Anticoagulation risk assessment for patients with non-valvular atrial fibrillation and venous thromboembolism: A clinical review

Positive Predictive Value of Non-Traumatic Bleeding Diagnoses in the Danish National Patient Register

Purpose

The majority of bleeding diagnoses in the Danish National Patient Registry have not been validated despite extensive use in epidemiological research. Therefore, we examined the positive predictive value (PPV) of non-traumatic bleeding diagnoses in the Danish National Patient Registry.

Study Design

Population-based validation study.

Patients and Methods

Based on a manual review of electronic medical records, we estimated the PPV of diagnostic coding (International Classification of Diseases, Tenth Revision (ICD-10)) for non-traumatic bleeding for all patients ≥65 years of age with any hospital contact in the North Denmark Region during March-December 2019 as registered in the Danish National Patient Registry. We calculated PPVs and associated 95% confidence intervals (CI) for non-traumatic bleeding diagnoses overall and stratified according to primary or secondary diagnosis, and according to major anatomical sites.

Results

A total of 907 electronic medical records were available for review. The population mean age was 79.33 years (standard deviation (SD)=7.73) and 57.6% were males. Primary bleeding diagnoses accounted for 766 of the records and 141 were secondary bleeding diagnoses. The overall PPV for bleeding diagnoses was 94.0% (95% CI: 92.3-95.4). The PPV was 98.7% (95% CI: 97.6-99.3) for the primary diagnoses and 68.8% (95% CI: 60.7-75.9) for the secondary diagnoses. When stratified according to subgroups of major anatomical sites, the PPVs ranged between 94.1% and 100% for the primary diagnoses, and between 53.8% and 100% for secondary diagnoses.

Conclusion

The overall validity of non-traumatic bleeding diagnoses in the Danish National Patient Registry is high and considered acceptable for epidemiological research. However, PPVs were substantially higher for primary than for secondary diagnosis.

Derivation and validation of predictors of oral anticoagulant-related adverse events in seniors transitioning from hospital to home

INTRODUCTION

Oral anticoagulant (OAC)-related adverse events are high post-hospitalization. We planned to develop and validate a prediction model for OAC-related harm within 30 days of hospitalization.

METHODS

We undertook a population-based study of adults aged ≥66 years who were discharged from hospital on an OAC from September 2010 to March 2015 in Ontario, Canada. The primary outcome was a composite of time to first hospitalization or emergency department visit for a hemorrhagic or thromboembolic event, or mortality within 30 days of hospital discharge. Cox proportional hazards regression was used to build the model.

RESULTS

We included 120,721 patients of which 5423 experienced the outcome. Most patients were aged ≥75 years (59.5%) and were female (55.6%). Sixty percent of the cohort had a follow-up visit with a healthcare provider within 7 days of discharge. Patients discharged on a direct acting OAC versus warfarin (apixaban: Hazard Ratio [HR] 0.82, 95% confidence interval [CI] 0.71-0.94; dabigatran: HR 0.73, 95% CI 0.63-0.84; rivaroxaban: HR 0.79, 95% CI 0.71-0.88), were prevalent users of the dispensed OAC versus incident users (HR 0.82, 95% CI 0.69-0.96), had a joint replacement in the past 35 days (HR 0.40, 95% CI 0.33-0.50) or major surgery during index hospital stay (HR 0.69, 95% CI 0.60-0.80) had a lower risk for the outcome. The Cox model was stable with acceptable discrimination but poor goodness-of-fit.

CONCLUSIONS

A model for OAC-related harm in the early post-discharge period was developed. External validation studies are required to understand the model's poor calibration.

A Review of Biomarkers for Ischemic Stroke Evaluation in Patients With Non-valvular Atrial Fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia worldwide and results in a significantly increased ischemic stroke (IS) risk. IS risk stratification tools are widely being applied to guide anticoagulation treatment decisions and duration in patients with non-valvular AF (NVAF). The CHA₂DS₂-VASc score is largely validated and currently recommended by renowned guidelines. However, this score is heavily dependent on age, sex, and comorbidities, and exhibits only moderate predictive power. Finding effective and validated clinical biomarkers to assist in personalized IS risk evaluation has become one of the promising directions in the prevention and treatment of NVAF. A number of studies in recent years have explored differentially expressed biomarkers in NVAF patients with and without IS, and the potential role of various biomarkers for prediction or early diagnosis of IS in patients with NVAF. In this review, we describe the clinical application and utility of AF characteristics, cardiac imaging and electrocardiogram markers, arterial stiffness and atherosclerosis-related markers, circulating biomarkers, and novel genetic markers in IS diagnosis and management of patients with NVAF. We conclude that at present, there is no consensus understanding of a desirable biomarker for IS risk stratification in NVAF, and enrolling these biomarkers into extant models also remains challenging. Further prospective cohorts and trials are needed to integrate various clinical risk factors and biomarkers to optimize IS prediction in patients with NVAF. However, we believe that the growing insight into molecular mechanisms and in-depth understanding of existing and emerging biomarkers may further improve the IS risk identification and guide anticoagulation therapy in patients with NVAF.

Comparative Analysis of Risk Stratification Scores in Atrial Fibrillation

BACKGROUND

Atrial Fibrillation (AF) has become a major global health concern and is associated with an increased risk of poor outcomes. Identifying risk factors in patients with AF can be challenging, given the high burden of comorbidities in these patients. Risk stratification schemes appear to facilitate accurate prediction of outcomes and assist therapeutic management decisions.

OBJECTIVE

To summarize current evidence on risk stratification scores for patients with AF.

RESULTS

Traditional risk models rely heavily on demographics and comorbidities, while newer tools have been gradually focusing on novel biomarkers and diagnostic imaging to facilitate more personalized risk assessment. Several studies have been conducted to compare existing risk schemes and identify specific patient populations in which the prognostic ability of each scheme excels. However, current guidelines do not appear to encourage the implementation of risk models in clinical practice, as they have not incorporated new ones in their recommendations for the management of patients with AF for almost a decade.

CONCLUSION

Further work is warranted to analyze new reliable risk stratification schemes and optimally implement them into routine clinical life.

GARFIELD-AF risk score for mortality, stroke and bleeding within 2 years in patients with atrial fibrillation

Aims

To determine whether the Global Anticoagulant Registry in the FIELD–Atrial Fibrillation (GARFIELD-AF) integrated risk tool predicts mortality, non-haemorrhagic stroke/systemic embolism, and major bleeding for up to 2 years after new-onset AF and to assess how this risk tool performs compared with CHA₂DS₂-VASc and HAS-BLED.

Methods and results

Potential predictors of events included demographic and clinical characteristics, choice of treatment, and lifestyle factors. A Cox proportional hazards model was identified for each outcome by least absolute shrinkage and selection operator methods. Indices were evaluated in comparison with CHA₂DS₂-VASc and HAS-BLED risk predictors. Models were validated internally and externally in ORBIT-AF and Danish nationwide registries. Among the 52 080 patients enrolled in GARFIELD-AF, 52 032 had follow-up data. The GARFIELD-AF risk tool outperformed CHA₂DS₂-VASc for all-cause mortality in all cohorts. The GARFIELD-AF risk score was superior to CHA₂DS₂-VASc for non-haemorrhagic stroke, and it outperformed HAS-BLED for major bleeding in internal validation and in the Danish AF cohort. In very low- to low-risk patients [CHA₂DS₂-VASc 0 or 1 (men) and 1 or 2 (women)], the GARFIELD-AF risk score offered strong discriminatory value for all the endpoints when compared to CHA₂DS₂-VASc and HAS-BLED. The GARFIELD-AF tool also included the effect of oral anticoagulation (OAC) therapy, thus allowing clinicians to compare the expected outcome of different anticoagulant treatment decisions [i.e. no OAC, non-vitamin K antagonist (VKA) oral anticoagulants, or VKAs].

Conclusions

The GARFIELD-AF risk tool outperformed CHA₂DS₂-VASc at predicting death and non-haemorrhagic stroke, and it outperformed HAS-BLED for major bleeding in overall as well as in very low- to low-risk group patients with AF.

Clinical trial registration

URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF: NCT01090362, ORBIT-AF I: NCT01165710; ORBIT-AF II: NCT01701817.

Bleeding Risk Assessment in Patients with Venous Thromboembolism

The recommended treatment for patients with venous thromboembolism (VTE) is anticoagulation for at least 3 months. However, anticoagulant treatment increases the risk of bleeding, and patients at high risk for major bleeding might benefit from treatment discontinuation. In this review, we discuss strategies for assessing bleeding risk and compare different bleeding risk tools. Bleeding risk assessment is best viewed as a continuous approach with varying challenges throughout the acute and chronic phase. At diagnosis, bleeding risk factors must be identified and reversible risk factors treated or modified. After initial treatment, repeated bleeding risk assessment is crucial for the decision on extended/long-term anticoagulation. Current clinical prediction models (e.g., HAS-BLED, RIETE, or VTE-BLEED scores) are externally validated tools with relevant differences in specificity and sensitivity, which can aid in clinical decision-making. Unfortunately, none of the current bleeding risk assessment tools has been investigated in clinical trials and provides evidence to withhold anticoagulation treatment based on the score. Nevertheless, the HAS-BLED or RIETE score can be used to identify patients at high risk for major bleeding during the initial treatment phase, while the VTE-BLEED score might be used to identify patients at low risk for bleeding and, therefore, to safely administer extended/long-term anticoagulation for secondary thromboprophylaxis. As clinical prediction scores still lack predictive value, future research should focus on developing biomarker-based risk assessment models.