Study population
This multicenter, prospective, observational study in NVAF patients
treated with rivaroxaban or apixaban was carried out in the National
Heart Center Singapore and Khoo Teck Puat Hospital, and approved by the
Domain Specific Review Board (Study reference number: 2017/00815).
Patients were recruited between 5 October 2017 and 6 February 2020.
After providing their signed informed consent, NVAF patients who were at
least 21 years of age and on rivaroxaban or apixaban for at least 3
continuous days were included in the study. Pregnant or breastfeeding
women or women who had given birth in the past 90 days and patients
enrolled in another drug or device study were excluded. A total of 106
rivaroxaban and 40 apixaban patients were recruited. The choice and dose
of DOAC prescription was based on their physician’s discretion.
Baseline characteristics including gender, ethnicity, age, height,
weight, smoking history, alcohol consumption, serum creatinine,
co-morbidities and concomitant medications were recorded. Body mass
index (BMI) and CHA2DS2-VASc scores were
computed based on the collected records. Creatinine clearance (CrCl) was
estimated via the Cockcroft-Gault equation [19]. Patients were
followed up by phone at week 2, months 1, 3, 6 and 12. At each
check-point, patients were interviewed on compliance and clotting or
bleeding events.