Anticoagulation Control in Different Ethnic Groups Receiving Vitamin K Antagonist for Stroke Prevention in Atrial Fibrillation

SAMe-TT2R2 Score to Predict Time in Therapeutic Range of Vitamin K Antagonists in Asian and Non-Asian patients: A Systematic Review and Meta-analysis

BACKGROUND

Sex, age, medical history, treatment, tobacco use, and race (SAMe-TT2R2) score helps detect patients at risk of suboptimal anticoagulation control. A score above two suggests poor control; however, non-Caucasian status being assigned two points might hinder the recognition of poor control in patients of other races.

OBJECTIVE

To evaluate the SAMe-TT2R2 score's ability to predict poor anticoagulation control [defined as time in therapeutic range (TTR) < 60-70%] in Asian and non-Asian populations on vitamin K antagonists (VKAs).

METHODS

We searched PubMed, Cochrane Library, Scopus, SpringerLink, and Web of Science using the keyword "SAMe-TT2R2." Articles published before April 2022 were screened. We gathered mean TTR and diagnostic accuracy data for different SAMe-TT2R2 thresholds and conducted meta-analyses using random-effects models.

RESULTS

A total of 30 studies were included (N = 36,690). The overall mean TTR differences were - 4.88 and - 6.41 for the cutoffs of ≥ 3 and ≥ 4, respectively. For non-Asian patients, the mean TTR differences were - 3.86, - 5.12, and - 8.09 for the cutoffs ≥ 2, ≥ 3, and ≥ 4, respectively. For Asian patients, the mean TTR differences were - 3.99 and - 4.07 for the cut-offs ≥ 3 and ≥ 4, respectively. The highest positive likelihood ratio (LR+) for the Asian subgroup was 1.17 [95% confidence interval (CI): 1.06-1.28; I2 = 0%, p heterogeneity = 0.500] at cutoff ≥ 4 and for the non-Asian subgroup, at cut-off ≥ 3, the LR+ was 1.24 (95% CI 1.14-1.34; I2 = 0% p heterogeneity = 0.455). The lowest LR- was found at a lower cutoff for both races (at cutoff ≥ 3 and ≥ 2 for Asian and non-Asian subgroups, respectively). The pooled results of other accuracy parameters were modest at all cutoffs, except for the sensitivity at cutoff ≥ 3 in the Asian subgroup (83.05%).

CONCLUSION

Our study results suggest that a higher SAMe-TT2R2 score resulted in a greater reduction of TTR among Asian and all races. The accuracy parameters showed the highest sensitivity for poor TTR at the SAMe-TT2R2 cutoff of ≥ 3 for Asian patients. However, the ability to identify patients likely to have poor TTR was limited. Further research is needed to enhance the risk assessment for poor anticoagulation control with VKAs.

REGISTRATION

The protocol of this systematic review was registered in the International Prospective Register of Scientific Reviews: PROSPERO, registration number CRD42021291865.

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.

Selection of Non-vitamin K Antagonist Oral Anticoagulant for Stroke Prevention in Atrial Fibrillation Based on Patient Profile: Perspectives from Vietnamese Experts. Part 1

In Asia, especially Vietnam, AF is a common arrhythmia and is linked to a higher risk of stroke and systemic embolism. Anticoagulation therapy for stroke prevention in AF patients can result in bleeding complications. To effectively manage AF, adopting appropriate anticoagulation and addressing modifiable risk factors are crucial. Vietnamese clinicians are particularly interested in non-vitamin K antagonist oral anticoagulants (NOACs), a recent development in AF treatment. However, the lack of head-to-head trials comparing NOACs makes selecting a specific NOAC challenging. This review aims to provide a comprehensive overview of the available clinical evidence on NOACs for stroke prevention in AF to assist clinicians in making informed decisions and improving treatment outcomes in patients with AF. The first part of this review will present the current landscape of AF in Vietnam, focusing on AF prevalence and highlighting gaps in clinical practice. Furthermore, this part extensively discusses the anticoagulation strategy for both primary and secondary stroke prevention in AF.