Oral anticoagulation therapy using acenocoumarol during the month of ramadan: a comparative study between fasting and non-fasting patients

Abstract

Background and objectives: The effect of Ramadan fasting on anticoagulation by vitamin K antagonists has been previously investigated in small
scale studies with controversial results. From this perspective, this study aimed to compare the fluctuations of anticoagulation in fasting and nonfasting patients taking
Acenocoumarol and to identify the factors associated with such
fluctuations.

Methods: The study, conducted between May and August 2018, was a comparative one. Three study periods were defined: before Ramadan
(BR), Ramadan and after Ramadan (AR). Enrolment involved ambulatory patients aged over eighteen, without medical contraindications to fasting
(for the fasting group) and whom international normalized ratio (INR) was within the therapeutic target range during the last three months BR.
Anticoagulation monitoring consisted in five consecutive INR assays; INR0 (during the 14 days BR), INR1 (between the 1st and the 14th day of
Ramadan), INR2 (between the 15th and the 28th day of Ramadan), INR3 (28 days after INR2) and INR4 (28 days after INR3). INR stability was
assessed by calculating four percentages of time in therapeutic range (TTR); TTR0 (between INR0 and INR1), TTR1 (between INR0 and INR2),
TTR2 (between INR2 and INR3) and TTR3 (between INR3 and INR4). The null hypothesis was the occurrence of an anticoagulation imbalance
(evaluated by TTR) in fasting patients in comparison with non-fasting ones.

Results: One hundred and twenty-two patients (84 fasting patients), aged 60 ± 19 years, were included. In fasting patients, the average differences
of INR1, 2, 3 and 4 compared with INR0 were statistically non-significant and accounted for +0.46, +0.34, +0.28 and +0.30 respectively. Among the
three TTRs, only TTR2 significantly decreased in comparison with TTR0 in fasting group (50.3 ± 37.4 vs. 63.6 ± 39.3%, p=0.004). TTR1, 2 and 3
were comparable between fasting and non-fasting patients.
Conclusions: The fluctuations of anticoagulation balance, assessed by TTR, were comparable between fasting and non-fasting patients taking
Acenocoumarol.