Cardiovascular events in cancer patients with bone metastases—A Danish population‐based cohort study of 23,113 patients

INTRODUCTION: The incidence of cardiovascular events among cancer patients with bone metastases is poorly understood. We examined rates of cardiovascular events among cancer patients with bone metastases and mortality following such events. METHODS: Using Danish health registries, we identified all Danish cancer patients diagnosed with bone metastases (1994–2013) and followed them from bone metastasis diagnosis. We computed incidence rates (IR) per 100 person‐years and cumulative incidence for first‐time inpatient hospitalization or outpatient clinic visit for cardiovascular events, defined as myocardial infarction, ischemic stroke, or venous thromboembolism (VTE). We also analyzed all‐cause mortality rates including cardiovascular events as time‐varying exposure with adjustment for age, sex, and Charlson Comorbidity Index score. All analyses were performed overall and stratified by cancer type (prostate, breast, lung, and other). RESULTS: We included 23,113 cancer patients with bone metastases. The cumulative incidence of cardiovascular events was 1.3% at 30 days, 3.7% at 1 year, and 5.2% at 5 years of follow‐up. The highest IR was observed for VTE, followed by ischemic stroke and myocardial infarction, both overall and by cancer types. Lung cancer patients with bone metastases had the highest incidence of cardiovascular events followed by prostate and breast cancer. Occurrence of any cardiovascular event was a strong predictor of death (5 years following the event, the adjusted hazard ratio was 1.8 [95% confidence interval: 1.7–1.9]). CONCLUSION: Cancer patients with bone metastases had a substantial risk of developing cardiovascular events, and these events were associated with a subsequent increased mortality. Our findings underscore the importance of continuous optimized prevention of and care for cardiovascular disease among cancer patients with bone metastases.