ObjectiveTo systematically evaluate the risk factors of new-onset atrial fibrillation (NOAF) after off-pump coronary bypass grafting (OPCABG). MethodsPubMed, EMbase, Web of Science, The Cochrane Library, Wanfang data, CBM, VIP, and CNKI databases were systematically searched by computer to collect studies related to the risk factors for NOAF after OPCABG from the establishment of the database to July 2023. Literature screening and quality evaluation were conducted independently by two researchers. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the literature. RevMan 5.3 software and Stata15.0 software were used for meta-analysis. ResultsFinally, 19 case-control studies related to the risk factors for NOAF after OPCABG were included, all of which were high-quality literature with NOS total score≥6 points, with a total of 7019 subjects. The results of meta-analysis showed that: (1) the patient's own factors: age (MD=3.51, 95%CI 2.39 to 4.63, P<0.01), history of hypertension (OR=1.17, 95%CI 1.04 to 1.32, P=0.01), history of myocardial infarction (OR=1.21, 95%CI 1.06 to 1.38, P<0.01), history of percutaneous coronary intervention (OR=2.22, 95%CI 1.03 to 4.77, P=0.04); (2) preoperative factors: EuroSCOREⅡ score (MD=0.59, 95%CI 0.25 to 0.94, P<0.01), low density lipoprotein (MD=0.11, 95%CI 0.02 to 0.20, P=0.02), left atrial diameter (MD=1.64, 95%CI 0.24 to 3.04, P=0.02); (3) postoperative and treatment factors: left ventricular end-diastolic diameter (MD=1.16, 95%CI 0.33 to 1.99, P<0.01), left ventricular ejection fraction (MD=0.90, 95%CI 0.07 to 1.73, P=0.03), mechanical ventilation time (MD=2.78, 95%CI 1.65 to 3.90, P<0.01), B-type natriuretic peptide (MD=219.67, 95%CI 27.46 to 411.88, P=0.03), ICU retention time (MD=7.07, 95%CI 5.64 to 8.50, P<0.01) were associated with NOAF after OPCABG. ConclusionThe existing evidence shows that age, history of hypertension, history of myocardial infarction, history of percutaneous coronary intervention, preoperative EuroSCOREⅡscore, preoperative low-density lipoprotein, preoperative left atrial diameter, postoperative left ventricular end-diastolic diameter, postoperative left ventricular ejection fraction, postoperative mechanical ventilation time, postoperative B-type natriuretic peptide, and postoperative ICU retention time are all risk factors for NOAF after OPCABG. Clinical attention should be paid to the above factors and early identification to reduce the incidence of NOAF after OPCABG, and improve the clinical prognosis of patients.