Usage Patterns and Bleeding Complications of Non-vitamin K Antagonist Oral Anticoagulants in Patients at Srinagarind Hospital: A Retrospective Descriptive Study

Abstract

Background and Objective: Stroke and thromboembolism represent major public health concerns, especially for patients with atrial fibrillation (AF) who are at high risk. Although non-vitamin K antagonist oral anticoagulants (NOACs) have advantages over warfarin, real-world data on their usage patterns and safety, particularly the risk of bleeding in the Thai population, are still limited. Therefore, this study aimed to investigate the utilization patterns of NOACs, patient characteristics, the incidence of bleeding, and factors associated with bleeding events. The findings will contribute to the development of enhanced pharmaceutical care and patient management guidelines.

Methods: This retrospective descriptive study included 1,654 patients treated with NOACs at Srinagarind Hospital from 1 December 2014 to 31 December 2023. We collected data on patient demographics, diagnoses, comorbidities, CHA₂DS₂-VASc and HAS-BLED scores, renal and hepatic function, medication type and dosage, concomitant medications, and the occurrence of bleeding events.

Results: Of the 1,654 patients who received NOACs between December 2014 and December 2023 at Srinagarind Hospital, 54.8% were male, with a mean age of 70.6 years. A significant portion of the patients (43.2%) was aged 75 years or older. The primary diagnosis was atrial fibrillation (AF) in 65.1% of patients. Hypertension and diabetes were common comorbidities. The mean CHA₂DS₂-VASc score was 2.9, and the mean HAS-BLED score was 1.2. Apixaban 5 mg/tab was the most frequently prescribed NOAC (27.5%). Bleeding events occurred in 34 patients (2.1%), with the majority being gastrointestinal bleeding (85.3%). Of those who experienced bleeding, 25 had one primary diagnosis, while 9 had two or more. There were no bleeding-related deaths. A higher HAS-BLED score was identified as a significant risk factor for bleeding (p < 0.05). The use and dosing of NOACs were generally appropriate for patients' renal function. Notably, the group receiving edoxaban 30 mg had the lowest mean creatinine clearance (CrCl) of approximately 48 mL/min, reflecting its selection for patients with renal impairment. Overall hepatic function was within normal limits, with a mean aspartate Aminotransferase: AST of 32.9 U/L and a mean Alanine aminotransferase: ALT of 27.9 U/L. Although 17.2% of patients had an AST ≥40 U/L and 11.7% had an ALT ≥41 U/L, no significant signals of hepatotoxicity were observed.

Conclusion: NOACs demonstrate excellent safety profile in real-world clinical practice with a low bleeding incidence rate (2.1%). However, individual risk assessment remains crucial. Pharmacists and multidisciplinary healthcare teams play essential roles in optimizing medication management and ensuring patient safety.