Study design and data collection:
The study is a retrospective propensity score matched study that was conducted at a tertiary Cardiac center It included adult patients above or equal to 18 years who underwent any cardiac surgery with cardiopulmonary bypass, had congestive heart failure (either decreased left ventricular EF or severe left-sided valvular heart disease (based on transthoracic echocardiography) and had preoperative PFT during the time period from May 2015 to December 2019. Patients who did not have preoperative PFT were excluded from the study.
Data were collected on patients’ demographics, preoperative PFT parameters, operative data and postoperative data and complications from electronic medical records. Echocardiographic parameters were obtained from the echocardiographic laboratory databases.
The pulmonary functions test results were classified into obstructive or restrictive patterns and then classified in severity according to the American Thoracic Society (ATS) grading system 6,7. The patients were divided into two groups: Group 1; who had a normal or mild reduction in PFT and Group 2; who had moderate to severe reduction in PFT. The postoperative outcomes, including pulmonary complications, were compared between the two groups.
The Institutional Review Board approved the data collection of this study, and they waived the need for patients’ consent because of the retrospective nature of the study.