2.4 Assessment of baseline profile, follow-up, and outcomes
Patients received warfarin for anticoagulation for 6 months after operation in accordance with published guideline13 and were followed up for one year after operation.
The primary outcome included indexed EOA and mean gradient, which were assessed by hemodynamic performance at 30 days, 3 months, 6 months and 1 year after operation.
Secondary outcomes were perioperative data and early clinical outcomes, included transfusion requirement, mechanical ventilation time, length of ICU and hospital stay, reoperation, PVL, perioperative comobidities, prosthesis-related mortality and all-cause mortality. Among them, major bleeding event was defined as blood loss of more than 500 ml within 1 hour or 200 ml per hour for 3 hours or more. Cardiac tamponade and degree of PVL were determined by echocardiography. Diagnosis of myocardial infarction was based on the elevation of high-sensitivity cardiac troponin T and creatine kinase isoenzyme, the onset of new pathologic Q-waves or new left bundle branch block, or the imaging evidence of new wall motion abnormality.14-15The cerebrovascular accident was determined by CT or magnetic resonance imaging (MRI) of the head in the presence of new onset of neurological deficit. Diagnosis of endocarditis was based on the scientific statement from American Heart Association.16 Respiratory failure was defined as partial pressure of oxygen in arterial blood (PaO2) < 60 mmHg.