Risk of cardiovascular disease in cancer survivors: A cohort study of 446,384 New Zealand primary care patients

BACKGROUND: Given advances in the management of cancer, it is increasingly important for clinicians to appropriately manage the risk of cardiovascular disease (CVD) among cancer survivors. It is unclear whether CVD risk is increased among cancer survivors overall, and there is inconsistency in evidence to date about CVD incidence and mortality by cancer type. METHODS: Patients aged 30‐74 years entered an open cohort study at the time of first CVD risk assessment, between 2004 and 2018, in primary care in New Zealand. Patients with established CVD or cancer within 2 years prior to study entry were excluded. Cancer diagnosis (1995–2016) was determined from a national cancer registry. Cause‐specific hazard models were used to examine the association between history of cancer and two outcomes: (1) CVD‐related hospitalization and/or death and (2) CVD death. RESULTS: The study included 446,384 patients, of whom 14,263 (3.2%) were cancer survivors. Risk of CVD hospitalization and/or death was increased among cancer survivors compared with patients without cancer at cohort entry (multivariable‐adjusted hazard ratio, mHR, 1.11, 95% CI 1.05‐1.18), more so for CVD death (1.31, 1.14‐1.52). Risk of CVD hospitalization and/or death was increased in patients with myeloma (2.66, 1.60‐4.42), lung cancer (2.19, 1.48‐3.24) and non‐Hodgkin lymphoma (1.90, 1.42‐2.54), but not for some cancers (e.g., colorectal, 0.87, 0.71‐1.06). Risk of CVD death was increased in several cancer types including melanoma (1.73, 1.25‐2.38) and breast cancer (1.56, 1.16‐2.11). CONCLUSION: CVD risk management needs to be prioritized among cancer survivors overall, and particularly in those with myeloma, lung cancer and non‐Hodgkin lymphoma given consistent evidence of increased risk.