Factors Associated with Adverse Cardiovascular Events After Coronary Artery Bypass Grafting and Their Relationship with Left Atrial Function: A Retrospective Cohort Study

Background: This study aimed to investigate clinical and echocardiographic factors associated with major adverse cardiovascular events (MACE) following coronary artery bypass grafting (CABG), with particular emphasis on the association between MACE and preoperative left atrial function.

Methods: This retrospective cohort study included 198 patients with coronary heart disease (CHD) who underwent CABG at our hospital between October 2020 and June 2023. The primary endpoint was the first occurrence of postoperative MACE within 24 months after CABG. Patients were divided into a MACE group (n=92) and a non-MACE group (n=106). Baseline characteristics, echocardiographic parameters, and laboratory indicators were compared between groups. Candidate variables were screened using least absolute shrinkage and selection operator (LASSO) regression, and the selected variables were entered simultaneously into a multivariable Cox proportional hazards regression model. Receiver operating characteristic (ROC) curves and area under the curve (AUC) values were used for exploratory evaluation of the discrimination of left atrial strain parameters.

Results: Significant differences were observed between the MACE and non-MACE groups in age, prevalence of hypertension, American Society of Anesthesiologists (ASA) classification, left atrial reservoir strain (LASr), left atrial conduit strain (LAScd), left atrial contraction strain (LASct), cardiac troponin I (cTnI), and brain natriuretic peptide (BNP) levels (P < 0.05). LASSO regression retained seven variables: hypertension, ASA classification, LASr, LAScd, LASct, cTnI, and BNP. In the multivariable Cox model, LAScd [hazard ratio (HR)=0.904] and LASct (HR=0.880) were associated with a lower hazard of MACE after CABG, whereas cTnI (HR=1.227), BNP (HR=1.009), and ASA classification (HR=1.908) were associated with a higher hazard of MACE after CABG. ROC curve analysis showed AUC values of 0.716 and 0.793 for LAScd and LASct, respectively. Their sensitivities were 0.481 and 0.689, and their specificities were 0.924 and 0.783, respectively.

Conclusions: Preoperative left atrial function, cTnI, BNP, and ASA classification were associated with MACE occurrence after CABG. LAScd and LASct may serve as adjunctive markers for postoperative risk stratification, but their clinical use requires validation in larger prospective cohorts.