As a means of assessing the adequacy of anticoagulation with warfarin the time in the therapeutic range TTR method has become a common reportable measure especially in recent clinical trials. The median times below and above the therapeutic range were 17 IQR 8-29 and 10 IQR 3-19 respectively.

Recent Advances In Oral Anticoagulation Therapy For Patients With Atrial Fibrillation

Patients with renal dysfunction advanced heart failure frailty prior valve surgery and higher risk for bleeding ATRIA score or stroke CHA2DS2-VASc score had significantly lower TTR P.

Therapeutic range for warfarin. Diagnosis Target INR Duration Deep Vein Thrombosis. In a 2011 retrospective cohort study of 1378 patients Finkelman et al. 2 to 3 Duration of therapy.

Warfarin is a commonly prescribed anticoagulant that is difficult to use because of the wide interindividual variation in dose requirements the narrow therapeutic range and the risk of serious bleeding. The time in the therapeutic range an international normalized ratio INR between 20 and 30 TTR has been used as a measure of warfarin W therapy quality. If additional risk factors for thromboembolism are present AF previous thromboembolism left ventricular dysfunction a target INR of 25 range 20-30 is recommended.

Recommended Therapeutic Range for Warfarin Therapy. 5 TTR represents the percentage of time in which the INR remains in the 20 to 30 target range across time. Today Im going to focus on time within the therapeutic range TTR using warfarin for stroke prevention in atrial fibrillation.

If additional risk factors for thromboembolism are present AF previous thromboembolism left ventricular dysfunction a target INR of 25 range 20-30 is recommended. Recommended Therapeutic Range and Duration of Warfarin Therapy. Patients taking warfarin need regular International Normalised Ratio INR blood tests to ensure that their levels remain within a set therapeutic range.

2 to 10 mg orally once a day. Although generally useful in clinical care and better than other alternatives in recent new oral anticoagulant NOAC versus W trials in atrial fibrillation AF its utility has been overvalued. Warfarin substantially reduces the risk of such thromboembolic events.

2 to 5 mg orally once a day. 1 The safety and effectiveness of warfarin depends greatly on the proportion of time in the therapeutic range TTR of the international normalized ratio INR blood test however. Simplistically the TTR should be an easily understandable and easily calculated number.

8 To date only a few multicenter studies have examined patients TTR in clinical practice in the United States. Should patients fall below this range they will be at higher risk of developing a venous thromboembolism VTE. 17 compared a pharmacogenetic algorithm to other dosing strategies and found it was significantly better at predicting the correct warfarin dose 52 of patients within the therapeutic dose range than any of the other methods evaluated including empiric dosing putting.

Target of 35 is also recommended for patients who suffer recurrence of VTE whilst on warfarin with an INR between 20 and 30 prosthetic heart valves long-term for patients in whom valve type and location are known specific target INRs are recommended 1. A time-weighted average TTR for the clinic was determined to be 5876 based on 183 452 patient-days taking warfarin. For patients with a bioprosthetic valve in the mitral position therapy with warfarin to a target INR of 25 range 20-30 for the first 3 months after valve insertion is recommended.

Transient risk - 1stepisode idiopathic 1stepisode recurrent VTE associated active malignancy 20-30 3 months At least 6-12 months Indefinite Until remission. Usual Adult Dose for Prevention of Thromboembolism in Atrial Fibrillation. The regression analysis did not find a statistically significant association between TTR and any predictors.

If patients INR were to go above range they are at greater risk of bleeding. Objectives Warfarin remains widely used with a time in therapeutic range TiTR above 65 recommended for best outcomes. The clinical benefit and risks of warfarin are associated with the proportion of time that international normalized ratio INR values are between 2 and 3 meaning the time in therapeutic range TTR.

Many of us believe that the TTR is generally in the mid-60 to high. Treatment of DVTPE Systemic embolus Atrial fibrillation TIAs LV mural thrombus Mitral valve repair. For patients with a bioprosthetic valve in the mitral position therapy with warfarin to a target INR of 25 range 20-30 for the first 3 months after valve insertion is recommended.

Patients not achieving or maintaining this warfarin control may be better suited to alternate anticoagulants. NOAC studies were based on comparisons with warfarin arms with times in therapeutic range TTRs of 552 to 649 making the results less credible in health care systems with higher TTRs.