Objective To investigate the incidence and associated factors of postoperative cardiac complications in elderly patients with lung cancer. MethodsClinical data of elderly patients (age≥60 years) who underwent pulmonary resection for lung cancer at the Department of Thoracic Surgery, Beijing Hospital, from 2019 to 2022 were retrospectively analyzed. Based on the occurrence of cardiac complications (including arrhythmias, myocardial injury, and heart failure) between surgery and hospital discharge, the patients were divided into a complication group and a non-complication group. Univariate analysis was performed for the initial screening of variables. After addressing missing data using multiple imputation, a Firth’s bias-corrected multivariable logistic regression model was employed to identify independent associated factors for postoperative cardiac complications. Results There were 270 patients in the entire cohort, including 123 (45.6%) males and 147 (54.4%) females, with a median age of 71.0 (65.0, 77.0) years. The incidence of postoperative cardiac complications was 20.0% (54/270). Univariate analysis showed that age, pulmonary hypertension, pleural adhesion, and intraoperative blood transfusion were positively associated with postoperative cardiac complications, whereas body mass index (BMI) and a family history of cancer showed an inverse association (all P<0.05). Multivariable analysis further demonstrated that BMI was inversely associated with the incidence of postoperative cardiac complications [adjusted odds ratio (aOR)=0.868, 95%CI (0.778, 0.968), P=0.011], indicating that a lower BMI is an independent risk factor; pleural adhesion showed a positive association [aOR=2.130, 95%CI (1.104, 4.107), P=0.024]; and a family history of cancer exhibited an exploratory inverse association [aOR=0.249, 95%CI (0.068, 0.912), P=0.036]. ConclusionAmong elderly patients undergoing surgery for lung cancer, a lower BMI and the presence of pleural adhesion are independent risk factors for a higher incidence of postoperative cardiac complications, whereas a family history of cancer demonstrates an exploratory inverse association. In clinical practice, a comprehensive evaluation incorporating the patient's nutritional and functional reserves, as well as the extent of pleural adhesion, is recommended, alongside vigilant monitoring for early postoperative cardiac complications. The findings regarding a family history of cancer should be interpreted with caution, and all the above findings warrant further validation through large-scale, multicenter, prospective studies.