Methods: This retrospective cohort study involved 168 patients (131 males, 37 females; mean age: 61.2±9.7 years; range, 51 to 72 years) undergoing isolated coronary artery bypass grafting surgery between December 2021 and December 2023. The study examined factors such as age, sex, comorbidities, blood test results, vaccination status, operative parameters, and postoperative complications. Patients" health records were reviewed to confirm the presence of previous COVID-19 pneumonia and vaccination status. Patients were divided into two groups based on their history of COVID-19 pneumonia: Group 1 included 140 who had not been diagnosed with COVID-19 pneumonia, and Group 2 included 28 patients who had a documented history of COVID-19 pneumonia. Postoperative pulmonary complications, including atelectasis, pleural effusion, acute respiratory distress syndrome, and pneumonia, were noted.

Results: Patients with a history of COVID-19 pneumonia (Group 2, n=28) demonstrated significantly higher seropositivity for COVID-19 (89.3% vs. 29.3%, p=0.001) compared to those without a history (Group 1, n=140). Although pulmonary complications were higher in Group 2 (17.9% vs. 3.6%, p=0.013), postoperative mortality rates did not differ significantly between the groups. Pleural effusion was markedly higher in Group 2 (14.3% vs. 2.1%, p=0.015). Vaccination did not significantly affect perioperative and postoperative outcomes, except for a minor difference in postoperative drainage volume.

Conclusion: This study highlights the impact of prior COVID-19 pneumonia on postoperative outcomes in coronary artery bypass grafting patients. Although there was a rise in pulmonary complications, the mortality rates stayed similar among individuals with and without a prior history of COVID-19 pneumonia. Vaccination did not significantly influence outcomes, emphasizing the need for further research with larger cohorts to validate and expand upon these findings.