TITLE:
Assessment of Oral Anticoagulation with Vitamin K Antagonists in Patients Living in a Low-Income Country of West Africa
AUTHORS:
Komlavi Yayehd, Tchaa Tcherou, Hervé Libérus A. Edorh, Agossou Defodji, Mohamed Kpelafia, Ekpé Togbossi, Ablawa Adzodo, Soulemane Pessinaba, Machihude Pio, Soodogoua Baragou, Findibe Damorou
KEYWORDS:
Vitamin K Antagonists, Time in Therapeutic Range, Lomé, Togo
JOURNAL NAME:
World Journal of Cardiovascular Diseases,
Vol.14 No.1,
January
29,
2024
ABSTRACT: Introduction: Despite the rise of direct
oral anticoagulants (DOACs), vitamin K antagonists (VKA) remain the most widely
used oral anticoagulants in developing countries. The aim of this study was to
estimate the prevalence of good anticoagulation in patients treated with VKA in
Lomé and describe associated factors. Methods: This was a
cross-sectional study conducted from November 2019 to October 2020 in the
cardiology departments of two University teaching hospitals in Lomé (CHU
Sylvanus Olympio and CHU Campus), involving patients on VKA for ≥3 months, with
a target international normalized ratio (INR) of 2.5 and a therapeutic margin
between 2 and 3. The quality of anticoagulation was assessed by the time in therapeutic range (TTR) which was assessed by the Rosendaal method. Good
anticoagulation was defined by a TTR > 70%. Results: A total of 344
patients were included (mean age = 58 ± 13.8 years, women = 56.1%). Indications
for VKA treatment were represented by venous thromboembolic disease (43.3%),
supraventricular arrhythmia (28.2%), severe left ventricular systolic dysfunction
(19.8%) and pulmonary hypertension (8.7%). The average TTR was 47.6 ± 20.8%.
The rate of good anticoagulation was 17.7%. Factors associated with good
anticoagulation were the use of fluindione vs acenocoumarol (OR = 11.17; 95%
CI: 3.2 - 39.6; p = 0.0002), concomitant low-dose aspirin (OR 4.44; 95% CI: 1.4
- 13.9; p = 0.01) and INR monitoring exclusively by the patient himself (OR =
4.92; 95% CI: 1.5 - 16.3; p = 0.008). The rate of thromboembolic and
hemorrhagic complications was each 2.6% and was not correlated with the quality
of anticoagulation. Quality of anticoagulation by VKAs was poor in our
practice. Factors associated with good anticoagulation were the use of
fluindione vs acenocoumarol, concomitant low-dose aspirin and monitoring of INR
exclusively by the patient himself. Conclusion: The quality of oral
anticoagulation by VKAs could be improved in our practice by the creation of
anticoagulation clinics for better therapeutic education of patients and
efficient management of VKA dose, and the use of prescription assistance
software.