Cardiac surgery elicits pericardial inflammatory responses that are distinct compared with postcardiopulmonary bypass systemic inflammation

Ali Fatehi Hassanabad; Friederike I Schoettler; William D T Kent; Corey A Adams; Daniel D Holloway; Imtiaz S Ali; Richard J Novick; Muhammad R Ahsan; Robert Scott McClure; Ganesh Shanmugam; William T Kidd; Teresa M Kieser; Paul W M Fedak; Justin F Deniset

doi:10.1016/j.xjon.2023.06.022

Cardiac surgery elicits pericardial inflammatory responses that are distinct compared with postcardiopulmonary bypass systemic inflammation

JTCVS Open. 2023 Jul 27:16:389-400. doi: 10.1016/j.xjon.2023.06.022. eCollection 2023 Dec.

Authors

Ali Fatehi Hassanabad^{1

2}, Friederike I Schoettler^{1

2

3}, William D T Kent^{1

2}, Corey A Adams^{1

2}, Daniel D Holloway^{1

2}, Imtiaz S Ali^{1

2}, Richard J Novick^{1

2

4}, Muhammad R Ahsan^{1

2}, Robert Scott McClure^{1

2}, Ganesh Shanmugam^{1

2}, William T Kidd^{1

2}, Teresa M Kieser^{1

2}, Paul W M Fedak^{1

2}, Justin F Deniset^{2

5}

Affiliations

¹ Section of Cardiac Surgery, Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
² Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
³ Department of Cardiac Surgery, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany.
⁴ Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
⁵ Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.

Abstract

Objectives: Cardiac surgery using cardiopulmonary bypass contributes to a robust systemic inflammatory process. Local intrapericardial postsurgical inflammation is believed to trigger important clinical implications, such as postoperative atrial fibrillation and postsurgical intrathoracic adhesions. Immune mediators in the pericardial space may underlie such complications.

Methods: In this prospective pilot clinical study, 12 patients undergoing isolated coronary artery bypass graft surgery were enrolled. Native pericardial fluid and venous blood samples (baseline) were collected immediately after pericardiotomy. Postoperative pericardial fluid and venous blood samples were collected 48-hours after cardiopulmonary bypass and compared with baseline. Flow cytometry determined proportions of specific immune cells, whereas multiplex analysis probed for inflammatory mediators.

Results: Neutrophils are the predominant cells in both the pericardial space and peripheral blood postoperatively. There are significantly more CD163^lo macrophages in blood compared with pericardial effluent after surgery. Although there are significantly more CD163^hi macrophages in native pericardial fluid compared with baseline blood, after surgery there are significantly fewer of these cells present in the pericardial space compared with blood. Postoperatively, concentration of interleukin receptor antagonist 6, and interleukin 8 were significantly higher in the pericardial space compared with blood. After surgery, compared with blood, the pericardial space has a significantly higher concentration of matrix metalloproteinase 3, matrix metalloproteinase 8, and matrix metalloproteinase 9. The same trend was observed with transformational growth factor β.

Conclusions: Cardiac surgery elicits an inflammatory response in the pericardial space, which differs from systemic inflammatory responses. Future work should determine whether or not this distinct local inflammatory response contributes to postsurgical complications and could be modified to influence clinical outcomes.

Keywords: cardiac surgery; cardiopulmonary bypass; inflammation; pericardial space.