TY - JOUR
T1 - Changes in quality of vitamin K antagonist treatment and clinical outcomes during Ramadan
T2 - a Dutch population-based cohort study
AU - Kempers, Eva K.
AU - Chen, Qingui
AU - van Rein, Nienke
AU - Atiq, Ferdows
AU - Schindhelm, Roger K.
AU - Wiersma, Nynke M.
AU - Dronkers, Charlotte E.A.
AU - Beinema, Maarten
AU - ten Cate-Hoek, Arina J.
AU - Nierman, Melchior C.
AU - Stork, Alexander D.M.
AU - Moriarty, Patricia
AU - Klok, Frederikus A.
AU - Cannegieter, Suzanne C.
AU - Kruip, Marieke J.H.A.
N1 - Funding Information:
A.D.M.S. has received speaker and consultancy fees from Amaryn, Astra, Boehringer-Ingelheim, NovoNordisk, Sanofi, and Viatris. F.A.K. has received research support from Bayer, BMS, BSCI, AstraZeneca, Angiodynamics, MSD, Leo Pharma, Actelion, Farm-X, The Netherlands Organisation for Health Research and Development , the Dutch Thrombosis Foundation , the Dutch Heart Foundation , and the Horizon Europe Program, all outside this project and paid to his institution. M.J.H.A.K. has received research support from The Netherlands Organisation for Health Research and Development, the Dutch Thrombosis Foundation , and the Horizon Europe Program, and speaker\u2019s fees from Roche, all outside this project and paid to her institution. All other authors have nothing to declare.
Publisher Copyright:
© 2025 The Author(s)
PY - 2025/8/1
Y1 - 2025/8/1
N2 - Background: Ramadan fasting alters the timing and content of food, including dietary vitamin K, and medication intake, potentially affecting stability of vitamin K antagonist (VKA) treatment and clinical outcomes. Objectives: To assess population-level changes in VKA treatment quality and incidence of clinical events, including bleeding and venous and arterial thromboembolism, during Ramadan in the Netherlands. Methods: Data from 17 Dutch anticoagulation clinics were linked to Statistics Netherlands. Prevalent VKA users in 2013-2019 with an immigration background who were likely to fast during Ramadan (ie, the Ramadan cohort) were studied from 2 months preceding Ramadan until 2 months after. During each 30-day interval, VKA treatment quality and risk of clinical events were assessed. A cohort of native Dutch VKA users was studied as negative control. Results: The Ramadan cohort included 3835 VKA users (median age 65.8 years, 55.2% male). Frequency of international normalized ratio (INR) monitoring, INR variability, and time within target range remained similar across Ramadan. However, the proportion of supratherapeutic INRs was slightly higher during (18.9% ± 31.5% [mean ± SD]) and after Ramadan (month +1, 19.9% ± 32.7% and month +2, 19.7% ± 32.8%) compared with before (month –2, 18.1 ± 30.9% and month –1, 17.8 ± 31.5%). Meanwhile, there was a higher proportion of clinically relevant dose reductions during Ramadan (4.7%) than the other months (3.6%-4.3%). These were not observed in the native Dutch cohort (N = 139,207). Monthly risk of the composite of bleeding and thromboembolic events remained unchanged across Ramadan in both cohorts. Conclusion: There were no clinically relevant population-level changes across Ramadan in VKA treatment quality and clinical outcomes, except for a slightly higher proportion of supratherapeutic INRs and dose reductions.
AB - Background: Ramadan fasting alters the timing and content of food, including dietary vitamin K, and medication intake, potentially affecting stability of vitamin K antagonist (VKA) treatment and clinical outcomes. Objectives: To assess population-level changes in VKA treatment quality and incidence of clinical events, including bleeding and venous and arterial thromboembolism, during Ramadan in the Netherlands. Methods: Data from 17 Dutch anticoagulation clinics were linked to Statistics Netherlands. Prevalent VKA users in 2013-2019 with an immigration background who were likely to fast during Ramadan (ie, the Ramadan cohort) were studied from 2 months preceding Ramadan until 2 months after. During each 30-day interval, VKA treatment quality and risk of clinical events were assessed. A cohort of native Dutch VKA users was studied as negative control. Results: The Ramadan cohort included 3835 VKA users (median age 65.8 years, 55.2% male). Frequency of international normalized ratio (INR) monitoring, INR variability, and time within target range remained similar across Ramadan. However, the proportion of supratherapeutic INRs was slightly higher during (18.9% ± 31.5% [mean ± SD]) and after Ramadan (month +1, 19.9% ± 32.7% and month +2, 19.7% ± 32.8%) compared with before (month –2, 18.1 ± 30.9% and month –1, 17.8 ± 31.5%). Meanwhile, there was a higher proportion of clinically relevant dose reductions during Ramadan (4.7%) than the other months (3.6%-4.3%). These were not observed in the native Dutch cohort (N = 139,207). Monthly risk of the composite of bleeding and thromboembolic events remained unchanged across Ramadan in both cohorts. Conclusion: There were no clinically relevant population-level changes across Ramadan in VKA treatment quality and clinical outcomes, except for a slightly higher proportion of supratherapeutic INRs and dose reductions.
KW - 4-hydroxycoumarins
KW - hemorrhage
KW - international normalized ratio
KW - Ramadan fasting
KW - thromboembolism
U2 - 10.1016/j.rpth.2025.103010
DO - 10.1016/j.rpth.2025.103010
M3 - Article
SN - 2475-0379
VL - 9
JO - Research and practice in thrombosis and haemostasis
JF - Research and practice in thrombosis and haemostasis
IS - 6
M1 - 103010
ER -