10-year experience with the ATS mechanical valve in the mitral position

Background. The ATS Medical Open Pivot mechanical heart valve was introduced in 1992. Previous reports have focused on the low rate of thromboembolic complications in the aortic position. The purpose of this retrospective study is to analyze the rate of midterm thromboembolic events and other valve-related complications when the ATS Open Pivot valve is implanted in the mitral position. Methods. Between June 1992 and June 2002, 177 patients (63 male and 114 female; mean age 57.5 years) underwent mitral replacement with an ATS Open Pivot mechanical heart valve. Preoperatively, 17 patients (10%) were in New York Heart Association functional class II, 117 patients (66%) in class III, and 43 patients (24%) in class IV. Seventy-four patients (42%) were in chronic atrial fibrillation. Seventy-f our mitral valve replacements (42%) were associated with other cardiac procedures. Etiologies included degenerative disease (56%), rheumatic disease (38%), and endocarditis (6%). On the second postoperative day, 100 mg acetylsalicylic acid and oral acenocournarol (Sintrom) was introduced to obtain a target INR of 2.0 to 3.0. All patients were followed up by one cardiologist and underwent annual transthoracic echocardiographic examination. Results. Percent follow-up was 90.4%. Data represent 724 total patient-years. Mean follow-up was 48 +/- 34 months (range, 1 to 119). Operative morbidity was 15%. Overall hospital mortality was 2.8% (5 patients). At hospital discharge, the mean INR for all the patients was 2.38 +/- 0.68 (range, 1.32 to 6.44). Five early neurologic complications occurred: 3 transient cerebrovascular accidents and 2 strokes. Three late transient cerebrovascular ischemic accidents occurred at 3, 4, and 6 years, respectively. No other complications such as paravalvular leak, valve dysfunction, thrombosis, or valve explant occurred. Postoperative echocardiographic data revealed low mean pressure gradient as related to the valvular size. Conclusions. The ATS Medical Open Pivot mitral valve demonstrates low rates of bleeding, thromboembolic, and other valve-related complications. (c) 2005 by The Society of Thoracic Surgeons.