemic, there was no significant difference in RBC units per patient per ICU stay (relative risk [RR], 0.91 [95% CI, 0.79 to 1.05]; P = .19; absolute reduction of 7.24 RBC units/100 patients per ICU stay [95% CI, -3.28 to 19.44]). In a prespecified secondary analysis (n = 27 411 patients), RBC units per patient per ICU stay decreased after transition from standard-volume to small-volume tubes (RR, 0.88 [95% CI, 0.77 to 1.00]; P = .04; absolute reduction of 9.84 RBC units/100 patients per ICU stay [95% CI, 0.24 to 20.76]). Median decrease in transfusion-adjusted hemoglobin was not statistically different in the primary population (mean difference, 0.10 g/dL [95% CI, -0.04 to 0.23]) and lower in the secondary population (mean difference, 0.17 g/dL [95% CI, 0.05 to 0.29]). Specimens with insufficient quantity for analysis were rare (≤0.03%) before and after transition. Conclusions and Relevance: Use of small-volume blood collection tubes in the ICU may decrease RBC transfusions without affecting laboratory analysis. Trial Registration: ClinicalTrials.gov Identifier: NCT03578419.

Effects of oral anticoagulation in people with atrial fibrillation after spontaneous intracranial haemorrhage (COCROACH): prospective, individual participant data meta-analysis of randomised trials.

BACKGROUND: The safety and efficacy of oral anticoagulation for prevention of major adverse cardiovascular events in people with atrial fibrillation and spontaneous intracranial haemorrhage are uncertain. We planned to estimate the effects of starting versus avoiding oral anticoagulation in people with spontaneous intracranial haemorrhage and atrial fibrillation. METHODS: In this prospective meta-analysis, we searched bibliographic databases and trial registries using the strategies of a Cochrane systematic review (CD012144) on June 23, 2023. We included clinical trials if they were registered, randomised, and included participants with spontaneous intracranial haemorrhage and atrial fibrillation who were assigned to either start long-term use of any oral anticoagulant agent or avoid oral anticoagulation (ie, placebo, open control, another antithrombotic agent, or another intervention for the prevention of major adverse cardiovascular events). We assessed eligible trials using the Cochrane Risk of Bias tool. We sought data for individual participants who had not opted out of data sharing from chief investigators of completed trials, pending completion of ongoing trials in 2028. The primary outcome was any stroke or cardiovascular death. We used individual participant data to construct a Cox regression model of the time to the first occurrence of outcome events during follow-up in the intention-to-treat dataset supplied by each trial, followed by meta-analysis using a fixed-effect inverse-variance model to generate a pooled estimate of the hazard ratio (HR) with 95% CI. This study is registered with PROSPERO, CRD42021246133. FINDINGS: We identified four eligible trials; three were restricted to participants with atrial fibrillation and intracranial haemorrhage (SoSTART [NCT03153150], with 203 participants) or intracerebral haemorrhage (APACHE-AF [NCT02565693], with 101 participants, and NASPAF-ICH [NCT02998905], with 30 participants), and one included a subgroup of participants with previous intracranial haemorrhage (ELDERCARE-AF [NCT02801669], with 80 participants). After excluding two participants who opted out of data sharing, we included 412 participants (310 [75%] aged 75 years or older, 249 [60%] with CHA2DS2-VASc score ≤4, and 163 [40%] with CHA2DS2-VASc score >4). The intervention was a direct oral anticoagulant in 209 (99%) of 212 participants who were assigned to start oral anticoagulation, and the comparator was antiplatelet monotherapy in 67 (33%) of 200 participants assigned to avoid oral anticoagulation. The primary outcome of any stroke or cardiovascular death occurred in 29 (14%) of 212 participants who started oral anticoagulation versus 43 (22%) of 200 who avoided oral anticoagulation (pooled HR 0·68 [95% CI 0·42-1·10]; I2=0%). Oral anticoagulation reduced the risk of ischaemic major adverse cardiovascular events (nine [4%] of 212 vs 38 [19%] of 200; pooled HR 0·27 [95% CI 0·13-0·56]; I2=0%). There was no significant increase in haemorrhagic major adverse cardiovascular events (15 [7%] of 212 vs nine [5%] of 200; pooled HR 1·80 [95% CI 0·77-4·21]; I2=0%), death from any cause (38 [18%] of 212 vs 29 [15%] of 200; 1·29 [0·78-2·11]; I2=50%), or death or dependence after 1 year (78 [53%] of 147 vs 74 [51%] of 145; pooled odds ratio 1·12 [95% CI 0·70-1·79]; I2=0%). INTERPRETATION: For people with atrial fibrillation and intracranial haemorrhage, oral anticoagulation had uncertain effects on the risk of any stroke or cardiovascular death (both overall and in subgroups), haemorrhagic major adverse cardiovascular events, and functional outcome. Oral anticoagulation reduced the risk of ischaemic major adverse cardiovascular events, which can inform clinical practice. These findings should encourage recruitment to, and completion of, ongoing trials. FUNDING: British Heart Foundation.

Oral Anticoagulation Use and Left Atrial Appendage Occlusion in LAAOS III.

BACKGROUND: LAAOS III (Left Atrial Appendage Occlusion Study III) showed that left atrial appendage (LAA) occlusion reduces the risk of ischemic stroke or systemic embolism in patients with atrial fibrillation undergoing cardiac surgery. This article examines the effect of LAA occlusion on stroke reduction according to variation in the use of oral anticoagulant (OAC) therapy. METHODS: Information regarding OAC use was collected at every follow-up visit. Adjusted proportional hazards modeling, including using landmarks of hospital discharge, 1 and 2 years after randomization, evaluated the effect of LAA occlusion on the risk of ischemic stroke or systemic embolism, according to OAC use. Adjusted proportional hazard modeling, with OAC use as a time-dependent covariate, was also performed to assess the effect of LAA occlusion, according to OAC use throughout the study. RESULTS: At hospital discharge, 3027 patients (63.5%) were receiving a vitamin K antagonist, and 879 (18.5%) were receiving a non-vitamin K antagonist oral anticoagulant (direct OAC), with no difference in OAC use between treatment arms. There were 2887 (60.5%) patients who received OACs at all follow-up visits, 1401 (29.4%) who received OAC at some visits, and 472 (9.9%) who never received OACs. The effect of LAA occlusion on the risk of ischemic stroke or systemic embolism was consistent after discharge across all 3 groups: hazard ratios of 0.70 (95% CI, 0.51-0.96), 0.63 (95% CI, 0.43-0.94), and 0.76 (95% CI, 0.32-1.79), respectively. An adjusted proportional hazards model with OAC use as a time-dependent covariate showed that the reduction in stroke or systemic embolism with LAA occlusion was similar whether patients were receiving OACs or not. CONCLUSIONS: The benefit of LAA occlusion was consistent whether patients were receiving OACs or not. LAA occlusion provides thromboembolism reduction in patients independent of OAC use.

Plasma angiopoietin-2 and its association with heart failure in patients with atrial fibrillation.

AIMS: Several biomarkers are associated with clinical outcomes in patients with atrial fibrillation (AF), but a causal relationship has not been established. This study aimed to evaluate angiopoietin-2, a novel candidate biomarker of endothelial inflammation and vascular remodelling, in patients with AF. METHODS AND RESULTS: Angiopoietin-2 was measured in plasma obtained from patients with AF treated with aspirin monotherapy (exploration cohort, n = 2987) or with oral anticoagulation (validation cohort, n = 13 079). Regression models were built to assess the associations between angiopoietin-2, clinical characteristics, and outcomes. In both cohorts, plasma angiopoietin-2 was independently associated with AF on the baseline electrocardiogram and persistent/permanent AF, age, history of heart failure, female sex, tobacco use/smoking, body mass index, renal dysfunction, diabetes, and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Angiopoietin-2 was independently associated with subsequent hospitalization for heart failure after adjusting for age, creatinine, and clinical characteristics in the exploration cohort [c-index 0.79, 95% confidence interval (CI) 0.75-0.82; third vs. first quartile, hazard ratio (HR) 1.74, 95% CI 1.26-2.41] and in the validation cohort (c-index 0.76, 95% CI 0.74-0.78; HR 1.58, 95% CI 1.37-1.82). In both cohorts, the association persisted when also adjusting for NT-proBNP (P ≤ 0.001). In full multivariable models also adjusted for NT-proBNP, angiopoietin-2 did not show statistically significant associations with ischaemic stroke, cardiovascular and all-cause death, or major bleeding that were consistent across the two cohorts. CONCLUSIONS: In patients with AF, plasma levels of angiopoietin-2 were independently associated with subsequent hospitalization for heart failure and provided incremental prognostic value to clinical risk factors and NT-proBNP.

Small-volume tubes to reduce anemia and transfusion (STRATUS): a pilot study.

PURPOSE: Blood sampling for diagnostic testing causes blood loss. Small-volume tubes have the same cost, dimensions, and blood-draw techniques as standard-volume tubes, and are compatible with laboratory equipment; however, they are not commonly used. We sought to assess the feasibility of a stepped-wedge cluster trial to determine whether small-volume tubes reduce transfusion compared with standard-volume tubes in intensive care unit (ICU) patients. METHODS: We conducted a prospective mixed-methods pilot study (before-after design) in one ICU with a six-week control period (standard-volume tubes) and a six-week intervention period (small-volume tubes). All patients admitted to the ICU were included. Feasibility was assessed as successful switch to small-volume tubes; adherence to tube size; sufficient volume for testing; user acceptance; barriers and facilitators to implementation; and 95% transfusion collection. We explored end-user acceptability using focus groups. RESULTS: One hundred and sixty-five patients were included in the standard-volume and 204 in the small-volume periods. Transition to small-volume tubes was successful. Random audits showed 100% compliance. The proportion of samples with inadequate volume for testing was the same for both groups (both, 0.2%). Based on ten focus groups, small-volume tubes were acceptable with no barriers identified. Transfusion data collection was 100%. Median [interquartile range] estimated blood loss due to laboratory testing per patient per day in ICU was 11 [8-17] mL with standard-volume and 6 [4-8] mL with small-volume tubes. CONCLUSION: Small-volume tubes can be implemented with acceptability to end-users and without barriers. They did not result in an increased frequency of inadequate samples. These results inform a trial to determine whether small-volume tubes reduce transfusion. STUDY REGISTRATION: ClinicalTrials.gov (NCT03284944); registered 15 September 2017.

RéSUMé: OBJECTIF: Les prélèvements sanguins pour les tests diagnostiques provoquent des pertes de sang. Les tubes de prélèvement de petit volume entraînent le même coût, ont les mêmes dimensions et nécessitent les mêmes techniques de prélèvement sanguin que les tubes de volume standard, en plus d'être compatibles avec l'équipement de laboratoire; cependant, ils ne sont pas couramment utilisés. Nous avons cherché à évaluer la faisabilité d'un essai clinique à intervention échelonnée visant à déterminer si les tubes de petit volume réduisaient la transfusion par rapport aux tubes de volume standard chez les patient·es de l'unité de soins intensifs (USI). MéTHODE: Nous avons mené une étude pilote prospective à méthodes mixtes (conception avant-après) dans une unité de soins intensifs, avec une période de contrôle de six semaines (tubes de volume standard) et une période d'intervention de six semaines (tubes de petit volume). Tou·tes les patient·es admis·es à l'USI ont été inclus·es. La faisabilité a été évaluée comme étant la transition réussie vers des tubes de petit volume; le respect de la taille du tube; un volume suffisant pour les tests sanguins; l'acceptation de l'utilisateur·trice; les obstacles et les facilitateurs à la mise en œuvre; et une collecte de données de transfusion de 95 %. Nous avons exploré l'acceptabilité par l'utilisateur·trice final·e à l'aide de groupes de discussion. RéSULTATS: Cent soixante-cinq patient·es ont été inclus·es dans le groupe volume standard et 204 dans les groupes pour la période de petit volume. La transition vers des tubes de petit volume a été couronnée de succès. Les audits aléatoires ont montré une observance de 100 %. La proportion d'échantillons dont le volume était insuffisant pour l'analyse était la même dans les deux groupes (0,2 % dans les deux cas). D'après dix groupes de discussion, les tubes de faible volume étaient acceptables et aucun obstacle n'a été identifié. La collecte de données transfusionnelles était de 100 %. Les pertes de sang médianes estimées [écart interquartile] dues aux tests de laboratoire par patient·e et par jour à l'USI étaient de 11 [8 à 17] mL avec un volume standard et de 6 [4 à 8] mL avec des tubes de petit volume. CONCLUSION: Les tubes de petit volume peuvent être mis en œuvre en étant acceptés par les utilisateur·trices et sans obstacles. Ils n'ont pas entraîné une augmentation de la fréquence des échantillons inadéquats. Ces résultats procurent des informations pour une étude visant à déterminer si les tubes de petit volume réduisent la transfusion. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03284944); enregistré le 15 septembre 2017.

Cost Implications of Left Atrial Appendage Occlusion During Cardiac Surgery: A Cost Analysis of the LAAOS III Trial.

Background The LAAOS III (Left Atrial Appendage Occlusion Study) clinical trial demonstrated that concomitant left atrial appendage (LAA) occlusion leads to a lower risk of ischemic stroke or systemic embolism compared with no occlusion in participants with atrial fibrillation and a CHA2DS2-VASc score of ≥2 undergoing cardiac surgery for another indication. We report the cost implications of concomitant LAA occlusion during cardiac surgery. Methods and Results Using LAAOS III data, we compared the costs (in US dollars) associated with LAA occlusion to no occlusion from the perspective of the Centers for Medicare and Medicaid Services. We calculated the average cost per participant during the trial by applying Medicare reimbursement costs to cardiovascular events for all trial participants. We conducted sensitivity analyses, varying the cost of stroke ±25% and occlusion technique use. Cost neutrality was defined as a mean cost difference within ±5% of the cost per participant in the no-occlusion group. Total study cost per participant was $3878 in the LAA occlusion group and $4490 in the no-occlusion group, a mean difference of -$612 (95% CI, -$1276 to $45). The main drivers of cost savings were fewer stroke events during the trial (mean difference of -$1021). In sensitivity analyses, LAA occlusion was cost saving for suture and stapler techniques but more expensive with closure device. Conclusions Concomitant LAA occlusion was cost saving for participants in LAAOS III. Our findings support concomitant LAA occlusion as an economically dominant strategy for patients with atrial fibrillation and a CHA2DS2-VASc score of ≥2 undergoing cardiac surgery.

Association of the Timing and Extent of Cardiac Implantable Electronic Device Infections With Mortality.

Importance: Cardiac implantable electronic device (CIED) infection is a potentially devastating complication with an estimated 12-month mortality of 15% to 30%. The association of the extent (localized or systemic) and timing of infection with all-cause mortality has not been established. Objective: To evaluate the association of the extent and timing of CIED infection with all-cause mortality. Design, Setting, and Participants: This prospective observational cohort study was conducted between December 1, 2012, and September 30, 2016, in 28 centers across Canada and the Netherlands. The study included 19 559 patients undergoing CIED procedures, 177 of whom developed an infection. Data were analyzed from April 5, 2021, to January 14, 2023. Exposures: Prospectively identified CIED infections. Main Outcomes and Measures: Time-dependent analysis of the timing (early [≤3 months] or delayed [3-12 months]) and extent (localized or systemic) of infection was performed to determine the risk of all-cause mortality associated with CIED infections. Results: Of 19 559 patients undergoing CIED procedures, 177 developed a CIED infection. The mean (SD) age was 68.7 (12.7) years, and 132 patients were male (74.6%). The cumulative incidence of infection was 0.6%, 0.7%, and 0.9% within 3, 6, and 12 months, respectively. Infection rates were highest in the first 3 months (0.21% per month), reducing significantly thereafter. Compared with patients who did not develop CIED infection, those with early localized infections were not at higher risk for all-cause mortality (no deaths at 30 days [0 of 74 patients]: adjusted hazard ratio [aHR], 0.64 [95% CI, 0.20-1.98]; P = .43). However, patients with early systemic and delayed localized infections had an approximately 3-fold increase in mortality (8.9% 30-day mortality [4 of 45 patients]: aHR, 2.88 [95% CI, 1.48-5.61]; P = .002; 8.8% 30-day mortality [3 of 34 patients]: aHR, 3.57 [95% CI, 1.33-9.57]; P = .01), increasing to a 9.3-fold risk of death for those with delayed systemic infections (21.7% 30-day mortality [5 of 23 patients]: aHR, 9.30 [95% CI, 3.82-22.65]; P < .001). Conclusions and Relevance: Findings suggest that CIED infections are most common within 3 months after the procedure. Early systemic infections and delayed localized infections are associated with increased mortality, with the highest risk for patients with delayed systemic infections. Early detection and treatment of CIED infections may be important in reducing mortality associated with this complication.