Monitoring of NOAC Therapy: Standardizing Reference Intervals

Monitoring of NOAC Therapy: Standardizing Reference Intervals

This study is aimed to establish reference intervals of NOAC (dabigatran, apixaban and rivaroxaban) in ethnic Chinese patients.

360 patients who are on dabigatran, apixaban and rivaroxaban based on the above inclusion and exclusion criteria will be recruited. After the informed consent, the patient will be needed for blood taking before and 2 hours after the medication (NOAC). The patient's demographic data and medical history will also be retreived from Central Medical Syetem too.

Inclusion Criteria:

1. Ethnic Chinese ONLY
2. 18 years old or above
3. Non-valvular atrial fibrillation
4. Duration of NOAC use at least 3 months
5. No changes in NOAC dosage or type within 3 months
6. Creatinine Clearance (by Cockcroft-Gault formula) >/=30mL/min

Exclusion Criteria:

1. Valvular atrial fibrillation or no atrial fibrillation
2. Recent haemorrhage or ischemia within 1 year
3. Active liver disease
4. Abnormal baseline clotting profile
5. Abnormal baseline thrombocytopenia or thrombocytosis
6. Thromboembolic tendency other than atrial fibrillation (e.g. antiphospholipid syndrome, protein C, S, anti-thrombin III deficiency)
7. Non-compliant patients, defined as missing any doses of NOAC in recent 1 month
8. Anticoagulation for disorders other than AF
9. Pregnancy