Study Design and Subjects
This was a retrospective, matched cohort study using data from the Hua-Shan Cardiac Surgery Registry. The consecutive coronary artery disease patients aged ≥ 18 years who were underwent OPCAB procedures between 01 January 2016 and 31 December 2019 were enrolled. OPCAB were performed by one fully trained cardiac surgeon team, whose members had already performed a minimum of 50 off-pump operations. To be included, eligible patients had to have continuous medical record during preoperative, intraoperative and postoperative period. Patients were excluded if they were unable to understand given information or were reluctant to participate, had resection of ventricular aneurysm or re-do cardiac surgery, were technically not feasible for OPCAB, and had other logistic reasons that made routine follow up impossible.
Preoperatively, patient demographics were recorded. Patients were divided into two cohorts determined by left ventricular ejection fraction using the transthoracic echocardiogram: the left ventricular dysfunction (LVD) cohort consisted of those who had LVEF<50%, and the normal left ventricular function (NLVF) cohort included patients had LVEF≥50%. Intraoperative variables were documented for all cohorts. All the eligible patients were periodically followed by on-site visit, telephone call or mailed questionnaire up to 31 June 2020. During on-site follow up, the computed tomographic angiography (CTA) or digital subtraction angiography (DSA) were used to assess the graft and echocardiography were used to measure the ventricular chamber size and LVEF. The blood pressure, lipid profile and blood glucose level of patients, which were directly associated with middle and long-term outcomes of grafts, were monitored. Patients reported events of clinical interest were collected and assessed systematically during follow up stages.
The present study was approved by the Ethic Committee of Hua Shan Hospital and conducted in concordance with Good Clinical Practice.