Real –life International Normalized Ratio (INR) profile ; Egyptian study

O.Arafa, A.Hassan, S.Ebrahim, A.Abd-El-Aziz and H.Mohamed"


Warfarin remains widely used by patients with cardiovascular diseases[.Due to high interindividual variability, the anticoagulant activity of warfarin has to be monitored using the international normalized ratio (INR).The most widely recommended approach for evaluating the quality and safety of anticoagulation is to estimate the percentage of time in therapeutic range (TTR). It was a single center, cross-sectional observational study that was conducted at cardiology department at Benha University Hospital. This study was designed to: Study the INR values in patients on VKAs in the selected area., Calculation of the time in the therapeutic range (TTR) when is possible according to the number of INR/Patient., Find out which patient characteristics that are associated with good INR control. Patients were subdivided into two sub groups; sub group I : patients with TTR ≥ 65% , sub group II : patients with TTR < 65% .The study was designed to screen not less than 2000 INR laboratory tests from these patients. Mean TTR was 60.27%+_24.48% for the Rosendaal method. After multivariate adjustment,variables associated with good anticoagulation control were university studies (OR: 1.99, 95% CI: 1.08-3.64), chronic hepatic disease (OR: 8.15, 95% CI: 1.57-42.24), low comorbidity expressed as Charlson index(OR: 0.87, 95% CI: 0.76-0.99) , no previous cardiac disease (OR: 0.64, 95% CI: 0.41-0.98), lower risk of bleeding assessed as hypertension, abnormal enal/liver function, stroke, bleeding history or predisposition, rlabile international normalized ratio, elderly age, and use of drugs or alcohol { HAS-BLED} (OR: 0.81, 95% CI: 0.69-0.95), and lower heart rate OR: 0.99, 95% CI: 0.98-0.99). Our study shows a rate of inadequate control with AVKs of 54%, and 46% of the patients spent more than half the time outside the therapeutic range. .In our study, having a university degree was associated with adequate anticoagulation control.We believe that higher education helps patients to understand the importance of anticoagulant treatment adherence.

Key words

Warfarin, International normalized ratio (INR), Time in therapeutic range (TTR), Education and control.