Original scientific paper
https://doi.org/10.3325/cmj.2019.60.2
Poor warfarin anticoagulation in long-term thromboprophylaxis: a survey in a southern Croatian county
Aleksandar Knežević
; Department of Health Studies, Zadar University, Zadar, Croatia
Marijana Nadinić
; County General Hospital Zadar, Zadar, Croatia
Irena Užović Frakin
; County General Hospital Zadar, Zadar, Croatia Zadar, Croatia
Vladimir Trkulja
orcid.org/0000-0002-0968-1194
; Department of Pharmacology University of Zagreb School ofMedicine, Zagreb, Croatia
Abstract
Aim To assess the quality of real-life warfarin anticoagulation
in patients requiring chronic thromboprophylaxis in a
southern Croatian county.
Methods We retrospectively analyzed international normalized
ratio (INR) values determined over one year (2016-
2017) at the Zadar County General Hospital in warfarintreated
patients requiring chronic thromboprophylaxis. The
values represent 83.0% of all INRs and were determined in
84.0% of all warfarin-treated patients in the county during
the observed period.Results Overall 31 162 INRs were taken from 3697 patients,
2240 of whom (20 851 INRs, 3-56 per patient, median 9)
were referred with diagnoses requiring chronic thromboprophylaxis:
mainly atrial fibrillation/flutter (n = 1508,
14 902 INRs) but also cardiac implants, valvular disease,
severe heart failure, and cerebrovascular disease (“other”,
n = 732, 5949 INRs). Only 50.1% of all INRs were within the
target range, 2.0-3.5, while 43.6% were <2.0, and 6.3% were
>3.5. Median crude individual proportion of INRs within
the range was 50.0%, while it was 42.0% for INRs <2.0.
Only 23.0% of the patients had ≥70% of the INRs within
the target range (adequately anticoagulated), while 35.5%
had ≤33.3% of the INRs within the range. Conversely, 66.5%
of the patients had ≥33.3% INRs <2.0. Adjusted probability
of adequate anticoagulation in atrial fibrillation/flutter
patients was consistently 25.5% to 27.7%, regardless of the
number of determined INRs, while in patients with other
conditions it increased from 9.5% to 25.2% with a higher
number of INRs.Conclusion The achieved level of warfarin anticoagulation
in this real-life setting is far below what is needed for
effective long-term thromboprophylaxis
Keywords
Hrčak ID:
239728
URI
Publication date:
15.2.2019.
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