Development of a Contemporary Bleeding Risk Model for Elderly Warfarin Recipients

Patients treated with vitamin K oral anticoagulants in family practice: a new approach to bleeding risk assessment. An ancillary study by the CACAO prospective general practice cohort

BACKGROUND

The ability of bleeding risk scores to predict major bleeding (MB) or clinically relevant nonmajor bleeding (CRNMB) remains a topic of contention, particularly in nonselected patients in family practice. In addition, the capacity to predict bleeding risk using simple variables has yet to be established.

OBJECTIVES

The main objective was to confirm that severe anemia was the most predictive factor for the estimation of bleeding risk in patients treated with vitamin K antagonists (VKAs). Secondary objectives were to test the capacity of different bleeding scores to detect high-risk patients. Subsequently, the impact of functional decline on bleeding incidence was explored.

METHODS

The CACAO study was a multicenter prospective cohort study of patients who, due to nonvalvular atrial fibrillation (NVAF) and/or venous thromboembolism (VTE), had been prescribed an oral anticoagulant by their general practitioner (GP) as a prophylactic measure. Patient characteristics were collected at the time of inclusion by GPs, who then monitored them in accordance with standard practice for one year. MB and CRNMB were the main outcomes for one year. By applying this approach, a total of 13 scores were analyzed.

RESULTS

Aaemia was found to be strongly associated with MB (HR: 2.77, 95% CI: 1.2-6.36), with a particularly pronounced association observed in cases of severe anemia (HR: 12.9, 95% CI: 2.76-60.35). Twelve out of 27 MB cases were not identified by at least half of the scores. By contrast, functional decline was identified as a novel factor associated with MB (HR: 2.45, 95% CI: 1.13-5.31).

CONCLUSIONS

Preexisting anemia is a major prognostic factor associated with the occurrence of bleeding. It seems relevant to suggest that functional decline should be considered by GPs when assessing bleeding risk.

Optimizing Dual Antiplatelet Therapy in the Perioperative Period for Spine Surgery After Recent Percutaneous Coronary Intervention: A Comprehensive Review, Synthesis, and Catalyst for Protocol Formulation

The increased incidence of spine surgery within the past decade has highlighted the importance of robust perioperative management to improve patient outcomes overall. Coronary artery disease is a common medical comorbidity present in the population of individuals who receive surgery for spinal pathology that is often treated with dual antiplatelet therapy (DAPT) after percutaneous coronary intervention. Discontinuation of DAPT before surgical intervention is typically indicated; however, contradictory evidence exists in the literature regarding the timing of DAPT use and discontinuation in the perioperative period. We review the most recent cardiac and spine literature on the intricacies of percutaneous coronary intervention and its associated risks in the postoperative period. We further propose protocols for DAPT use after both elective and urgent spine surgery to optimize perioperative care.

Oral anticoagulant safety in family practice: prognostic accuracy of Bleeding Risk Scores (from the CACAO study)

BACKGROUND

To assess bleeding risk of patients treated by oral anticoagulants, several scores have been constructed to assist physicians in the evaluation of the benefit risk. Most of these scores lack a strong enough level of evidence for use in family practice.

OBJECTIVE

To assess the predictive prognostic accuracy of 13 scores designed to assess the risk of major or clinically relevant non-major (CRNM) bleeding events in a French ambulatory cohort receiving Vitamin-K antagonists (VKA) or direct oral anticoagulants (DOACs) in a family practice setting.

METHODS

CACAO (Comparison of Accidents and their Circumstances with Oral Anticoagulants) was a multicentre prospective cohort of ambulatory patients prescribed oral anticoagulants. We selected patients from the cohort who had received an oral anticoagulant because of non-valvular atrial fibrillation (NVAF) and/or venous thromboembolism (VTE) to be followed during one year by their GP. The following scores were calculated: mOBRI, Shireman, Kuijer, HEMORR2HAGES, ATRIA, HAS-BLED, RIETE, VTE-BLEED, ACCP score, Rutherford, ABH-Score, GARFIEL-AF, and Outcomes Registry for Better InformedTreatment of Atrial Fibrillation (ORBIT). Prognostic accuracy was assessed by using receiver operating characteristic curves and c-statistics.

RESULTS

During 1 year, 3,082 patients were followed. All of the scores demonstrated only poor to moderate ability to predict major bleeding or CRNM in NVAF patients on DOACs (c-statistic: 0.41-0.66 and 0.45-0.58), respectively. The results were only slightly better for patients prescribed VKA (0.47-0.66 and 0.5-0.55, respectively) in this indication. The results were also unsatisfactory in patients treated for VTE.

CONCLUSION

None of the scores demonstrated satisfactory discriminatory ability when used in family practice.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02376777.

A Novel Nomogram for Predicting Warfarin-Related Bleeding: A Retrospective Cohort Study

Warfarin is a widely used anticoagulant, and bleeding complications are the main reason why patients discontinue the drug. Currently, there is no nomogram model for warfarin-associated bleeding risk. The aim of this study was to develop a risk-prediction nomogram model for warfarin-related major and clinically relevant non-major (CRNM) bleeding. A total of 280 heart disease outpatients taking warfarin were enrolled, 42 of whom experienced major or CRNM bleeding at the one-year follow-up. The Least Absolute Shrinkage and Selection Operator regression model was employed to identify potential predictors. Backward stepwise selection with the Akaike information criterion was used to establish the optimal predictive nomogram model. The receiver operating characteristic (ROC) curve, calibration plot, Hosmer-Lemeshow goodness-of-fit test, and decision curve analysis (DCA) were used to evaluate the performance of the nomogram. The nomogram consisted of four predictors: female (OR = 1.85; 95% CI: 0.91-3.94), TIA (OR = 6.47; 95% CI: 1.85-22.7), TTR (OR = 0.99; 95% CI: 0.97-1.00), and anemia (OR = 2.30; 95% CI: 1.06-4.84). The model had acceptable discrimination (area under the ROC curve = 0.68, 95% CI: 0.59-0.78), and was significantly better than the existing nine warfarin-related bleeding prediction scoring systems. The calibration plot and Hosmer-Lemeshow test (χ² = 7.557; P = .478) indicated well-calibrated data in the model. The DCA demonstrated good clinical utility. In this study, we developed a nomogram to predict the risk of warfarin-related major or CRNM bleeding. The model has good performance, allows rapid risk stratification of warfarin users, and provides a basis for personalized treatment.

Thrombin Generation Is Associated with Venous Thromboembolism Recurrence, but Not with Major Bleeding and Death in the Elderly: A Prospective Multicenter Cohort Study

It is currently unknown whether thrombin generation is associated with venous thromboembolism (VTE) recurrence, major bleeding, or mortality in the elderly. Therefore, our aim was to prospectively study the association between thrombin generation and VTE recurrence, major bleeding, and mortality in elderly patients with acute VTE. Consecutive patients aged ≥65 years with acute VTE were followed for 2 years, starting from 1 year after the index VTE. Primary outcomes were VTE recurrence, major bleeding, and mortality. Thrombin generation was assessed in 551 patients 1 year after the index VTE. At this time, 59% of the patients were still anticoagulated. Thrombin generation was discriminatory for VTE recurrence, but not for major bleeding and mortality in non-anticoagulated patients. Moreover, peak ratio (adjusted subhazard ratio 4.09, 95% CI, 1.12-14.92) and normalized peak ratio (adjusted subhazard ratio 2.18, 95% CI, 1.28-3.73) in the presence/absence of thrombomodulin were associated with VTE recurrence, but not with major bleeding and mortality after adjustment for potential confounding factors. In elderly patients, thrombin generation was associated with VTE recurrence, but not with major bleeding and/or mortality. Therefore, our study suggests the potential usefulness of thrombin generation measurement after anticoagulation completion for VTE to help identify among elderly patients those at higher risk of VTE recurrence.

Reducing bleeding risk in patients on oral anticoagulation therapy

INTRODUCTION

Oral anticoagulation (OAC) significantly mitigates thromboembolism risks in atrial fibrillation (AF) and venous thromboembolism (VTE) patients yet concern about major bleeding events persist. In fact, clinically relevant hemorrhages can be life-threatening. Bleeding risk is dynamic and influenced by factors such as age, new comorbidities, and drug therapies, and should not be assessed solely based on static baseline factors.

AREAS COVERED

We comprehensively review the bleeding risk associated with OAC therapy. Emphasizing the importance of assessing both thromboembolic and bleeding risks, we present clinical tools for estimating stroke and systemic embolism (SSE) and bleeding risk in AF and VTE patients. We also address overlapping risk factors and the dynamic nature of bleeding risk.

EXPERT OPINION

The OAC management is undergoing constant transformation, motivated by the primary objective of mitigating thromboembolism and bleeding hazards, thereby amplifying patient safety throughout the course of treatment. The future of OAC embraces personalized approaches and innovative therapies, driven by advanced pathophysiological insights and technological progress. This holds promise for improving patient outcomes and revolutionizing anticoagulation practices.

Incidence, source, and prognostic impact of major bleeding across the spectrum of aortic stenosis

BACKGROUND

Severe aortic stenosis (AS) has been associated with bleeding. However, there is a lack of prospective assessment of bleeding events and their clinical significance in a large population of outpatients with variable degree of AS severity.

OBJECTIVES

To assess the incidence, source, determinants, and prognostic impact of major bleeding in patients with variable degree of AS severity.

METHODS

Between May 2016 and December 2017, consecutive outpatients were included. Major bleeding was defined as type ≥3 bleed using the Bleeding Academic Research Consortium definition. Cumulative incidence was calculated with death as the competing event. Data was censored at time of aortic valve replacement.

RESULTS

Among 2,830 patients, 46 major bleeding events occurred (0.7%/year) during a median follow-up of 2.1 years (interquartile range: 1.4-2.7). Most frequent sites of bleeding were gastrointestinal (50%) and intracranial (30.4%). Major bleeding was significantly associated with all-cause mortality (hazard ratio: 5.93 (95% confidence interval 3.64-9.65); P < .001). AS severity was associated with major bleedings (P = .041). By multivariable analysis, severe AS was an independent determinant of major bleeding (hazard ratio vs mild AS: 3.59 [95% confidence interval 1.56-8.29]; P = .003). The increased risk of bleeding associated with severe AS was significantly exacerbated in patients using oral anticoagulation.

CONCLUSION

In AS patients, major bleeding is rare but a strong independent predictor of death. AS severity is a determinant of bleeding events. Severe AS and oral anticoagulation should be identified as an association at very high risk of major bleeding.

Safety and efficacy of direct oral anticoagulants in patients with anaemia and atrial fibrillation: an observational nationwide Danish cohort study

AIMS

The aim of this study was to evaluate the risk of stroke and bleeding among patients with atrial fibrillation (AF) treated with direct oral anticoagulants (DOACs) despite anaemia at treatment initiation time.

METHODS AND RESULTS

All Danish patients (N = 41 321) diagnosed with incident AF, having a baseline haemoglobin (Hb), and subsequently initiated DOAC therapy between 2012 and 2019 were identified through administrative registry databases. Patients with anaemia were subdivided according to the World Health Organization classification of anaemia and evaluated regarding risk of stroke and composite bleeding endpoint [hospitalization due to urogenital, gastrointestinal (GI), or intracranial bleeding or epistaxis]. Standardized absolute 1-year risks of stroke and composite bleeding endpoint were calculated using multivariable Cox regression analyses. The standardized absolute 1-year risk difference for composite bleeding increased by 0.96% [95% confidence interval (CI) 0.38-1.54] for patients with moderate/severe anaemia compared with patients with no anaemia. This risk was mainly driven by an increase in standardized absolute 1-year risk for serious GI bleeding, which increased by 0.41% (95% CI 0.19-0.63). No significant difference in standardized absolute 1-year bleeding risk was observed among patients with mild anaemia compared with patients with no anaemia 0.36% (95% CI -0.10 to 0.82). No significant difference in standardized absolute 1-year risk of stroke was observed among patients with mild anaemia, -0.16% (95% CI -0.13 to 0.15), and moderate/severe anaemia, -0.47% (95% CI -0.16 to 0.19), compared with patients with no anaemia.

CONCLUSION

For AF patients receiving DOACs, moderate/severe anaemia is a risk factor for serious GI bleeding, while stroke risk is the same regardless of whether anaemia was present at baseline or not.

Comparative effectiveness and safety of extended anticoagulant therapy among Medicare beneficiaries with venous thromboembolism

Guidelines recommend an extended course of anticoagulation therapy for patients who experienced venous thromboembolism (VTE) without transient provocation, however, optimal duration remains uncertain. We assessed effectiveness and safety of extended use of apixaban and warfarin greater than 6 months of initial treatment in patients with VTE. We conducted a retrospective cohort study of Medicare beneficiaries aged greater than or equal to 18 years with deep vein thrombosis or pulmonary embolism. Patients were required to have initiated anticoagulants within 30 days of their first VTE diagnosis, completed 6 months of initial anticoagulant treatment, and received extended phase treatment with apixaban (the apixaban group) or warfarin (the warfarin group) or no extended therapy. Multivariable Cox proportional hazards modeling with inverse probability treatment weighting was used to compare recurrent VTE, mortality, and major bleeding risks among the three groups. Mean extended-treatment duration was up to 10 months and 14 months in apixaban and warfarin groups, respectively. Compared with no extended treatment, apixaban use was associated with decreased risks of recurrent VTE (hazard ratio [HR] = 0.08, [95% confidence interval [CI]: 0.01-0.41]) and mortality (HR = 0.37, [95% CI: 0.27-0.51]) without increased major bleeding risk (HR = 1.29, [95% CI: 0.68-2.45]); warfarin use was associated not with recurrent VTE risk change but with increased major bleeding risk (HR = 2.14, [95% CI: 1.26-3.65]) and decreased mortality risk (HR = 0.39, [95% CI: 0.29-0.51]). Compared with warfarin, apixaban use was associated with decreased recurrent VTE (HR = 0.13, [95% CI: 0.03-0.63]) and major bleeding (HR = 0.56, [95% CI: 0.32-0.98]) risks. Subgroup and sensitivity analyses (e.g., intention-to-treat) findings remained consistent. Compared with warfarin or no extended therapy, extended-apixaban use was associated with reduced risk of recurrent VTE without increased major bleeding risk. Continuing anticoagulant therapy with apixaban greater than 6 months may be effective and safe.

Bleeding Risk Assessment in End-Stage Kidney Disease: Validation of Existing Risk Scores and Evaluation of a Machine Learning-Based Approach

BACKGROUND

 Patients with end-stage kidney disease (ESKD) on hemodialysis (HD) are at increased risk for bleeding. However, despite relevant clinical implications regarding dialysis modalities or anticoagulation, no bleeding risk assessment strategy has been established in this challenging population.

METHODS

 Analyses on bleeding risk assessment models were performed in the population-based Vienna InVestigation of Atrial fibrillation and thromboemboLism in patients on hemoDialysIs (VIVALDI) study including 625 patients. In this cohort study, patients were prospectively followed for a median observation period of 3.5 years for the occurrence of major bleeding. First, performances of existing bleeding risk scores (i.e., HAS-BLED, HEMORR2HAGES, ATRIA, and four others) were evaluated in terms of discrimination and calibration. Second, four machine learning-based prediction models that included clinical, dialysis-specific, and laboratory parameters were developed and tested using Monte Carlo cross-validation.

RESULTS

 Of 625 patients (median age: 66 years, 37% women), 89 (14.2%) developed major bleeding, with a 1-year, 2-year, and 3-year cumulative incidence of 6.1% (95% confidence interval [CI]: 4.2-8.0), 10.3% (95% CI: 8.0-12.8), and 13.5% (95% CI: 10.8-16.2), respectively. C-statistics of the seven contemporary bleeding risk scores ranged between 0.54 and 0.59 indicating poor discriminatory performance. The HAS-BLED score showed the highest C-statistic of 0.59 (95% CI: 0.53-0.66). Similarly, all four machine learning-based predictions models performed poorly in internal validation (C-statistics ranging from 0.49 to 0.55).

CONCLUSION

 Existing bleeding risk scores and a machine learning approach including common clinical parameters fail to assist in bleeding risk prediction of patients on HD. Therefore, new approaches, including novel biomarkers, to improve bleeding risk prediction in patients on HD are needed.

Assessment and Mitigation of Bleeding Risk in Atrial Fibrillation and Venous Thromboembolism: Executive Summary of a European and Asia-Pacific Expert Consensus Paper

While there is a clear clinical benefit of oral anticoagulation in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision for initiating and continuing anticoagulation is often based on a careful assessment of both thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static "one-off" assessment based on baseline factors but is dynamic, being influenced by aging, incident comorbidities, and drug therapies. In this executive summary of a European and Asia-Pacific Expert Consensus Paper, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with a view to summarizing "best practice" when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, and review established bleeding risk factors and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism, are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Effectiveness and Safety of Extended Oral Anticoagulant Therapy in Patients with Venous Thromboembolism: A Retrospective Cohort Study

Limited real-world evidence exists for effectiveness and safety of extended oral anticoagulation beyond 6 months of initial treatment in prevention of recurrent venous thromboembolism (VTE) and adverse major bleeding events among patients with VTE. Using MarketScan Commercial and Medicare Supplemental databases (2013-2019), we conducted a retrospective cohort study to compare the risk of recurrent VTE and major bleeding events during extended treatment among patients with VTE who completed the 6-month initial treatment and received extended oral anticoagulant treatment with apixaban, warfarin, or no extended treatment. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards modeling with inverse probability treatment weighting. We identified 14,818 patients with extended treatment of apixaban (n = 4,338), warfarin (n = 5,298), or no extended treatment (n = 5,182). Compared with no extended treatment, apixaban use was associated with decreased risk of recurrent VTE (HR: 0.10, 95% CI: 0.04-0.26) without increased risk of major bleeding events (HR: 1.06, 95% CI: 0.52-2.17); warfarin use was associated with decreased risk of recurrent VTE (HR: 0.23, 95% CI: 0.12-0.44) but with increased risk of major bleeding events (HR: 2.64, 95% CI: 1.51-4.59). Compared with warfarin, apixaban use was associated with decreased risk of major bleeding events (HR: 0.42, 95% CI: 0.22-0.80) but no difference in risk of recurrent VTE (HR: 0.46, 95% CI: 0.15-1.36). In a real-world clinical setting, extended anticoagulation with apixaban or warfarin was associated with decreased risk of recurrent VTE compared with no extended treatment, and apixaban had a better safety profile with fewer major bleeding events compared with warfarin among commercially insured patients with VTE.

Anemia and iron deficiency in patients with atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac tachyarrhythmia and has a rising global prevalence. Given the increasing burden of AF-related symptoms and complications, new approaches to management are required. Anemia and iron deficiency are common conditions in patients with AF. Furthermore, emerging evidence suggests that the presence of anemia may be associated with worse outcome in these patients. The role of anemia and iron deficiency has been extensively explored in other cardiovascular states, such as heart failure and ischemic heart disease. In particular, the role of iron repletion amongst patients with heart failure is now an established treatment modality. However, despite the strong bidirectional inter-relationship between AF and heart failure, the implications of anemia and iron-deficiency in AF have been scarcely studied. This area is of mechanistic and clinical relevance given the potential that treatment of these conditions may improve symptoms and prognosis in the increasing number of individuals with AF. In this review, we summarise the current published literature on anemia and iron deficiency in patients with AF. We discuss AF complications such as stroke, bleeding, and heart failure, in addition to AF-related symptoms such as exercise intolerance, and the potential impact of anemia and iron deficiency on these. Finally, we summarize current research gaps on anemia, iron deficiency, and AF, and underscore potential research directions.

Assessment and mitigation of bleeding risk in atrial fibrillation and venous thromboembolism: A Position Paper from the ESC Working Group on Thrombosis, in collaboration with the European Heart Rhythm Association, the Association for Acute CardioVascular Care and the Asia-Pacific Heart Rhythm Society

Whilst there is a clear clinical benefit of oral anticoagulation (OAC) in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision to initiate and continue anticoagulation is often based on a careful assessment of both the thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static 'one off' assessment based on baseline factors but is dynamic, being influenced by ageing, incident comorbidities, and drug therapies. In this Consensus Document, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with the view to summarizing 'best practice' when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, review established bleeding risk factors, and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

The development and validation of a multivariable model to predict the bleeding risk score for patients with non-valvular atrial fibrillation using direct oral anticoagulants in the Arab population

Background

Frequently used models, such as the HAS-BLED, ATRIA, ORBIT, and GARFIELD-AF evaluate the risk of bleeding when using an anticoagulant, for example warfarin, in patients with non-valvular atrial fibrillation. Limited studies are available reporting a model with a good discriminative ability to predict the bleeding risk score when using direct oral anticoagulants.

Methods

Patient data were collected from King Abdulaziz Medical City, King Fahad Cardiac Center, and Prince Sultan Cardiac Center in Riyadh, from outpatients, inpatients, or primary care clinics. In total, 1722 patients with a prescription for a new oral anticoagulant, Dabigatran, Rivaroxaban, or Apixaban, were enrolled. A resampling approach for variable selection was used and a five-fold cross-validation to assess the model fit and misclassification probabilities. The analysis used the receiver operating characteristics curve (ROC) and the concordance (c) statistic to assess the validation models’ discriminative power. The final penalized likelihood parameters were used for the development of the risk prediction tool. The accuracy of a classification and the prediction are reported with the sensitivity, specificity, and Brier score.

Results

Bleeding occurred in 11.15% of cases, of which 23.08% required a blood transfusion and 51.65% had a reduction in haemoglobin of more than 2 gm. The variable selection model identified 15 predictors associated with major bleeding. The discriminative ability of the model was good (c-statistic 0.75, p = 0.035). The Brier score of the model was 0.095. With a fixed cut-off probability value of 0.12 for the logistic regression equation, the sensitivity was 72.7%, and the specificity 66.3%.

Conclusion

This model demonstrated a good performance in predicting the bleeding risk in Arab patients treated with novel oral anticoagulants. This easy to use bleeding risk score will allow the clinician to quickly classify patients according to their risk category, supporting close monitoring and follow-up for high-risk patients, without laboratory and radiological monitoring.

Bleeding risk assessment for venous thromboembolism prophylaxis

Venous thromboembolism (VTE) is one of the main preventable causes of morbidity and mortality in hospitalized patients and fatal pulmonary embolism (PE) may be its first manifestation. Several national and international guidelines recommend using risk assessment models for prescription of VTE prophylaxis in hospitalized patients. Despite evidence and guidelines supporting VTE prevention, use of VTE prophylaxis in hospitalized patients remains suboptimal, which may be because of low awareness of the benefits of VTE prophylaxis, but might also reflect fear of bleeding complications in these patients, since this constitutes one of the main reasons for underutilization of thromboprophylaxis worldwide. Bleeding risk assessment is therefore necessary for adequate prophylaxis prescription and should be carried out concurrently with assessment of the risk of thrombosis. The purpose of this review is to highlight the importance of jointly assessing risk of VTE and risk of bleeding in hospitalized patients.

Beyond the 2020 guidelines on atrial fibrillation of the European society of cardiology

The most recent atrial fibrillation (AF) guidelines delivered by European Society of Cardiology (ESC) offer an updated approach to AF management, with the perspective of improved characterization of the arrhythmia, the cardiac substrate and the patients profile in terms of associated risk factors and comorbidities. Recommendations were based on careful scrutiny and assessment of all available evidence with the final aim to offer to practitioners a lower level of uncertainty in the complex process of decision making for patients with AF. The 2020 ESC guidelines on AF propose a paradigm shift in the clinical approach to AF patients, moving from a single-domain AF classification to comprehensive characterization of AF patients. Given the complex nature of AF, an integrated holistic management of AF patients is suggested by the guidelines for improving patients outcomes through the formal introduction of the CC (Confirm AF and Characterize AF) to ABC (Atrial fibrillation Better Care) pathway. In line with this concept, these new guidelines underline the importance of a more comprehensive management of AF patients which should not be limited to simply prescribe oral anticoagulation or decide between a rhythm or rate control strategy. Indeed, each step of the ABC pathway represents one of the pivotal pillars in the management of AF and only a holistic approach has the potential to improve patients' outcomes. In this review we will discuss the background that supports some of the new recommendations of 2020 ESC guidelines, with important implications for daily management of AF patients.

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.

Stroke and bleeding risk stratification in atrial fibrillation: a critical appraisal

Atrial fibrillation (AF) significantly increases the risk of stroke and, therefore, stroke prevention is an essential component of the management for patients with AF. This requires formal assessment of the individual risk of stroke to determine if the patient is eligible for oral anticoagulation (OAC), and if so, their risk of bleeding on OAC, before a treatment decision regarding stroke prevention is made. Risk of stroke is not homogenous; it depends on the presence or absence of risk factors. A plethora of stroke and bleeding risk factors has been identified, including common and less-well established clinical risk factors, plus imaging, urine, and blood biomarkers. Consequently, there are several stroke and bleeding risk stratification scores available and this article provides an overview of them, the risk factors included and how they are scored, and provides a critical appraisal of them. The review also discusses the debate regarding whether female sex is a risk factor or a risk modifier, and highlights the dynamic nature of both stroke and bleeding risk and the need to re-assess these risks periodically to ensure treatment is optimal to reduce the risk of adverse outcomes. This review also summarizes the recommended stroke and bleeding risk stratification scores from all current major international guidelines.

Prediction and treatment of bleeding in patients under anticoagulant treatment

Major bleeding is a common complication of anticoagulant treatment. Risk assessment tools are relevant in the management of patients with atrial fibrillation and venous thromboembolism. The combination of clinical, biological and genetic markers is incorporated to build predictive scores to help in the decision process about intensity and duration of treatment. The optimal management of bleeding involves the application of predictive scores in combination with anticoagulant reversal strategies.

Gastrointestinal bleeding in patients with atrial fibrillation treated with Apixaban or warfarin: Insights from the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial

OBJECTIVES

A history of gastrointestinal bleeding (GIB) in patients with atrial fibrillation (AF) may impact decisions about anticoagulation treatment. We sought to determine whether prior GIB in patients with AF taking anticoagulants was associated with an increased risk of stroke or major hemorrhage.

METHODS

We analyzed key efficacy and safety outcomes in patients with prior GIB in ARISTOTLE. Centrally adjudicated outcomes according to GIB history were analyzed using Cox proportional hazards models adjusted for randomized treatment and established risk factors.

RESULTS

A total of 784 (4.3%) patients had prior GIB events (321 [41%] lower, 463 [59%] upper); 215 (27%) occurred <1 year before study enrollment. Patients with prior GIB were older, had more comorbidities, and higher CHADS₂ and HAS-BLED scores than those with no GIB. Major GIB occurred more frequently in those with prior GIB (lower: aHR 1.72, 95% CI 0.86-3.42; upper: aHR 3.13, 95% CI 1.97-4.96). This association with major GIB was more pronounced in patients with GIB <1 year before randomization versus no recent GIB (recent lower: aHR 2.58, 95% CI 0.95-7.01; recent upper: aHR 5.16, 95% CI 2.66-10.0). There was no association between prior GIB and risk of stroke/systemic embolism or all-cause death. In those with prior GIB, the apixaban versus warfarin relative risks for stroke/systemic embolism, hemorrhagic stroke, death, or major bleeding were consistent with the results of the overall trial.

CONCLUSIONS

In patients with AF on oral anticoagulants, prior GIB was associated with an increased risk of subsequent major GIB but not stroke, intracranial bleeding, or all-cause mortality. For the key outcomes of stroke, hemorrhagic stroke, death, and major bleeding, we found no evidence that the treatment effect (apixaban vs. warfarin) was modified by a history of GIB.

Stroke and Bleeding Risk Assessments in Patients With Atrial Fibrillation: Concepts and Controversies

Risk assessments are an important element in the management of patients with atrial fibrillation (AF). In this review, we aim to discuss the concepts and controversies surrounding the various risk factors for stroke and bleeding in AF. Indeed, there are a variety of clinical, electrical, biological, and genetic markers to guide stroke and bleeding risk assessments in AF. The more common factors have been used to formulate risk stratification scores. Some risk factors have shown promise, but others remain less well-defined. Our aim is to discuss concepts and controversies surrounding current evidence of risk factors for stroke and bleeding assessments in AF.

Considerations when restarting anticoagulants in patients with atrial fibrillation after bleeding

Introduction: Oral anticoagulants (OACs) are established treatments to reduce thromboembolic risk in patients with atrial fibrillation (AF). Due to their mechanisms of action, they are associated with increased bleeding risk. Evaluation with bleeding risk scores may be useful to identify patients at high risk. However, the approach in patients who have suffered a recent bleeding event while on OACs is a contentious issue. If a decision is made to re-initiate OACs, the optimal timing for this remains controversial. Areas covered: Bleeding risk scores were designed to evaluate risk in patients with AF and indications for OACs. Some practical schemes were created to manage bleeding in this population. The types of bleeding were classified as minor, major non-life-threatening and major life-threatening bleeding. In AF patients suffering from severe acute bleeding, it is recommended to withhold OACs until the underlying cause is identified and treated. Each case will require an individualized decision to restarting OAC therapy after consideration of the risks, benefits, alternatives and patient's choice in the matter. Expert opinion: Management of major bleeding and restarting OACs in patients with a recent major bleeding poses a special challenge due to high bleeding and thrombotic risk. This will be discussed in this review.

Biomarkers Associated with Bleeding Risk in the Setting of Atrial Fibrillation

BACKGROUND

Prevention of thromboembolic disease, mainly stroke, with oral anticoagulants remains a major therapeutic goal in patients with atrial fibrillation. Unfortunately, despite the high efficacy, anticoagulant therapy is associated with a significant risk of, frequently catastrophic, and hemorrhagic complications. Among different clinical and laboratory parameters related to an increased risk of bleeding, several biological markers have been recognized and various risk scores for bleeding have been developed.

OBJECTIVES/METHODS

The aim of the present study is to review current evidence regarding the different biomarkers associated with raised bleeding risk in atrial fibrillation.

RESULTS

Data originating from large cohorts or the recent large-scale trials of atrial fibrillation have linked numerous individual biomarkers to an increased bleeding risk. Such a relation was revealed for markers of cardiac physiology, such as troponin, BNP and NT-proBNP, markers of renal function, such as GFR and Cystatin or hepatic function, markers involving the system of coagulation, such as D-dimer and Von Willebrand factor, hematologic markers, such as low haemoglobin or low platelets, inflammatory markers, such as interleukin-6, other factors such as GDF-15 and vitamin-E and finally genetic polymorphisms. Many such biomarkers are incorporated in the bleeding risk schemata developed for the prediction of the hemorrhagic risk.

CONCLUSIONS

Biomarkers were introduced in clinical practice in order to better estimate the potential risk of haemorrhage in these patients and increase the prognostic impact of clinical risk scores. In the last years this concept is gaining significant importance.

Risk of bleeding in hospitalized patients on anticoagulant therapy: Prevalence and potential risk factors

INTRODUCTION

Bleeding is the most important complication of treatment with anticoagulant therapy. Although several studies have identified risk factors of bleeding in outpatients, no studies have been performed that evaluated prevalence and potential risk factors of bleeding in hospitalized patients treated with anticoagulant therapy.

METHODS

The primary objective of this study was to determine the prevalence of bleeding in anticoagulant users during hospitalization. The secondary objective was to identify potential risk factors of bleeding in hospitalized patients on anticoagulant therapy. A prospective, observational cohort study was conducted in two Dutch hospitals. Adult patients hospitalized between October 2015 and October 2016 treated with anticoagulant therapy were included. Bleeding was defined as a composite endpoint of major bleeding and non-major bleeding according to the International Society on Thrombosis and Heamostasis (ISTH) criteria. Data analysis was performed by multivariate logistic regression.

RESULTS

The prevalence of in-hospital bleeding in patients using anticoagulant therapy was 7.2%; 95% confidence interval [95% CI] 5.5-9.1 (65 out of 906 patients). Multivariate logistic regression analysis indicated that female gender (adjusted odds ratio [ORadj] 2.1; 95% CI 1.2-3.7), high-bleeding-risk surgical procedure (ORadj 5.3; 95% CI 2.7-10.2), low-bleeding-risk surgical procedure (ORadj 4.9; 95% CI 1.9-12.6), and non-surgical interventions (ORadj 6.2; 95% CI 3.0-12.6) were associated with bleeding events in hospitalized patients treated with anticoagulants.

CONCLUSIONS

The prevalence of bleeding in anticoagulant users during hospitalization was 7.2%. This study detected potential risk factors that can help to identify patients on anticoagulants who have an increased risk of bleeding during hospitalization.

Comparison of prediction value of four bleeding risk scores for pulmonary embolism with anticoagulation: A real-world study in Chinese patients

BACKGROUND

Major bleeding (MB) and clinically relevant bleeding (CRB) are the most common seen complications associated with anticoagulation treatment for pulmonary embolism (PE) patients. A bleeding risk score (BRS) may help to accurately determine the risk of bleeding and make better decisions for patients in clinical practice.

METHODS

Patients diagnosed as acute PE and who met the inclusion criteria in Beijing Chao-Yang Hospital from January 2009 to September 2013 were consecutively enrolled. Baseline data were collected. Four BRS (Kuijer score, RIETE score, Kearon score and Nieuwenhuis score) were assessed and compared using the area under the receiver operating characteristic curve (AUC).

RESULTS

A total number of 563 patients were included in the study. Of which, 16 had MB and 89 had CRB within three months of anticoagulation treatment. Three months' cumulative incidence for MB and CRB events was 0.03 (95% CI 0.01-0.05) and 0.17 (95% CI 0.12-0.21), respectively. In our study population, the AUCs for Kuijer, RIETE, Kearon and Nieuwenhuis scores were 0.57 (95% CI 0.44~0.68), 0.56 (95% CI 0.45-0.71), 0.75 (95% CI 0.60~0.89) and 0.59 (95% CI 0.41~0.74), respectively. In addition, the AUCs of four BRS for CRB were all poor, with values less than 0.65.

CONCLUSIONS

Only the Kearon score appeared to have more accuracy in predicting the risk of MB. Further large prospective studies are needed to externally validate a BRS for CRB.

A high Gas6 level in plasma predicts venous thromboembolism recurrence, major bleeding and mortality in the elderly: a prospective multicenter cohort study

Essentials Predictive ability of pro-hemostatic Gas6 for recurrent venous thromboembolism (VTE) is unknown. We measured Gas6 levels in 864 patients with VTE over 3 years. High Gas6 (> 157%) at diagnosis is associated with VTE recurrence, major bleeding and mortality. Gas6 plasma levels measured 12 months after the index VTE are discriminatory for VTE recurrence. SUMMARY: Background Growth arrest-specific gene 6 (Gas6) is a prohemostatic protein with an unknown predictive ability for recurrent venous thromboembolism (VTE). In the elderly, VTE results in higher mortality but does not have a higher rate of recurrence than in younger patients. Consequently, anticoagulation management in the elderly is challenging. Objective To prospectively investigate the performance of Gas6 in predicting VTE recurrence, major bleeding and mortality in the elderly. Methods Consecutive patients aged ≥ 65 years with acute VTE were followed for a period of 3 years. Primary outcomes were symptomatic VTE recurrence, major bleeding, and mortality. Plasma Gas6 was measured with ELISA. Results Gas6 levels were measured in 864 patients at the time of the index VTE (T1) and, in 70% of them, also 12 months later (T2). The Gas6 level at T1 was discriminatory for VTE recurrence (C-statistic, 0.56; 95% confidence interval [CI] 0.51-0.62), major bleeding (0.60, 95% CI 0.55-0.65) and mortality (0.69, 95% CI 0.65-0.73) up to 36 months. VTE recurrence up to 24 months after T2 was discriminated by the Gas6 level at T2 (0.62, 95% CI 0.54-0.71). High Gas6 levels (> 157%) and continuous Gas6 levels at T1 were associated with VTE recurrence up to 6 months and 12 months, respectively. Conclusions In elderly patients, a high Gas6 level is associated with higher risks of VTE recurrence, major bleeding, and death. These findings support further studies to assess the performance of Gas6 in adjusting the length of anticoagulation.

Bleeding Complications in Warfarin-Treated Patients Admitted to the Emergency Department

Background

Increased use of warfarin for the treatment and prophylaxis of many diseases has increased the frequency of adverse events. Emergency departments (EDs) are the first places where early interventions for bleeding and other complaints related to warfarin use are performed. This study assessed the characteristics of patients receiving warfarin and the risk factors for bleeding complication among those admitted to the ED.

Methods

Patients admitted to the ED for any reason other than trauma during a 1-year period were retrospectively reviewed. The study population consisted of 96 patients who had received warfarin and had an international normalized ratio (INR) ≥ 3. Patient demographics and medical history were recorded.

Results

The mean age of the patients (female, 52.1%) was 64.9 ± 14.5 years. Fatigue was the most common presenting complaint (61%). At least one major and/or minor bleeding event had occurred in 32 (33.3%) of the patients. Patients with (n = 32) and without (n = 64) bleeding complications did not significantly differ with respect to age, sex, reason for warfarin initiation, duration of warfarin use, concomitant diseases, and concurrent medications. There were also no significant differences in the distribution of patient admissions in terms of season at presentation, INR level, and weekly warfarin dose.

Conclusions

While the parameters evaluated in this study did not significantly differ among warfarin-treated patients, they may nonetheless pose a risk of bleeding. Further large-scale and long-term studies that take into account biological variation are required to precisely identify the risk factors for bleeding.

Follow-up and management of valvular heart disease patients with prosthetic valve: a clinical practice guideline for Indian scenario

PURPOSE

Valvular heart disease (VHD) patients after prosthetic valve implantation are at risk of thromboembolic events. Follow-up care of patients with prosthetic valve has a paramount role in reducing the morbidity and mortality. Currently, in India, there is quintessential need to stream line the follow-up care of prosthetic valve patients. This mandates the development of a consensus guideline for the antithrombotic therapy in VHD patients post prosthetic valve implantation.

METHODS

A national level panel was constituted comprising 13 leading cardio care experts in India who thoroughly reviewed the up to date literature, formulated the recommendations, and developed the consensus document. Later on, extensive discussions were held on this draft and the recommendations in 8 regional meetings involving 79 additional experts from the cardio care in India, to arrive at a consensus. The final consensus document is developed relying on the available evidence and/or majority consensus from all the meetings.

RESULTS

The panel recommended vitamin K antagonist (VKA) therapy with individualized target international normalized ratio (INR) in VHD patients after prosthetic valve implantation. The panel opined that management of prosthetic valve complications should be personalized on the basis of type of complications. In addition, the panel recommends to distinguish individuals with various co-morbidities and attend them appropriately.

CONCLUSIONS

Anticoagulant therapy with VKA seems to be an effective option post prosthetic valve implantation in VHD patients. However, the role for non-VKA oral therapy in prosthetic valve patients and the safety and efficacy of novel oral anticoagulants in patients with bioprosthetic valve need to be studied extensively.

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).

Predictive ability of scores for bleeding risk in heart disease outpatients on warfarin in Brazil

Introduction

Bleeding is a common complication in patients taking warfarin. We sought to compare the performance of nine prediction models for bleeding risk in warfarin-treated Brazilian outpatients.

Methods

The dataset was derived from a clinical trial conducted to evaluate the efficacy of an anticoagulation clinic at a public hospital in Brazil. Overall, 280 heart disease outpatients taking warfarin were enrolled. The prediction models OBRI, Kuijer et al., Kearon et al., HEMORR₂HAGES, Shireman et al., RIETE, HAS-BLED, ATRIA and ORBIT were compared to evaluate the overall model performance by Nagelkerke’s R² estimation, discriminative ability based on the concordance (c) statistic and calibration based on the Hosmer-Lemeshow goodness-of-fit statistic. The primary outcomes were the first episodes of major bleeding, clinically relevant non-major bleeding and non-major bleeding events within 12 months of follow-up.

Results

Major bleeding occurred in 14 participants (5.0%), clinically relevant non-major bleeding in 29 (10.4%), non-major bleeding in 154 (55.0%) and no bleeding at all in 115 (41.1%). Most participants with major bleeding had their risk misclassified. All the models showed low overall performance (R² 0.6–9.3%) and poor discriminative ability for predicting major bleeding (c <0.7), except Shireman et al. and ORBIT models (c 0.725 and 0.719, respectively). Results were not better for predicting other bleedings. All models showed good calibration for major bleeding.

Conclusions

Only two models (Shireman et al. and ORBIT) showed at least acceptable performance in the prediction of major bleeding in warfarin-treated Brazilian patients. Accurate models warrant further investigation to be used in similar populations.

The prevention of venous thromboembolism recurrence in the elderly: a still open issue

INTRODUCTION

Venous thromboembolism (VTE) is frequent in the elderly, with an unclear recurrence risk. After the initial and early maintenance anticoagulant treatment, the decision about its extension versus recurrences is difficult because of the high risk of bleeding in this population. Areas covered: This paper analyzes recent literature on VTE recurrence and risk of bleeding associated with extended anticoagulation in elderly patients with VTE, focusing on available data regarding efficacy and safety of old anticoagulant or recent direct oral anticoagulant (DOACs). Expert commentary: The following are clinically important and still unmet needs in elderly patients with VTE: the current real risks for recurrence or for bleeding are still uncertain; the available clinical predictive rules for recurrence are of less use; in general, the phase III trials on DOACs proved less satisfactory in the elderly than in the general population; low dose DOACs use for extended treatment seems promising and data on long periods of therapy are needed; low dose aspirin does not seem an appropriate therapeutic alternative to anticoagulants due to the high rate of bleeding in the elderly; antithrombotic drugs, with low risk of bleeding should be assessed as alternative therapeutic options for extended treatment in the elderly.

Anticoagulation Resumption After Intracerebral Hemorrhage

Purpose of review

Decision-making on resuming oral anticoagulant (OAC) after intracerebral hemorrhage (ICH) evokes significant debate among clinicians. Such patients have been excluded from randomized clinical trials. This review article provides a comprehensive summary of the evidence on anticoagulation resumption after ICH.

Recent findings

OAC resumption does not increase the risk of recurrent ICH and can also reduce the risk of all-cause mortality. OAC cessation exposes patients to a significantly higher risk of thromboembolism, which could be reduced by resumption. The optimal timing of anticoagulation resumption after ICH is still unknown. Both early (< 2 weeks) and late (> 4 weeks) resumption should be reached only after very careful assessment of risks for ICH recurrence and thromboembolism. The introduction of new oral anticoagulants and other interventions, such as left atrial appendage closure, has provided some patients with more alternatives.

Summary

Given the lack of high-quality evidence to guide clinical decision-making, clinicians must carefully balance the risks of thromboembolism and recurrent ICH in individual patients. We propose a management approach which would facilitate the decision-making process on whether anticoagulation is appropriate, as well as when and how to restart anticoagulation after ICH.

Anemia and bleeding in patients receiving anticoagulant therapy for venous thromboembolism: comment

Kuperman et al. found that patients with anemia had a higher risk of major bleeding (RR 2.84; 95% CI 2.52-3.39) in RIETE database. Anemia appeared to be an independent predictive factor for major bleeding [hazard ratio (HR) 1.95; 95% CI 1.72-2.20] in this registry. Unfortunately, selection bias due to enrolled patients does not allowed us to use these major results in ambulatory care. The aim of SCORE study was to refine bleeding risk estimation in French vitamin K antagonist (VKA) treated patients and to identifying one or several parameters of prognostic significance. We conducted a prospective, multi-center cohort study of 962 consecutive outpatients from private angiologic offices, clinics and hospitals enrolled in grenoble angiologic network for thromboembolic diseases between May 2009 and December 2010, followed during 1 year by their general practitioner. Main outcome was the occurrence of major bleeding or clinically non major relevant bleeding (CNMRB). Incidence rates major bleeding and CNMRB were 2.86 (95% CI 1.95-4.2) events per 100 patient-years and 12% (95% CI 9.89-14.11) respectively. Cox multivariate analyses showed that only anemia was strongly associated with a risk of major bleeding (HR 6.1; 95% CI 2.7-13.8; p = 0.001). Logistic regression analyses performed in CNMRB showed that anemia, prior gastro-intestinal bleeding and antiplatelet drug use were strongly associated with a risk of CNMRB at 1 year, respectively OR 2.53, 95% CI (1.4-4.56); p = 0.002, OR 3.32, 95% CI (1.51-7.31); p = 0.003 and OR 1.77, 95% CI (1.1-2.83); p = 0.017. These new data were consistent between major and CRNM bleeding in VKA treated patients. The key role of anemia should be confirmed in other prospective cohort studies, with different anticoagulants use such as direct oral anticoagulant in ambulatory care settings.

Development of a clinical prediction model for an international normalised ratio ≥ 4·5 in hospitalised patients using vitamin K antagonists

Vitamin K antagonists (VKAs) used for the prevention and treatment of thromboembolic disease, increase the risk of bleeding complications. We developed and validated a model to predict the risk of an international normalised ratio (INR) ≥ 4·5 during a hospital stay. Adult patients admitted to a tertiary hospital and treated with VKAs between 2006 and 2010 were analysed. Bleeding risk was operationalised as an INR value ≥4·5. Multivariable logistic regression analysis was used to assess the association between potential predictors and an INR ≥ 4·5 and validated in an independent cohort of patients from the same hospital between 2011 and 2014. We identified 8996 admissions of patients treated with VKAs, of which 1507 (17%) involved an INR ≥ 4·5. The final model included the following predictors: gender, age, concomitant medication and several biochemical parameters. Temporal validation showed a c statistic of 0·71. We developed and validated a clinical prediction model for an INR ≥ 4·5 in VKA-treated patients admitted to our hospital. The model includes factors that are collected during routine care and are extractable from electronic patient records, enabling easy use of this model to predict an increased bleeding risk in clinical practice.

Influence of Age on Warfarin Dose, Anticoagulation Control, and Risk of Hemorrhage

OBJECTIVE

We assessed the influence of age on warfarin dose, percentage time in target range (PTTR), and risk of major hemorrhage.

DESIGN

Warfarin users recruited into a large prospective inception cohort study were categorized into three age groups: young (younger than 50 yrs), middle aged (50-70 yrs), and elderly (older than 70 yrs). The influence of age on warfarin dose and PTTR was assessed using regression analysis; risk of major hemorrhage was assessed using proportional hazards analysis. Models were adjusted for demographic, clinical, and genetic factors.

SETTING

Two outpatient anticoagulation clinics.

PARTICIPANTS

A total of 1498 anticoagulated patients.

OUTCOMES

Warfarin dose (mg/day), PTTR, major hemorrhage.

RESULTS

Of the 1498 patients, 22.8% were young, 44.1% were middle aged, and 33.1% were elderly. After accounting for clinical and genetic factors, compared with young warfarin users, warfarin dose requirements were 10.6% lower among the middle aged and an additional 10.6% lower for the elderly. Compared with young patients, middle-aged and elderly patients spent more time in target international normalized ratio (INR) range (p<0.0001), despite having fewer INR assessments (p<0.0001). Compared with young warfarin users, absolute risk of hemorrhage was marginally higher among the middle aged (p=0.08) and significantly higher among the elderly (p=0.016). Compared with young warfarin users, after adjustment, the relative risk of hemorrhage increased by 31% for each age category (p=0.026).

CONCLUSIONS

In a real-world setting, despite achieving better anticoagulation control, elderly patients had a higher risk of major hemorrhagic events. As the population ages and the candidacy for oral anticoagulation increases, strategies that mitigate the elevated risk of hemorrhage need to be identified.

Bleeding risk assessment and management in atrial fibrillation patients

In this executive summary of a Consensus Document from the European Heart Rhythm Association, endorsed by the European Society of Cardiology Working Group on Thrombosis, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in atrial fibrillation (AF) patients. The main aim of the document was to summarise ‘best practice’ in dealing with bleeding risk in AF patients when approaching antithrombotic therapy, by addressing the epidemiology and size of the problem, and review established bleeding risk factors. We also summarise definitions of bleeding in the published literature. Patient values and preferences balancing the risk of bleeding against thromboembolism as well as the prognostic implications of bleeding are reviewed. We also provide an overview of published bleeding risk stratification and bleeding risk schema. Brief discussion of special situations (e.g. periablation, peri-devices such as implantable cardioverter defibrillators [ICD] or pacemakers, presentation with acute coronary syndromes and/or requiring percutanous coronary interventions/stents and bridging therapy) is made, as well as a discussion of the prevention of bleeds and managing bleeding complications. Finally, this document puts forwards consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Differences among western European countries in anticoagulation management of atrial fibrillation

Due to improved implementation of guidelines, new scoring approaches to improve risk categorisation, and introduction of novel oral anticoagulants, medical management of patients with atrial fibrillation (AF) is continuously improving. The PREFER in AF registry enrolled 7,243 consecutive patients with ECG-confirmed AF in seven European countries in 2012–2013 (mean age: 71.5 ± 10.7 years; 60.1% males; mean CHA2DS 2 -VASc score: 3.4). While patient characteristics were generally homogeneous across countries, anticoagulation management showed important differences: the proportion of patients taking vitamin K antagonists (VKAs) varied between 86.0% (in France) and 71.4% (in Italy). Warfarin was used predominantly in the UK and Italy (74.9% and 62.0%, respectively), phenprocoumon in Germany (74.1%), acenocoumarol in Spain (67.3%), and fluindione in France (61.8 %). The major sites for international normalised ratio (INR) measurements were biology laboratories in France anticoagulation clinics in Italy, Spain, and the UK, and physicians’ offices or self-measurement in Germany. Temporary VKA discontinuation and bridging with other anticoagulants was frequent (at least once in the previous 12 months for 22.9% of the patients, on average; ranging from 29.7% in Germany to 14.9% in the UK). Time in therapeutic range (TTR), defined as at least two of the last three available INR values between 2.0–3.0 prior to enrolment, ranged from 70.3% in Spain to 81.4% in Germany. TTR was constantly overestimated by physicians. While the type and half-lives of VKA as well as the mode of INR surveillance differed, overall quality of anticoagulation management by TTR was relatively homogenous in AF patients across countries.

Poor predictive value of contemporary bleeding risk scores during long-term treatment of venous thromboembolism

Bleeding is a common and feared complication of oral anticoagulant therapy. Several prediction models have been recently developed, but there is a lack of evidence in patients with venous thromboembolism (VTE). The aim of this study was to validate currently available bleeding risk scores during long-term oral anticoagulation for VTE. We retrospectively included adult patients on vitamin K antagonists for VTE secondary prevention, followed by five Italian Anticoagulation Clinics (Cuneo, Livorno, Mantova, Napoli, Varese), between January 2010 and August 2012. All bleeding events were classified as major bleeding (MB) or clinically-relevant-non-major-bleeding (CRNMB). A total of 681 patients were included (median age 63 years; 52.0% female). During a mean follow-up of 8.82 (± 3.59) months, 50 bleeding events occurred (13 MB and 37 CRNMB), for an overall bleeding incidence of 9.99/100 patient-years. The rate of bleeding was higher in the first three months of treatment (15.86/100 patient-years) than afterwards (7.13/100 patient-years). The HAS-BLED showed the best predictive value for bleeding complications during the first three months of treatment (area under the curve [AUC] 0.68, 95% confidence interval [CI] 0.59–0.78), while only the ACCP score showed a modest predictive value after the initial three months (AUC 0.61, 95%CI 0.51–0.72). These two scores had also the highest sensitivity and the highest negative predictive value. None of the scores predicted MB better than chance. Currently available bleeding risk scores had only a modest predictive value for patients with VTE. Future studies should aim at the creation of a new prediction rule, in order to better define the risk of bleeding of VTE patients.

Long-term outcomes of elderly patients with CYP2C9 and VKORC1 variants treated with vitamin K antagonists

Essentials The long-term effects of VKORC1 and CYP2C9 variants on clinical outcomes remains unclear. We followed 774 patients ≥65 years with venous thromboembolism for a median duration of 30 months. Patients with CYP2C9 variants are at increased risk of death and non-major bleeding. Patients with genetic variants have a slightly lower anticoagulation quality only.

SUMMARY

Background The long-term effect of polymorphisms of the vitamin K-epoxide reductase (VKORC1) and the cytochrome P450 enzyme gene (CYP2C9) on clinical outcomes remains unclear. Objectives We examined the association between CYP2C9/VKORC1 variants and long-term clinical outcomes in a prospective cohort study of elderly patients treated with vitamin K antagonists for venous thromboembolism (VTE). Methods We followed 774 consecutive patients aged ≥ 65 years with acute VTE from nine Swiss hospitals for a median duration of 30 months. The median duration of initial anticoagulant treatment was 9.4 months. The primary outcome was the time to any clinical event (i.e. the composite endpoint of overall mortality, major and non-major bleeding, and recurrent VTE. Results Overall, 604 (78%) patients had a CYP2C9 or VKORC1 variant. Three hundred and thirty-four patients (43.2%) had any clinical event, 119 (15.4%) died, 100 (12.9%) had major and 167 (21.6%) non-major bleeding, and 100 had (12.9%) recurrent VTE. After adjustment, CYP2C9 (but not VKORC1) variants were associated with any clinical event (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.08-1.66), death (HR, 1.74; 95% CI, 1.19-2.52) and clinically relevant non-major bleeding (sub-hazard ratio [SHR], 1.39; 95% CI, 1.02-1.89), but not with major bleeding (SHR, 1.03; 95% CI, 0.69-1.55) or recurrent VTE (SHR, 0.95; 95% CI, 0.62-1.44). Patients with genetic variants had a slightly lower anticoagulation quality. Conclusions CYP2C9 was associated with long-term overall mortality and non-major bleeding. Although genetic variants were associated with a slightly lower anticoagulation quality, there was no relationship between genetic variants and major bleeding or VTE recurrence.

Evaluation of the predictive performance of bleeding risk scores in patients with non-valvular atrial fibrillation on oral anticoagulants

WHAT IS KNOWN AND OBJECTIVE

Bleeding risk scores (BRSs) aid in the assessment of oral anticoagulant-related bleeding risk in patients with atrial fibrillation. Ideally, the applicability of a BRS needs to be assessed, prior to its routine use in a population other than the original derivation cohort. Therefore, we evaluated the performance of 6 established BRSs to predict major or clinically relevant bleeding (CRB) events associated with the use of oral anticoagulant (OAC) among Malaysian patients.

METHODS

The pharmacy supply database and the medical records of patients with non-valvular atrial fibrillation (NVAF) receiving warfarin, dabigatran or rivaroxaban at two tertiary hospitals were reviewed. Patients who experienced an OAC-associated major or CRB event within 12 months of follow-up, or who have received OAC therapy for at least 1 year, were identified. The BRSs were fitted separately into patient data. The discrimination and the calibration of these BRSs as well as the factors associated with bleeding events were then assessed.

RESULTS

A total of 1017 patients with at least 1-year follow-up period, or those who developed a bleeding event within 1 year of OAC use, were recruited. Of which, 23 patients experienced a first major bleeding event, whereas 76 patients, a first CRB event. Multivariate logistic regression results show that age of 75 or older, prior bleeding and male gender are associated with major bleeding events. On the other hand, prior gastrointestinal bleeding, a haematocrit value of less than 30% and renal impairment are independent predictors of CRB events. All the BRSs show a satisfactory calibration for major and CRB events. Among these BRSs, only HEMORR₂ HAGES (C-statistic = 0.71, 95% CI 0.60-0.82, P < .001) and ATRIA score (C-statistic = 0.70, 95% CI 0.58-0.82, P < .001) show acceptable discrimination performance for major bleeding events. All the 6 BRSs, however, lack acceptable predictive performance for CRB events.

WHAT IS NEW AND CONCLUSION

To the best of our knowledge, this is the first evaluation study of the predictive performance of these 6 BRSs on clinically relevant bleeding events applied to the same cohort consisting of mainly Asian novel oral anticoagulant users. These BRSs show poor to acceptable predictive performance on OAC-induced major or CRB events. An improvement in the existing BRSs for OAC users is warranted.

Bleeding Risk Scores in Atrial Fibrillation and Venous Thromboembolism

Patients receiving oral anticoagulant (OAC) therapy for stroke prevention in atrial fibrillation (AF) and prevention of venous thromboembolism (VTE) face an increased risk of bleeding with OAC treatment. Clinicians need to weigh the benefits of OAC treatment against the risk of bleeding. To help formalize bleeding risk assessment, various bleeding risk scores have been developed to help predict the risk of bleeding in AF and VTE patients receiving OAC therapy. This review summarizes the literature involving original studies deriving bleeding risk scores and validation studies of these scores for stroke prevention in AF and treatment/prevention of VTE. To date, there are 10 bleeding risk scores, 6 for use in AF populations, 3 in VTE cohorts, and 1 for mixed indications; they differ markedly in the number of, and risk factors for, bleeding and complexity. In conclusion, many clinical prediction tools to assess bleeding risk prior to starting OAC treatment for either stroke prevention in AF or treatment of VTE are available and should be used in clinical practice to identify and manage modifiable risk factors.

Predicting Major Bleeding in Ischemic Stroke Patients With Atrial Fibrillation

BACKGROUND AND PURPOSE

Performance of risk scores for major bleeding in patients with atrial fibrillation and a previous transient ischemic attack or ischemic stroke is not well established. We aimed to validate risk scores for major bleeding in patients with atrial fibrillation treated with oral anticoagulants after cerebral ischemia and explore the net benefit of oral anticoagulants among bleeding risk categories.

METHODS

We analyzed 3623 patients with a history of transient ischemic attack or stroke included in the RE-LY trial (Randomized Evaluation of Long-Term Anticoagulation Therapy). We assessed performance of HEMORR₂HAGES (hepatic or renal disease, ethanol abuse, malignancy, older age, reduced platelet count or function, hypertension [uncontrolled], anemia, genetic factors, excessive fall risk, and stroke), Shireman, HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly), ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation), and ORBIT scores (older age, reduced haemoglobin/haematocrit/history of anaemia, bleeding history, insufficient kidney function, and treatment with antiplatelet) with C statistics and calibration plots. Net benefit of oral anticoagulants was explored by comparing risk reduction in ischemic stroke with risk increase in major bleedings on warfarin.

RESULTS

During 6922 person-years of follow-up, 266 patients experienced a major bleed (3.8 per 100 person-years). C statistics ranged from 0.62 (Shireman) to 0.67 (ATRIA). Calibration was poor for ATRIA and moderate for other models. The reduction in recurrent ischemic strokes on warfarin was larger than the increase in major bleeding risk, irrespective of bleeding risk category.

CONCLUSIONS

Performance of prediction models for major bleeding in patients with cerebral ischemia and atrial fibrillation is modest but comparable with performance in patients with only atrial fibrillation. Bleeding risk scores cannot guide treatment decisions for oral anticoagulants but may still be useful to identify modifiable risk factors for bleeding. Clinical usefulness may be best for ORBIT, which is based on a limited number of easily obtainable variables and showed reasonable performance.