Edoxaban Versus Low-Molecular-Weight Heparin in Hospitalized COVID-19 Patients With Atrial Fibrillation.

OBJECTIVE: During the first wave of the SARS-CoV-2 pandemic, management of anticoagulation therapy in hospitalized patients with atrial fibrillation (AF) was simplified to low-molecular-weight heparin (LMWH) followed by oral anticoagulation, mainly owing to the risk of drug-drug interactions. However, not all oral anticoagulants carry the same risk. METHODS: Observational, retrospective, and multicenter study that consecutively included hospitalized patients with AF anticoagulated with LMWH followed by oral anticoagulation or edoxaban concomitantly with empirical COVID-19 therapy. Time-to-event (mortality, total bleeds, and admissions to ICU) curves, using an unadjusted Kaplan-Meier method and Cox regression model adjusted for potential confounders were constructed. RESULTS: A total of 232 patients were included (80.3 ± 7.7 years, 50.0% men, CHA2DS2-VASc 4.1 ± 1.4; HAS-BLED 2.6 ± 1.0). During hospitalization, patients were taking azithromycin (98.7%), hydroxychloroquine (89.7%), and ritonavir/lopinavir (81.5%). The mean length of hospital stay was 14.6 ± 7.2 days, and total follow-up was 31.6 ± 13.4 days; 12.9% of patients required admission to ICU, 18.5% died, and 9.9% had a bleeding complication (34.8% major bleeding). Length of hospital stay was longer in patients taking LMWH (16.0 ± 7.7 vs 13.3 ± 6.5 days; P = .005), but mortality and total bleeds were similar in patients treated with edoxaban and those treated with LMWH followed by oral anticoagulation. CONCLUSIONS: Mortality rates, arterial and venous thromboembolic complications, and bleeds did not significantly differ between AF patients receiving anticoagulation therapy with edoxaban or LMWH followed by oral anticoagulation. However, the duration of hospitalization was significantly lower with edoxaban. Edoxaban had a similar therapeutic profile to LMWH followed by oral anticoagulation and may provide additional benefits.

Impact of atrial fibrillation and anticoagulation on the risk of death, thromboembolic disease and bleeding in patients with COVID-19: the ACO-VID Registry.

OBJECTIVE: To describe the clinical profile, risk of complications and impact of anticoagulation in COVID-19 hospitalized patients, according to the presence of atrial fibrillation (AF). METHODS: Multicenter, retrospective, and observational study that consecutively included patients >55 years admitted with COVID-19 from March to October 2020. In AF patients, anticoagulation was chosen based on clinicians' judgment. Patients were followed-up for 90 days. RESULTS: A total of 646 patients were included, of whom 75.2% had AF. Overall, mean age was 75 ± 9.1 years and 62.4% were male. Patients with AF were older and had more comorbidities. The most common anticoagulants used during hospitalization in patients with AF were edoxaban (47.9%), low molecular weight heparin (27.0%), and dabigatran (11.7%) and among patients without AF, these numbers were 0%, 93.8% and 0%. Overall, during the study period (68 ± 3 days), 15.2% of patients died, 8.2% of patients presented a major bleeding and 0.9% had a stroke/systemic embolism. During hospitalization, patients with AF had a higher risk of major bleeding (11.3% vs 0.7%; p < .01), COVID-19-related deaths (18.0% vs 4.5%; p = .02), and all-cause deaths (20.6% vs 5.6%; p = .02). Age (HR 1.5; 95% CI 1.0-2.3) and elevated transaminases (HR 3.5; 95% CI 2.0-6.1) were independently associated with all-cause mortality. AF was independently associated with major bleeding (HR 2.2; 95% CI 1.1-5.3). CONCLUSIONS: Among patients hospitalized with COVID-19, patients with AF were older, had more comorbidities and had a higher risk of major bleeding. Age and elevated transaminases during hospitalization, but not AF nor anticoagulant treatment increased the risk of all-cause death.

Refractory atrial fibrillation with rapid ventricular response as a heralding sign of propofol infusion syndrome in a patient with COVID-19.

A woman in her 40s was transferred to the medical intensive care unit due to severe COVID-19 infection causing respiratory failure. Her respiratory failure worsened rapidly, requiring intubation and continuous sedation with fentanyl and propofol infusions. She required progressive increases in the rates of the propofol infusion, as well as addition of midazolam and cisatracurium due to ventilator dyssynchrony. To support the high sedative doses, norepinephrine was administered as a continuous infusion. She developed atrial fibrillation with rapid ventricular response, with rates ranging between 180 and 200 s which did not respond to intravenous adenosine, metoprolol, synchronised cardioversion or amiodarone. A blood draw revealed lipaemia, and triglyceride levels were noted to be elevated to 2018. The patient developed high-grade fevers up to 105.3 and acute renal failure with severe mixed respiratory and metabolic acidosis, indicating propofol-related infusion syndrome. Propofol was promptly discontinued. An insulin-dextrose infusion was initiated which improved patient's fevers and hypertriglyceridaemia.

Mortality risk factors in patients with SARS-CoV-2 infection and atrial fibrillation: Data from the SEMI-COVID-19 registry. / Factores de riesgo de mortalidad en pacientes con infección por SARS-CoV-2 y fibrilación auricular: datos del registro SEMI-COVID-19.

INTRODUCTION: Atrial fibrillation and associated comorbidities pose a risk factor for mortality, morbidity and development of complications in patients admitted for COVID-19. OBJECTIVES: To describe the clinical, epidemiological, radiological and analytical characteristics of patients with atrial fibrillation admitted for COVID-19 in Spain. Secondarily, we aim to identify those variables associated with mortality and poor prognosis of COVID-19 in patients with atrial fibrillation. METHODS: Retrospective, observational, multicenter, nationwide, retrospective study of patients hospitalized for COVID-19 from March 1 to October 1, 2020. Data were obtained from the SEMI-COVID-19 Registry of the Spanish Society of Internal Medicine (SEMI) in which 150 Spanish hospitals participate. RESULTS: Between March 1 and October 1, 2020, data from a total of 16,461 patients were entered into the SEMI-COVID-19 registry. 1816 (11%) had a history of atrial fibrillation and the number of deaths among AF patients amounted to 738 (41%). Regarding clinical characteristics, deceased patients were admitted with a higher heart rate (88.38 vs. 84.95; P>0.01), with a higher percentage of respiratory failure (67.2 vs. 20.1%; P<0.01) and high tachypnea (58 vs. 30%; P<0.01). The comorbidities that presented statistically significant differences in the deceased group were: age, hypertension and diabetes with target organ involvement. There was also a higher prevalence of a history of cardiovascular disease in the deceased. On multivariate analysis, DOACs treatment had a protective role for mortality (OR: 0.597; CI: 0.402-0.888; P=0.011). CONCLUSIONS: Previous treatment with DOACs and DOACs treatment during admission seem to have a protective role in patients with atrial fibrillation, although this fact should be verified in prospective studies.

Does early detection of atrial fibrillation reduce the risk of thromboembolic events? Rationale and design of the Heartline study.

BACKGROUND: The impact of using direct-to-consumer wearable devices as a means to timely detect atrial fibrillation (AF) and to improve clinical outcomes is unknown. METHODS: Heartline is a pragmatic, randomized, and decentralized application-based trial of US participants aged ≥65 years. Two randomized cohorts include adults with possession of an iPhone and without a history of AF and those with a diagnosis of AF taking a direct oral anticoagulant (DOAC) for ≥30 days. Participants within each cohort are randomized (3:1) to either a core digital engagement program (CDEP) via iPhone application (Heartline application) and an Apple Watch (Apple Watch Group) or CDEP alone (iPhone-only Group). The Apple Watch Group has the watch irregular rhythm notification (IRN) feature enabled and access to the ECG application on the Apple Watch. If an IRN notification is issued for suspected AF then the study application instructs participants in the Apple Watch Group to seek medical care. All participants were "watch-naïve" at time of enrollment and have an option to either buy or loan an Apple Watch as part of this study. The primary end point is time from randomization to clinical diagnosis of AF, with confirmation by health care claims. Key secondary endpoint are claims-based incidence of a 6-component composite cardiovascular/systemic embolism/mortality event, DOAC medication use and adherence, costs/health resource utilization, and frequency of hospitalizations for bleeding. All study assessments, including patient-reported outcomes, are conducted through the study application. The target study enrollment is approximately 28,000 participants in total; at time of manuscript submission, a total of 26,485 participants have been enrolled into the study. CONCLUSION: The Heartline Study will assess if an Apple Watch with the IRN and ECG application, along with application-facilitated digital health engagement modules, improves time to AF diagnosis and cardiovascular outcomes in a real-world environment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04276441.

An Analysis of Telehealth in the Outpatient Management of Atrial Fibrillation During the COVID-19 Pandemic.

The COVID-19 pandemic accelerated adaption of a telehealth care model. We studied the impact of telehealth on the management of atrial fibrillation (AF) by electrophysiology providers in a large, multisite clinic. Clinical outcomes, quality metrics, and indicators of clinical activity for patients with AF during the 10-week period of March 22, 2020 to May 30, 2020 were compared with those from the 10-week period of March 24, 2019 to June 1, 2019. There were 1946 unique patient visits for AF (1,040 in 2020 and 906 in 2019). During 120 days after each encounter, there was no difference in hospital admissions (11.7% vs 13.5%, p = 0.25) or emergency department visits (10.4% vs 12.5%, p = 0.15) in 2020 compared with 2019. There was a total of 31 deaths within 120 days, with similar rates in 2020 and 2019 (1.8% vs 1.3%, p = 0.38). There was no significant difference in quality metrics. The following clinical activities occurred less frequently in 2020 than in 2019: offering escalation of rhythm control (16.3% vs 23.3%, p <0.001), ambulatory monitoring (29.7% vs 51.7%, p <0.001), and electrocardiogram review for patients on antiarrhythmic drug therapy (22.1% vs 90.2%, p <0.001). Discussions about risk factor modification were more frequent in 2020 compared with 2019 (87.9% vs 74.8%, p <0.001). In conclusion, the use of telehealth in the outpatient management of AF was associated with similar clinical outcomes and quality metrics but differences in clinical activity compared with traditional ambulatory encounters. Longer-term outcomes warrant further investigation.

COVID-19 and comedications in atrial fibrillation-a case-control study in Stockholm.

To test the main hypothesis that anticoagulation reduces risk of hospitalization, intensive care unit (ICU) admission and death in COVID-19. Nested case-control study among patients with atrial fibrillation (AF) in Stockholm. COVID-19 cases were matched to five disease-free controls with same sex, born within ± 1 years. Source population was individuals in Stockholm with AF 1997-2020. Swedish regional and national registers are used. National registers cover hospitals and outpatient clinics, local registers cover primary care. Records were linked through the personal identity number assigned to each Swedish resident. Cases were individuals with COVID-19 (diagnosis, ICU admission, or death). The AF source population consisted of 179,381 individuals from which 7548 cases were identified together with 37,145 controls. The number of cases (controls) identified from hospitalization, ICU admission or death were 5916 (29,035), 160 (750) and 1472 (7,360). The proportion of women was 40% for hospitalization and death, but 20% and 30% for admission to ICU in wave one and two, respectively. Primary outcome was mortality, secondary outcome was hospitalization, tertiary outcome was ICU admission, all with COVID-19. Odds ratios (95% confidence interval) for antithrombotics were 0.79 (0.66-0.95) for the first wave and 0.80 (0.64-1.01) for the second wave. Use of anticoagulation among patients with arrythmias infected with COVID-19 is associated with lower risk of hospitalization and death. If further COVID-variants emerge, or other infections with prothrombotic properties, this emphasize need for physicians to ensure compliance among vulnerable patients.

Association between oral anticoagulants and COVID-19-related outcomes: a population-based cohort study.

BACKGROUND: Early evidence has shown that anticoagulant reduces the risk of thrombotic events in those infected with COVID-19. However, evidence of the role of routinely prescribed oral anticoagulants (OACs) in COVID-19 outcomes is limited. AIM: To investigate the association between OACs and COVID-19 outcomes in those with atrial fibrillation and a CHA2DS2-VASc score of 2. DESIGN AND SETTING: On behalf of NHS England, a population-based cohort study was conducted. METHOD: The study used primary care data and pseudonymously-linked SARS-CoV-2 antigen testing data, hospital admissions, and death records from England. Cox regression was used to estimate hazard ratios (HRs) for COVID-19 outcomes comparing people with current OAC use versus non-use, accounting for age, sex, comorbidities, other medications, deprivation, and general practice. RESULTS: Of 71 103 people with atrial fibrillation and a CHA2DS2-VASc score of 2, there were 52 832 current OAC users and 18 271 non-users. No difference in risk of being tested for SARS-CoV-2 was associated with current use (adjusted HR [aHR] 0.99, 95% confidence interval [CI] = 0.95 to 1.04) versus non-use. A lower risk of testing positive for SARS-CoV-2 (aHR 0.77, 95% CI = 0.63 to 0.95) and a marginally lower risk of COVID-19-related death (aHR, 0.74, 95% CI = 0.53 to 1.04) were associated with current use versus non-use. CONCLUSION: Among those at low baseline stroke risk, people receiving OACs had a lower risk of testing positive for SARS-CoV-2 and severe COVID-19 outcomes than non-users; this might be explained by a causal effect of OACs in preventing severe COVID-19 outcomes or unmeasured confounding, including more cautious behaviours leading to reduced infection risk.

Drug-drug interaction between dexamethasone and direct-acting oral anticoagulants: a nested case-control study in the National COVID Cohort Collaborative (N3C).

OBJECTIVE: The goal of this work is to evaluate if there is an increase in the risk of thromboembolic events (TEEs) due to concomitant exposure to dexamethasone and apixaban or rivaroxaban. Direct oral anticoagulants (DOACs), as well as corticosteroid dexamethasone, are commonly used to treat individuals hospitalised with COVID-19. Dexamethasone induces cytochrome P450-3A4 enzyme that also metabolises DOACs apixaban and rivaroxaban. This raises a concern about possible interaction between dexamethasone and DOACs that may reduce the efficacy of the DOACs and result in an increased risk of TEE. DESIGN: We used nested case-control study design. SETTING: This study was conducted in the National COVID Cohort Collaborative (N3C), the largest electronic health records repository for COVID-19 in the USA. PARTICIPANTS: Study participants were adults over 18 years who were exposed to a DOAC for 10 or more consecutive days. Exposure to dexamethasone was at least 5 or more consecutive days. PRIMARY AND SECONDARY OUTCOME MEASURES: Our primary exposure variable was concomitant exposure to dexamethasone for 5 or more days after exposure to either rivaroxaban or apixaban for 5 or more consecutive days. We used McNemar's Χ2 test and adjusted logistic regression to evaluate association between concomitant use of dexamethasone with either apixaban or rivaroxaban. RESULTS: McNemar's Χ2 test did not find a discernible association of TEE in patients concomitantly exposed to dexamethasone and a DOAC (χ2=0.5, df=1, p=0.48). In addition, a conditional logistic regression model did not find an increase in the risk of TEE (adjusted OR 1.15, 95% CI 0.32 to 4.18). CONCLUSION: This nested case-control study did not find evidence of an association between concomitant exposure to dexamethasone and a DOAC with an increase in risk of TEE. Due to small sample size, an association cannot be completely ruled out.

Management of Adults with Newly Diagnosed Atrial Fibrillation with and without CKD.

BACKGROUND: Atrial fibrillation (AF) is highly prevalent in CKD and is associated with worse cardiovascular and kidney outcomes. Limited data exist on use of AF pharmacotherapies and AF-related procedures by CKD status. We examined a large "real-world" contemporary population with incident AF to study the association of CKD with management of AF. METHODS: We identified patients with newly diagnosed AF between 2010 and 2017 from two large, integrated health care delivery systems. eGFR (≥60, 45-59, 30-44, 15-29, <15 ml/min per 1.73 m2) was calculated from a minimum of two ambulatory serum creatinine measures separated by ≥90 days. AF medications and procedures were identified from electronic health records. We performed multivariable Fine-Gray subdistribution hazards regression to test the association of CKD severity with receipt of targeted AF therapies. RESULTS: Among 115,564 patients with incident AF, 34% had baseline CKD. In multivariable models, compared with those with eGFR >60 ml/min per 1.73 m2, patients with eGFR 30-44 (adjusted hazard ratio [aHR] 0.91; 95% CI, 0.99 to 0.93), 15-29 (aHR, 0.78; 95% CI, 0.75 to 0.82), and <15 ml/min per 1.73 m2 (aHR, 0.64; 95% CI, 0.58-0.70) had lower use of any AF therapy. Patients with eGFR 15-29 ml/min per 1.73 m2 had lower adjusted use of rate control agents (aHR, 0.61; 95% CI, 0.56 to 0.67), warfarin (aHR, 0.89; 95% CI, 0.84 to 0.94), and DOACs (aHR, 0.23; 95% CI, 0.19 to 0.27) compared with patients with eGFR >60 ml/min per 1.73 m2. These associations were even stronger for eGFR <15 ml/min per 1.73 m2. There was also a graded association between CKD severity and receipt of AF-related procedures (vs eGFR >60 ml/min per 1.73 m2): eGFR 30-44 ml/min per 1.73 (aHR, 0.78; 95% CI, 0.70 to 0.87), eGFR 15-29 ml/min per 1.73 m2 (aHR, 0.73; 95% CI, 0.61 to 0.88), and eGFR <15 ml/min per 1.73 m2 (aHR, 0.48; 95% CI, 0.31 to 0.74). CONCLUSIONS: In adults with newly diagnosed AF, CKD severity was associated with lower receipt of rate control agents, anticoagulation, and AF procedures. Additional data on efficacy and safety of AF therapies in CKD populations are needed to inform management strategies.

Impact of COVID-19 on the Prescribing Pattern of Oral Anticoagulants for Atrial Fibrillation After Cardiac Surgery.

BACKGROUND: Because of logistic challenges associated with the COVID-19 pandemic, direct oral anticoagulants (DOAC) were favored over warfarin in patients presenting postoperative atrial fibrillation (AF) after cardiac surgery in our institution. Considering the limited evidence supporting the use of DOAC in this context, we sought to evaluate the safety and efficacy of this practice change. METHODS: A retrospective study was performed with patients from the Quebec City metropolitan area who were hospitalized at the Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval following cardiac surgery and who required oral anticoagulant (OAC) for postoperative AF. The primary objective was to compare the pre- and peri-COVID-19 period for OAC prescribing patterns and the incidence of thrombotic and bleeding events at 3 months post-surgery. The secondary objective was to compare DOAC to warfarin in terms of thrombotic events and bleeding events. RESULTS: A total of 233 patients were included, 142 from the pre-COVID-19 and 91 from the peri-COVID-19 period, respectively. Both groups had equivalent proportions of preoperative AF (48%) and new-onset postoperative AF (52%). The proportion of patients treated with a DOAC increased from 13% pre-COVID-19 to 82% peri-COVID-19. This change in practice was not associated with a significant difference in the incidence of thrombotic or bleeding events 3 months postoperatively. However, compared to DOAC, warfarin was associated with a higher incidence of major bleeding. Only 1 thrombotic event was reported with warfarin, and none were reported with DOAC. CONCLUSION: This study suggests that DOAC are an effective and safe alternative to warfarin to treat postoperative AF after cardiac surgery and that this practice can be safely maintained.

Integrated care for optimizing the management of stroke and associated heart disease: a position paper of the European Society of Cardiology Council on Stroke.

The management of patients with stroke is often multidisciplinary, involving various specialties and healthcare professionals. Given the common shared risk factors for stroke and cardiovascular disease, input may also be required from the cardiovascular teams, as well as patient caregivers and next-of-kin. Ultimately, the patient is central to all this, requiring a coordinated and uniform approach to the priorities of post-stroke management, which can be consistently implemented by different multidisciplinary healthcare professionals, as part of the patient 'journey' or 'patient pathway,' supported by appropriate education and tele-medicine approaches. All these aspects would ultimately aid delivery of care and improve patient (and caregiver) engagement and empowerment. Given the need to address the multidisciplinary approach to holistic or integrated care of patients with heart disease and stroke, the European Society of Cardiology Council on Stroke convened a Task Force, with the remit to propose a consensus on Integrated care management for optimizing the management of stroke and associated heart disease. The present position paper summarizes the available evidence and proposes consensus statements that may help to define evidence gaps and simple practical approaches to assist in everyday clinical practice. A post-stroke ABC pathway is proposed, as a more holistic approach to integrated stroke care, would include three pillars of management: A: Appropriate Antithrombotic therapy.B: Better functional and psychological status.C: Cardiovascular risk factors and Comorbidity optimization (including lifestyle changes).

The pharmacology of anticoagulant drug treatment options in COVID-19 patients: reviewing real-world evidence in clinical practice.

INTRODUCTION: The optimal anticoagulation strategy for venous thromboembolism (VTE) prevention among COVID-19 patients, hospitalized or in the community setting, is still challenging and largely based on real-world evidence. AREAS COVERED: We analyzed real-world data regarding the safety and effectiveness of anticoagulant treatment, both parenteral and oral, for VTE prevention or atrial fibrillation (AF)/VTE treatment among COVID-19 patients. EXPERT OPINION: The efficacy of low-molecular-weight heparin (LMWH) doses for VTE prevention correlates with COVID-19 disease status. LMWH prophylactic dose may be useful in COVID-19 patients at the early stage of the disease. LMWH intermediate or therapeutic dose is recommended in COVID-19 patients with an advanced stage of the disease. COVID-19 patients on VKA therapy for atrial fibrillation (AF) and VTE should switch to NOACs in the community setting or LMWH in the hospital setting. No definitive data on de-novo starting of NOACs or VKA therapy for VTE prevention in COVID-19 outpatients are available. In patients at high risk discharged after hospitalization due to COVID-19, thromboprophylaxis with NOACs may be considered.

Impact of apixaban treatment discontinuation on the risk of hospitalization among patients with nonvalvular atrial fibrillation and COVID-19.

INTRODUCTION: This study evaluated the risk of hospitalization among nonvalvular atrial fibrillation (NVAF) patients with an outpatient COVID-19 diagnosis who discontinued vs continued apixaban treatment. METHODS: Adult patients with NVAF with an apixaban prescription prior to an outpatient COVID-19 diagnosis were identified from Optum Clinformatics claims database (1 April 2020-31 March 2021). Continuers were those who continued apixaban as of the index date (date of initial outpatient COVID-19 diagnosis) and discontinuers were those who had the last day of apixaban supply on or before index. Patients were followed from COVID-19 diagnosis to change of continuation/discontinuation status, switch, death, end of continuous coverage or study end, whichever occurred first. Inverse probability treatment weighting (IPTW) was performed to balance cohorts. Cox proportional hazard models were used to compare the risk of all-cause hospitalization and hospitalization for ischemic stroke (IS), venous thromboembolism (VTE), myocardial infarction (MI), bleeding and mortality. RESULTS: A total of 7869 apixaban patients with COVID-19 were included: 6676 continuers (84.8%) and 1193 discontinuers (15.2%). Compared with continuers, discontinuers had a higher risk of all-cause hospitalization (hazard ratio [HR]: 1.23; 95% confidence interval [CI]: 1.08-1.40), IS (HR: 2.00; 95% CI: 1.03-3.87), VTE (HR: 2.37; 95% CI: 1.06-5.27) and mortality (HR: 2.28; 95% CI: 1.85-2.80). There were no significant differences in the risk of MI (HR: 1.01; 95% CI: 0.54-1.90) or bleeding-related hospitalization (HR: 1.13; 95% CI: 0.73-1.76). CONCLUSION: NVAF patients with COVID-19 who discontinued apixaban had a higher risk of hospitalization and thrombotic events vs those who continued apixaban, with no significant difference in bleeding-related hospitalization.

Design and rationale of the mobile health intervention for rural atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a highly morbid condition which requires long-term adherence to oral anticoagulation and may be associated with adverse quality of life and health care utilization. We developed a relational agent-an interactive smartphone-based intervention accessible regardless of digital or health literacy-to assist individuals residing in rural, Western Pennsylvania, with AF with chronic disease self-management. METHODS: The "Mobile health intervention for rural atrial fibrillation" is a single center, parallel-arm randomized clinical trial for adults with AF funded by the National Institute of Health's National Heart, Lung, and Blood Institute to enroll 264 participants. All participants receive a smartphone with data plan: The intervention is a 4 month relational agent coupled with the AliveCor Kardia for heart rate and rhythm monitoring provided by smartphone, and the control a pre-installed, smartphone-based application for health-related information (WebMD). The study uses remote recruitment and engagement to enroll individuals who would otherwise be unlikely to participate in clinical research due to rurality. The primary outcome of the trial is adherence to oral anticoagulation, determined by proportion of days covered, as measured at 12 months. The secondary outcomes are quality of life, both AF-specific and general, and health care utilization. The study entails a baseline visit, a 4 month intervention phase, and 8 and 12 month follow-up visits. CONCLUSIONS: This mobile health trial tests the effectiveness of a smartphone-based relational agent to improve clinical and patient-reported outcomes in rural-dwelling individuals.

Preadmission Oral Anticoagulation for Atrial Fibrillation/Flutter and Death or Thrombotic Events During COVID-19 Admission.

Atrial fibrillation/flutter (AF) and COVID-19 are associated with an elevated risk of arterial and venous thrombosis. Whether preadmission oral anticoagulation (OAC) for AF reduces the incidence of in-hospital death or thrombotic events among patients with COVID-19 is unknown. We identified 630 patients with pre-existing AF and a hospitalization diagnosis of COVID-19 and stratified them according to preadmission OAC use. Multivariable logistic regression was employed to relate preadmission OAC to composite in-hospital mortality or thrombotic events. Unadjusted composite in-hospital mortality or thrombotic complications occurred less often in those on than not on preadmission OAC (27.1% vs 46.8%, p <0.001). After adjustment, the incidence of composite in-hospital all-cause mortality or thrombotic complications remained lower with preadmission OAC (odds ratio 0.37, confidence interval 0.25 to 0.53, p <0.0001). Secondary outcomes including all-cause mortality (16.3% vs 24.9%, p = 0.007), intensive care unit admission (14.7% vs 29.0%, p <0.001), intubation (6.4% vs 18.6%, p <0.001), and noninvasive ventilation (18.6% vs 27.5%, p = 0.007) occurred less frequently, and length of stay was shorter (6 vs 7 days, p <0.001) in patients on than those not on preadmission OAC. A higher CHA₂DS₂-VASc score was associated with an increased risk of thrombotic events. In conclusion, among patients with baseline AF who were hospitalized with COVID-19, those on preadmission OAC had lower rates of death, arterial and venous thrombotic events, and less severe COVID-19.