Citrated Kaolin Reaction Time on Thromboelastography 6s Identifies Bleeding-Prone Phenotypes in Older Adults with Atrial Fibrillation Receiving Direct Oral Anticoagulant Therapy.

PURPOSE: Older adults with atrial fibrillation (AF) receiving direct oral anticoagulants (DOACs) remain at increased bleeding risk, and conventional clinical scores offer limited predictive value. Thromboelastography (TEG6s) provides point-of-care assessment of global hemostasis; however, its clinical utility remains unclear. This study investigated the association between TEG6s parameters and bleeding events in older adults with AF receiving DOAC therapy.

METHODS

We prospectively enrolled 100 patients aged ≥ 75 years with non-valvular AF receiving DOAC therapy. Baseline TEG6s parameters, including citrated kaolin reaction time (CKR), were obtained. Bleeding events were classified per International Society on Thrombosis and Haemostasis criteria. Logistic regression and receiver operating characteristic (ROC) analyses identified predictors of clinically relevant bleeding, defined as major and clinically relevant non-major bleeding.

RESULTS

Clinically relevant bleeding occurred in 33 patients during a 1-year follow-up. Prolonged CKR was independently associated with increased bleeding risk in multivariate analysis (hazard ratio 1.36; 95% confidence interval: 1.10-1.70; p = 0.005). ROC analysis demonstrated fair discriminative performance for CKR (area under the curve = 0.712), suggesting a potential role as a biomarker for bleeding risk stratification. Other TEG parameters and conventional clinical risk scores were not significant predictors.

CONCLUSION

Prolonged CKR was significantly associated with clinically relevant bleeding events in older adults with AF receiving DOAC therapy. CKR may reflect an underlying bleeding tendency and could serve as an investigational biomarker for bleeding risk stratification. However, its clinical utility requires confirmation in larger, multicenter studies.