Prospective evaluation of an index for predicting the risk of major bleeding in outpatients treated with warfarin

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.

Outcomes of deep venous thrombosis management and associated factors among patients in tertiary hospitals in Addis Ababa, Ethiopia: a multicenter retrospective cohort study

BACKGROUND

Pulmonary embolism (PE) and deep venous thrombosis (DVT) are the two most important manifestations of venous thromboembolism (VTE). DVT remains a significant condition since associated morbidity is significant and has elevated healthcare-related costs.

METHODS

A retrospective cohort study was conducted among DVT patients admitted to Tikur Anbessa Specialized Hospital, Zewditu Memorial Hospital and St. Paul's Hospital Millennium Medical College on follow-up from July 1, 2017, to July 01, 2020. Data on sociodemographic characteristics, types of DVT, laboratory findings, medications, risk factors of DVT, complications and outcomes of DVT were collected. The data were analyzed using SPSS version 25. Multivariate logistic regression analysis was conducted to determine predictors of DVT recurrence and major bleeding. A P value < 0.05 was considered to identify significant predictors.

RESULTS

The mean age of the participants was 45.2 years, with SD of 15.36. The major causes of DVT included immobilization (29.9%), previous surgery (27.5%) and cancer (21.1%). The DVT recurrence rate was 22.5%. Nine (2.2%) of the participants died, and 19.9% developed complications. Bilateral DVT (Adjusted odds ratio (AOR) = 2.8, 95% Confidence interval (CI) = 1.14, 6.66), obesity (AOR = 3.3, 95% CI = 1.15, 9.59), hypertension (AOR = 6.5, 95% CI = 2.90, 14.70) and retroviral infection (AOR = 6.3, 95% CI = 2.34, 16.94) were predictors of recurrent DVT. Nineteen (4.7%) patients had major bleeding, and patients with bilateral DVT, active cancer and terminal age had an increased risk of major bleeding.

CONCLUSIONS

The overall DVT recurrence rate was alarmingly high and further complicated by PE, post thrombotic syndrome and chronic vein insufficiency, resulting in a 2.2% death rate. Major bleeding after DVT and PE remained high. Close monitoring should be performed for patients with advanced age, active cancer, bilateral DVT, retroviral infection, obesity and hypertension to prevent the recurrence of DVT and major bleeding.

A deep-learning approach to predict bleeding risk over time in patients on extended anticoagulation therapy

BACKGROUND

Thus far, all the clinical models developed to predict major bleeding in patients on extended anticoagulation therapy use the baseline predictors to stratify patients into different risk groups. Therefore, these models do not account for the clinical changes and events that occur after the baseline visit, which can modify risk of bleeding. However, it is difficult to develop predictive models from the routine follow-up clinical interviews, which are irregular sequences of multivariate time series data.

OBJECTIVES

To demonstrate that deep learning can incorporate patient time series follow-up data to improve prediction of major bleeding.

METHODS

We used the baseline and follow-up data that were collected over 8 years in a longitudinal cohort study of 2542 patients, of whom 118 had major bleeding. Four supervised neural network-based machine-learning models were trained on the baseline, follow-up, or both datasets using 70% of the data. The performance of these models was evaluated, along with modified versions of 6 previously developed clinical models, on the remaining 30% of the data.

RESULTS

An ensemble of feedforward and recurrent neural networks that used the baseline and follow-up data was the best-performing model, achieving a sensitivity and a specificity of 61% and 82%, respectively, in identifying major bleeding, and it outperformed the previously developed clinical models in terms of area under the receiver operating characteristic curve (82%) and area under the precision-recall curve (14%).

CONCLUSION

Time series follow-up data can improve major bleeding prediction in patients on extended anticoagulation therapy.

Performance of risk scores in predicting major bleeding in left ventricular assist device recipients: a comparative external validation

Background

Implantation of a left ventricular assist device (LVAD) is a crucial therapeutic option for selected end-stage heart failure patients. However, major bleeding (MB) complications postimplantation are a significant concern.

Objectives

We evaluated current risk scores' predictive accuracy for MB in LVAD recipients.

Methods

We conducted an observational, single-center study of LVAD recipients (HeartWare or HeartMate-3, November 2010-December 2022) in the Netherlands. The primary outcome was the first post-LVAD MB (according to the International Society on Thrombosis and Haemostasis [ISTH] and Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS], and INTERMACS combined with intracranial bleeding [INTERMACS+] criteria). Mortality prior to MB was considered a competing event. Discrimination (C-statistic) and calibration were evaluated for the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly score, Hepatic or Renal Disease, Ethanol Abuse, Malignancy, Older Age, Reduced Platelet Count or Function, Re-Bleeding, Hypertension, Anemia, Genetic Factors, Excessive Fall Risk and Stroke score, Anticoagulation and Risk Factors in Atrial Fibrillation score, Outpatient Bleeding Risk Index, venous thromboembolism score, atrial fibrillation score, and Utah Bleeding Risk Score (UBRS).

Results

One hundred four patients were included (median age, 64 years; female, 20.2%; HeartWare, 90.4%; HeartMate-3, 9.6%). The cumulative MB incidence was 75.7% (95% CI 65.5%-85.9%) by ISTH and INTERMACS+ criteria and 67.0% (95% CI 56.0%-78.0%) per INTERMACS criteria over a median event-free follow-up time of 1916 days (range, 59-4521). All scores had poor discriminative ability on their intended prediction timeframe. Cumulative area under the receiving operator characteristic curve ranged from 0.49 (95% CI 0.35-0.63, venous thromboembolism-BLEED) to 0.56 (95% CI 0.47-0.65, UBRS) according to ISTH and INTERMACS+ criteria and from 0.48 (95% CI 0.40-0.56, Anticoagulation and Risk Factors in Atrial Fibrillation) to 0.56 (95% CI 0.47-0.65, UBRS) per INTERMACS criteria. All models showed poor calibration, largely underestimating MB risk.

Conclusion

Current bleeding risk scores exhibit inadequate predictive accuracy for LVAD recipients. There is a need for an accurate risk score to identify LVAD patients at high risk of MB who may benefit from patient-tailored antithrombotic therapy.

Machine learning analysis of bleeding status in venous thromboembolism patients

Background

Anticoagulation therapy is the mainstay of therapy for patients with venous thromboembolism (VTE). However, continuing or stopping anticoagulants after the first 3 to 6 months is a difficult decision that requires ascertainment of the risk of bleeding and recurrent VTE. Despite the development of several statistical models to predict bleeding, the benefit of machine learning (ML) models has not been investigated in depth.

Objectives

To assess the benefits of ML algorithms in bleeding risk evaluation in VTE patients and gain insight into their baseline information.

Methods

The baseline clinical, demographic, and genotype information was collected for 2542 patients with VTE who were on extended anticoagulation therapy. Six unsupervised dimensionality reduction and clustering ML algorithms were used to visualize and cluster the data for patients with major bleeding (118 patients) and nonbleeders. Eight supervised ML algorithms were trained and compared with the previously derived clinical models using a 5-fold nested cross-validation scheme.

Results

The baseline dataset for bleeders and nonbleeders showed a high degree of similarity. Two novel clusters were discovered within the dataset for bleeders based on the presence of isolated pulmonary embolism or isolated deep vein thrombosis, though the difference in bleeding risks was not statistically significant (P = .32). The supervised analysis showed that the ML and clinical models have similar discrimination (c-statistics, ∼62%) and calibration performance (Brier score, ∼0.045).

Conclusion

The clinical variables recorded at baseline are not distinctive enough to improve bleeding prediction beyond the performance of the existing models, and other strategies or data modalities should be considered.

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.

Prognostic Significance of Heart Failure in Acute Pulmonary Embolism: A Comprehensive Assessment of 30-Day Outcomes

INTRODUCTION

Patients with heart failure (HF) are known to have an increased risk of pulmonary embolism (PE), but there is limited evidence regarding the prognostic implications of HF in patients with acute PE and the relationship between PE prognosis and left ventricular ejection fraction (LVEF). The primary objective of this study was the development of a composite outcome (mortality, major bleeding, and recurrence) within the first 30 days. The secondary objective was to identify the role of LVEF in predicting the development of early complications in patients with both HF and reduced LVEF.

MATERIAL AND METHODS

A prospective study was conducted at two tertiary hospitals between January 2012 and December 2022 to assess differences among patients diagnosed with acute PE based on the presence or absence of a history of HF. Cox regression models were employed to assess the impact of HF and reduced LVEF on the composite outcome at 30 days.

RESULTS

Out of 1991 patients with acute symptomatic PE, 7.13% had a history of HF. Patients with HF were older and had more comorbidities. The HF group exhibited higher mortality (11.27% vs. 4.33%, p < 0.001) and a higher incidence of major bleeding (9.86% vs. 4.54%, p = 0.005). In the multivariate analysis, HF was an independent risk factor for the development of the composite outcome (HR 1.93; 95% CI 1.35-2.76). Reduced LVEF was independently associated with a higher risk of major bleeding (HR 3.44; 95% CI 1.34-8.81).

CONCLUSION

In patients with acute pulmonary embolism, heart failure is independently associated with a higher risk of early complications. Additionally, heart failure with reduced LVEF is an independent risk factor for major bleeding.

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.

Risk Scores in Venous Thromboembolism Guidelines of ESC, ACCP, and ASH: An Updated Review

Venous thromboembolism (VTE) is associated with high morbidity and mortality. Risk scores associated with VTE have been widely used in clinical practice. Among numerous scores published, those included in guidelines are usually typical risk scores which have been extensively validated and globally recognized. This review provides an updated overview of the risk scores associated with VTE endorsed by 3 guidelines which are highly recognized in the field of VTE including the European Society of Cardiology, American College of Chest Physicians, and American Society of Hematology, focusing on the development, modification, validation, and comparison of these scores, to provide a comprehensive and updated understanding of all the classic risk scores associated with VTE to medical readers including but not limited to cardiologists, pulmonologists, hematologists, intensivists, physicians, surgeons, and researchers. Although each score recommended by these guidelines was more or less validated, there may still be room for further improvement. It may still be necessary to seek simpler, more practical, and more universally applicable VTE-related risk scores in the future.

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.

Impact of Clinical Pharmacist Running Anticoagulation Clinic in Saudi Arabia

Despite the effectiveness of warfarin in extended anticoagulation, its narrow therapeutic index requires frequent dose adjustments and careful patient monitoring. Thus, we aimed to evaluate the outcomes of clinical pharmacists' intervention in warfarin therapy management in terms of International Normalized Ratio (INR) control, reduction of bleeding, and hospitalization in a tertiary care hospital. An observational retrospective cohort study was conducted on 96 patients taking warfarin therapy in a clinical pharmacist-led anticoagulation clinic. We observed that 39.6% of patients required dose adjustments at their first and second visits. However, dose adjustments during the third, fourth, and fifth weeks were required at 31.1%, 20.8%, and 4.2%, respectively, to achieve INR levels. We also observed that 36.46% of the patients attained the target INR at baseline, which was increased over the first week to the fifth week to 57.29%, 61.46%, 61.46%, 68.75%, and 85.42%, respectively. No one reported the ADR between the third and fifth weeks. Based on our findings, the study strongly suggests that pharmacists' interventions can improve the health-related quality of life of patients undergoing warfarin therapy. Thus, competent pharmacy personnel must be a priority in both usual patient care and critical care among primary care networks.

Machine learning to predict major bleeding during anticoagulation for venous thromboembolism: possibilities and limitations

Predictive tools for major bleeding (MB) using machine learning (ML) might be advantageous over traditional methods. We used data from the Registro Informatizado de Enfermedad TromboEmbólica (RIETE) to develop ML algorithms to identify patients with venous thromboembolism (VTE) at increased risk of MB during the first 3 months of anticoagulation. A total of 55 baseline variables were used as predictors. New data prospectively collected from the RIETE were used for further validation. The RIETE and VTE-BLEED scores were used for comparisons. External validation was performed with the COMMAND-VTE database. Learning was carried out with data from 49 587 patients, of whom 873 (1.8%) had MB. The best performing ML method was XGBoost. In the prospective validation cohort the sensitivity, specificity, positive predictive value and F1 score were: 33.2%, 93%, 10%, and 15.4% respectively. F1 value for the RIETE and VTE-BLEED scores were 8.6% and 6.4% respectively. In the external validation cohort the metrics were 10.3%, 87.6%, 3.5% and 5.2% respectively. In that cohort, the F1 value for the RIETE score was 17.3% and for the VTE-BLEED score 9.75%. The performance of the XGBoost algorithm was better than that from the RIETE and VTE-BLEED scores only in the prospective validation cohort, but not in the external validation cohort.

Risk and Management of Bleeding Complications with Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Venous Thromboembolism: a Narrative Review

Atrial fibrillation (AF) and venous thromboembolism (VTE) are highly prevalent conditions with a significant healthcare burden, and represent the main indications for anticoagulation. Direct oral anticoagulants (DOACs) are the first choice treatment of AF/VTE, and have become the most prescribed class of anticoagulants globally, overtaking vitamin K antagonists (VKAs). Compared to VKAs, DOACs have a similar or better efficacy/safety profile, with reduced risk of intracerebral hemorrhage (ICH), while the risk of major bleeding and other bleeding harms may vary depending on the type of DOAC. We have critically reviewed available evidence from randomized controlled trials and observational studies regarding the risk of bleeding complications of DOACs compared to VKAs in patients with AF and VTE. Special patient populations (e.g., elderly, extreme body weights, chronic kidney disease) have specifically been addressed. Management of bleeding complications and possible resumption of anticoagulation, in particular after ICH and gastrointestinal bleeding, are also discussed. Finally, some suggestions are provided to choose the optimal DOAC to minimize adverse events according to individual patient characteristics and bleeding risk.

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.

Established Clinical Prediction Rules for Bleeding had Mediocre Discrimination in Left Ventricular Assist Device Recipients

Left ventricular assist devices (LVAD) reduce mortality in patients with end-stage heart failure, but LVAD management is frequently complicated by bleeding. Bleeding prediction post-LVAD implantation is challenging as prediction rules for hemorrhage have not been rigorously studied in this population. We aimed to validate clinical prediction rules for bleeding, derived in the atrial fibrillation and venous thromboembolism populations, in an LVAD cohort. This was a retrospective cohort study of LVAD recipients at an academic center. The primary end-point was time to gastrointestinal bleed or intracranial hemorrhage after implant; the secondary end-point was time to any major hemorrhage after hospital discharge. Four hundred and eighteen patients received an LVAD (135 HeartMate II, 125 HeartMate 3, 158 HVAD) between November 2009 and January 2019. The primary end-point occurred in 169 (40.4%) patients with C-statistics ranging 0.55-0.58 (standard deviation [SD] 0.02 for all models). The secondary end-point occurred in 167 (40.0%) patients with C-statistics ranging 0.53-0.58 (SD 0.02 for all models). Modifying the age and liver function thresholds increased the C-statistic range to 0.56-0.60 for the primary and secondary end-points. In a sensitivity analysis of HeartMate 3 patients, prediction rules performed similarly. Existing prediction rules for major bleeding had mediocre discrimination in an LVAD cohort.

Severity and Hospitalization Cost Related to Warfarin-Related Adverse Events in a Tertiary Malaysian Hospital

Introduction: Oral anticoagulant is essential for the treatment and prevention of thromboembolism. Warfarin is an effective oral anticoagulant in prevention and treatment of thromboembolism. However, warfarin is frequently associated with adverse event (AE) requiring hospitalization. Method: We performed a retrospective cohort study of all patients admitted to a large tertiary public hospital for warfarin-related AEs. Patients were grouped based on bleeding severity and the direct medical cost was also calculated. Results: During the 4 years study period, a total of 224 patients were admitted for warfarin-related AEs. Mean age of patients admitted was 65.1 years (standard deviation [SD] = 11.5). More than half, 59.6%, of them were on warfarin for prevention of stroke in atrial fibrillation or atrial flutter. Major bleeding occurred among 50.9% of the patients with gastrointestinal bleed, 34 (29.8%), as the common site of bleed. Patients with major bleed had longer median hospital stay of 4 days (interquartile range [IQR] = 5) compared to 3 (IQR = 3) days in non-major bleed. There were 17 (14.9%) death among the major bleeders. Mean medical cost for managing warfarin-related AEs was USD 708.08. Conclusion: The admitted patients were equally distributed in terms of bleeding severity. Medical cost incurred for managing warfarin-related AEs increased with the severity of bleeding.

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.

Long-term clinical outcomes in older patients with acute venous thromboembolism who have renal impairment

INTRODUCTION

Renal impairment (RI) may induce an inflammatory/procoagulant state as well as platelet dysfunction. Little is known on the prevalence of RI and long-term prognosis of older patients with venous thromboembolism (VTE) who have concomitant RI.

METHODS

In a prospective multicenter cohort, we analyzed 912 patients aged ≥65 years with acute VTE. Using the CKD-EPI formula, we defined three categories of baseline renal function: estimated glomerular filtration rate ≥60 ml/min/1.73m² (no RI), 30-59 ml/min/1.73m² (moderate RI), and <30 ml/min/1.73m² (severe RI). The outcomes were VTE recurrence, major bleeding, and overall mortality. We examined the association between renal function and clinical outcomes using competing risk regression models, adjusting for relevant confounders and periods of anticoagulation.

RESULTS

We followed 912 patients over a median duration of 29.6 months. Overall, 313 (34%) patients had moderate and 51 (6%) severe RI. One hundred and seven patients (12%) had VTE recurrence, 125 (14%) had major bleeding, and 186 (20%) died during follow-up. After adjustment, severe RI was associated with a 2-fold increased risk of major bleeding (sub-hazard ratio [SHR] 2.1, 95% CI 1.1-4.0) compared to no RI, but not with VTE recurrence (SHR 0.6, 95% CI 0.2-1.8) or overall mortality (hazard ratio 1.0, 95% CI 0.6-1.9). Moderate RI was not significantly associated with adverse clinical outcomes.

CONCLUSIONS

RI was common among older patients with acute VTE. Severe RI was associated with a 2-fold increased long-term risk of major bleeding, without a risk increase in terms of VTE recurrence and overall mortality. Older patients with moderate RI did not carry worse prognosis.

Predictive Value of HAS-BLED Score Regarding Bleeding Events and Graft Survival following Renal Transplantation

Objective: Due to the high prevalence and incidence of cardio- and cerebrovascular diseases among dialysis-dependent patients with end-stage renal disease (ERSD) scheduled for kidney transplantation (KT), the use of antiplatelet therapy (APT) and/or anticoagulant drugs in this patient population is common. However, these patients share a high risk of complications, either due to thromboembolic or bleeding events, which makes adequate peri- and post-transplant anticoagulation management challenging. Predictive clinical models, such as the HAS-BLED score developed for predicting major bleeding events in patients under anticoagulation therapy, could be helpful tools for the optimization of antithrombotic management and could reduce peri- and postoperative morbidity and mortality. Methods: Data from 204 patients undergoing kidney transplantation (KT) between 2011 and 2018 at the University Hospital Leipzig were retrospectively analyzed. Patients were stratified and categorized postoperatively into the prophylaxis group (group A)—patients without pretransplant anticoagulation/antiplatelet therapy and receiving postoperative heparin in prophylactic doses—and into the (sub)therapeutic group (group B)—patients with postoperative continued use of pretransplant antithrombotic medication used (sub)therapeutically. The primary outcome was the incidence of postoperative bleeding events, which was evaluated for a possible association with the use of antithrombotic therapy. Secondary analyses were conducted for the associations of other potential risk factors, specifically the HAS-BLED score, with allograft outcome. Univariate and multivariate logistic regression as well as a Cox proportional hazard model were used to identify risk factors for long-term allograft function, outcome and survival. The calibration and prognostic accuracy of the risk models were evaluated using the Hosmer−Lemshow test (HLT) and the area under the receiver operating characteristic curve (AUC) model. Results: In total, 94 of 204 (47%) patients received (sub)therapeutic antithrombotic therapy after transplantation and 108 (53%) patients received prophylactic antithrombotic therapy. A total of 61 (29%) patients showed signs of postoperative bleeding. The incidence (p < 0.01) and timepoint of bleeding (p < 0.01) varied significantly between the different antithrombotic treatment groups. After applying multivariate analyses, pre-existing cardiovascular disease (CVD) (OR 2.89 (95% CI: 1.02−8.21); p = 0.04), procedure-specific complications (blood loss (OR 1.03 (95% CI: 1.0−1.05); p = 0.014), Clavien−Dindo classification > grade II (OR 1.03 (95% CI: 1.0−1.05); p = 0.018)), HAS-BLED score (OR 1.49 (95% CI: 1.08−2.07); p = 0.018), vit K antagonists (VKA) (OR 5.89 (95% CI: 1.10−31.28); p = 0.037), the combination of APT and therapeutic heparin (OR 5.44 (95% CI: 1.33−22.31); p = 0.018) as well as postoperative therapeutic heparin (OR 3.37 (95% CI: 1.37−8.26); p < 0.01) were independently associated with an increased risk for bleeding. The intraoperative use of heparin, prior antiplatelet therapy and APT in combination with prophylactic heparin was not associated with increased bleeding risk. Higher recipient body mass index (BMI) (OR 0.32 per 10 kg/m2 increase in BMI (95% CI: 0.12−0.91); p = 0.023) as well as living donor KT (OR 0.43 (95% CI: 0.18−0.94); p = 0.036) were associated with a decreased risk for bleeding. Regarding bleeding events and graft failure, the HAS-BLED risk model demonstrated good calibration (bleeding and graft failure: HLT: chi-square: 4.572, p = 0.802, versus chi-square: 6.52, p = 0.18, respectively) and moderate predictive performance (bleeding AUC: 0.72 (0.63−0.79); graft failure: AUC: 0.7 (0.6−0.78)). Conclusions: In our current study, we could demonstrate the HAS-BLED risk score as a helpful tool with acceptable predictive accuracy regarding bleeding events and graft failure following KT. The intensified monitoring and precise stratification/assessment of bleeding risk factors may be helpful in identifying patients at higher risks of bleeding, improved individualized anticoagulation decisions and choices of antithrombotic therapy in order to optimize outcome after kidney transplantation.

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.

Predicting major bleeding during extended anticoagulation for unprovoked or weakly provoked venous thromboembolism

No clinical prediction model has been specifically developed or validated to identify patients with unprovoked venous thromboembolism (VTE) who are at high risk of major bleeding during extended anticoagulation. In a prospective multinational cohort study of patients with unprovoked VTE receiving extended anticoagulation after completing ≥3 months of initial treatment, we derived a new clinical prediction model using a multivariable Cox regression model based on 22 prespecified candidate predictors for the primary outcome of major bleeding. This model was then compared with modified versions of 5 existing clinical scores. A total of 118 major bleeding events occurred in 2516 patients (annual risk, 1.7%; 95% confidence interval [CI], 1.4-2.1). The incidences of major bleeding events per 100 person-years in high-risk and non–high-risk patients, respectively, were 3.9 (95% CI, 3.0-5.1) and 1.1 (0.8-1.4) using the newly derived creatinine, hemoglobin, age, and use of antiplatelet agent (CHAP) model; 3.3 (2.6-4.1) and 1.0 (0.7-1.3) using modified ACCP score, 5.3 (0.6-19.2) and 1.7 (1.4-2.0) using modified RIETE score, 3.1 (2.3-3.9) and 1.1 (0.9-1.5) using modified VTE-BLEED score, 5.2 (3.3-7.8) and 1.5 (1.2-1.8) using modified HAS-BLED score, and 4.8 (1.3-12.4) and 1.7 (1.4-2.0) using modified outpatient bleeding index score. Modified versions of the ACCP, VTE-BLEED, and HAS-BLED scores help identify patients with unprovoked VTE who are at high risk of major bleeding and should be considered for discontinuation of anticoagulation after 3 to 6 months of initial treatment. The CHAP model may further improve estimation of bleeding risk by using continuous predictor variables, but external validation is required before its implementation in clinical practice.

Extended Anticoagulation for Venous Thromboembolism: A Survey of the American Venous Forum and the European Venous Forum

OBJECTIVE

Extended anticoagulation should always be considered after standard treatment for an unprovoked episode of venous thromboembolism (VTE). It may also be considered in selected patients with provoked VTE. However, evidence-based protocols suggested by some clinical guidelines and risk assessment tools to guide this practice are limited and ambiguous. The goal of this survey research was to analyze current practices in applying extended anticoagulation therapy in patients with VTE among members of the American Venous Forum (AVF) and the European Venous Forum (EVF).

METHODS

An online survey was created by the AVF Research Committee. The survey consisted of sixteen questions to identify the country of practice, specialty, experience of participating physicians, and their clinical practice patterns in applying extended anticoagulation in VTE patients. The survey was distributed over email to the members of the AVF and EVF.

RESULTS

A total of 144 practitioners, 48 (33%) AVF members and 96 (66%) EVF members, participated in the survey. The majority of respondents identified themselves as vascular specialists with primary certification in vascular surgery (70%), vascular medicine/angiology (9%), and venous disease/phlebology (3%). Seventy-two percent of participants believe that the risk of VTE recurrence generally overweighs the risk of bleeding in patients with unprovoked VTE. Extended anticoagulation may be utilized by 97% of providers. Different patterns in real world clinical practice were identified. More than half of practitioners estimated VTE recurrence and bleeding risk subjectively. The antithrombotic drugs most commonly used for secondary prophylaxis were rivaroxaban, apixaban, warfarin, dabigatran, and aspirin, in decreasing order of frequency. Among the reasons selected for not considering extended anticoagulation on a regular basis were the lack of specific clinical practice guidelines (24%), the lack of published evidence (9%), and the absence of valid VTE/bleeding risk prediction calculators (8%). Twelve participants (8%) stated that extended anticoagulation was not beneficial for the majority of patients with VTE. Ten participants (7%) indicated that prescribing extended anticoagulation was outside the scope of their specialty.

CONCLUSIONS

There are different practice patterns in extending anticoagulation beyond the standard treatment in patients with VTE. Major gaps in knowledge remain a serious challenge at least partially explaining inaccuracy and inconsistency in long-term VTE management. Appropriately designed studies are needed to evaluate risk stratification tools when contemporary best medical therapy is used, accurately predict VTE recurrence and its long-term outcomes, and to tailor safe and effective secondary prophylaxis.

In Search of the Appropriate Anticoagulant-Associated Bleeding Risk Assessment Model for Cancer-Associated Thrombosis Patients

Simple Summary

Patients with venous thromboembolism events in the context of cancer should receive anticoagulants as long as the cancer is active. Therefore, a tailor-made anticoagulation strategy should rely on an individualized assessment of the risks of recurrent venous thromboembolism and anticoagulant-associated bleeding. No existing risk assessment model for anticoagulant-associated bleeding risk has been validated for cancer-associated thrombosis. To obtain a better risk assessment model to assess anticoagulant-associated bleeding risk in cancer-associated thrombosis patients, we deemed it necessary to answer questions related to how and when to assess anticoagulant-associated bleeding risk as well as what factors to assess for which patients.

Abstract

Patients with venous thromboembolism events (VTE) in the context of cancer should receive anticoagulants as long as the cancer is active. Therefore, a tailor-made anticoagulation strategy should rely on an individualized risk assessment model (RAM) of recurrent VTE and anticoagulant-associated bleeding. The aim of this review is to investigate the applicability of the currently available RAMs for anticoagulant-associated bleeding after VTE in the CAT population and to provide new insights on how we can succeed in developing a new anticoagulant-associated bleeding RAM for the current medical care of CAT patients. A systematic search for peer-reviewed publications was performed in PubMed. Studies, including systematic reviews, were eligible if they comprised patients with VTE and used a design for developing a prediction model, score, or other prognostic tools for anticoagulant-associated bleeding during anticoagulant treatment. Out of 15 RAMs, just the CAT-BLEED was developed for CAT patients and none of the presented RAMs developed for the VTE general population were externally validated in a population of CAT patients. The current review illustrates the limitations of the available RAMs for anticoagulant-associated bleeding in CAT patients. The development of a RAM for bleeding risk assessment in patients with CAT is warranted.

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 high-risk bleeding category of different scores in patients with venous thromboembolism: Systematic review and meta-analysis

BACKGROUND

In patients with venous thromboembolism (VTE), bleeding risk should be carefully assessed but none of the available risk scores is currently recommended. The aim of this study was to systematically evaluate the performance of bleeding scores in patients with VTE focusing on high-risk patients.

METHODS

Longitudinal studies were searched in Medline and Cochrane Library, as well as reviews and references of retrieved articles. Studies were identified, data were extracted, and reporting quality was evaluated. We determined the sensitivity, specificity, positive likelihood ratio (LR+), and diagnostic odds ratio (DOR) of the 'high risk' category of each bleeding score. Random effects meta-analysis was performed in order to derive the central estimates and 95% confidence intervals (95% CI).

RESULTS

Twenty-one studies and ten bleeding scores fulfilled the inclusion criteria. VTE-BLEED showed the highest sensitivity but the second-lowest specificity (Se 76%; Sp 61%), followed by ACCP (Se 59%; Sp 57%). The remaining scores had high specificity (> 80%) but a low sensitivity (< 20%). HEMORR₂HAGES and Niewenhuis score showed the best performance regarding LR+ that was 2.67 and 5.91, respectively. Regarding DOR, the Niewenhuis score and VTE-BLEED were the best performers with 9.04; 95% CI 3.87-21.09 and 4.94 95% CI 2.66-9.09, respectively. In a cohort with patients predominantly treated with direct oral anticoagulants (DOACs), VTE-BLEED had the highest sensitivity (Se 77%; Sp 60%).

CONCLUSIONS

Overall, the majority of the risk scores showed a moderate ability to forecast major bleeding events, with the VTE-BLEED as the most sensitive in patients treated with DOACs.

Incidence, risk factors, and management of bleeding in patients receiving anticoagulants for the treatment of cancer-associated thrombosis

Updated clinical practice guidelines recommend the long-term use of low-molecular-weight heparins or direct oral anticoagulants as the preferred option for the treatment of cancer-associated thrombosis (CAT), using a personalized approach matching the right drug to the right patient. In most cases, the benefit of anticoagulant therapy outweighs the risk. However, the long-term use of anticoagulants is associated with a non-negligible risk of bleeding, which constitutes a rare but serious adverse effect. Bleeding complications have been reported to be overall 2 to 3 times more frequent in cancer patients with CAT receiving anticoagulation than in non-cancer patients, with a reported incidence of major bleeding ranging from 2.4 to 16.0% in randomized controlled trials (RCT). In the absence of validated risk assessment model to predict the risk of bleeding in these patients, a careful evaluation of each individual profile, with adequate selection of the most appropriate anticoagulant for each individual patient, is warranted for overcoming management challenges, taking in account the numerous factors which may potentiate the overall bleeding risk in these complex patients, such as advanced or metastatic disease, older age, anemia, thrombocytopenia, renal impairment, liver dysfunction, and concomitant anticancer therapies. The purpose of this review is to call for awareness on bleeding complications as a major safety issue of CAT treatment and to summarize data from recent RCT and real-world studies on the incidence and risk factors for bleeding in this unique and challenging population to further help clinicians in decision-making.

Novel bleeding prediction model in atrial fibrillation patients on new oral anticoagulants

OBJECTIVE

Clinical models such as the HAS-BLED (standing for Hypertension, Abnormal liver/renal function, Stroke history, Bleeding history or predisposition, Labile INR, Elderly, Drug/alcohol usage) were developed to predict risk of major bleeding on vitamin K antagonists/antiplatelet therapy. We aimed to develop a model that will improve the ability to predict major bleeding events in patients with non-valvular atrial fibrillation (AF) treated with new oral anticoagulants (NOACs).

METHODS

Clalit Health Services is the largest of four integrated healthcare organisations in Israel, which insures 4.7 million patients (53% of the population). We identified in Clalit Health Services all patients with AF, new users of an NOAC (2013-2017), and followed them until first occurrence of a major bleeding event, death, switch to another oral anticoagulant, 30 days after discontinuation of NOAC or end of follow-up (31 December 2019). Importance of the candidate model variables was estimated by inclusion frequencies across forward selection algorithm applied to 50 bootstrap samples. Then, backward selection algorithm using the modified Bayesian Information Criterion for competing risks was applied to select predictors for the final model.

RESULTS

47 623 patients with AF prescribed NOAC were studied. 28 055 patients with AF, initiators of apixaban (mean age 78.7, SD 9.0), were included in the first phase and had 662 major bleeding events. Nine variables were selected for inclusion in a final points-based risk-scoring system: male sex, anaemia, thrombocytopaenia (<99×10³/µL), concurrent antiplatelet therapy, hypertension, prior major bleeding, risk factors for a fall, low cholesterol level and low estimated glomerular filtration rate, with apparent area-under-curve (AUC) of 0.6546. Applicability of the model was then shown for 14 118 and 5450 patients with AF, initiators of dabigatran and rivaroxaban, where the score achieved c indices of 0.62 and 0.61, respectively.

CONCLUSIONS

We present a novel and simple risk score for prediction of major bleeding in patients with non-valvular AF treated with NOACs. Validation in additional cohorts is warranted.

Risk of recurrent venous thromboembolism and bleeding in patients with interstitial lung disease: a cohort study

Interstitial lung disease (ILD) encompasses various parenchymal lung disorders, which has the potential to increase the risk of venous thromboembolism (VTE). To evaluate, in patients with ILD and VTE, the risk of recurrent VTE during follow-up after stopping anticoagulation. This was a cohort of patients with a first VTE recruited between 1997 and 2015. The primary outcome was adjudicated fatal or nonfatal recurrent VTE after stopping anticoagulation. Main secondary outcomes were major or clinically relevant non-major bleeding under anticoagulation. Among 4314 patients with VTE, 50 had ILD diagnosed before VTE. Of these, anticoagulation was stopped in 30 patients after a median duration of 180 days and continued indefinitely in 20 patients. During a median follow-up of 27.8 months after anticoagulation discontinuation, recurrent VTE occurred in 15 on 30 patients (annual incidence of 19.2 events per 100-person-years [95%CI 12.0-29.3], case-fatality rate of 6.7% [95%CI 1.21-29.8]). The risk of recurrence was threefold higher when VTE was unprovoked and case-fatality rate of recurrence was increased by 3 when VTE index was PE. During the anticoagulant period, (median duration of 8.6 months), 6 patients had a major or clinically relevant bleeding (annual incidence of 7.3 events per 100-person-years [95%CI 3.4-15.1], case-fatality rate of 16.7% [95%CI 3.0-56.4]). In patients with ILD, the risk of recurrent VTE after stopping anticoagulation and the risk of bleeding under anticoagulation were very high. Our results suggest that anticoagulation should not be prolonged beyond 3-6 months of anticoagulation in most of cases.

Safety of Kidney Biopsy when Performed as an Outpatient Procedure

INTRODUCTION

Kidney biopsy remains the gold standard for the diagnosis of most renal diseases. A major obstacle to performing a biopsy is safety concerns. However, many safety measures are not evidence based and therefore vary widely between centers. We sought to determine the rate and timing of kidney biopsy complications in our center, to compare the complication rate between native and transplant kidney biopsies, to evaluate the feasibility of performing kidney biopsies as an outpatient procedure and the value of a postbiopsy ultrasound before discharge, and to identify risk factors for complications.

METHODS

We performed a single-center, retrospective, observational study at the Division of Nephrology of the University Hospital Zurich including all patients who underwent renal biopsy between January 2005 and December 2017. Major bleeding (primary outcome) and any other bleeding or nonbleeding complications (secondary outcomes) were compared between native and transplant kidney biopsies and between inpatient and outpatient procedures and correlated with clinical factors possibly affecting bleeding risk.

RESULTS

Overall, 2,239 biopsies were performed in 1,468 patients, 732 as inpatient and 1,507 as outpatient procedures. Major bleeding was observed in 28 (3.8%) inpatient and in 15 (1.0%) outpatient procedures, totaling to 43 (1.9%) of all biopsies. Major bleeding requiring intervention amounted to 1.0% (0.5% of outpatient procedures). Rate of major bleeding was similar between native and transplant kidneys. 13/15 (87%) bleeding episodes in planned outpatient procedures were detected during the 4-h surveillance period. Risk factors for bleeding were aspirin use, low eGFR, anemia, cirrhosis, and amyloidosis. Routine postbiopsy ultrasound did not change management.

CONCLUSIONS

Kidney biopsy is an overall safe procedure and can be performed as an outpatient procedure in most patients with an observation period as short as 4 h. The value of routine postbiopsy ultrasound is questionable.

TGF-β1 polymorphism increases the risk of bleeding complications in patients on oral anticoagulant after cardiac valve replacement

Although an elevated INR is highly associated with an increased risk of warfarin-associated bleeding, it has been reported that some patients also experience bleeding complications at therapeutic INRs. TGF-β1 polymorphisms has been reported to cause vascular malformations, resulting in bleeding complications, but there are few published genetic studies regarding bleeding complications in patients on warfarin therapy. This study aimed to determine if there is an association between transforming growth factor beta-1 (TGF-β1) polymorphisms and bleeding complications in patients who maintain international normalized ratios (INRs) of 2.0-3.0 with warfarin therapy after cardiac valve replacement. Eleven single nucleotide polymorphis (SNPs) of TGF-β1 (rs1800469, rs2241718, rs4803455, rs2241717, rs2241716, rs2241715, rs2241714, rs11083616, rs2317130, rs747857, and rs1982073) were analyzed. Univariate and multivariable analyses were conducted to evaluate the associations between genetic polymorphisms and bleeding risk. Attributable risk and the number needed to genotype (NNG) were calculated to identify the potential clinical value of genotyping. A discrimination of model was assessed via an analysis of the area under the receiver operating curve (AUROC). To test the model's goodness of fit, a Hosmer-Lemeshow test was performed. Of 142 patients, 21 experienced bleeding complications. Among analyzed single nucleotide polymorphis (SNPs) of TGF-β1 (rs1800469, rs2241718, rs4803455, rs2241717, rs2241716, rs2241715, rs2241714, rs11083616, rs2317130, rs747857, and rs1982073), AA genotype carriers in rs2241718 had about 5.5 times more bleeding complications than those with the G allele after adjusting for other confounders. The attributable risk and NNG for rs2241718 were 81.9% and 57.8, respectively. The presence of atrial fibrillation and myocardial infarction increased bleeding complications 3.9- and 9.8-fold, compared with those without atrial fibrillation and myocardial infarction, respectively. Bleeding complications during warfarin therapy in patients with mechanical heart valves were associated with TGF-β1 polymorphisms as well as atrial fibrillation and myocardial infarction.

Comparison of Bleeding Risk Scores in Elderly Patients Receiving Extended Anticoagulation with Vitamin K Antagonists for Venous Thromboembolism

BACKGROUND

 In elderly patients with venous thromboembolism (VTE), the decision to extend anticoagulation beyond 3 months must be weighed against the bleeding risk. We compared the predictive performance of 10 clinical bleeding scores (VTE-BLEED, Seiler, Kuijer, Kearon, RIETE, ACCP, OBRI, HEMORR₂HAGES, HAS-BLED, ATRIA) in elderly patients receiving extended anticoagulation for VTE.

METHODS

 In a multicenter Swiss cohort study, we analyzed 743 patients aged ≥65 years who received extended treatment with vitamin K antagonists after VTE. The outcomes were the time to a first major and clinically relevant bleeding. For each score, we classified patients into two bleeding risk categories (low/moderate vs. high). We calculated likelihood ratios and the area under the receiver operating characteristic (ROC) curve for each score.

RESULTS

 Over a median anticoagulation duration of 10.1 months, 45 patients (6.1%) had a first major and 127 (17.1%) a clinically relevant bleeding. The positive likelihood ratios for predicting major bleeding ranged from 0.69 (OBRI) to 2.56 (Seiler) and from 1.07 (ACCP) to 2.36 (Seiler) for clinically relevant bleeding. The areas under the ROC curves were poor to fair and varied between 0.47 (OBRI) and 0.70 (Seiler) for major and between 0.52 (OBRI) and 0.67 (HEMORR₂HAGES) for clinically relevant bleeding.

CONCLUSION

 The predictive performance of most clinical bleeding risk scores does not appear to be sufficiently high to identify elderly patients with VTE who are at high risk of bleeding and who may therefore not be suitable candidates for extended anticoagulation.

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.

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.

Risk Stratification in Acute Pulmonary Embolism: The Latest Algorithms

Pulmonary embolism (PE) is a common clinical entity, which most clinicians will encounter. Appropriate risk stratification of patients is key to identify those who may benefit from reperfusion therapy. The first step in risk assessment should be the identification of hemodynamic instability and, if present, urgent patient consideration for systemic thrombolytics. In the absence of shock, there is a plethora of imaging studies, biochemical markers, and clinical scores that can be used to further assess the patients' short-term mortality risk. Integrated prediction models incorporate more information toward an individualized and precise mortality prediction. Additionally, bleeding risk scores should be utilized prior to initiation of anticoagulation and/or reperfusion therapy administration. Here, we review the latest algorithms for a comprehensive risk stratification of the patient with acute PE.

Associations of anemia with stroke, bleeding, and mortality in atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Anemia frequently coexists with atrial fibrillation (AF) and has been variably associated with worse outcomes. We performed a systematic review and meta-analysis to comprehensively assess the effect of anemia on mortality, stroke/systemic thromboembolism, and bleeding events in patients with AF.

METHODS

MEDLINE and Embase were searched from inception until May 2020. Studies examining associations of anemia with the above outcomes in AF patients were included, and maximally adjusted hazard ratios (HRs) meta-analysed. PROSPERO registration number CRD42020171113.

RESULTS

Twenty-eight studies involving 365 484 patients (41% female, mean age 74.7 years) were included. The average study follow-up ranged from 0.2 to 4.0 years, and the prevalence of anemia was 16%. Anemia was associated with a 78% increase in all-cause mortality (HR, 1.78; 95% confidence interval [CI], 1.44-2.20), 60% increase in cardiovascular mortality (HR, 1.60; 95% CI, 1.17-2.19), 134% increase in noncardiovascular mortality (HR, 2.34; 95% CI, 1.58-3.47) 15% increase in stroke/systemic thromboembolism (HR, 1.15; 95% CI, 1.01-1.31), 78% increase in major bleeding (HR, 1.78; 95% CI, 1.54-2.05), and 77% increase in gastrointestinal bleeding (HR, 1.77; 95% CI, 1.23-2.55). Sensitivity analyses including studies that reported odds ratios did not result in any material change.

CONCLUSION

Anemia is a frequently observed comorbidity in patients with AF, and is associated with an increased risk of all-cause, cardiovascular and noncardiovascular mortality, stroke/systemic thromboembolism, and major and gastrointestinal bleeding. Future studies are required to explore the causes of anemia in AF, and whether investigation and treatment may be clinically beneficial in affected individuals.

Risk of developing diabetes in patients with atrial fibrillation taking non-vitamin K antagonist oral anticoagulants or warfarin: A nationwide cohort study

AIM

To compare the risk of diabetes development in patients with atrial fibrillation (AF) treated with non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin.

MATERIALS AND METHODS

We conducted a nationwide retrospective cohort study using Taiwan's National Health Insurance Research Database. Adult patients with new onset of AF, treated with NOACs or warfarin between 2012 and 2016, were included. The NOAC cohort was further divided into dabigatran, rivaroxaban and apixaban groups. The primary outcome was incident diabetes requiring treatment with antidiabetic drugs. Fine and Gray subdistribution hazards models were used to estimate the adjusted hazard ratio (aHR). Propensity score matching was performed for each head-to-head comparison.

RESULTS

A total of 10 746 new-onset AF patients were included in our study. During the mean 2.4-year follow-up, NOACs were associated with a lower risk of developing diabetes than warfarin (aHR = 0.80, 95% confidence interval [CI]: 0.68-0.94, P = .007). Subgroup analyses confirmed that dabigatran, rivaroxaban and apixaban each had a reduced diabetes risk. Stratified analyses showed that the lower risk of diabetes associated with NOAC treatment was specific to patients aged 65 years or older (aHR = 0.74, 95% CI: 0.62-0.89, P = .002) and those with good medication adherence (aHR = 0.70, 95% CI: 0.58-0.84, P < .001).

CONCLUSIONS

Taking an NOAC was associated with a lower risk of developing diabetes than taking warfarin in patients with AF.

Comparative effectiveness and safety of direct oral anticoagulants versus warfarin in UK patients with atrial fibrillation and type 2 diabetes: A retrospective cohort study

PURPOSE

To estimate the effectiveness and safety of direct oral anticoagulants (DOACs) compared with warfarin in AF patients with type 2 diabetes (T2DM).

METHODS

A retrospective cohort study was designed, using the UK Clinical Practice Research Datalink (August 2011-June 2018). Participants were 1-year naïve users of DOACs or warfarin, followed from the date of first prescription of an oral anticoagulant until the end of the study period, death, discontinuation of treatment, switching to another anticoagulant, or an outcome of interest, whichever came first. Cox regression analysis was performed to estimate the hazard ratio (HR) adjusted for potential confounders.

RESULTS

A total of 8555 patients were identified. No significant differences were found between DOACs and warfarin in the risk of stroke (adjusted HR 1.15; 95% CI 0.82-1.60), ischemic and unspecified stroke (adjusted HR 1.23; 95% CI 0.86-1.76) or haemorrhagic stroke (adjusted HR 0.75; 95% CI 0.30-1.85), and myocardial infarction (adjusted HR 1.39;95% CI 0.99-1.97). DOAC and warfarin users were comparable with respect to risk of major bleed (adjusted HR 0.83; 95% CI 0.68-1.03), intracranial bleeding (HR 0.66; 95% CI 0.34-1.30), gastrointestinal bleeding (HR 0.88; 95% CI 0.60-1.30), and bleeding on other clinically relevant sites (HR 0.89; 95% CI 0.60-1.31). In the subgroup analyses stratified by gender and diabetes severity, the risk for stroke and bleeding remained consistent.

CONCLUSION

DOACs are effective and safe alternatives to warfarin for the prevention of stroke in AF patients with T2DM.

Predictive value of the Kuijer score for bleeding and other adverse in-hospital events in patients with venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) constitute a major global burden of disease. Current international guidelines recommend treatment with anticoagulant therapy after VTE for a duration of at least 3 months. Since anticoagulation also imposes an increased risk for bleeding events, the individual risk has to be evaluated to determine adequate treatment plans.

METHODS

The nationwide German inpatient sample of the years 2005-2017 was used for this analysis. Hospitalized VTE patients were stratified according to Kuijer risk class and the performance of the Kuijer score was evaluated to predict adverse in-hospital events.

RESULTS

Overall, 1,204,895 VTE patients were treated between 2005 and 2017 in Germany and were included in the present study (839,143 patients had deep venous thrombosis and/or thrombophlebitis and 669,881 patients pulmonary embolism). According to Kuijer risk class stratification, in total, 176,723 (14.7%) of the hospitalized VTE patients were classified as low risk, 914,964 (75.9%) as intermediate risk and 113,208 (9.4%) as high risk. A higher Kuijer risk class was predictive for in-hospital death (odds ratio [OR] 1.99 [95% confidence interval (CI) 1.96-2.02], P < 0.001), major adverse cardiovascular and cerebrovascular events (MACCE, OR 1.90 [95%CI 1.87-1.93], P < 0.001), intracerebral bleeding (OR 1.28 [95%CI 1.14-1.44], P < 0.001), gastrointestinal bleeding (OR 1.56 [95%CI 1.48-1.64], P < 0.001) as well as necessity of transfusion of blood constituents (OR 2.94 [95%CI 2.88-3.00], P < 0.001) independently of important comorbidities.

CONCLUSIONS

The Kuijer score is an important risk stratification tool to predict individual risk regarding in-hospital outcomes comprising major bleeding events such as intracerebral bleeding and necessity of transfusion of blood constituents, but also in-hospital mortality and MACCE in VTE patients.

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.

Association between Patients' Knowledge and Adherence to Anticoagulants, and Its Effect on Coagulation Control

BACKGROUND

Warfarin requires strict monitoring by measuring prothrombin time (PT), international normalized ratio (INR), and time in therapeutic range (TTR). Several factors can lead to poor PT/INR control including vitamin K status, medication adherence, knowledge, and quality of life. The present study aims to assess patient adherence to warfarin treatment and its correlation with INR control.

METHODS

A cross-sectional study was conducted between October 2017 and January 2018 at Tripoli University Hospital. Data were collected by structured questionnaires which included; demographic and clinical characteristics, the Oral Anticoagulation Knowledge (OAK) test, and the Morisky Medication Adherence Scale (MMAS-8).

RESULTS

The final analysis included 88 out of 140 patients (73.33%). There were significant differences in age range, gender, marital status, and education level between the 2 groups (poor knowledge and adequate knowledge) (p < 0.05). There was a significant positive correlation between OAK test score and TTR. Overall, 76.2% of patients were adherent to warfarin (MMAS score ≥6) and 20.45% of patients were of high adherence (MMAS score of 8). The median score was 6 (IQR 6-7). A statistically significant, strong positive correlation between adherence to medication and TTR as an indicator of INR control was found (rs[86] = 0.472, p < 0.0001).

CONCLUSION

The study addressed and identified several areas for future improvement of patient outcomes. The implementation of new approaches to enhance patient knowledge and adherence is warranted, and measures to provide treatment for all patients that require it are needed, to improve outcomes and decrease adverse drug effects.

Frailty and Co-Prescribing of Potentially Interacting Drugs in New Users of Warfarin

Background

Warfarin is underutilised in frail older people because of the fear of bleeding complications. Drug interactions are an independent bleeding risk factor. However, the extent to which potential drug interactions are taken into account at warfarin therapy initiation in frail patients is not known.

Objective

The objective of this study was to investigate the use of potentially interacting drugs increasing the bleeding risk before and after warfarin initiation in frail and non-frail patients.

Methods

We conducted an observational study including inpatients aged ≥ 60 years initiated on warfarin in a tertiary hospital in Adelaide, South Australia. Frailty status was assessed with the Reported Edmonton Frail Scale. Medication charts were reviewed before and after warfarin initiation.

Results

In total, 151 patients (102 non-frail and 49 frail) were included. Before warfarin initiation, the use of clopidogrel and acetaminophen was more common in frail patients compared with non-frail patients (25.5% vs 10.2%, p = 0.0135, 63.8% vs 35.7% p = 0.0014, respectively). The use of non-steroidal anti-inflammatory drugs, 9.2% in non-frail patients and 6.4% in frail patients before warfarin initiation, was completely stopped after warfarin initiation in both groups. The use of antiplatelet drugs decreased from 56.1% in non-frail patients and 66.0 % in frail patients to 12.2% and 14.9%, respectively. Instead, the use of drugs affecting the metabolism of warfarin or vitamin K increased in both groups. No statistically significant difference was seen in the exposure to interacting drugs between study groups after warfarin initiation. Acetaminophen, senna glycosides and cytochrome P450 2C9 inhibiting drugs were the most common interacting drugs at discharge used in 49.0%, 18.4% and 20.4% of non-frail patients and 53.2%, 29.8% and 19.1% of frail patients, respectively.

Conclusions

The overall frequency of potential drug interactions was moderate and frail patients were not exposed to warfarin drug interactions more often than non-frail patients. Further studies in larger study populations are required to verify these results.

Electronic supplementary material

The online version of this article (10.1007/s40266-020-00755-0) contains supplementary material, which is available to authorized users.

Risk Factors for Major Bleeding During Anticoagulation Therapy in Cancer-Associated Venous Thromboembolism - From the COMMAND VTE Registry

BACKGROUND

Patients with cancer-associated venous thromboembolism (VTE) are at high risk for recurrent VTE and are recommended to receive prolonged anticoagulation therapy if they are at a low risk for bleeding. However, there are no established risk factors for bleeding during anticoagulation therapy.

METHODS AND RESULTS

The COMMAND VTE Registry is a multicenter retrospective registry enrolling 3,027 consecutive patients with acute symptomatic VTE among 29 Japanese centers. The present study population consisted of 592 cancer-associated VTE patients with anticoagulation therapy. We constructed a multivariable Cox proportional hazard model to estimate the hazard ratio (HR) and 95% confidence interval (CI) of the potential risk factors for major bleeding. During a median follow-up period of 199 days, major bleeding occurred in 72 patients. The cumulative incidence of major bleeding was 5.8% at 3 months, 13.8% at 1 year, 17.5% at 2 years, and 28.1% at 5 years. The most frequent major bleeding site was gastrointestinal tract (47%). Terminal cancer (adjusted HR, 4.17; 95% CI, 2.22-7.85, P<0.001), chronic kidney disease (adjusted HR, 1.89; 95% CI 1.06-3.37, P=0.031), and gastrointestinal cancer (adjusted HR, 1.78; 95% CI, 1.04-3.04, P=0.037) were independently associated with an increased risk of major bleeding.

CONCLUSIONS

Major bleeding events were common during anticoagulation therapy in real-world cancer-associated VTE patients. Terminal cancer, chronic kidney disease, and gastrointestinal cancer were the independent risk factors for major bleeding.

Severe undernutrition increases bleeding risk on vitamin-K antagonists

INTRODUCTION

Hemorrhage occurs in 7-10% of patients treated with vitamin K antagonist (VKA), with major bleeding in 1-3%. Impact of nutritional status on the bleeding risk of patients on anticoagulants is still poorly documented. Our study aimed to analyze the link between the nutritional status of patients on VKA and the occurrence of hemorrhagic events. We also analyzed micronutrients status.

METHODS

A case-control, monocentric, and prospective study was conducted from August 2012 to October 2015. The case patients were those presenting with major bleeding and control patients those without any bleeding under VKA treatment.

RESULTS

Overall, 294 patients under VKA treatment were paired according to age, gender, and index normalized ratio (INR). Out of these, 98 (33.3%) had major bleeding and 196 (66.7%) did not have any bleeding. Additionally, more than two-thirds of patients displayed undernutrition, which was more prevalent in bleeding than non-bleeding patients (OR = 1.85, CI95%: 1.07-3.21). There was a higher bleeding risk for those with severe undernutrition (OR = 2.66, CI95%: 1.58-4.46), with no difference found concerning moderate undernutrition. Bleeding patients had lower plasma-zinc concentrations than non-bleeding patients (9.4 ± 3.6 vs. 10.5 ± 3.7 μmol/L, p = 0.003); among them, there was a higher rate of patients with plasma zinc under 5 μmol/L (9% vs. 2%, p < 0.001).

CONCLUSION

Patients with undernutrition on VKA exhibit a significantly higher bleeding risk, which increases three-fold in case of severe undernutrition. The evaluation of nutritional status provides additional, valuable prognosis information prior to initiating VKA therapy. CLINICALTRIALS.

GOV NUMBER

NCT01742871.

How I assess and manage the risk of bleeding in patients treated for venous thromboembolism

For patients with venous thromboembolism (VTE), prediction of bleeding is relevant throughout the course of treatment, although the means and goal of this prediction differ between the subsequent stages of treatment: treatment initiation, hospital discharge, 3-month follow-up, and long-term follow-up. Even in the absence of fully established risk prediction schemes and outcome studies using a prediction scheme for treatment decisions, the present evidence supports screening for and targeting of modifiable risk factors for major bleeding, as well as the application of decision rules to identify patients at low risk of bleeding complications, in whom long-term anticoagulant treatment is likely safe. Moving forward, prediction tools need to be incorporated in well-designed randomized controlled trials aiming to establish optimal treatment duration in patients at high risk of recurrent VTE. Moreover, the benefit of their longitudinal assessment rather than application as stand-alone baseline assessments should be studied, because changes in bleeding risk over time likely constitute the best predictor of major bleeding. We provide the state-of-the-art of assessing and managing bleeding risk in patients with acute VTE and highlight a practical approach for daily practice illustrated by 2 case scenarios.