Patient population, Study Design and Outcome Measures
The PC-ECMO registry is a multicenter observational study enrolling patients undergoing VA-ECMO following adult cardiac surgery at 19 centers from Belgium, Czech Republic, Finland, France, Germany, Italy, Saudi Araba, Sweden, and the United Kingdom from January 2010 to March 2018. The present study is registered in Clinicaltrials.gov (Identifier: NCT03508505), and its detailed protocol with definition criteria have been previously published [5]. Briefly, patients aged ≥18 years who required VA-ECMO for PCS following cardiac surgery were included. Exclusion criteria encompassed patients with preoperative VA-ECMO, patients with descending thoracic aorta repair, or those receiving VA-ECMO after implantation of ventricular assist device or heart transplantation. Patients without baseline data on arterial lactate level at the start of VA-ECMO were also excluded from the present analysis because of its impact on patient outcome. The primary end-point was in-hospital mortality. The study complies with the Strengthening the Reporting of Observational Studies in Epidemiology reporting requirements for observational studies (Supplemental Table 1) [10].