Major Hemorrhagic and Thromboembolic Complications in Patients with Mechanical Heart Valves Receiving Oral Anticoagulant Therapy

Introduction: Patients with mechanical heart valve prostheses are obligated to receive lifelong oral anticoagulant therapy to prevent thromboembolic complications; however, this treatment is associated with an increased risk of bleeding. The aim of this study was to evaluate the frequency of major hemorrhagic and thromboembolic complications in patients with mechanical heart valves who received oral anticoagulant therapy. Materials and Methods: The analysis involved 225 patients who underwent successful surgery in 2000; the mean (+/-SD) follow-up period was 43.3 +/- 9.2 months. Aortic, mitral, and double valve replacement was performed in 128 (56.7%), 70 (31.1%), and 27 (12.1%) of the patients, respectively. There were 128 men (57.3%), and the mean patient age was 57.9 +/- 18.8 years. The following data were assessed: rate of major hemorrhagic and thromboembolic complications, frequency of international normalized ratio (INR) rate measurements, and percentage of results within the therapeutic range. Results: Major hemorrhagic and thromboembolic complications occurred in 25 patients (11.1%). Seventeen patients (7.5%) survived, and 8 (3.6%) died of the complications. Major hemorrhagic and thromboembolic complications occurred in 17 patients (7.6%) and 8 patients (3.6%), respectively. The mean time between sequential measurements was 4.3 +/- 3.0 weeks, and of all the INR values collected, 42.4% were within, 31.3% were below, and 26.3% were above the target ranges. Conclusions: Patients with a mechanical heart valve prosthesis receiving acenocoumarol are susceptible to major hemorrhagic and thromboembolic complications, some of which lead to death. Despite the danger related to these complications, patients receiving anticoagulant therapy still have difficulty achieving INR values within the therapeutic range.