Mitochondrial DNA Copy Number Is Increased in Plasma and Associated with Postoperative Complications After Coronary Artery Bypass Grafting

To determine the mtDNA-copy number in the blood of patients before and within 10 days after coronary artery bypass grafting (CABG), and to assess the association between mtDNA-copy number and the postoperative complications was aims of this study. Methods. This single-center, prospective, non-blinded study enrolled 26patients who underwent CABG, with a median age of 67 years (IQR: 58-71). Blood plasma and peripheral blood mononuclear cells (PBMCs) were collected from patients before CABG and at 3, 5, 7, and 10 days post-CABG. Mitochondrial DNA copy number was measured using digital PCR. Results. In plasma, the median mtDNA-copy number was 5.12(3.35-7.44) million copies per mL before CABG, 2.65 (1.88-3.04) on 3rd day, 4.04 (2.28-7.00) on 5th day, 6.50 (3.47-11.31), on 7th day, and 10 (7.2-13.4) on 10th day. The median mtDNA-copy number in PBMCs was 79 (63.5-95.2) copies per cell before CABG and did not significantly change post-CABG (р>0.05). Patients with complications had a significantly increased plasma mtDNA-copy number (198%; interquartile range: 101; 321%) compared with patients without complications (11%; interquartile range: -36; 127%; p = 0.008). Conclusions. Increases mtDNA-copy number by 10th day post-CABG is associated with postoperative complications. The mtDNA-copy number in PBMCs did not significantly change after CABG. Clinical Trial registration: The study protocol was registered at ClinicalTrials.gov: NCT05770349. Registration date 02/21/2023.