Warfarin Management and Outcomes in Patients with Nonvalvular Atrial Fibrillation Within an Integrated Health Care System

Association of Direct Oral Anticoagulation Management Strategies With Clinical Outcomes for Adults With Atrial Fibrillation

Importance

Anticoagulation management services (AMSs; ie, warfarin clinics) have evolved to include patients treated with direct oral anticoagulants (DOACs), but it is unknown whether DOAC therapy management services improve outcomes for patients with atrial fibrillation (AF).

Objective

To compare outcomes associated with 3 DOAC care models for preventing adverse anticoagulation-related outcomes among patients with AF.

Design, Setting, and Participants

This retrospective cohort study included 44 746 adult patients with a diagnosis of AF who initiated oral anticoagulation (DOAC or warfarin) between August 1, 2016, and December 31, 2019, in 3 Kaiser Permanente (KP) regions. Statistical analysis was conducted from August 2021 through May 2023.

Exposures

Each KP region used an AMS to manage warfarin but used distinct approaches to DOAC care: (1) usual care (UC) by the prescribing clinician, (2) UC plus an automated population management tool (PMT), or (3) pharmacist-managed AMS care. Propensity scores and inverse probability of treatment weights (IPTWs) were estimated. Direct oral anticoagulant care models were first indirectly compared using warfarin as a common comparator within each region and then directly compared across regions.

Main Outcomes and Measures

Patients were followed up until the first occurrence of an outcome (composite of thromboembolic stroke, intracranial hemorrhage, other major bleeding, or death), discontinuation of KP membership, or December 31, 2020.

Results

Overall, 44 746 patients were included: 6182 in the UC care model (3297 DOAC; 2885 warfarin), 33 625 in the UC plus PMT care model (21 891 DOAC; 11 734 warfarin), and 4939 in the AMS care model (2089 DOAC; 2850 warfarin). Baseline characteristics (mean [SD] age, 73.1 [10.6] years, 56.1% male, 67.2% non-Hispanic White, median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes, stroke, vascular disease, age 65-74 years, female sex] score of 3 [IQR, 2-5]) were well balanced after IPTW. Over a median follow-up of 2 years, patients who received the UC plus PMT or AMS care model did not have significantly better outcomes than those who received UC. The incidence rate of the composite outcome was 5.4% per year for DOAC and 9.1% per year for warfarin for those in the UC group, 6.1% per year for DOAC and 10.5% per year for those in the UC plus PMT group, and 5.1% per year for DOAC and 8.0% per year for those in the AMS group. The IPTW-adjusted hazard ratios (HRs) for the composite outcome comparing DOAC vs warfarin were 0.91 (95% CI, 0.79-1.05) in the UC group, 0.85 (95% CI, 0.79-0.90) in the UC plus PMT group, and 0.84 (95% CI, 0.72-0.99) in the AMS group (P = .62 for heterogeneity across care models). When directly comparing patients receiving DOAC, the IPTW-adjusted HR was 1.06 (95% CI, 0.85-1.34) for the UC plus PMT group vs the UC group and 0.85 (95% CI, 0.71-1.02) for the AMS group vs the UC group.

Conclusions and Relevance

This cohort study did not find appreciably better outcomes for patients receiving DOAC who were managed by either a UC plus PMT or AMS care model compared with UC.

Clinical decision support to Optimize Care of patients with Atrial Fibrillation or flutter in the Emergency department: protocol of a stepped-wedge cluster randomized pragmatic trial (O'CAFÉ trial)

BACKGROUND

Management of adults with atrial fibrillation (AF) or atrial flutter in the emergency department (ED) includes rate reduction, cardioversion, and stroke prevention. Different approaches to these components of care may lead to variation in frequency of hospitalization and stroke prevention actions, with significant implications for patient experience, cost of care, and risk of complications. Standardization using evidence-based recommendations could reduce variation in management, preventable hospitalizations, and stroke risk.

METHODS

We describe the rationale for our ED-based AF treatment recommendations. We also describe the development of an electronic clinical decision support system (CDSS) to deliver these recommendations to emergency physicians at the point of care. We implemented the CDSS at three pilot sites to assess feasibility and solicit user feedback. We will evaluate the impact of the CDSS on hospitalization and stroke prevention actions using a stepped-wedge cluster randomized pragmatic clinical trial across 13 community EDs in Northern California.

DISCUSSION

We hypothesize that the CDSS intervention will reduce hospitalization of adults with isolated AF or atrial flutter presenting to the ED and increase anticoagulation prescription in eligible patients at the time of ED discharge and within 30 days. If our hypotheses are confirmed, the treatment protocol and CDSS could be recommended to other EDs to improve management of adults with AF or atrial flutter.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05009225 .  Registered on 17 August 2021.

Integrated Care for Atrial Fibrillation Management: The Role of the Pharmacist

Within Europe and the Asia-Pacific, the Atrial Fibrillation Better Care (ABC) pathway is the gold standard integrated care strategy for atrial fibrillation management. Atrial fibrillation diagnosis should be confirmed and characterized (CC) prior to implementation of ABC pathway components: 1) "A"- Anticoagulation/Avoid stroke; 2) "B"- Better symptom management; and 3) "C"- Cardiovascular and other comorbidity optimization. Pharmacists have the potential to expedite integrated care for atrial fibrillation across the health care continuum: hospital, community pharmacy, and general practice. This review summarizes the available evidence base for pharmacist-led implementation of the "CC to ABC" model.

Automated abstraction of myocardial perfusion imaging reports using natural language processing

BACKGROUND

Findings and interpretations of myocardial perfusion imaging (MPI) studies are documented in free-text MPI reports. MPI results are essential for research, but manual review is prohibitively time consuming. This study aimed to develop and validate an automated method to abstract MPI reports.

METHODS

We developed a natural language processing (NLP) algorithm to abstract MPI reports. Randomly selected reports were double-blindly reviewed by two cardiologists to validate the NLP algorithm. Secondary analyses were performed to describe patient outcomes based on abstracted-MPI results on 16,957 MPI tests from adult patients evaluated for suspected ACS.

RESULTS

The NLP algorithm achieved high sensitivity (96.7%) and specificity (98.9%) on the MPI categorical results and had a similar degree of agreement compared to the physician reviewers. Patients with abnormal MPI results had higher rates of 30-day acute myocardial infarction or death compared to patients with normal results. We identified issues related to the quality of the reports that not only affect communication with referring physicians but also challenges for automated abstraction.

CONCLUSION

NLP is an accurate and efficient strategy to abstract results from the free-text MPI reports. Our findings will facilitate future research to understand the benefits of MPI studies but requires validation in other settings.

Sustainability of a Clinical Decision Support Intervention for Outpatient Care for Emergency Department Patients With Acute Pulmonary Embolism

IMPORTANCE

Physicians commonly hospitalize patients presenting to the emergency department (ED) with acute pulmonary embolism (PE), despite eligibility for safe outpatient management. Risk stratification using electronic health record-embedded clinical decision support systems can aid physician site-of-care decision-making and increase safe outpatient management. The long-term sustainability of early improvements after the cessation of trial-based, champion-led promotion is uncertain.

OBJECTIVE

To evaluate the sustainability of recommended site-of-care decision-making support 4 years after initial physician champion-led interventions to increase outpatient management for patients with acute PE.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted in 21 US community hospitals in an integrated health system. Participants included adult patients presenting to the ED with acute PE. Study sites had participated in an original decision-support intervention trial 4 years prior to the current study period: 10 sites were intervention sites, 11 sites were controls. In that trial, decision support with champion promotion resulted in significantly higher outpatient management at intervention sites compared with controls. After trial completion, all study sites were given continued access to a modified decision-support tool without further champion-led outreach. Data were analyzed from January 2019 to February 2020.

EXPOSURES

ED treatment with a modified clinical decision support tool.

MAIN OUTCOMES AND MEASURES

The main outcome was frequency of outpatient management, defined as discharge home directly from the ED, stratified by the PE Severity Index. The safety measure of outpatient care was 7-day PE-related hospitalization.

RESULTS

This study included 1039 patients, including 533 (51.3%) women, with a median (IQR) age of 65 (52-74) years. Nearly half (474 patients [45.6%]) were rated lower risk on the PE Severity Index. Overall, 278 patients (26.8%) were treated as outpatients, with only four 7-day PE-related hospitalizations (1.4%; 95% CI, 0.4%-3.6%). The practice gap in outpatient management created by the earlier trial persisted in the outpatient management for patients with lower risk: 109 of 236 patients (46.2%) at former intervention sites vs 81 of 238 patients (34.0%) at former control sites (difference, 12.2; [95% CI, 3.4-20.9] percentage points; P = .007), with wide interfacility variation (range, 7.1%-47.1%).

CONCLUSIONS AND RELEVANCE

In this cohort study, a champion-led, decision-support intervention to increase outpatient management for patients presenting to the ED with acute pulmonary embolism was associated with sustained higher rates of outpatient management 4 years later. The application of our findings to improving sustainability of practice change for other clinical conditions warrants further study.

Predictors of Acute Atrial Fibrillation and Flutter Hospitalization across 7 U.S. Emergency Departments: A Prospective Study

INTRODUCTION

International rates of hospitalization for atrial fibrillation and flutter (AFF) from the emergency department (ED) vary widely without clear evidence to guide the identification of high-risk patients requiring inpatient management. We sought to determine (1) variation in hospital admission and (2) modifiable factors associated with hospitalization of AFF patients within a U.S. integrated health system.

METHODS

This multicenter prospective observational study of health plan members with symptomatic AFF was conducted using convenience sampling in 7 urban community EDs from 05/2011 to 08/2012. Prospective data collection included presenting symptoms, characteristics of atrial dysrhythmia, ED physician impression of hemodynamic instability, comorbid diagnoses, ED management, and ED discharge rhythm. All centers had full-time on-call cardiology consultation available. Additional variables were extracted from the electronic health record. We identified factors associated with hospitalization and included predictors in a multivariate Poisson Generalized Estimating Equations regression model to estimate adjusted relative risks while accounting for clustering by physician.

RESULTS

Among 1,942 eligible AFF patients, 1,074 (55.3%) were discharged home and 868 (44.7%) were hospitalized. Hospitalization rates ranged from 37.4% to 60.4% across medical centers. After adjustment, modifiable factors associated with increased hospital admission from the ED included non-sinus rhythm at ED discharge, no attempted cardioversion, and heart rate reduction.

DISCUSSION

Within an integrated health system, we found significant variation in AFF hospitalization rates and identified several modifiable factors associated with hospital admission. Standardizing treatment goals that specifically address best practices for ED rate reduction and rhythm control may reduce hospitalizations.

Automated Identification and Extraction of Exercise Treadmill Test Results

Background

Noninvasive cardiac tests, including exercise treadmill tests (ETTs), are commonly utilized in the evaluation of patients in the emergency department with suspected acute coronary syndrome. However, there are ongoing debates on their clinical utility and cost‐effectiveness. It is important to be able to use ETT results for research, but manual review is prohibitively time‐consuming for large studies. We developed and validated an automated method to interpret ETT results from electronic health records. To demonstrate the algorithm's utility, we tested the associations between ETT results with 30‐day patient outcomes in a large population.

Methods and Results

A retrospective analysis of adult emergency department encounters resulting in an ETT within 30 days was performed. A set of randomly selected reports were double‐blind reviewed by 2 physicians to validate a natural language processing algorithm designed to categorize ETT results into normal, ischemic, nondiagnostic, and equivocal categories. Natural language processing then searched and categorized results of 5214 ETT reports. The natural language processing algorithm achieved 96.4% sensitivity and 94.8% specificity in identifying normal versus all other categories. The rates of 30‐day death or acute myocardial infarction varied (P<0.001) by categories for normal (0.08%), ischemic (1.9%), nondiagnostic (0.77%), and equivocal (0.58%) groups achieving good discrimination (C‐statistic, 0.81; 95% CI, 0.7–0.92).

Conclusions

Natural language processing is an accurate and efficient strategy to facilitate large‐scale outcome studies of noninvasive cardiac tests. We found that most patients are at low risk and have normal ETT results, while those with abnormal, nondiagnostic, or equivocal results have slightly higher risks and warrant future investigation.

Predicting Thromboembolic and Bleeding Event Risk in Patients with Non-Valvular Atrial Fibrillation: A Systematic Review

BACKGROUND

 Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of stroke. Medical therapy for decreasing stroke risk involves anticoagulation, which may increase bleeding risk for certain patients. In determining the optimal therapy for stroke prevention for patients with AF, clinicians use tools with various clinical, imaging and patient characteristics to weigh stroke risk against therapy-associated bleeding risk.

AIM

 This article reviews published literature and summarizes available risk stratification tools for stroke and bleeding prediction in patients with AF.

METHODS

 We searched for English-language studies in PubMed, Embase and the Cochrane Database of Systematic Reviews published between 1 January 2000 and 14 February 2018. Two reviewers screened citations for studies that examined tools for predicting thromboembolic and bleeding risks in patients with AF. Data regarding study design, patient characteristics, interventions, outcomes, quality, and applicability were extracted.

RESULTS

 Sixty-one studies were relevant to predicting thromboembolic risk and 38 to predicting bleeding risk. Data suggest that CHADS₂, CHA₂DS₂-VASc and the age, biomarkers, and clinical history (ABC) risk scores have the best evidence for predicting thromboembolic risk (moderate strength of evidence for limited prediction ability of each score) and that HAS-BLED has the best evidence for predicting bleeding risk (moderate strength of evidence).

LIMITATIONS

 Studies were heterogeneous in methodology and populations of interest, setting, interventions and outcomes analysed.

CONCLUSION

 CHADS₂, CHA₂DS₂-VASc and ABC scores have the best prediction for stroke events, and HAS-BLED provides the best prediction for bleeding risk. Future studies should define the role of imaging tools and biomarkers in enhancing the accuracy of risk prediction tools.

PRIMARY FUNDING SOURCE

 Patient-Centered Outcomes Research Institute (PROSPERO #CRD42017069999).

Anticoagulation with rivaroxaban in a hematology unit: clinical profile, events and discontinuation rates in real-life patients with nonvalvular atrial fibrillation

AIM

To assess the clinical profile and thromboembolic and bleeding events in patients with nonvalvular atrial fibrillation (AF) who were attended in a hematology unit.

METHODS

Retrospective study of AF patients that started treatment with rivaroxaban between February 2012 and June 2016 in a hematology unit from a tertiary hospital in Spain.

RESULTS

Overall, 243 patients (mean age 78.4 ± 10.1 years; 47.5% women, CHA₂DS₂-VASc 3.7 ± 1.5) were included. After a mean follow-up of 16.5 ± 12.7 months, rivaroxaban was discontinued in only 2.4% of patients. During the follow-up, seven (2.0 events/100 patient-years) patients had a thromboembolic event and six patients (1.7 events/100 patient-years) a major bleeding.

CONCLUSION

Rivaroxaban was effective and safe among AF patients treated in a hematology unit, with very low discontinuation rates.

Thromboprophylaxis for Patients with High-risk Atrial Fibrillation and Flutter Discharged from the Emergency Department

Introduction

Many patients with atrial fibrillation or atrial flutter (AF/FL) who are high risk for ischemic stroke are not receiving evidence-based thromboprophylaxis. We examined anticoagulant prescribing within 30 days of receiving dysrhythmia care for non-valvular AF/FL in the emergency department (ED).

Methods

This prospective study included non-anticoagulated adults at high risk for ischemic stroke (ATRIA score ≥7) who received emergency AF/FL care and were discharged home from seven community EDs between May 2011 and August 2012. We characterized oral anticoagulant prescribing patterns and identified predictors of receiving anticoagulants within 30 days of the index ED visit. We also describe documented reasons for withholding anticoagulation.

Results

Of 312 eligible patients, 128 (41.0%) were prescribed anticoagulation at ED discharge or within 30 days. Independent predictors of anticoagulation included age (adjusted odds ratio [aOR] 0.89 per year, 95% confidence interval [CI] 0.82–0.96); ED cardiology consultation (aOR 1.89, 95% CI [1.10–3.23]); and failure of sinus restoration by time of ED discharge (aOR 2.65, 95% CI [1.35–5.21]). Reasons for withholding anticoagulation at ED discharge were documented in 139 of 227 cases (61.2%), the most common of which were deferring the shared decision-making process to the patient’s outpatient provider, perceived bleeding risk, patient refusal, and restoration of sinus rhythm.

Conclusion

Approximately 40% of non-anticoagulated AF/FL patients at high risk for stroke who presented for emergency dysrhythmia care were prescribed anticoagulation within 30 days. Physicians were less likely to anticoagulate older patients and those with ED sinus restoration. Opportunities exist to improve rates of thromboprophylaxis in this high-risk population.