Factors Affecting the Quality of Anticoagulation With Vitamin K Antagonists in Venous Thromboembolism Patients.
Treatment of venous thromboembolism (VTE) is classically based on oral vitamin K antagonists (VKAs). Due to the disadvantages and side effects of these drugs, monitoring the quality of anticoagulation by assessing time within therapeutic range (TTR) is recommended. Variables altering the TTR in patients with VTE are yet to be determined. The aim of this study was to analyze the quality of anticoagulation in patients with VTE treated with VKAs and to identify factors associated with poor-quality anticoagulation.



A retrospective observational study was performed in a cohort of 94 patients diagnosed with VTE undergoing treatment with VKAs. The TTR at 6 months was analyzed by the Rosendaal method. Univariate and a multivariate logistic regression analyses were performed to unravel factors that increase risk of poor-quality anticoagulation.



The TTR at 6 months in this cohort was 60.5%; 54 patients had a TTR < 65%. In the univariate analysis, female sex, age ≥ 65 years, and renal impairment were significantly associated with poor-quality anticoagulation. However, in the multivariate logistic regression model, only renal impairment was independently associated with poor-quality anticoagulation (odds ratio = 3.31, 95% confidence interval [1.049, 10.486], p = .041).



The average quality of anticoagulation was 60.5%, and a high percentage of patients had a quality of anticoagulation below recommended levels. Study findings indicate that renal impairment is an independent risk factor for poor-quality anticoagulation in patients with VTE treated with VKAs.
1 Department of Cardiology, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.|2 School of Nursing, Universidad Católica de Murcia, Murcia, Spain.
José Miguel
JM
Rivera-Caravaca
2 School of Nursing, Universidad Católica de Murcia, Murcia, Spain.
Inmaculada
I
Viedma-Viedma
3 Department of Hematology and Clinical Oncology, Hospital Universitario Morales Meseguer, University of Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.
Vanessa
V
Roldán
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000188:drug therapy*; D014812:Vitamin K / Q000037:antagonists & inhibitors* / Q000627:therapeutic use*
D000925:Anticoagulants; D014812:Vitamin K
oral anticoagulants; quality of anticoagulation; thromboembolism; time in therapeutic range; vein thrombosis; vitamin K antagonists