Category: Professional Posters
Purpose: Available evidence indicates that SAMe-TT2R2 score (sex female, age < 60 years, medical history [more than two comorbidities], treatment [interacting drugs, e.g., amiodarone for rhythm control], tobacco use [doubled], race [doubled]) may predict optimum anticoagulation control among atrial fibrillation patients (reflected by time in therapeutic range (TTR) above 65-70% with SAMe-TT₂R₂ score of 0-1). However, association between the score and anticoagulation control in Venous Thromboembolism (VTE) patients is controversial.
The purpose of this study is to find out whether SAMe-TT₂R₂ score can be used to evaluate quality of anticoagulation control, measured by TTR, in patients treated with warfarin for VTE.
Methods: A retrospective cohort study. Adult patients treated with warfarin for Venous thromboembolism for at least 6 months in ambulatory anticoagulation clinics of two hospitals in Qatar were included. Patients with missing data (e.g., demographics, target INR), those known to have poor compliance to warfarin and/or clinic visits and those who lost follow up with the clinic were excluded.
Relevant data were collected through electronic chart review over one year. These include, patients’ demographics, indication and duration of warfarin therapy, target INR, comorbidities (e.g., diabetes, hypertension, pulmonary disease, previous stroke, renal and hepatic dysfunction), tobacco and alcohol use. For interacting medicines, drugs with warfarin interaction category (D and X) in lexi-comp were considered.
SAMe-TT2R2 score and TTR were calculated. TTR was calculated using linear interpolation method of Rosendaal et al.
Patients were categorized into low and high SAMe-TT2R2 score (0-1, 2 or more respectively); and good and poor INR control groups (TTR cutoff of 70%).
Categorical variables were compared using Chi-square test while continuous variables compared using T-test using SPSS. The study was conducted in full accordance with rules and regulations of research at Hamad Medical Corporation.
Results: A total of 295 patients were included (55.9% males), with majority being younger than 60 years old (77.3%). Target INR of 2-3 was the most common among all indications (88%). Deep Vein Thrombosis was the leading indication for warfarin (30.5%) followed by Pulmonary Embolism (20.6%).
The mean TTR was 76.6±18.6%.
Patients with low SAMe-TT2R2 score (zero or 1) had statistically significant higher TTR than those with high SAMe-TT2R2 score (2 or more) (95±3.2% vs 76±18.6%, p=0.022)
Compared to patients with good INR control (TTR >70%), those with poor control (TTR ≤70%) were more likely to have SAMe-TT2R2 score of 2 or more (OR: 1.495, 95%CI:1.38-1.62).
Conclusion: There is a significant association between lower SAMe-TT2R2 score and good anticoagulation control in a cohort of VTE patients treated with warfarin in Qatar. Contribution of other clinical factors and whether a different scoring may yield better prediction of anticoagulation control remains to be tested