Anticoagulation after valve replacement: a multicenter retrospective study

Area of Science:

• Cardiology
• Vascular Surgery
• Pharmacology

Background:

• Anticoagulant therapy is crucial for patients with mechanical heart valves to prevent thromboembolic events.
• The established therapeutic range for PT-INR (prothrombin time international normalized ratio) may not be universally applicable across diverse patient populations.

Purpose of the Study:

• To retrospectively evaluate the effectiveness of current anticoagulant therapy in Japanese patients after cardiac valve replacement.
• To assess the PT-INR (prothrombin time international normalized ratio) values associated with thromboembolic and bleeding complications in this cohort.

Main Methods:

• Retrospective analysis of 1,200 patients undergoing cardiac valve replacement in the Tokyo area.
• Monitoring of prothrombin time international normalized ratio (PT-INR) levels in relation to thromboembolic and bleeding events.
• Data collected as part of the Tokyo Area Study on Anticoagulation After Cardiac Valve Replacement Using PT-INR (TAS).

Main Results:

• Thromboembolic complications occurred in 21 patients and bleeding complications in 15 patients.
• A significant proportion of patients experiencing thromboembolism (71%) and bleeding (47%) had PT-INR levels within the accepted Japanese therapeutic range of 1.6 to 2.8.
• These findings suggest a potential mismatch between the current therapeutic range and optimal anticoagulation for Japanese patients.

Conclusions:

• The current PT-INR (prothrombin time international normalized ratio) therapeutic range of 1.6 to 2.8 may require re-evaluation for Japanese patients with mechanical heart valves.
• Prospective data from the ongoing TAS trial are necessary to determine a more appropriate PT-INR therapeutic range for this population.