Archive for the ‘warfarin’ Category

Quality of Warfarin Control and Events in Patients with Mechanical Heart Valves

Grzymala-Lubanski et al report a retrospective non-randomized multicenter cohort study of patients with mechanical heart valves to assess the relationship between the quality and intensity of warfarin therapy and outcomes (thrombosis/bleeding/death). Measures of better quality control were associated with a lower rate of adverse events. Higher intensity anticoagulation was associated with increased rates of bleeding and death.

Two editorials are available here and here.



To study the impact of time in therapeutic range (TTR) and international normalised ratio (INR)variability on the risk of thromboembolic events, major
bleeding complications and death after mechanical heart valve (MHV)implantation. Additionally, the importance of different target INR levels was elucidated.


A retrospective, non-randomised multicentre cohort study including all patients with mechanical heart valve (MVH) prosthesis registered in the Swedish
National Quality Registry Auricula from 2006 to 2011. Data were merged with the Swedish National Patient Registry, SWEDEHEART and Cause of Death Registry.


In total 4687 ordination periods,corresponding to 18 022 patient-years on warfarin, were included. High INR variability (above mean ≥0.40) or lower TTR (≤70%) was associated with a higher risk of bleeding (rate per 100 years 4.33 (95% CI 3.87 to 4.82) vs 2.08 (1.78 to 2.41); HR 2.15 (1.75 to 2.61) and
5.13 (4.51 to 5.82) vs 2.30 (2.03 to 2.60); HR 2.43 (2.02 to 2.89)), espectively. High variability and low TTR combined was associated with an even higher risk of bleedings (rate per 100 years 4.12 (95% CI 3.68 to 4.51) vs 2.02 (1.71 to 2.30); HR 2.16 (1.71 to 2.58) and 4.99 (4.38 to 5.52) vs 2.36 (2.06 to 2.60); HR 2.38 (2.05 to 2.85)) compared with the best group. Higher treatment intensity (mean INR 2.8–3.2 vs 2.2–2.7) was associated with higher rate of bleedings (2.92 (2.39 to 3.47) vs 2.48 (2.21 to 2.77); HR 1.29 (1.06 to 1.58)), death (3.36 (2.79 to 4.02) vs 1.89 (1.64 to 2.17), HR 1.65 (1.31 to 2.06)) and
complications in total (6.61 (5.74 to 7.46) vs 5.65 (5.20to 6.06); HR 1.24 (1.06 to 1.41)) after adjustment for MHV position, age and comorbidity.


A high warfarin treatment quality improves outcome after MHV implantation, both
measured with TTR and INR variability. No benefit was found with higher treatment intensity (mean INR 2.8–3.2 vs 2.2–2.7).