Warfarin treatment quality and prognosis in patients with mechanical heart valve prosthesis

• Published in: Heart (British Cardiac Society) Vol. 103; no. 3; pp. 198 - 203
• Main Authors: Grzymala-Lubanski, Bartosz, Svensson, Peter J, Renlund, Henrik, Jeppsson, Anders, Själander, Anders
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.02.2017
• Subjects: Aged; Anticoagulants; Anticoagulants - administration & dosage; Anticoagulants - adverse effects; Auricula; Cardiac and Cardiovascular Systems; Cardiac arrhythmia; Clinical Medicine; Disease; Drug dosages; Drug Monitoring - methods; Female; Fibrinolytic Agents - administration & dosage; Fibrinolytic Agents - adverse effects; Heart surgery; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation - adverse effects; Heart Valve Prosthesis Implantation - instrumentation; Heart Valve Prosthesis Implantation - mortality; Hemorrhage - chemically induced; Humans; International Normalized Ratio; Kardiologi; Klinisk medicin; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Middle Aged; Patients; Practice Patterns, Physicians' - trends; Predictive Value of Tests; Proportional Hazards Models; Prostheses; Quality Indicators, Health Care - trends; Registries; Retrospective Studies; Risk Factors; Sweden; Thromboembolism; Thromboembolism - diagnosis; Thromboembolism - etiology; Thromboembolism - mortality; Thromboembolism - prevention & control; Time Factors; Treatment Outcome; Warfarin - adverse effects; Warfarin - therapeutic use; Sweden
• ISSN: 1355-6037; 1468-201X; 1468-201X
• DOI: 10.1136/heartjnl-2016-309585

ObjectivesTo 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.MethodsA 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.ResultsIn 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)), respectively. 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 (5.20 to 6.06); HR 1.24 (1.06 to 1.41)) after adjustment for MHV position, age and comorbidity.ConclusionsA 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).