Atrial fibrillation after coronary artery bypass grafting: analysed impact of coronary artery calcification

Relevance. Atrial fibrillation (AF) is a significant problem in the postoperative period of coronary artery bypass grafting. The genesis of arrhythmia is not clear despite numerous studies. Identifying patients at high risk of postoperative AF remains a difficult and urgent task.

Aim. To evaluate the influence of coronary calcinosis and the corresponding surgical features of coronary artery bypass grafting on the occurrence of de novo atrial fibrillation in the postoperative period.

Materials and methods. The study included 35 patients with diffuse multivessel coronary disease, without a history of AF, aged 66±7 years; 77% were male patients. We preoperatively assessed the summed index of calcified lesions (SICL) and then its role in the occurrence of postoperative AF. There were two study groups: patients without AF (n=21) - no paroxysm of AF after CABG was registered - and patient with AF (n=14) - AF was detected in the postoperative period. We separately analysed patients’ findings in the subgroup of patients with SIBC> 12 points. Postoperative rhythm was assessed in the following way: daily ECG recording, continuous bedside ECG monitoring for up to 3 days, ECG Holter on the 4th-5th day after CABG. The median follow-up was 9 (7; 11) days.

Results. Having analyzed the frequency of postoperative AF in the group of patients with a diffuse type of lesion, and separately in the group of patients with a diffuse type of lesion and severe calcification, we detected the highest parameter in the latter - 40% vs 56%, respectively. Clinical, demographic and intraoperative parameters of CABG in the groups without AF and with AF were comparable. Echo parameters in the studied groups were also equivalent. It was found that the value of the summarized index of calcified coronary artery lesion more than 12 points determines the tendency for AF to occur in the postoperative period; OR = 3.60, 95% CI 0.870-14.904, p = 0.072.

Conclusions. Commonly accepted echo parameters (the left atrium size and volume) do not reflect the risks de novo of atrial fibrillation after coronary bypass surgery. The data of this study demonstrated that for patients with severe calcified coronary lesions, who underwent surgery using complex technical techniques, an increased frequency of postoperative AF is common in the postoperative period. Further studies are needed to assess the impact of the morphological type and severity of atherosclerotic lesions of the coronary arteries, as well as the corresponding technical features of coronary artery bypass grafting on the risk of AF after CABG; such an assessment will make a significant contribution to the potential prediction of the postoperative atrial fibrillation development.