Changes in Circulating Inflammatory and Cardiac Biomarkers at Three-Month Follow-Up After CABG

Background. Biomarkers associated with inflammation and the cardiovascular system are altered during the perioperative and immediate postoperative periods after coronary artery bypass grafting (CABG) but less is known about the changes occurring during the intermediate recovery phase. We measured levels of 7 inflammatory and cardiovascular biomarkers in CABG patients between the preoperative phase and follow-up three months after hospital discharge. We hypothesized that the circulating inflammatory and cardiac biomarker profile at three-month follow-up would differ from the preoperative profile. Methods. A prospective longitudinal observational cohort included 45 adults who underwent elective coronary artery bypass grafting between May 2025 and February 2026; 40 subjects had analyzable paired preoperative and three-month post-discharge biomarker samples. Plasma levels of the inflammatory and cardiovascular biomarkers, including high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), interleukin-18 (IL-18), resistin, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) were measured on the day before surgery and at three-month follow-up after hospital discharge. Results. The analyzed cohort had a median age of 69.0 years and included 33 men (82.5%). Following correction for multiple testing, only IL-18 (from 119.6 [87.9-155.0] to 163.6 [111.9-228.0], p = 0.007 [adjusted p = 0.025]) and NT-proBNP (221.0 [135.3-424.8] to 372.6 [213.4-632.0], p = 0.001 [adjusted p = 0.007]) had statistically significant longitudinal increases. Secondary mixed-effects model analyses produced directionally consistent results, with follow-up-to-baseline ratios of 1.26 [95% confidence interval (CI) 1.05-1.52; p = 0.015] for IL-18 and 1.48 [95% CI 1.15-1.90; p = 0.003] for NT-proBNP. The levels of hsCRP, TNF-α, IL-6, resistin and cTnI did not change significantly over time. Conclusions. At three months after discharge, significant increases were confined to IL-18 and NT-proBNP rather than occurring across the broader circulating biomarker panel. These findings extend the limited prospective evidence on intermediate post-CABG biomarker changes and support further evaluation of IL-18 and NT-proBNP as candidate markers of postoperative recovery.