Risk of Stroke or Systemic Embolism According to Baseline Frequency and Duration of Subclinical Atrial Fibrillation: Insights From the ARTESiA Trial.

BACKGROUND: In the ARTESiA trial (Apixaban for the Reduction of Thromboembolism in Patients With Device-Detected Subclinical Atrial Fibrillation), apixaban, compared with aspirin, reduced stroke or systemic embolism in patients with device-detected subclinical atrial fibrillation (SCAF). Clinical guidelines recommend considering SCAF episode duration when deciding whether to prescribe oral anticoagulation for this population. METHODS: We performed a retrospective cohort study in ARTESiA. Using Cox regression adjusted for CHA2DS2-VASc score and treatment allocation (apixaban or aspirin), we assessed frequency of SCAF episodes and duration of the longest SCAF episode in the 6 months before randomization as predictors of stroke risk and of apixaban treatment effect. RESULTS: Among 3986 patients with complete baseline SCAF data, 703 (17.6%) had no SCAF episode ≥6 minutes in the 6 months before enrollment. Among 3283 patients (82.4%) with ≥1 episode of SCAF ≥6 minutes in the 6 months before enrollment, 2542 (77.4%) had up to 5 episodes, and 741 (22.6%) had ≥6 episodes. The longest episode lasted <1 hour in 1030 patients (31.4%), 1 to <6 hours in 1421 patients (43.3%), and >6 hours in 832 patients (25.3%). Higher baseline SCAF frequency was not associated with increased risk of stroke or systemic embolism: 1.1% for 1 to 5 episodes versus 1.2%/patient-year for ≥6 episodes (adjusted hazard ratio, 0.89 [95% CI, 0.59-1.34]). In an exploratory analysis, patients with previous SCAF but no episode ≥6 minutes in the 6 months before enrollment had a lower risk of stroke or systemic embolism than patients with at least one episode during that period (0.5% versus 1.1%/patient-year; adjusted hazard ratio, 0.48 [95% CI, 0.27-0.85]). The frequency of SCAF did not modify the reduction in stroke or systemic embolism with apixaban (Pinteraction=0.1). The duration of the longest SCAF episode in the 6 months before enrollment was not associated with the risk of stroke or systemic embolism during follow-up (<1 hour: 1.0%/patient-year [reference]; 1-6 hours: 1.2%/patient-year [adjusted hazard ratio, 1.27 (95% CI, 0.85-1.90)]; >6 hours: 1.0%/patient-year [adjusted hazard ratio, 1.02 (95% CI, 0.63-1.66)]). SCAF duration did not modify the reduction in stroke or systemic embolism with apixaban (Ptrend=0.1). CONCLUSIONS: In ARTESiA, baseline SCAF frequency and longest episode duration were not associated with risk of stroke or systemic embolism and did not modify the effect of apixaban on reduction of stroke or systemic embolism. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01938248.

Residual Stroke Risk Among Patients With Atrial Fibrillation Prescribed Oral Anticoagulants: A Patient-Level Meta-Analysis From COMBINE AF.

BACKGROUND: Despite oral anticoagulation, patients with atrial fibrillation (AF) remain at risk of ischemic stroke and systemic embolism (SE) events. For patients whose residual risk is sufficiently high, additional therapies might be useful to mitigate stroke risk. METHODS AND RESULTS: Individual patient data from 5 landmark trials testing oral anticoagulation in AF were pooled in A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in AF (COMBINE AF). We calculated the rate of ischemic stroke/SE among oral anticoagulation-treated patients with a CHA2DS2-VASc score≥2, across strata of CHA2DS2-VASc score, stroke history, and AF type, as either paroxysmal or nonparoxysmal. We included 71 794 patients with AF (median age 72 years, interquartile range, 13 years, 61.3% male) randomized to a direct oral anticoagulant or vitamin K antagonist, and followed for a mean of 2.1 (±0.8) years. The median CHA2DS2-VASc score was 4 (interquartile range, 3-5), 18.8% had a prior stroke, and 76.4% had nonparoxysmal AF. The overall rate of stroke/SE was 1.33%/y (95% CI, 1.27-1.39); 1.38%/y (95% CI, 1.31-1.45) for nonparoxysmal AF, and 1.15%/y (95% CI, 1.05-1.27) for paroxysmal AF. The rate of ischemic stroke/SE increased by a rate ratio of 1.36 (95% CI, 1.32-1.41) per 1-point increase in CHA2DS2-VASc, reaching 1.67%/y (95% CI, 1.59-1.75) ≥4 CHA2DS2-VASc points. Patients with both nonparoxysmal AF and CHA2DS2-VASc ≥4 had a stroke/SE rate of 1.75%/y (95% CI, 1.66-1.85). In patients with a prior stroke, the risk was 2.51%/y (95% CI, 2.33-2.71). CONCLUSIONS: AF type, CHA2DS2-VASc score, and stroke history can identify patients with AF, who despite oral anticoagulation have a residual stroke/SE risk of 1.5% to 2.5% per year. Evaluation of additional stroke/SE prevention strategies in high-risk patients is warranted.

Apixaban vs Aspirin According to CHA2DS2-VASc Score in Subclinical Atrial Fibrillation: Insights From ARTESiA.

BACKGROUND: ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation) demonstrated that apixaban, compared with aspirin, significantly reduced stroke and systemic embolism (SE) but increased major bleeding in patients with subclinical atrial fibrillation. OBJECTIVES: To help inform decision making, the authors evaluated the efficacy and safety of apixaban according to baseline CHA2DS2-VASc score. METHODS: We performed a subgroup analysis according to baseline CHA2DS2-VASc score and assessed both the relative and absolute differences in stroke/SE and major bleeding. RESULTS: Baseline CHA2DS2-VASc scores were <4 in 1,578 (39.4%) patients, 4 in 1,349 (33.6%), and >4 in 1,085 (27.0%). For patients with CHA2DS2-VASc >4, the rate of stroke was 0.98%/year with apixaban and 2.25%/year with aspirin; compared with aspirin, apixaban prevented 1.28 (95% CI: 0.43-2.12) strokes/SE per 100 patient-years and caused 0.68 (95% CI: -0.23 to 1.57) major bleeds. For CHA2DS2-VASc <4, the stroke/SE rate was 0.85%/year with apixaban and 0.97%/year with aspirin. Apixaban prevented 0.12 (95% CI: -0.38 to 0.62) strokes/SE per 100 patient-years and caused 0.33 (95% CI: -0.27 to 0.92) major bleeds. For patients with CHA2DS2-VASc =4, apixaban prevented 0.32 (95% CI: -0.16 to 0.79) strokes/SE per 100 patient-years and caused 0.28 (95% CI: -0.30 to 0.86) major bleeds. CONCLUSIONS: One in 4 patients in ARTESiA with subclinical atrial fibrillation had a CHA2DS2-VASc score >4 and a stroke/SE risk of 2.2% per year. For these patients, the benefits of treatment with apixaban in preventing stroke/SE are greater than the risks. The opposite is true for patients with CHA2DS2-VASc score <4. A substantial intermediate group (CHA2DS2-VASc =4) exists in which patient preferences will inform treatment decisions. (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation; NCT01938248).

Sodium Intake and Incident Atrial Fibrillation in Individuals With Vascular Disease.

Importance: Numerous prospective cohort studies have reported a J-shaped association of urinary sodium excretion with cardiovascular events and mortality. Objective: To study the association between sodium intake and incident atrial fibrillation (AF). Design, Setting, and Participants: This cohort study included participants in the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) and Telmisartan Randomised Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease (TRANSCEND) multicenter, randomized clinical trials comparing the effect of ramipril 10 mg daily with telmisartan 80 mg daily, or their combination (ONTARGET) or 80 mg telmisartan daily with placebo (TRANSCEND) for the outcome of death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for heart failure. ONTARGET and TRANSCEND included 31 546 participants with vascular disease or high-risk diabetes, and this study excluded participants without a urine sample for sodium measurement, missing data for key covariates, a history of AF, or AF detected in the first year after enrollment. Analyses were performed in July 2023 to May 2024. Exposure: Estimated sodium intake from a morning fasting urine sample (Kawasaki formula). Main Outcomes and Measures: The main outcome was incident AF. The association between estimated sodium intake and incident AF was modeled using multivariable adjusted Cox regression and cubic splines. Results: A total of 27 391 participants (mean [SD] age, 66.3 [7.2] years; 19 310 [70.5%] male) were included. Mean (SD) estimated sodium intake was 4.8 (1.6) g/d. During a mean (SD) follow-up of 4.6 (1.0) years, 1562 participants (5.7%) had incident AF. After multivariable adjustment, a J-shaped association between sodium intake and AF risk was observed (P for nonlinearity = .03). Sodium intake of 8 g/d or greater (3% of participants) was associated with incident AF (hazard ratio, 1.32; 95% CI, 1.01-1.74) compared with sodium intake of 4 to 5.99 g/d. Cubic splines showed that sodium intake greater than 6 g/d (19% of participants) was associated with a 10% increased AF risk per additional 1-g/d sodium intake (hazard ratio, 1.10; 95% CI, 1.03-1.18), but with no further lowering of AF risk at lower levels of sodium intake. Conclusions and Relevance: In this cohort study of sodium intake and AF risk, there was a J-shaped association between sodium intakes and AF risk in patients with cardiovascular disease or diabetes. Lowering sodium intake for AF prevention is best targeted at individuals who consume high sodium diets.

Results of the COMPASS Trial Analyzed Using Win Ratio Compared With Conventional Analytic Approaches.

BACKGROUND: Win ratio (WR) is a newer analytic approach for trials with composite end points that accounts for the relative importance of individual components. Our objective was to compare the results of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial analyzed using WR with those obtained using conventional statistical approaches. METHODS: We used an unmatched WR analysis for first and total (first plus recurrent) events to examine effects of rivaroxaban with aspirin and rivaroxaban alone vs aspirin alone on primary efficacy (cardiovascular death, stroke, myocardial infarction), safety (modified International Society on Thrombosis and Haemostasis major bleeding), and net clinical benefit (primary efficacy plus fatal or critical organ bleeding) end points. We compared the WR results with those obtained using the Cox proportional hazards regression model for first events and Anderson-Gill method for total events. We calculated the win difference to estimate absolute treatment effects. RESULTS: The WR approach produced results consistent with those obtained using conventional statistical methods for the primary composite end point (first event: WR, 1.32 [95% confidence interval (CI), 1.14-1.52]; 1/Cox hazard ratio, 1.32 [95% CI, 1.16-1.52]; total [first plus recurrent] events: WR, 1.32 [95% CI, 1.14-1.52]; 1/Anderson-Gill hazard ratio, 1.32 [95% CI, 1.16-1.54]) as well as for main safety and net clinical benefit end points. The absolute benefits of the combination of rivaroxaban and aspirin compared with aspirin alone calculated using the win difference were greatest in those with multiple high-risk features. CONCLUSIONS: Reanalysis of the COMPASS trial results using WR produced results that were consistent with those obtained using conventional statistical approaches. CLINICAL TRIAL REGISTRATION: NCT01776424.

Mortality and Morbidity in Adults With Rheumatic Heart Disease.

Importance: Rheumatic heart disease (RHD) remains a public health issue in low- and middle-income countries (LMICs). However, there are few large studies enrolling individuals from multiple endemic countries. Objective: To assess the risk and predictors of major patient-important clinical outcomes in patients with clinical RHD. Design, Setting, and Participants: Multicenter, hospital-based, prospective observational study including 138 sites in 24 RHD-endemic LMICs. Main Outcomes and Measures: The primary outcome was all-cause mortality. Secondary outcomes were cause-specific mortality, heart failure (HF) hospitalization, stroke, recurrent rheumatic fever, and infective endocarditis. This study analyzed event rates by World Bank country income groups and determined the predictors of mortality using multivariable Cox models. Results: Between August 2016 and May 2022, a total of 13 696 patients were enrolled. The mean age was 43.2 years and 72% were women. Data on vital status were available for 12 967 participants (94.7%) at the end of follow-up. Over a median duration of 3.2 years (41 478 patient-years), 1943 patients died (15% overall; 4.7% per patient-year). Most deaths were due to vascular causes (1312 [67.5%]), mainly HF or sudden cardiac death. The number of patients undergoing valve surgery (604 [4.4%]) and HF hospitalization (2% per year) was low. Strokes were infrequent (0.6% per year) and recurrent rheumatic fever was rare. Markers of severe valve disease, such as congestive HF (HR, 1.58 [95% CI, 1.50-1.87]; P < .001), pulmonary hypertension (HR, 1.52 [95% CI, 1.37-1.69]; P < .001), and atrial fibrillation (HR, 1.30 [95% CI, 1.15-1.46]; P < .001) were associated with increased mortality. Treatment with surgery (HR, 0.23 [95% CI, 0.12-0.44]; P < .001) or valvuloplasty (HR, 0.24 [95% CI, 0.06-0.95]; P = .042) were associated with lower mortality. Higher country income level was associated with lower mortality after adjustment for patient-level factors. Conclusions and Relevance: Mortality in RHD is high and is correlated with the severity of valve disease. Valve surgery and valvuloplasty were associated with substantially lower mortality. Study findings suggest a greater need to improve access to surgical and interventional care, in addition to the current approaches focused on antibiotic prophylaxis and anticoagulation.

Perioperative management and outcomes in patients receiving low-dose rivaroxaban and/or aspirin: a subanalysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial.

BACKGROUND: No study has investigated the perioperative management and clinical outcomes in patients who are receiving rivaroxaban 2.5 mg twice a day and acetylsalicylic acid (ASA) 81 to 100 mg daily. OBJECTIVE: To assess perioperative management and outcomes in patients who are receiving low-dose rivaroxaban, 2.5 mg twice-daily, and low-dose ASA, 81 to 100 mg daily. To assess perioperative management and outcomes in patients who are receiving low-dose rivaroxaban, 2.5 mg twice-daily, and low-dose ASA, 81 to 100 mg daily. METHODS: Subanalysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial was performed to assess perioperative management and clinical outcomes in patients with stable coronary or peripheral artery disease who were randomized to receive rivaroxaban 2.5 mg twice a day plus ASA 100 mg daily, rivaroxaban 5 mg twice a day, or ASA 100 mg daily. Patients studied required a surgery/procedure during the trial. The study outcomes, which included myocardial infarction, angina, stroke, acute limb ischemia, bleeding, and death, were assessed according to treatment allocation. RESULTS: There were 2632 patients studied (mean age, 68 years; 80% male) who had a surgery/procedure, comprising percutaneous coronary interventions (∼43%), carotid or other arterial angioplasty (∼15%), pacemaker or internal cardiac defibrillator implantation (∼9%), and coronary artery bypass graft surgery (∼7%). Perioperative study drug management varied, with about one-third of patients not interrupting study drug and the remainder interrupting it between 1 and ≥10 days preprocedure. The incidences of adverse outcomes across treatment groups were 12.7% to 15.3% for myocardial ischemia, 0.8% to 1.2% for stroke, 0.1% to 0.2% for venous thromboembolism, and 3.1% to 4.2% for any bleeding. There was no statistically significant difference in outcome rates across treatment groups. CONCLUSION: In patients in the COMPASS trial who required a surgery/procedure, there was no significant difference in perioperative adverse outcomes whether patients were receiving rivaroxaban 2.5 mg twice a day and ASA 100 mg daily, rivaroxaban 5 mg twice a day, or ASA alone.

Hemorrhagic Transformation in Noncardioembolic Acute Ischemic Stroke: MRI Analysis From PACIFIC-STROKE.

BACKGROUND: In the phase 2 PACIFIC-STROKE trial (Proper Dosing and Safety of the Oral FXIa Inhibitor BAY 2433334 in Patients Following Acute Noncardioembolic Stroke), asundexian, an oral factor XIa inhibitor, did not increase the risk of hemorrhagic transformation (HT). In this secondary analysis, we aimed to investigate the frequency, types, and risk factors of HT on brain magnetic resonance imaging (MRI). METHODS: This was a secondary analysis of the PACIFIC-STROKE trial. Patients with mild-to-moderate acute noncardioembolic ischemic stroke were randomly assigned to asundexian or placebo plus guideline-based antiplatelet therapy. Brain MRIs were required at baseline (≤120 hours after stroke onset) and at 26 weeks or end-of-study. HT was defined using the Heidelberg classification and classified as early HT (identified on baseline MRI) or late HT (new HT by 26 weeks) based on iron-sensitive sequences. Multivariable logistic regression models were used to test factors that are associated with early HT and late HT, respectively. RESULTS: Of 1745 patients with adequate baseline brain MRI (mean age, 67 years; mean National Institutes of Health Stroke Scale score, 2.8), early HT at baseline was detected in 497 (28.4%). Most were hemorrhagic infarctions (hemorrhagic infarction type 1: 15.2%; HI2: 12.7%) while a few were parenchymal hematomas (parenchymal hematoma type 1: 0.4%; parenchymal hematoma type 2: 0.2%). Early HT was more frequent with longer symptom onset-to-MRI interval. Male sex, diabetes, higher National Institutes of Health Stroke Scale large (>15 mm) infarct size, cortical involvement by infarct, higher number of acute infarcts, presence of chronic brain infarct, cerebral microbleed, and chronic cortical superficial siderosis were independently associated with early HT in the multivariable logistic regression model. Of 1507 with follow-up MRI, HT was seen in 642 (42.6%) overall, including 361 patients (23.9%) with late HT (new HT: 306; increased grade of baseline HT: 55). Higher National Institutes of Health Stroke Scale, large infarct size, cortical involvement of infarct, and higher number of acute infarcts predicted late HT. CONCLUSIONS: About 28% of patients with noncardioembolic stroke had early HT, and 24% had late HT detectable by MRI. Given the high frequency of HT on MRI, more research is needed on how it influences treatment decisions and outcomes.

Andexanet for Factor Xa Inhibitor-Associated Acute Intracerebral Hemorrhage.

BACKGROUND: Patients with acute intracerebral hemorrhage who are receiving factor Xa inhibitors have a risk of hematoma expansion. The effect of andexanet alfa, an agent that reverses the effects of factor Xa inhibitors, on hematoma volume expansion has not been well studied. METHODS: We randomly assigned, in a 1:1 ratio, patients who had taken factor Xa inhibitors within 15 hours before having an acute intracerebral hemorrhage to receive andexanet or usual care. The primary end point was hemostatic efficacy, defined by expansion of the hematoma volume by 35% or less at 12 hours after baseline, an increase in the score on the National Institutes of Health Stroke Scale of less than 7 points (scores range from 0 to 42, with higher scores indicating worse neurologic deficit) at 12 hours, and no receipt of rescue therapy between 3 hours and 12 hours. Safety end points were thrombotic events and death. RESULTS: A total of 263 patients were assigned to receive andexanet, and 267 to receive usual care. Efficacy was assessed in an interim analysis that included 452 patients, and safety was analyzed in all 530 enrolled patients. Atrial fibrillation was the most common indication for factor Xa inhibitors. Of the patients receiving usual care, 85.5% received prothrombin complex concentrate. Hemostatic efficacy was achieved in 150 of 224 patients (67.0%) receiving andexanet and in 121 of 228 (53.1%) receiving usual care (adjusted difference, 13.4 percentage points; 95% confidence interval [CI], 4.6 to 22.2; P = 0.003). The median reduction from baseline to the 1-to-2-hour nadir in anti-factor Xa activity was 94.5% with andexanet and 26.9% with usual care (P<0.001). Thrombotic events occurred in 27 of 263 patients (10.3%) receiving andexanet and in 15 of 267 (5.6%) receiving usual care (difference, 4.6 percentage points; 95% CI, 0.1 to 9.2; P = 0.048); ischemic stroke occurred in 17 patients (6.5%) and 4 patients (1.5%), respectively. There were no appreciable differences between the groups in the score on the modified Rankin scale or in death within 30 days. CONCLUSIONS: Among patients with intracerebral hemorrhage who were receiving factor Xa inhibitors, andexanet resulted in better control of hematoma expansion than usual care but was associated with thrombotic events, including ischemic stroke. (Funded by Alexion AstraZeneca Rare Disease and others; ANNEXA-I ClinicalTrials.gov number, NCT03661528.).

Total intracranial hemorrhage volume measurement summating all compartments best in traumatic and nontraumatic intracranial bleeding.

BACKGROUND AND PURPOSE: The ANNEXA-4 trial measured hemostatic efficacy of andexanet alfa in patients with major bleeding taking factor Xa inhibitors. A proportion of this was traumatic and nontraumatic intracranial bleeding. Different measurements were applied in the trial including volumetrics to assess for intracranial bleeding depending on the compartment involved. We aimed to determine the most reliable way to measure intracranial hemorrhage (ICrH) volume by comparing individual brain compartment and total ICrH volume. METHODS: Thirty patients were randomly selected from the ANNEXA-4 database to assess measurement of ICrH volume by compartment and in total. Total and compartmental hemorrhage volumes were measured by five readers using Quantomo software. Each reader measured baseline hemorrhage volumes twice separated by 1 week. Twenty-eight different ANNEXA-4 subjects were also randomly selected to assess intra-rater reliability of total ICrH volume measurement change at baseline and 12-h follow up, performed by three readers twice to assess hemostatic efficacy categories used in ANNEXA-4. RESULTS: Compartmental minimal detectable change percentages (MDC%) ranged between 9.72 and 224.13, with the greatest measurement error occurring in patients with a subdural hemorrhage. Total ICrH volume measurements had the lowest MDC%, which ranged between 6.57 and 33.52 depending on the reader. CONCLUSION: Measurement of total ICrH volumes is more accurate than volume by compartment with less measurement error. Determination of hemostatic efficacy was consistent across readers, and within the same reader, as well as when compared to consensus read. Volumetric analysis of intracranial hemostatic efficacy is feasible and reliable when using total ICrH volumes.

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.

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.

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.

Andexanet alfa versus non-specific treatments for intracerebral hemorrhage in patients taking factor Xa inhibitors - Individual patient data analysis of ANNEXA-4 and TICH-NOAC.

BACKGROUND: Data comparing the specific reversal agent andexanet alfa with non-specific treatments in patients with non-traumatic intracerebral hemorrhage (ICH) associated with factor-Xa inhibitor (FXaI) use are scarce. AIM: The study aimed to determine the association between the use of andexanet alfa compared with non-specific treatments with the rate of hematoma expansion and thromboembolic complications in patients with FXaI-associated ICH. METHODS: We performed an individual patient data analysis combining two independent, prospective studies: ANNEXA-4 (180 patients receiving andexanet alfa, NCT02329327) and TICH-NOAC (63 patients receiving tranexamic acid or placebo ± prothrombin complex concentrate, NCT02866838). The primary efficacy outcome was hematoma expansion on follow-up imaging. The primary safety outcome was any thromboembolic complication (ischemic stroke, myocardial infarction, pulmonary embolism, or deep vein thrombosis) at 30 days. We used binary logistic regression models adjusted for baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively. RESULTS: Among 243 participants included, the median age was 80 (IQR 75-84) years, baseline hematoma volume was 9.1 (IQR 3.4-21) mL and anti-Xa activity 118 (IQR 78-222) ng/mL. Times from last FXaI intake and symptom onset to treatment were 11 (IQR 7-16) and 4.7 (IQR 3.0-7.6) h, respectively. Overall, 50 patients (22%) experienced hematoma expansion (ANNEXA-4: n=24 (14%); TICH-NOAC: n=26 (41%)). After adjusting for pre-specified confounders (baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively), treatment with andexanet alfa was independently associated with decreased odds for hematoma expansion (aOR 0.33, 95% CI 0.13-0.80, p = 0.015). Overall, 26 patients (11%) had any thromboembolic complication within 30 days (ANNEXA-4: n=20 (11%); TICH-NOAC: n=6 (10%)). There was no association between any thromboembolic complication and treatment with andexanet alfa (aOR 0.70, 95% CI 0.16-3.12, p = 0.641). CONCLUSION: The use of andexanet alfa compared to any other non-specific treatment strategy was associated with decreased odds for hematoma expansion, without increased odds for thromboembolic complications.

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.).