The importance of mean platelet volume to lymphocyte ratio in predicting atrial fibrillation after coronary bypass operations

Abstract

Background/Aim: The rate of postoperative atrial fibrillation (PoAF) after coronary artery bypass graft (CABG) operations ranges between 25-40%. Inflammation plays an important role in the pathogenesis of PoAF, and mean platelet volume and lymphocyte count are important inflammatory parameters. This study aimed to investigate the importance of the mean platelet to lymphocyte ratio (MPVLR) in predicting PoAF after CABG operations. Methods: Three hundred and eighty consecutive patients who underwent on-pump CABG in our clinic between August 2016 and August 2020 were included in this retrospective observational cohort study. Patients with a known history of atrial fibrillation, reoperations, emergency operations, patients who had acute coronary syndrome within the last month, combined surgeries, those with systemic inflammatory disease, chronic autoimmune disease, chronic liver/kidney disease, and hematological diseases, and patients under steroid therapy were excluded from the study. Patients who did not develop postoperative PoAF were included in Group 1, while those who did were included in Group 2. Results: There were 319 patients in Group 1 with a median age of 59 (32-83) years, and 61 patients in Group 2, with a median age of 66 (38-86) years (P<0.001). There was no difference between the groups in terms of gender distribution, hypertension (HT), diabetes mellitus (DM), smoking, body mass index, hyperlipidemia, ejection fraction, and current medical treatments (such as Angiotensin-converting enzyme inhibitor and beta-blocker therapy). The rate of chronic obstructive pulmonary disease (P=0.017), as well as MPV, MPVLR, intensive care unit stay and total hospitalization times were significantly higher (P<0.001 for all) in Group 2, while lymphocyte levels were significantly lower (P=0.006). Based on multivariate analysis, being over 70 years old (OR: 2.432, CI 95%: 1.966-3.723, P<0.001), having an ejection fraction below 35% (OR: 1.325, CI 95%: 1.190-1.1894, P=0.021) and MPVLR (OR: 1.821, 95%CI: 1.645-2.1592, P<0.001) were independent predictors of PoAF. Conclusion: We found that the preoperative MPVLR value, which can be obtained from a simple hemogram test, is an important predictor of PoAF in patients who underwent CABG. MPVLR value can be a marker in determining risky groups preoperatively.