In mild ischemic stroke or high-risk TIA, DAPT started ≤72 h after onset reduced new stroke and increased bleeding at 90 d.

SOURCE CITATION: Gao Y, Chen W, Pan Y, et al; INSPIRES Investigators. Dual antiplatelet treatment up to 72 hours after ischemic stroke. N Engl J Med. 2023;389:2413-2424. 38157499.

Heterogeneity of State Stroke Center Certification and Designation Processes.

BACKGROUND: Stroke centers are critical for the timely diagnosis and treatment of acute stroke and have been associated with improved treatment and outcomes; however, variability exists in the definitions and processes used to certify and designate these centers. Our study categorizes state stroke center certification and designation processes and provides examples of state processes across the United States, specifically in states with independent designation processes that do not rely on national certification. METHODS: In this cross-sectional study from September 2022 to April 2023, we used peer-reviewed literature, primary source documents from states, and communication with state officials in all 50 states to capture each state's process for stroke center certification and designation. We categorized this information and outlined examples of processes in each category. RESULTS: Our cross-sectional study of state-level stroke center certification and designation processes across states reveals significant heterogeneity in the terminology used to describe state processes and the processes themselves. We identify 3 main categories of state processes: No State Certification or Designation Process (category A; n=12), State Designation Reliant on National Certification Only (category B; n=24), and State Has Option for Self-Certification or Independent Designation (category C; n=14). Furthermore, we describe 3 subcategories of self-certification or independent state designation processes: State Relies on Self-Certification or Independent Designation for Acute Stroke Ready Hospital or Equivalent (category C1; n=3), State Has Hybrid Model for Acute Stroke Ready Hospital or Equivalent (category C2; n=5), and State Has Hybrid Model for Primary Stroke Center and Above (category C3; n=6). CONCLUSIONS: Our study found significant heterogeneity in state-level processes. A better understanding of how these differences may impact the rigor of each process and clinical performance of stroke centers is worthy of further investigation.

In ischemic stroke without large or medium vessel occlusion, tirofiban increased likelihood of an excellent outcome.

SOURCE CITATION: Zi W, Song J, Kong W, et al; RESCUE BT2 Investigators. Tirofiban for stroke without large or medium-sized vessel occlusion. N Engl J Med. 2023;388:2025-2036. 37256974.

Ischemic stroke and systemic embolism among patients with non-valvular atrial fibrillation who abandon oral anticoagulant therapy.

OBJECTIVES: To compare the risk of stroke and systemic embolism (SE) among patients with nonvalvular atrial fibrillation (NVAF) who abandoned their first direct oral anticoagulant (DOAC) fill ("abandoners") relative to patients who continued DOACs beyond the first fill ("continuers"). METHODS: In this retrospective longitudinal study, adults with NVAF prescribed DOACs were selected from Symphony Health, an ICON plc Company, PatientSource, 1 April 2017 to 31 October 2020. A 90-day landmark period following the first DOAC fill was used to classify patients as abandoners or continuers. Inverse probability of treatment weighting was used to balance baseline characteristics between cohorts. Time to ischemic stroke/SE was described and compared between cohorts using weighted Kaplan-Meier and Cox proportional hazard models from the end of the landmark period until end of clinical activity or data. RESULTS: After weighting, 200,398 and 211,352 patients comprised the abandoner and continuer cohorts, respectively. The mean duration of follow-up was 14.9 and 15.7 months, respectively. At 12 months of follow-up, the probability of ischemic stroke/SE was 1.34% in the abandoner cohort and 1.00% in the continuer cohort; the risk of ischemic stroke/SE was 35% higher in the abandoner versus continuer cohort (hazard ratio [95% confidence interval] = 1.35 [1.20, 1.51]; p < 0.0001). CONCLUSIONS: Patients with NVAF who abandoned the first DOAC fill had significantly higher risk of ischemic stroke/SE compared to patients who continued therapy beyond the first fill. There is an unmet need for better access to DOACs so that the long-term risk of poor outcomes may be minimized.

After ICH, starting long-term therapeutic oral anticoagulation in patients with AF reduces MACE at 1 to 3 y.

SOURCE CITATION: Cochrane A, Chen C, Stephen J, et al. Antithrombotic treatment after stroke due to intracerebral haemorrhage. Cochrane Database Syst Rev. 2023;1:CD012144. 36700520.

Identifying Best Practices to Improve Evaluation and Management of In-Hospital Stroke: A Scientific Statement From the American Heart Association.

This scientific statement describes a path to optimizing care for patients who experience an in-hospital stroke. Although these patients are in a monitored environment, their evaluation and treatment are often delayed compared with patients presenting to the emergency department, contributing to higher rates of morbidity and mortality. Reducing delays and optimizing treatment for patients with in-hospital stroke could improve outcomes. This scientific statement calls for the development of hospital systems of care and targeted quality improvement for in-hospital stroke. We propose 5 core elements to optimize in-hospital stroke care: 1. Deliver stroke training to all hospital staff, including how to activate in-hospital stroke alerts. 2. Create rapid response teams with dedicated stroke training and immediate access to neurological expertise. 3. Standardize the evaluation of patients with potential in-hospital stroke with physical assessment and imaging. 4. Address barriers to treatment potentially, including interfacility transfer to advanced stroke treatment. 5. Establish an in-hospital stroke quality oversight program delivering data-driven performance feedback and driving targeted quality improvement efforts. Additional research is needed to better understand how to reduce the incidence, morbidity, and mortality of in-hospital stroke.

Effectiveness and Safety of Rivaroxaban versus Warfarin Among Nonvalvular Atrial Fibrillation Patients with Obesity and Polypharmacy.

BACKGROUND: Current evidence suggests that rivaroxaban may be well tolerated and effective in patients with nonvalvular atrial fibrillation (NVAF) and obesity; however, there is limited evidence on the impact of polypharmacy in this population. This study evaluated real-world clinical outcomes with rivaroxaban versus warfarin in patients with NVAF and obesity according to the number of concurrent medications. METHODS: This retrospective cohort study identified patients with one or more pharmacy claim for rivaroxaban or warfarin from two large claims databases. Patients were required to have an atrial fibrillation diagnosis, body mass index ≥ 30 kg/m2 and the presence of polypharmacy (1-4, 5-9, or ≥ 10 concurrent medications). Outcomes of stroke, systemic embolism, and major bleeding were compared between the rivaroxaban and warfarin cohorts after propensity score matching (PSM). RESULTS: A total of 95,875 patients were identified with one or more claim for either rivaroxaban or warfarin. After PSM, patient characteristics were balanced between cohorts (n = 21,547 in each cohort). The overall composite risk of stroke and systemic embolism was significantly lower in the rivaroxaban cohort compared with the warfarin cohort (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.70-0.84; p < 0.001). The risks of ischemic stroke, hemorrhagic stroke, and systemic embolism separately were also significantly reduced with rivaroxaban. Major bleeding risk was similar between cohorts (HR 0.93, 95% CI 0.81-1.06; p = 0.2842), and results were consistent across the three polypharmacy groups. CONCLUSIONS: In this real-world study of NVAF patients with obesity, rivaroxaban was associated with lower risks of stroke and systemic embolism and similar risk of major bleeding versus warfarin across polypharmacy categories.

Ischemic Stroke in Patients With Pulmonary Arteriovenous Fistulas.

BACKGROUND AND PURPOSE: Pulmonary arteriovenous fistulas (PAVFs) are a treatable cause of acute ischemic stroke (AIS), not mentioned in current American Heart/Stroke Association guidelines. PAVFs are recognized as an important complication of hereditary hemorrhagic telangiectasia. METHODS: The prevalence of PAVF and hereditary hemorrhagic telangiectasia among patients admitted with AIS in the United States (2005-2014) was retrospectively studied, utilizing the Nationwide Inpatient Sample database. Clinical factors, morbidity, mortality, and management were compared in AIS patients with and without PAVF/hereditary hemorrhagic telangiectasia. RESULTS: Of 4 271 910 patients admitted with AIS, 822 (0.02%) were diagnosed with PAVF. Among them, 106 of 822 (12.9%) were diagnosed with hereditary hemorrhagic telangiectasia. The prevalence of PAVF per million AIS admissions rose from 197 in 2005 to 368 in 2014 (Ptrend, 0.026). Patients with PAVF were younger than AIS patients without PAVF (median age, 57.5 versus 72.5 years), had lower age-adjusted inpatient morbidity (defined as any discharge other than home; 39.6% versus 46.9%), and had lower in-hospital case fatality rates (1.8% versus 5.1%). Multivariate analyses identified the following as independent risk markers (odds ratio [95% CI]) for AIS in patients with PAVF: hypoxemia (8.4 [6.3-11.2]), pulmonary hemorrhage (7.9 [4.1-15.1]), pulmonary hypertension (4.3 [4.1-15.1]), patent foramen ovale (4.2 [3.5-5.1]), epistaxis (3.7 [2.1-6.8]), venous thrombosis (2.6 [1.9-3.6]), and iron deficiency anemia (2 [1.5-2.7]). Patients with and without PAVF received intravenous thrombolytics at a similar rate (5.9% versus 5.8%), but those with PAVF did not receive mechanical thrombectomy (0% versus 0.7%). CONCLUSIONS: Pulmonary arteriovenous fistula-related ischemic stroke represents an important younger demographic with a unique set of stroke risk markers, including treatable conditions such as causal PAVFs and iron deficiency anemia.

Risk of Stroke Outcomes in Atrial Fibrillation Patients Treated with Rivaroxaban and Warfarin.

OBJECTIVES: In a previous real-world study, rivaroxaban reduced the risk of stroke overall and severe stroke compared with warfarin in patients with nonvalvular atrial fibrillation (NVAF). The aim of this study was to assess the reproducibility in a different database of our previously observed results (Alberts M, et al. Stroke. 2020;51:549-555) on the risk of severe stroke among NVAF patients in a different population treated with rivaroxaban or warfarin. MATERIAL AND METHODS: This retrospective cohort study included patients from the IBM® MarketScan® Commercial and Medicare databases (2011-2019) who initiated rivaroxaban or warfarin after a diagnosis of NVAF, had ≥6 months of continuous health plan enrollment, had a CHA2DS2-VASc score ≥2, and had no history of stroke or anticoagulant use. Patient data were assessed until the earliest occurrence of a primary inpatient diagnosis of stroke, death, end of health plan enrollment, or end of study. Stroke severity was defined by National Institutes of Health Stroke Scale (NIHSS) score, imputed by random forest model. Cox proportional hazard regression was used to compare risk of stroke between cohorts, balanced by inverse probability of treatment weighting. RESULTS: The mean observation period from index date to either stroke, or end of eligibility or end of data was 28 months. Data from 13,599 rivaroxaban and 39,861 warfarin patients were included. Stroke occurred in 272 rivaroxaban-treated patients (0.97/100 person-years [PY]) and 1,303 warfarin-treated patients (1.32/100 PY). Rivaroxaban patients had lower risk for stroke overall (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.76-0.88) and for minor (NIHSS 1 to <5; HR, 0.83; 95% CI, 0.74-0.93), moderate (NIHSS 5 to <16; HR, 0.88; 95% CI, 0.78-0.99), and severe stroke (NIHSS 16 to 42; HR, 0.44; 95% CI, 0.22-0.91). CONCLUSIONS: The results of this study in a larger population of NVAF patients align with previous real-world findings and the ROCKET-AF trial by showing improved stroke prevention with rivaroxaban versus warfarin across all stroke severities.

Burden-of-Illness Associated with Bleeding-Related Hospitalizations in Atrial Fibrillation Patients: Findings from the Nationwide Readmission Database.

Introduction A paucity of contemporary data examining bleeding-related hospitalization outcomes in atrial fibrillation (AF) patients exists. Methods Adults in the Nationwide Readmissions Database (January 2016-November 2016) with AF and hospitalized for intracranial hemorrhage (ICH), gastrointestinal, genitourinary, or other bleeding were identified. Association between bleed types and outcomes were assessed using multivariable regression (gastrointestinal defined as referent) and reported as crude incidences and adjusted odds ratios (ORs) or mean differences with 95% confidence intervals (CIs). Results In total, 196,878 index bleeding-related hospitalizations were identified in this AF cohort (CHA2DS2VASc score ≥2 in 95.1%), with 70.8% classified as gastrointestinal. The overall incidences of in-hospital mortality, need for post-discharge out-of-home care, and 30-day readmission were 4.9, 50.8, and 18.2%, respectively. Multivariable regression suggested traumatic and nontraumatic ICHs were associated with higher odds of in-hospital mortality (OR = 3.99, 95% CI = 3.79, 4.19; OR = 13.09, 95% CI = 12.24, 13.99) and need for post-discharge out-of-home care (OR = 2.92, 95% CI = 2.83, 3.01; OR = 2.74, 95% CI = 2.59, 2.90), and increases in mean index hospitalization length-of-stay (8.31 days, 95% CI = 8.03, 8.60, 6.27 days, 95% CI = 5.97, 6.57) versus gastrointestinal bleeding. Genitourinary and other bleeds were associated with lower mortality (OR = 0.37, 95% CI = 0.25, 0.55; OR = 0.59, 95% CI = 0.53, 0.64) and reduced length-of-stays (-2.84 days, 95% CI = - 2.91, -2.76; -2.06 days, 95% CI = - 2.11, -2.01) versus gastrointestinal bleeding. Genitourinary bleeds were also associated with a reduced need for post-discharge out-of-home care (OR = 0.86, 95% CI = 0.77, 0.97). Conclusion The burden of bleeding-related hospitalizations was notably driven by relatively rare but severe and life-threatening ICH, and less morbid but more frequent gastrointestinal bleeding. There is need for continued research on bleeding risk factors and mitigation techniques to avoid bleeding-related patient hospitalizations.

In ischemic stroke, thrombectomy alone was noninferior to thrombectomy plus alteplase for functional outcome at 90 days.

SOURCE CITATION: Yang P, Zhang Y, Zhang L, et al. Endovascular thrombectomy with or without intravenous alteplase in acute stroke. N Engl J Med. 2020;382:1981-93. 32374959.

Novel GDF2 Gene Mutation Associated with Pulmonary Arteriovenous Malformation.

Pulmonary arteriovenous malformations (PAVMs) are pathologic low-resistance conduits between a pulmonary artery and vein. Over 80% PAVMs occur in patients with hereditary hemorrhagic telangiectasia (HHT) and result from mutations in the transforming growth factor-beta signaling pathway. Mutations in the Growth Differentiation Factor 2 (GDF2) gene have recently been described to result in a vascular-anomaly syndrome with phenotypic overlap with HHT. We report a 43-year-old woman with a PAVM related ischemic stroke who was subsequently found to have a novel GDF2 gene mutation. The patient underwent coil-embolization of the PAVM with stable clinical and radiographic follow-up. It is important to diagnose PAVMs as they are an important cause of stroke-in-young; and can be treated definitively, reducing risk of recurrent stroke and migraine.

Machine learning provides evidence that stroke risk is not linear: The non-linear Framingham stroke risk score.

Current stroke risk assessment tools presume the impact of risk factors is linear and cumulative. However, both novel risk factors and their interplay influencing stroke incidence are difficult to reveal using traditional additive models. The goal of this study was to improve upon the established Revised Framingham Stroke Risk Score and design an interactive Non-Linear Stroke Risk Score. Leveraging machine learning algorithms, our work aimed at increasing the accuracy of event prediction and uncovering new relationships in an interpretable fashion. A two-phase approach was used to create our stroke risk prediction score. First, clinical examinations of the Framingham offspring cohort were utilized as the training dataset for the predictive model. Optimal Classification Trees were used to develop a tree-based model to predict 10-year risk of stroke. Unlike classical methods, this algorithm adaptively changes the splits on the independent variables, introducing non-linear interactions among them. Second, the model was validated with a multi-ethnicity cohort from the Boston Medical Center. Our stroke risk score suggests a key dichotomy between patients with history of cardiovascular disease and the rest of the population. While it agrees with known findings, it also identified 23 unique stroke risk profiles and highlighted new non-linear relationships; such as the role of T-wave abnormality on electrocardiography and hematocrit levels in a patient's risk profile. Our results suggested that the non-linear approach significantly improves upon the baseline in the c-statistic (training 87.43% (CI 0.85-0.90) vs. 73.74% (CI 0.70-0.76); validation 75.29% (CI 0.74-0.76) vs 65.93% (CI 0.64-0.67), even in multi-ethnicity populations. The clinical implications of the new risk score include prioritization of risk factor modification and personalized care at the patient level with improved targeting of interventions for stroke prevention.

Four-year incidence of major adverse cardiovascular events in patients with atherosclerosis and atrial fibrillation.

BACKGROUND: There is a paucity of contemporary data assessing the implications of atrial fibrillation (AF) on major adverse cardiovascular events (MACE) in patients with or at high-risk for atherosclerotic disease managed in routine practice. HYPOTHESIS: We sought to evaluate the 4-year incidence of MACE in patients with or at risk of atherosclerotic disease in the presence of AF. METHODS: Using US MarketScan data, we identified AF patients ≥45 years old with billing codes indicating established coronary artery disease, cerebrovascular disease, or peripheral artery disease or the presence of ≥3 risk factors for atherosclerotic disease from January 1, 2013 to December 31, 2013 with a minimum of 4-years of available follow-up. We calculated the 4-year incidence of MACE (cardiovascular death or hospitalization with a primary billing code for myocardial infarction or ischemic stroke). Patients were further stratified by CHA2 DS2 -VASc score and oral anticoagulation (OAC) use at baseline. RESULTS: We identified 625,951 patients with 4-years of follow-up, of which 77,752 (12.4%) had comorbid AF. The median (25%, 75% range) CHA2 DS2 -VASc score was 4 (3, 5) and 64% of patients received an OAC at baseline. The incidence of MACE increased as CHA2 DS2 -VASc scores increased (P-interaction<.0001 for all). AF patients receiving an OAC were less likely to experience MACE (8.9% vs 11.6%, P < .0001) including ischemic stroke (5.4% vs 6.7%, P < .0001). CONCLUSION: Comorbid AF carries a substantial risk of MACE in patients with or at risk of atherosclerotic disease. MACE risk increases with higher CHA2 DS2 -VASc scores and is more likely in patients without OAC.

Incidence and Predictors of Major Adverse Cardiovascular Events in Patients With Established Atherosclerotic Disease or Multiple Risk Factors.

Background There is a paucity of contemporary data estimating the incidence of major adverse cardiovascular events (MACE) in patients with established atherosclerotic disease or multiple risk factors managed in routine practice. We estimated 1- and 4-year incidences of MACE and the association between MACE and vascular beds affected in these patients. Methods and Results Using US IBM MarketScan data from January 1, 2013 to December 31, 2017, we identified patients ≥45 years old with established coronary artery disease, cerebrovascular disease, peripheral artery disease, or the presence of ≥3 risk factors for atherosclerosis during 2013 with a minimum of 4 years of follow-up. We calculated 1- and 4-year incidences of MACE (cardiovascular death or hospitalization for myocardial infarction or ischemic stroke). A Cox proportional hazards regression model adjusted for age and sex was used to evaluate the association between vascular bed number/location(s) affected and MACE. We identified 1 302 856 patients with established atherosclerotic disease or risk factors for atherosclerosis. Coronary artery disease was present in 16.9% of patients, cerebrovascular disease in 7.6%, peripheral artery disease in 13.6%, and risk factors for atherosclerosis only in 66.0%. The 1- and 4-year incidences of MACE were 1.4% and 6.9%, respectively. At 4 years, MACE was more frequent in patients with atherosclerotic disease in a single (hazard ratio=1.51, 95% CI=1.48-1.55), 2-(hazard ratio=2.35, 95% CI=2.27-2.44), or all 3 vascular beds (hazard ratio=3.30, 95% CI=2.97-3.68) compared with having risk factors for atherosclerosis. Conclusions Patients with established atherosclerotic disease or who have multiple risk factors and are treated in contemporary, routine practice carry a substantial risk for MACE at 1- and 4- years of follow-up. MACE risk was shown to vary based on the number and location of vascular beds involved.

Effectiveness and safety of rivaroxaban vs. warfarin in patients with non-valvular atrial fibrillation and coronary or peripheral artery disease.

AIMS: There are scarce data evaluating the effectiveness and safety of rivaroxaban vs. warfarin in non-valvular atrial fibrillation (NVAF) patients with concomitant coronary artery disease (CAD) and/or peripheral artery disease (PAD) treated in routine practice. METHODS AND RESULTS: Using MarketScan data from January 2012 to December 2017, we identified oral anticoagulant (OAC)-naïve NVAF patients receiving rivaroxaban (15-20 mg once daily) or warfarin, with comorbid CAD and/or PAD and ≥12 months of insurance coverage before OAC initiation. Differences in baseline covariates between cohorts were adjusted using inverse probability-of-treatment weights based on propensity scores (standardized differences <0.1 achieved for all covariates after adjustment). Endpoints included a composite of major thrombotic vascular events (MTVEs) (including ischaemic stroke, myocardial infarction, or need for lower limb revascularization/major amputation) and major bleeding. Patients were followed until an event-of-interest, discontinuation/switch of index OAC, insurance disenrolment, or end-of-data availability. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox regression. We identified 3257 rivaroxaban (30.4% received a 15 mg dose) and 5046 warfarin users with NVAF and comorbid CAD and/or PAD. Rivaroxaban was associated with a 32% (95% CI = 8-50%) reduction in the composite of MTVE. No significant difference in major bleeding was observed (HR = 1.13, 95% CI = 0.84-1.52). No statistical interactions were noted in subgroup analyses performed on the MTVE (P-interaction ≥ 0.35 for all) or major bleeding endpoints (P-interaction ≥ 0.09 for all). CONCLUSION: Among patients with NVAF and comorbid CAD and/or PAD, rivaroxaban use was associated with a reduced risk of MTVEs vs. warfarin, without significantly increasing major bleeding risk.

Cost and inpatient burden of peripheral artery disease: Findings from the National Inpatient Sample.

BACKGROUND AND AIMS: We aimed to examine the prevalence, demographics, clinical outcomes and economic burden of hospitalizations for patients with PAD. METHODS: Using the National Inpatient Sample, we retrospectively evaluated patients hospitalized with PAD in 2014. Hospitalizations in patients with PAD were identified by the presence of an International Classification of Diseases-9th Revision (ICD-9) diagnosis code of 440.20-440.24. We calculated hospitalization rates/100,000 patients, the proportion of hospitalizations with a major adverse limb event (MALE), as well as minor amputation, mortality, median (interquartile range) length-of-stay (LOS) and treatment costs (in 2017 US$). A separate analysis of hospitalizations of patients with clinical limb ischemia defined as Fontaine class III or IV PAD (440.22, resting pain; 440.23-440.24, ulcers or gangrene) was also performed. RESULTS: We identified 286,160 hospitalizations for patients with PAD. The rate of hospitalizations for PAD was 89.5/100,000, with 137,050 (or 45%) of these having Fontaine class III-IV disease. The proportion of hospitalizations resulting in MALE, major or minor lower extremity amputation or in-hospital death was 45.8%, 8.9%, 8.2% and 3.1%, respectively. Median hospital LOS was 5 (3, 9) days and costs were $15,755 ($8972, $27,800), resulting in an annual cost burden for hospitalization of patients with PAD of ∼$6.31 billion. In hospitalizations of Fontaine class III-IV PAD, MALE, major and minor amputation and death occurred in 60.9%, 16.8%, 15.8% and 3.3% of cases, respectively. Median LOS and costs were 7 (4, 11) days and $18,984 ($10,913, $31,816). CONCLUSIONS: Hospitalizations of patients with PAD represent a substantial medical and financial burden for patients and the US healthcare system.

Safety and effectiveness of oral factor Xa inhibitors versus warfarin in nonvalvular atrial fibrillation patients at high-risk for falls.

Prescribers' concern regarding falls resulting in intracranial hemorrhage is often cited as a justification for under-utilization of oral anticoagulation. We evaluated the safety and effectiveness of oral factor Xa inhibitors versus warfarin in nonvalvular atrial fibrillation patients at high-risk for falls. Using MarketScan claims from 11/2012-3/2017, we identified adult, oral anticoagulation-naïve, new-initiators of oral factor Xa inhibitors or warfarin with nonvalvular atrial fibrillation, ≥ 12 months of insurance coverage prior to starting oral anticoagulation and a predicted 2-year risk of falls ≥ 15%. Differences in baseline covariates between cohorts were balanced using inverse probability-of-treatment weights based on propensity scores. Hazard ratios (HRs) and 95% confidence intervals (CIs) for intracranial hemorrhage and stroke or systemic embolism were estimated. Among 25,144 nonvalvular atrial fibrillation patients at high-risk for falls (observed fall rate = 11.8%/person-year), oral factor Xa inhibitor use was associated with a 43% (95% CI = 5-65%) reduced hazard of intracranial hemorrhage compared to warfarin. Oral factor Xa inhibitors did not significantly reduce the hazard of stroke or systemic embolism versus warfarin (HR = 0.86, 95% CI = 0.66-1.11). Findings for the intracranial hemorrhage and stroke or systemic embolism endpoints were similar when apixaban and rivaroxaban were evaluated separately versus warfarin (p-interaction ≥ 0.64 for all). Oral factor Xa inhibitors reduced patients' risk of intracranial hemorrhage and were at least as effective in preventing stroke or systemic embolism as warfarin in nonvalvular atrial fibrillation patients at high-risk for falls.