Evaluation of inflammatory processes in the pleura following cardiac surgery in patients with coronary artery disease

The accumulation of fluid in the pleural cavity is one of the most common multifactorial complications after cardiac surgery; the incidence of this condition varies from 23% to 50%. Leading role in the development of this condition plays the inflammation process in the pleura. To date, there are no laboratory methods for the qualitative and quantitative assessment of the severity of inflammation of the pleura. The aim of the present work was to study the activity of matrix metalloproteinase-9 isozyme (mmp-9) in the pleural fluid for qualitative and quantitative assessment of inflammation in the pleural cavity in patients after cardiac surgery. The study included 54 patients with coronary artery disease who underwent heart bypass surgery. In the early postoperative period, screening ultrasound examinations of pleural cavities were carried out. Patients were divided into two groups: group 1 (n=25; 46.2%) consisted of patients who required only one thoracentesis procedure; group 2 (n=29; 53.7%) consisted of patients who required more than 1 thoracentesis procedures. Amount of pleural fluid removed during one procedure, incidence of atelectasis, and LDH plasma-pleural effusion gradient did not significantly differ between groups. At the same time, there was statistically significant tendency to differences in the concentration of pro-mmp-9 enzyme in patients of group 1 and group 2: 0.376+0.012 ng/mL and 0.501+0.024 g/mL, respectively (p=0.004). Detection of mmp-9 concentrations in punctate from the pleural cavity provides the way for quantitative and qualitative evaluation of the inflammatory changes in the pleura in patients after cardiac surgery.