Development and Validation of the DOAC Score: A Novel Bleeding Risk Prediction Tool for Patients With Atrial Fibrillation on Direct-Acting Oral Anticoagulants

Clinical decisions for appropriate management of patients with atrial fibrillation

The management of patients with atrial fibrillation (AF) requires intricate clinical decision-making to optimize outcomes. In everyday clinical practice, physicians undergo difficult choices to better manage patients with AF. They need to balance thromboembolic and bleeding risk to focus on patients' symptoms and to manage a variety of multiple comorbidities. In this review, we aimed to explore the multifaceted dimensions of clinical decision-making in AF patients, encompassing the definition and diagnosis of clinical AF, stroke risk stratification, oral anticoagulant therapy selection, consideration of bleeding risk, and the ongoing debate between rhythm and rate control strategies. We will also focus on possible grey zones for the management of AF patients. In navigating this intricate landscape, clinicians must reconcile the dynamic interplay of patient-specific factors, evolving guidelines, and emerging therapies. The review underscores the need for personalized, evidence-based clinical decision-making to tailor interventions for optimal outcomes according to specific AF patient profiles.

Advances in the medical treatment and diagnosis of intracranial hemorrhage associated with oral anticoagulation

INTRODUCTION

With the increasing prevalence of atrial fibrillation (AF), it entails expanding oral anticoagulants (OACs) use, carrying a higher risk of associated hemorrhagic events, including intracranial hemorrhage (ICH). Despite advances in OACs development with a better safety profile and reversal agent for these anticoagulants, there is still no consensus on the optimal management of patients with OACs-associated ICH.

AREAS COVERED

In this review, the authors have carried out an exhaustive search on the advances in recent years. The authors provide an update on the management of ICH in anticoagulated patients, as well as an update on the latest evidence on anticoagulation resumption, recent therapeutic strategies, and investigational drugs that could play a role in the future.

EXPERT OPINION

Following an ICH event in an anticoagulated patient, a comprehensive clinical evaluation is imperative. Anticoagulation should be promptly withdrawn and reversed. Once the patient is stabilized, a reintroduction of anticoagulation should be considered, typically within a timeframe of 4-8 weeks, if feasible. If re-anticoagulation is not possible, alternative options such as Left Atrial Appendage Occlusion are available.

The use of reduced DOAC doses in atrial fibrillation patients does not always lead to good anticoagulation levels and avoid adverse events

BACKGROUND

The MAS study (Blood Advances 2024) showed that a high proportion of Italian AF patients treated with direct oral anticoagulants (DOACs) receive reduced doses. This sub-analysis of MAS data aimed to analyze the effects of reduced (appropriate or not)- or standard-dose use on DOAC activity assessed at baseline and the occurrence of thrombotic or bleeding complications during follow-up.

METHODS

The MAS study design, the methods for DOAC measurement, the results, and the adverse events during follow-up, are described in detail elsewhere.

RESULTS

Seven hundred AF patients (42 % of the total 1657) received a reduced dose (considered inappropriate in 140 [20 %]). They were older, more frequently women, with lower body mass index (BMI), hemoglobin levels, and creatinine clearance. They more often had cerebral or cardiovascular diseases, were taking more medications, with higher scores for thrombotic or bleeding risk. Despite the use of low doses, 133 (19.0 %) patients had high standardized C-trough DOAC levels and experienced a high proportion of bleeding events (8.3 % per year). Conversely, some patients (4.7 %) had very low levels, resulting in a high incidence of thrombotic events (6.7 % per year). No difference was detected if the reduced dose was appropriate or not.

CONCLUSION

The unpredictable, highly variable inter-individual anticoagulant effect of DOACs may lead to either too low or too high anticoagulant levels, increasing the risk of thrombotic or bleeding events. This is particularly relevant for patients with high-risk conditions, such as those chosen for reduced-dose treatment. Further studies are needed to investigate this important clinical issue.

Anticoagulation in Chronic Kidney Disease

The nuanced landscape of anticoagulation therapy in patients with chronic kidney disease (CKD) presents a formidable challenge, intricately balancing the dual hazards of hemorrhage and thrombosis. These patients find themselves in a precarious position, teetering on the edge of these risks due to compromised platelet functionality and systemic disturbances within their coagulation frameworks. The management of such patients necessitates a meticulous approach to dosing adjustments and vigilant monitoring to navigate the perilous waters of anticoagulant therapy. This is especially critical considering the altered pharmacokinetics in CKD, where the clearance of drugs is significantly impeded, heightening the risk of accumulation and adverse effects. In the evolving narrative of anticoagulation therapy, the introduction of direct oral anticoagulants (DOACs) has heralded a new era, offering a glimmer of hope for those navigating the complexities of CKD. These agents, with their promise of easier management and a reduced need for monitoring, have begun to reshape the contours of care, particularly for patients not yet on dialysis. However, this is not without its caveats. The application of DOACs in the context of advanced CKD remains a largely uncharted territory, necessitating a cautious exploration to unearth their true potential and limitations. Moreover, the advent of innovative strategies such as left atrial appendage occlusion (LAAO) underscores the dynamic nature of anticoagulation therapy, potentially offering a tailored solution for those at the intersection of CKD and elevated stroke risk. Yet the journey toward integrating such advancements into standard practice is laden with unanswered questions, demanding rigorous investigation to illuminate their efficacy and safety across the spectrum of kidney disease. In summary, the management of anticoagulation in CKD is a delicate dance, requiring a harmonious blend of precision, caution, and innovation. As we venture further into this complex domain, we must build upon our current understanding, embracing both emerging therapies and the need for ongoing research. Only then can we hope to offer our patients a path that navigates the narrow strait between bleeding and clotting, toward safer and more effective care.

Clinical and Economic Consequences of a First Major Bleeding Event in Patients Treated with Direct Factor Xa Inhibitors in Spain: A Long-Term Observational Study

Aims: Our aims were to describe the clinical characteristics, adverse clinical events, healthcare resource utilization (HCRU) and costs of patients with major bleeding during direct Factor Xa inhibitor (FXai) use. Methods: This is a retrospective cohort study that included secondary data from computerized health records of seven Spanish Autonomous Communities. Patients with a first major bleeding during treatment with a direct FXai were analyzed during a 3-year period. Results: Of 8972 patients taking a direct FXai, 470 (5.24%) had major bleeding (mean age (SD) 77.93 (9.71) years, 61.06% women). The most frequent indications for using FXais were atrial fibrillation (78.09%) and venous thromboembolism (17.66%). Among those with major bleeding, 88.94% presented with gastrointestinal bleeding, 6.81% intracranial bleeding, 2.13% trauma-related bleeding and 4.26% other major bleeding. Prothrombin complex concentrates were used in 63.19%, followed by transfusion of blood products (20.21%) and Factor VIIa (7.66%). In total, 4.26% of patients died in the hospital due to the first major bleeding. At the study end (after 3-year follow-up), 28.94% of the patients had died, 12.34% had a myocardial infarction and 9.15% an ischemic stroke. At year 3, overall bleeding cost was EUR 5,816,930.5, of which 79.74% accounted for in-hospital costs to treat the bleeding episode. Conclusions: Despite the use of replacement agents being high, major events were common, with a 29% mortality at the end of the follow up, and HCRU and costs were high, evidencing the need for new reversal treatment strategies.

Relative performance evaluation of four bleeding risk scores in atrial fibrillation patients. What does the new DOAC score provide?

BACKGROUND

Recently, the direct oral anticoagulant (DOAC) score was developed and better predicted major bleeding in DOAC-treated patients with atrial fibrillation (AF) than HASBLED did. Little is known on the new score's performance regarding other bleeding risk in AF.

METHODS

We studied 14,672 patients diagnosed with AF between 2014 and 2018. During follow-up, we assessed the performance of DOAC score compared with the HASBLED, ORBIT and SWISS scores at predicting major bleeding in DOACs and non-DOACs users. Discrimination, calibration and decision curve analysis (DCA) were used to assess the risk scorer's performance.

RESULTS

There were 1484 (10.1%) patients on DOACs, 9730 on vitamin K antagonist (VKA), and 3458 on non-oral anticoagulants. Over a median of 3.5 years of follow-up, 79 major bleedings occurred in the DOAC patients, and 486 in the VKA patients (cumulative incidences = 7.4 and 13.9 per 100 patient-years, respectively). Amongst the DOAC patients, the DOAC score discrimination was moderate (C-statistic = 0.711), but significantly higher than HASBLED (C = 0.640; p = 0.03), ORBIT (C = 0.660; p = 0.04), and SWISS scores (C = 0.637; p = 0.002). The DCA showed higher net benefit using DOAC score compared with the remaining scores. In the VKA patients, DOAC score showed the highest discrimination (c-statistic = 0.709), followed by ORBIT (C = 0.692; p = 0.07), HASBLED and SWISS (C = 0.635 and 0.624, respectively; p < 0.01). All risk scores calibrated well, although HASBLED showed relatively poor calibration.

CONCLUSIONS

The new DOAC bleeding risk score is a valid and reasonable predictor of major bleeding over a median of 3.5 years of follow-up. Physicians can be reassured about the applicability of DOAC score for bleeding risk stratification in AF patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04364516.

Performance of HAS-BLED and DOAC scores to predict major bleeding events in atrial fibrillation patients treated with direct oral anticoagulants: A report from a prospective European observational registry

BACKGROUND

The DOAC score has been recently proposed for bleeding risk stratification of patients with atrial fibrillation treated with direct oral anticoagulants (DOAC).

OBJECTIVE

To compare the performance of HAS-BLED and DOAC score in predicting major bleeding events in a contemporary cohort of European AF patients treated with DOAC.

METHODS

We included patients derived from a prospective observational registry of European AF patients. HAS-BLED and DOAC scores were calculated as per the original schemes. Our primary endpoint was major bleeding events. Receiver operating characteristic (ROC) curves were used to compare the predictive ability of the scores.

RESULTS

A total of 2834 AF patients (median age [IQR] 69 [62-77] years; 39.6 % female) treated with DOAC were included in the analysis. According to the HAS-BLED score, 577 patients (20.4 %) were categorized as very low risk of bleeding, as compared to 1276 (45.0 %) according to DOAC score. A total of 55 major bleeding events occurred with an overall incidence of 1.04 per 100 patient-years. Both scores showed only a modest ability for the prediction of bleeding events (HAS-BLED area under the curve [AUC], 0.65, 95 % confidence interval [CI] 0.55-0.70; DOAC score AUC 0.62, 95 % CI 0.59-0.71, p for difference = 0.332]. At calibration analysis, the DOAC score showed modest calibration, especially for patients at high risk, when compared to HAS-BLED.

CONCLUSION

In a contemporary cohort of DOAC-treated AF patients, both HAS-BLED and DOAC scores only modestly predicted the occurrence of major bleeding events. Our results do not support the preferential use of DOAC score over HAS-BLED.

Atrial High-Rate Episodes in Elderly Patients: The Anticoagulation Therapy Dilemma

Atrial fibrillation (AF) has been associated with higher morbidity and mortality rates, especially in older patients. Subclinical atrial fibrillation (SCAF) is defined as the presence of atrial high-rate episodes (AHREs) > 190 bpm for 10 consecutive beats > 6 min and <24 h, as detected by cardiac implanted electronic devices (CIEDs). The selection of eligible patients for anticoagulation therapy among elderly individuals with AHREs detected through CIEDs remains a contentious issue. The meta-analysis of ARTESiA and NOAH-AFNET 6 clinical trials revealed that taking Edoxaban or Apixaban as oral anticoagulation therapy can reduce the risk of stroke by approximately 32% while increasing the risk of major bleeding by approximately 62%. However, it is still unclear which are, among patients with SCAF, those who can take the highest net clinical benefit from anticoagulant therapy. The present review summarizes the current evidence on this intriguing issue and suggests strategies to try to better stratify the risk of stroke and systemic embolism in patients with AHREs. We propose incorporating some parameters including chronic kidney disease (CKD), obesity, enlarged left atrial volume, the efficacy in blood pressure management, and frailty into the traditional CHA2DS2-VASc score. Future trials will be needed to verify the clinical usefulness of the proposed prognostic score mainly in the view of a personalized therapeutic approach in patients with SCAF.

PAX1 methylation as a robust predictor: developing and validating a nomogram for assessing endocervical curettage (ECC) necessity in human papillomavirus16/18-positive women undergoing colposcopy

OBJECTIVE

The major challenge in routine endocervical curettage (ECC) among Human Papillomavirus (HPV) 16/18-positive patients is that only a small fraction benefit. Nevertheless, current reported models often overestimate the validity and necessity of ECC, making it difficult to improve benefits for patients. This research hypothesized that assessing paired boxed gene 1 methylation levels (PAX1m) and clinical characteristics could enhance the predictive accuracy of detecting additional high-grade squamous intraepithelial lesions or worse (HSIL +) through ECC that were not identified by colposcopy-directed biopsy (CDB).

METHODS

Data from 134 women with HPV16/18 positivity undergoing CDB and ECC between April 2018 and April 2022 were collected and analyzed. Quantitative methylation-specific polymerase chain reaction (qMSP) was utilized to measure PAX1m, expressed as ΔCp. Univariate and multivariate regression analyses were conducted to screen variables and select predictive factors. A nomogram was constructed using multivariate logistic regression to predict additional HSIL + detected by ECC. The discrimination, calibration, and clinical utility of the nomogram were evaluated using receiver operating characteristic curves (ROC) and the calibration plot.

RESULTS

Age (odds ratio [OR], 5.654; 95% confidence interval [CI], 1.131-37.700), cytology (OR, 24.978; 95% CI, 3.085-540.236), and PAX1 methylation levels by grade (PAX1m grade) (OR, 7.801; 95% CI, 1.548-44.828) were independent predictive factors for additional detection of HSIL + by ECC. In HPV16/18-positive women, the likelihood of additional detection of HSIL + through ECC increased with the severity of cytological abnormalities, peaking at 43.8% for high-grade cytological lesions. Moreover, when cytological findings indicated low-grade lesions, PAX1 methylation levels were positively correlated with the additional detection of HSIL + by ECC (P value < 0.001). A nomogram prediction model was developed (area under curve (AUC) = 0.946; 95% CI, 0.901-0.991), demonstrating high sensitivity (90.9%) and specificity (90.5%) at the optimal cutoff point of 107. Calibration analysis confirmed the model's strong agreement between predicted and observed probabilities.

CONCLUSION

The clinical nomogram presented promising predictive performance for the additional detection of HSIL + through ECC among women with HPV16/18 infection. PAX1 methylation level could serve as a valuable tool in guiding individualized clinical decisions regarding ECC for patients with HPV 16/18 infection, particularly in cases of low-grade cytological findings.

Exploring the Perioperative Use of DOACs, off the Beaten Track

A notable increase in direct oral anticoagulant (DOAC) use has been observed in the last decade. This trend has surpassed the prescription of vitamin K antagonists (VKAs) due to the absence of the need for regular laboratory monitoring and the more favorable characteristics in terms of efficacy and safety. However, it is very common that patients on DOACs need an interventional or surgical procedure, requiring a careful evaluation and a challenging approach. Therefore, perioperative anticoagulation management of patients on DOACs represents a growing concern for clinicians. Indeed, while several surgical interventions require temporary discontinuation of DOACs, other procedures that involve a lower risk of bleeding can be conducted, maintaining a minimal or uninterrupted DOAC strategy. Therefore, a comprehensive evaluation of patient characteristics, including age, susceptibility to stroke, previous bleeding complications, concurrent medications, renal and hepatic function, and other factors, in addition to surgical considerations, is mandatory to establish the optimal discontinuation and resumption timing of DOACs. A multidisciplinary approach is required for managing perioperative anticoagulation in order to establish how to face these circumstances. This narrative review aims to provide physicians with a practical guide for DOAC perioperative management, addressing the most controversial issues.

Optimizing Atrial Fibrillation Care: Comparative Assessment of Anticoagulant Therapies and Risk Factors

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) is a common arrhythmia associated with various risk factors and significant morbidity and mortality.

MATERIALS AND METHODS

This article presents findings from a study involving 345 patients with permanent AF. This study examined demographics, risk factors, associated pathologies, complications, and anticoagulant therapy over the course of a year.

RESULTS

The results showed a slight predominance of AF in males (55%), with the highest incidence in individuals aged 75 and older (49%). Common risk factors included arterial hypertension (54%), dyslipidemia, diabetes mellitus type 2 (19.13%), and obesity (15.65%). Comorbidities such as congestive heart failure (35.6%), mitral valve regurgitation (60%), and dilated cardiomyopathy (32%) were prevalent among the patients. Major complications included congestive heart failure (32%), stroke (17%), and myocardial infarction (5%). Thromboembolic and bleeding risk assessment using CHA2DS2-VASc and HAS-BLED scores demonstrated a high thromboembolic risk in all patients. The majority of patients were receiving novel oral anticoagulants (NOACs) before admission (73%), while NOACs were also the most prescribed antithrombotic therapy at discharge (61%).

CONCLUSIONS

This study highlights the importance of risk factor management and appropriate anticoagulant therapy in patients with AF, to reduce complications and improve outcomes. The results support the importance of tailored therapeutic schemes, for optimal care of patients with AF.

Development and Validation of a Predictive Model for Intracranial Haemorrhage in Patients on Direct Oral Anticoagulants

BACKGROUND

Intracranial haemorrhage (ICH) poses a significant threat to patients on Direct Oral Anticoagulants (DOACs), with existing risk scores inadequately predicting ICH risk in these patients. We aim to develop and validate a predictive model for ICH risk in DOAC-treated patients.

METHODS

24,794 patients treated with a DOAC were identified in a province-wide electronic medical and health data platform in Tianjin, China. The cohort was randomly split into a 4:1 ratio for model development and validation. We utilized forward stepwise selection, Least Absolute Shrinkage and Selection Operator (LASSO), and eXtreme Gradient Boosting (XGBoost) to select predictors. Model performance was compared using the area under the curve (AUC) and net reclassification index (NRI). The optimal model was stratified and compared with the DOAC model.

RESULTS

The median age is 68.0 years, and 50.4% of participants are male. The XGBoost model, incorporating six independent factors (history of hemorrhagic stroke, peripheral artery disease, venous thromboembolism, hypertension, age, low-density lipoprotein cholesterol levels), demonstrated superior performance in the development dateset. It showed moderate discrimination (AUC: 0.68, 95% CI: 0.64-0.73), outperforming existing DOAC scores (ΔAUC = 0.063, P = 0.003; NRI = 0.374, P < 0.001). Risk categories significantly stratified ICH risk (low risk: 0.26%, moderate risk: 0.74%, high risk: 5.51%). Finally, the model demonstrated consistent predictive performance in the internal validation.

CONCLUSION

In a real-world Chinese population using DOAC therapy, this study presents a reliable predictive model for ICH risk. The XGBoost model, integrating six key risk factors, offers a valuable tool for individualized risk assessment in the context of oral anticoagulation therapy.

Oral Anticoagulation for Atrial Fibrillation in Octogenarians Across the Renal Function Spectrum

PURPOSE

Our study aimed to describe the efficacy and safety of oral anticoagulation (OAC) use in octogenarians with atrial fibrillation (AF) across the spectrum of renal function.

METHODS

Data for this study were sourced from AF Research Database (NCT03760874). AF patients aged ≥ 80 who received OAC treatment, both direct oral anticoagulant (DOAC) and vitamin K antagonist (VKA) were selected. Participants were categorized in 2 groups according to creatinine clearance (CrCl) ≥ 45 and < 45 ml/min/1.73 m2. The primary safety outcome was the occurrence major bleeding. The primary effectiveness outcome was the occurrence of thromboembolic events.

RESULTS

A total of 901 AF patients (median age 84 [4.9] years; 44% men) with age ≥ 80 years on treatment with DOACs (n: 629, 70%) and VKA (n: 272, 30%) were included in the study. 303 patients (34%) had CrCl < 45 ml/min/1.73m2 and 598 (66%) had CrCl ≥ 45 ml/min/1.73m2. No significant differences were shown in major bleedings, minor bleedings and thromboembolic events between patients on DOACs vs VKAs, both in the group with CrCl ≥ 45 than < 45 ml/min. In the group with CrCl < 45 ml/min/1.73 m2, a total of 72 patients (23%) died during the follow-up, with higher mortality in VKA group compared to DOACs (45% vs 15%; p < 0.001). At multivariate regression analysis, age [OR: 1.15; p = 0.001] and coronary artery disease (CAD) [OR: 1.74; p = 0.04] were independently associated with mortality; in contrast, the use of DOACs were inversely associated with mortality [OR = 0.26; p < 0.001]. In patients with CrCl ≥ 45 ml/min/1.73 m2, DOACs group experienced less intra-cranial hemorrhage (ICH) (0.2% vs 2.8%; p = 0.01) compared to VKAs. VKAs patients showed higher mortality compared to those on DOACs (29.1% vs 7.9%; p < 0.001). At multivariate regression analysis, chronic heart failure [OR = 2.14; p = 0.01] was independently associated with death, whereas male gender [OR: 0.45; p = 0.009] and the use of DOACs [OR: 0.29; p < 0.001] were associated with lower mortality.

CONCLUSION

DOACs seem to be safe and effective in octogenarians with chronic kidney disease at stage ≥ G3b. As compared with VKA administration, the use of DOACs was associated with lower mortality rates among AF octogenarians with renal dysfunction.