A Retrospective Study to Collect the Data From the Patients Who Had the Perimount Heart Valve Replacement Surgery in China During 2001 to 2007

The objective of the study is to obtain the clinical data from patients who had the Perimount Heat Valve (Type:6900P and 2900) Replacement Surgery in Guangdong General Hospital during 2001-2007 in order to evaluate the performace of this heart valve prothesis and collect the patients' post-operation infomation including the current living status, mortality rate, and the possibility of re-operation，bleeding and thrombosis. This is a retrospective , observentional clinical study to be conducted in Guangdong General Hospital in China. This study will enroll up to 200 patients.