Apixaban to Prevent Recurrence After Cryptogenic Stroke in Patients With Atrial Cardiopathy: The ARCADIA Randomized Clinical Trial.

Importance: Atrial cardiopathy is associated with stroke in the absence of clinically apparent atrial fibrillation. It is unknown whether anticoagulation, which has proven benefit in atrial fibrillation, prevents stroke in patients with atrial cardiopathy and no atrial fibrillation. Objective: To compare anticoagulation vs antiplatelet therapy for secondary stroke prevention in patients with cryptogenic stroke and evidence of atrial cardiopathy. Design, Setting, and Participants: Multicenter, double-blind, phase 3 randomized clinical trial of 1015 participants with cryptogenic stroke and evidence of atrial cardiopathy, defined as P-wave terminal force greater than 5000 µV × ms in electrocardiogram lead V1, serum N-terminal pro-B-type natriuretic peptide level greater than 250 pg/mL, or left atrial diameter index of 3 cm/m2 or greater on echocardiogram. Participants had no evidence of atrial fibrillation at the time of randomization. Enrollment and follow-up occurred from February 1, 2018, through February 28, 2023, at 185 sites in the National Institutes of Health StrokeNet and the Canadian Stroke Consortium. Interventions: Apixaban, 5 mg or 2.5 mg, twice daily (n = 507) vs aspirin, 81 mg, once daily (n = 508). Main Outcomes and Measures: The primary efficacy outcome in a time-to-event analysis was recurrent stroke. All participants, including those diagnosed with atrial fibrillation after randomization, were analyzed according to the groups to which they were randomized. The primary safety outcomes were symptomatic intracranial hemorrhage and other major hemorrhage. Results: With 1015 of the target 1100 participants enrolled and mean follow-up of 1.8 years, the trial was stopped for futility after a planned interim analysis. The mean (SD) age of participants was 68.0 (11.0) years, 54.3% were female, and 87.5% completed the full duration of follow-up. Recurrent stroke occurred in 40 patients in the apixaban group (annualized rate, 4.4%) and 40 patients in the aspirin group (annualized rate, 4.4%) (hazard ratio, 1.00 [95% CI, 0.64-1.55]). Symptomatic intracranial hemorrhage occurred in 0 patients taking apixaban and 7 patients taking aspirin (annualized rate, 1.1%). Other major hemorrhages occurred in 5 patients taking apixaban (annualized rate, 0.7%) and 5 patients taking aspirin (annualized rate, 0.8%) (hazard ratio, 1.02 [95% CI, 0.29-3.52]). Conclusions and Relevance: In patients with cryptogenic stroke and evidence of atrial cardiopathy without atrial fibrillation, apixaban did not significantly reduce recurrent stroke risk compared with aspirin. Trial Registration: ClinicalTrials.gov Identifier: NCT03192215.

Atrial cardiopathy biomarkers and atrial fibrillation in the ARCADIA trial.

BACKGROUND: ARCADIA compared apixaban to aspirin for secondary stroke prevention in patients with cryptogenic stroke and atrial cardiopathy. One possible explanation for the neutral result is that biomarkers used did not optimally identify atrial cardiopathy. We examined the relationship between biomarker levels and subsequent detection of AF, the hallmark of atrial cardiopathy. METHODS: Patients were randomized if they met criteria for atrial cardiopathy, defined as P-wave terminal force >5000 µV*ms in ECG lead V1 (PTFV1), NT-proBNP >250 pg/mL, or left atrial diameter index (LADI) ⩾3 cm/m2. For this analysis, the outcome was AF detected per routine care. RESULTS: Of 3745 patients who consented to screening for atrial cardiopathy, 254 were subsequently diagnosed with AF; 96 before they could be randomized and 158 after randomization. In unadjusted analyses, ln(NT-proBNP) (RR per SD, 1.99; 95% CI, 1.85-2.13), PTFV1 (RR per SD, 1.15; 95% CI, 1.03-1.28) and LADI (RR per SD, 1.34; 95% CI, 1.20-1.50) were associated with AF. In a model containing all 3 biomarkers, demographics, and AF risk factors, age (RR per 10 years, 1.24; 95% CI, 1.09-1.41), ln(NT-proBNP) (RR per SD, 1.88; 95% CI, 1.67-2.11) and LADI (RR per SD, 1.25; 95% CI, 1.14-1.37) were associated with AF. These three variables together had a c-statistic of 0.82 (95% CI, 0.79-0.85) but only modest calibration. Discrimination was attenuated in sensitivity analyses of patients eligible for randomization who may have been more closely followed for AF. CONCLUSIONS: Biomarkers used to identify atrial cardiopathy in ARCADIA were moderately predictive of subsequent AF.

Participatory Design of a Clinical Trial Eligibility Criteria Simplification Method.

Clinical trial eligibility criteria are important for selecting the right participants for clinical trials. However, they are often complex and not computable. This paper presents the participatory design of a human-computer collaboration method for criteria simplification that includes natural language processing followed by user-centered eligibility criteria simplification. A case study on the ARCADIA trial shows how criteria were simplified for structured database querying by clinical researchers and identifies rules for criteria simplification and concept normalization.

Mentored peer review of standardized manuscripts as a teaching tool for residents: a pilot randomized controlled multi-center study.

BACKGROUND: There is increasing need for peer reviewers as the scientific literature grows. Formal education in biostatistics and research methodology during residency training is lacking. In this pilot study, we addressed these issues by evaluating a novel method of teaching residents about biostatistics and research methodology using peer review of standardized manuscripts. We hypothesized that mentored peer review would improve resident knowledge and perception of these concepts more than non-mentored peer review, while improving review quality. METHODS: A partially blinded, randomized, controlled multi-center study was performed. Seventy-eight neurology residents from nine US neurology programs were randomized to receive mentoring from a local faculty member or not. Within a year, residents reviewed a baseline manuscript and four subsequent manuscripts, all with introduced errors designed to teach fundamental review concepts. In the mentored group, mentors discussed completed reviews with residents. Primary outcome measure was change in knowledge score between pre- and post-tests, measuring epidemiology and biostatistics knowledge. Secondary outcome measures included level of confidence in the use and interpretation of statistical concepts before and after intervention, and RQI score for baseline and final manuscripts. RESULTS: Sixty-four residents (82%) completed initial review with gradual decline in completion on subsequent reviews. Change in primary outcome, the difference between pre- and post-test knowledge scores, did not differ between mentored (-8.5%) and non-mentored (-13.9%) residents (p = 0.48). Significant differences in secondary outcomes (using 5-point Likert scale, 5 = strongly agree) included mentored residents reporting enhanced understanding of research methodology (3.69 vs 2.61; p = 0.001), understanding of manuscripts (3.73 vs 2.87; p = 0.006), and application of study results to clinical practice (3.65 vs 2.78; p = 0.005) compared to non-mentored residents. There was no difference between groups in level of interest in peer review (3.00 vs 3.09; p = 0.72) or the quality of manuscript review assessed by the Review Quality Instrument (RQI) (3.25 vs 3.06; p = 0.50). CONCLUSIONS: We used mentored peer review of standardized manuscripts to teach biostatistics and research methodology and introduce the peer review process to residents. Though knowledge level did not change, mentored residents had enhanced perception in their abilities to understand research methodology and manuscripts and apply study results to clinical practice.