Objective To investigate the association between D-dimer levels within 2 hours of admission and in-hospital major adverse events (MAEs) in patients with acute type A aortic dissection (ATAAD) who underwent total arch replacement combined with frozen elephant trunk (FET) implantation. Methods This retrospective study included patients with ATAAD who underwent total arch replacement with FET implantation at Fuwai Yunnan Cardiovascular Hospital from September 2017 to December 2022. Patients were divided into two groups based on the occurrence of in-hospital MAEs: a MAEs group and a non-MAEs group (control). Perioperative data were compared between the two groups. Univariate and multivariate logistic regression analyses were performed to identify risk factors for in-hospital MAEs, which included in-hospital death, gastrointestinal bleeding, paraplegia, acute kidney injury, low cardiac output syndrome, stroke, respiratory failure, multiple organ dysfunction syndrome, and severe infection. The predictive value of D-dimer was evaluated using the area under the receiver operating characteristic curve (AUC). Results A total of 218 patients were included (157 males, 61 females), with a mean age of (51.54±9.79) years. There were 152 patients in the non-MAEs group and 66 in the MAEs group. The overall incidence of in-hospital MAEs was 30.3%, and the in-hospital mortality rate was 2.8% (6/218). Compared to the non-MAEs group, the MAEs group had significantly higher levels of D-dimer and lactate, as well as longer cardiopulmonary bypass time, aortic cross-clamp time, and ICU length of stay (all P<0.05). Multivariate logistic regression analysis identified D-dimer as an independent risk factor for in-hospital MAEs [OR=1.077, 95%CI (1.020, 1.137), P=0.013]. The AUC for the D-dimer level within 2 hours of admission to predict in-hospital MAEs was 0.83 [95%CI (0.736, 0.870), P<0.001]. The optimal cutoff value was 2.2 μg/mL, with a sensitivity of 84.8% and a specificity of 73.0%. Conclusion The serum D-dimer level is an independent risk factor for in-hospital MAEs in patients with ATAAD following total arch replacement with FET implantation. D-dimer levels on admission can help clinicians optimize risk stratification and perioperative management, potentially reducing the incidence of early adverse events.