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

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.

New score for predicting major bleeding in patients with atrial fibrillation using direct oral anticoagulants

PURPOSE

Our aim was to identify factors associated with major bleeding in patients with atrial fibrillation (AF) on direct oral anticoagulants (DOACs) and to construct and externally validate a predictive model that would provide a validated tool for clinical assessment of major bleeding.

METHODS

In the development cohort, prediction model was built by logistic regression, the area under the curve (AUC), and Nomogram. External validation, analytical identification and calibration of the model using AUC, calibration curves and Hosmer-Lemeshow test.

RESULTS

The development cohort consisted of 4209 patients from 7 centers and the external validation cohort consisted of 1800 patients from 12 centers. Multifactorial analysis showed that age > 65 years, history of bleeding, anemia, vascular disease, antiplatelet therapy/non-steroidal anti-inflammatory drugs and rivaroxaban were independent risk factors for major bleeding, and gastrointestinal protective agents was a protective factor. The Alfalfa-MB model was constructed using these seven factors (AUC = 0.807), and in the external validation cohort, the model showed good discriminatory power (AUC = 0.743) and good calibration (Hosmer-Lemeshow test P value of 0.205). The predictive power of the six bleeding scores was ORBIT (AUC = 0.706), HAS-BLED (AUC = 0.648), ATRIA (AUC = 0.645), HEMORR2 HAGES (AUC = 0.632), ABC (AUC = 0.619) and Shireman (AUC = 0.599) in descending order.

CONCLUSION

Based on 7 factors, we derived and externally validated a predictive model for major bleeding with DOACs in patients with AF (Alfalfa-MB). The model has good predictive value and may be an effective tool to help reduce the occurrence of major bleeding in patients with DOACs.

Predicting performance of the HAS-BLED and ORBIT bleeding risk scores in patients with atrial fibrillation treated with Rivaroxaban: Observations from the prospective EMIR Registry

BACKGROUND

Assessing bleeding risk during the decision-making process of starting oral anticoagulation (OAC) therapy in atrial fibrillation (AF) patients is essential. Several bleeding risk scores have been proposed for vitamin K antagonist users but, few studies have focused on validation of these bleeding risk scores in patients taking direct oral anticoagulants (DOACs). The aim was to compare the predictive ability of HAS-BLED and ORBIT bleeding risk scores in AF patients taking rivaroxaban in the EMIR ('Estudio observacional para la identificación de los factores de riesgo asociados a eventos cardiovasculares mayores en pacientes con fibrilación auricular no valvular tratados con un anticoagulante oral directo [Rivaroxaban]) Study.

METHODS AND RESULTS

EMIR Study was an observational, multicenter, post-authorization, and prospective study that involved AF patients under OAC with rivaroxaban at least 6 months before enrolment. We analysed baseline clinical characteristics and adverse events after 2.5 years of follow-up and validated the predictive ability of HAS-BLED and ORBIT scores for major bleeding (MB) events.We analysed 1433 patients with mean age of 74.2 ± 9.7 (44.5% female). Mean HAS-BLED score was 1.6 ± 1.0 and ORBIT score was 1.1 ± 1.2. The ORBIT score categorised a higher proportion of patients as 'low-risk' (87.1%) compared with 53.5% using the HAS-BLED score. There were 33 MB events (1.04%/year) and 87 patients died (2.73%/year). Both HAS-BLED and ORBIT had a good predictive ability for MB{Area under the curve (AUC) 0.770, [95% confidence interval (CI) 0.693-0.847; P <0.001] and AUC 0.765 (95% CI 0.672-0.858; P <0.001), respectively}. There was a non-significant difference for discriminative ability of the two tested scores (P = 0.930) and risk reclassification in terms of net reclassification improvement (NRI) -5.7 (95% CI -42.4-31.1; P = 0.762). HAS-BLED score showed the best calibration and ORBIT score showed the largest mismatch in calibration, particularly in higher predicted risk patients.

CONCLUSION

In a prospective real-world AF population under rivaroxaban from EMIR registry, the HAS-BLED score had good predictive performance and calibration compared with ORBIT score for MB events. ORBIT score presented worse calibration than HAS-BLED in this DOAC treated population.