Heart disease mortality in cancer survivors: A population-based study in Japan

Background The association between cancer survivors and heart disease mortality remains unclear. This study analyzed the risk of fatal heart disease in cancer survivors. Methods Data from the Osaka Cancer Registry collected between 1985 and 2013 and data from the vital statistics in Japan were retrospectively analyzed. Causes of death were investigated. Standardized mortality ratios (SMRs) were calculated to compare the risk of fatal heart disease between patients with cancer and the general population. Poisson regression models were used to estimate the risk of fatal heart disease in patients with cancer and other cancer subgroups. Results In total, 688,473 cancer patients were included in the analysis, and 337,117 patients died during the study period. Among them, 10,781 patients died of heart disease, with 5,020 of these patients having ischemic heart disease; 3,602 patients, heart failure; 441 patients, hypertensive disease; and 1,718 patients, other heart diseases. The SMR (95% confidence interval [CI]) for heart disease was 2.85 (2.80–2.91). The SMRs (95% CIs) for ischemic heart disease, heart failure, and hypertensive disease were 3.26 (3.17–3.35); 2.69 (2.60–2.78), and 4.47 (4.07–4.90), respectively. The risk of fatal heart disease increased over time after cancer diagnosis. The multivariable Poisson regression model showed that males were more likely to die of heart disease than females (relative risk, 1.39; 95% CI, 1.34–1.45). Notably, the risk of fatal heart disease among cancer survivors has decreased in recent years. Conclusions Cancer survivors have a higher risk of fatal heart disease than the general population.