Mid-term surgical results after valve replacement with the CarboMedics valve prosthesis

Important contributions to cardiothoracic surgery by Japanese thoracic and cardiac surgeons

Cardiothoracic surgeons in Japan have made outstanding contributions to our knowledge and therapy of diseases and anomalies of the heart, lungs, esophagus, chest wall and diaphragm. It is an honor for me to address this subject at the 57th Annual Meeting of the Japanese Association for Thoracic Surgery in Sapporo because your President, Tomio Abe, is a valued friend and colleague who worked with me and my group as a Research Fellow at Washington U. from 1970-1973. He was recommended by Prof. Juro Wada, then the Chief in Sapporo. I was privileged to meet Prof. Wada at U.S. meetings. One of Prof. Wada's many contributions was the first cardiac transplant in Japan. Dr. Abe's work in St. Louis led to 12 publications and he was the first author of two papers. Since, his contributions expanded to more than 550 publications on treatment of complex congenital heart diseases, ventricular assistance, myocardial protection, valvular heart disease and aortic aneurysms. An operation for correction of Taussig-Bing malformation reported in 1984 is now referred to as the Abe operation. Torikata, in 1925, introduced "free thoracotomy" with no differential pressure. In 1933, Ohsawa successfully resected the esophagus with immediate reconstruction-the first in the world. Wada, in 1963, developed a thermodisc oxygenator and in 1966 the first tilting disc heart valve-the Wada Cutter Valve and other contributions as a worldwide ambassador for Japanese Surgery. Kawata, et al. showed better ventricular function after patch reconstruction of left ventricular aneurysms. Ueda, et al. revived retrograde cerebral perfusion for repair of aortic arch aneurysms. Nakayama, Akiyama and Isono made important contributions to esophageal cancer surgery. Kimoto, et al., in 1956, performed open cardiac surgery under direct vision with brain cooling by irrigation. Sakakibara, et al., Hikasa, et al., Atsumi, et al., and Takano and Akutsu made contributions to cardiac surgery. There were many other contributions by Japanese Surgeons.

Antithrombotic Therapy in Valvular Heart Disease—Native and Prosthetic

This chapter about antithrombotic therapy in native and prosthetic valvular heart disease is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients with rheumatic mitral valve disease and atrial fibrillation (AF), or a history of previous systemic embolism, we recommend long-term oral anticoagulant (OAC) therapy (target international normalized ratio [INR], 2.5; range, 2.0 to 3.0) [Grade 1C+]. For patients with rheumatic mitral valve disease with AF or a history of systemic embolism who suffer systemic embolism while receiving OACs at a therapeutic INR, we recommend adding aspirin, 75 to 100 mg/d (Grade 1C). For those patients unable to take aspirin, we recommend adding dipyridamole, 400 mg/d, or clopidogrel (Grade 1C). In people with mitral valve prolapse (MVP) without history of systemic embolism, unexplained transient ischemic attacks (TIAs), or AF, we recommended against any antithrombotic therapy (Grade 1C). In patients with MVP and documented but unexplained TIAs, we recommend long-term aspirin therapy, 50 to 162 mg/d (Grade 1A). For all patients with mechanical prosthetic heart valves, we recommend vitamin K antagonists (Grade 1C+). For patients with a St. Jude Medical (St. Paul, MN) bileaflet valve in the aortic position, we recommend a target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A]. For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, we recommend a target INR of 3.0 (range, 2.5 to 3.5) [Grade 1C+]. For patients with caged ball or caged disk valves, we suggest a target INR of 3.0 (range, 2.5 to 3.5) in combination with aspirin, 75 to 100 mg/d (Grade 2A). For patients with bioprosthetic valves, we recommend vitamin K antagonists with a target INR of 2.5 (range, 2.0 to 3.0) for the first 3 months after valve insertion in the mitral position (Grade 1C+) and in the aortic position (Grade 2C). For patients with bioprosthetic valves who are in sinus rhythm and do not have AF, we recommend long-term (> 3 months) therapy with aspirin, 75 to 100 mg/d (Grade 1C+).

Ten year clinical experience with the CarboMedics heart valve implants

We reviewed the histories of 144 patients who underwent heart valve replacement with the CarboMedics prosthesis from 1990 to 2000. There were 74 males and 70 females, with a mean age of 52 years, including 69 aortic valve replacements, 48 mitral valve replacements, and 27 double (aortic and mitral) valve replacements. The mean duration of follow-up was 6.5 years. Early mortality was 7.6% (11 patients). Late deaths occurred in 14 patients, including cardiac-related late deaths in 9 and valve-related deaths in 3. The survival rate including early deaths was 84.7 +/- 3.2% at 5 years and 78 +/- 4.1% at 10 years. Preoperative New York Heart Association Class IV (p = 0.0001) was found to be a significant predictor of cardiac-related late death. Freedom rate from complications at 10 years were embolism 84.7 +/- 4.2% (linearized rate 1.8% per patient year), valve thrombosis 92.7 +/- 2.7% (linearized rate 0.8% per patient year), bleeding 95.6 +/- 2.6% (linearized rate 0.4% per patient year), reoperation 85.9 +/- 4% (linearized rate 1.5% per patient year), valve endocarditis 98.7 +/- 1.3% (linearized rate 0.1% per patient year), and nonstructural dysfunction 90 +/- 3.5% (linearized rate 1% per patient year). There was no structural deterioration. The early and long-term results with the CarboMedics heart valve implantation were acceptable, but valve thrombosis remains a concern in the present study. Further investigation for optimal anticoagulation therapy is necessary to reduce the incidence of valve thrombosis as well as embolic and bleeding complications.

Ten years' experience of aortic valve replacement with the Omnicarbon valve prosthesis

BACKGROUND

There are few clinical studies on late follow-up of the Omnicarbon monoleaflet valve. We report our 10-year experience with this valve in the aortic position and also compare late hemodynamic performance of this valve with that of the CarboMedics valve in the aortic position.

METHODS

From January 1985 to June 1995, 117 consecutive patients underwent aortic valve replacement (AVR) with the Omnicarbon valve. There were 66 men and 51 women aged 13 to 69 years (mean age, 50 +/- 12 years). They were divided into three groups: group 1 (43 patients) had isolated AVR, group 2 (36) had AVR and concomitant operations, and group 3 (38) had combined AVR and mitral valve replacement. Follow-up was 96.6% complete and consisted of 882.7 patient-years (range, 2.5 to 10.6 years; mean follow-up, 7.5 +/- 2.7 years).

RESULTS

There were three early deaths (2.6%) and 18 late deaths (2.0%/patient-year) ten of which were due to valve-related causes and eight, non-valve-related causes. Survival rates at 10 years in groups 1, 2, and 3 were 77.6%, 82.4%, and 78.6%, respectively. The overall rates of freedom from valve-related complications in groups 1, 2, and 3 at 10 years were 77.4%, 100%, and 80.9%, respectively. The rates of freedom from the following complications in groups 1, 2, and 3 at 10 years were as follows: thromboembolism--94.8%, 100%, and 89.4%, respectively; valvar thrombosis--95.0%, 100%, and 100%; anticoagulant-related hemorrhage--93.6%, 100%, and 93.4%; prosthetic valve endocarditis--93.0%, 100%, and 97.2%; and reoperation--90.6%, 100%, and 97.2%. There were no significant differences between groups. All survivors showed marked improvement in New York Heart Association functional class, from 86% in classes III and IV preoperatively to 96% in classes I and II postoperatively. The Omnicarbon valve exhibited no significant difference in hemodynamic performance after isolated AVR compared with the CarboMedics bileaflet valve at the same follow-up periods.

CONCLUSIONS

This 10-year study confirms that the Omnicarbon valve is a durable prosthesis and provides excellent functional improvement with low rates of thromboembolism and valvar thrombosis in the aortic position.