Introduction: Long-term comorbidity care for gastric cancer survivors has been emphasized to decrease mortality as well as the development of metabolic disease and cardiovascular diseases. However, evidence is scarce on the risk factors affecting the risks of adverse cardiovascular events in patients with gastric cancer. Methods: A nationwide cohort by the National Health Insurance Service in Korea was utilized. Patients who received gastrectomy or endoscopic submucosal dissection (ESD) for gastric cancer between 2004 and 2013 were identified. An adverse cardiovascular event was defined as a composite of acute myocardial infarction, coronary revascularization, or ischemic stroke. Fine and Gray method was used to evaluate associations between variables including treatment methods (subtotal or total gastrectomy, ESD) age, sex, body mass index (BMI), lifestyle, and comorbidities. Results: A total of 41,905 patients treated for gastric cancer (mean age, 60.9 ± 11.0 years; female, 26.6%) were included. The incidence of adverse cardiovascular events was 9.0 cases per 1000 person-years. In multivariable models, patients who received a total (hazard ratio [HR], 2.64; 95% confidence interval [CI]; 2.44 to 2.85; P < 0.001) or subtotal gastrectomy (HR, 1.38; 95% CI, 1.28 to 1.48; P < 0.001) had a higher risk of adverse cardiovascular events than those who received ESD (Figure). Adjuvant chemotherapy also increased the cardiovascular risk with an HR of 1.30 (95% CI, 1.12 to 1.51; P= 0.001). Current smokers had a higher risk of adverse cardiovascular events (HR, 1.25; 95% CI, 1.19 to 1.31; P< 0.001), and regular exercise was a preventive factor in a dose-dependent manner (14% decreased risk in patients with 1-4 days of exercise per week and 17% decreased risk in those with ≥5 days of exercise per week compared to those who do not exercise). Higher age, male, lower BMI, smoking, low income, and the presence of hypertension, diabetes, chronic kidney disease, and heart failure were independent predictors of adverse cardiovascular events (Figure). Conclusion: We identified independent predictors of adverse cardiovascular events in patients who received treatment for gastric cancer. Experimental studies to improve modifiable risk factors are needed to confirm these findings and develop post-cancer treatment strategies to prevent adverse cardiovascular events.Figure 1.: Multivariable analysis of associations between demographic characteristics, treatment methods, lifestyle variables, comorbidities, and the risk of adverse cardiovascular events in patients who are treated for gastric cancer.