Supplementary Material for: Association of Cancer and Its Interaction with Conventional Risk Factors on Cardiovascular Disease Risk

Introduction We sought to examine the association of cancer history with the incidence of individual cardiovascular disease events and to clarify whether the history of cancer modifies the relationship between conventional cardiovascular risk factors and incident cardiovascular disease.
Methods This retrospective cohort study used the JMDC Claims Database, including 3,531,683 individuals. The primary endpoint was the composite cardiovascular disease outcome, which included myocardial infarction, angina pectoris, stroke, heart failure, and atrial fibrillation.
Results During a follow-up, 144,162 composite endpoints were recorded. Individuals with a history of cancer had a higher risk of developing composite cardiovascular disease events (HR 1.26, 95% CI 1.22-1.29). The HRs for myocardial infarction, angina pectoris, stroke, heart failure, and atrial fibrillation were 1.11 (95% CI 0.98-1.27), 1.15 (95% CI 1.10-1.20), 1.11 (95% CI 1.05-1.18), 1.39 (95% CI 1.34-1.44), and 1.22 (95% CI 1.13-1.32), respectively. Individuals who required chemotherapy for cancer had a higher risk of developing cardiovascular disease. Although conventional risk factors (e.g., overweight/obesity, hypertension, and diabetes) were associated with incident composite cardiovascular disease even in individuals with a history of cancer, the total population-attributable fractions of conventional risk factors were less in individuals with a history of cancer.
Conclusion Individuals with a history of cancer (particularly those requiring chemotherapy) have a higher risk of cardiovascular disease. Traditional risk factors are important in the development of cardiovascular disease in individuals with and without a history of cancer. In individuals with a history of cancer, however, the total population-attributable fractions of conventional risk factors decreased.