Incidence rates of cardiovascular outcomes in a community‐based population of cancer patients

BACKGROUND: There are limited data on the incidence of cardiovascular disease among cancer patients in the pre‐tyrosine kinase inhibitor (TKI) era. Such data are important in order to contextualize the incidence of various cardiovascular outcomes among cancer patients enrolled in clinical trials of new agents and for postmarketing surveillance. METHODS: A retrospective cohort study was conducted using data from the Kaiser Permanente Northern California (KPNC) population of cancer patients. The inclusion criterion was a KPNC Cancer Registry diagnosis of any of several selected solid and hematologic tumors between 1997 and 2009 not treated with a TKI. Endpoints were identified using ICD‐9 codes and included acute coronary syndrome, heart failure, stroke, cardiac arrest, hypertension, venous thromboembolism, all‐cause mortality, and cardiovascular mortality. Event rates were calculated according to type of cancer and number of cardiovascular risk factors. RESULTS: The study included almost 165 000 individuals with a broad variety of tumor types. The parent cohort was 54% female and 35% were ≥70 years old. Cardiovascular risk factors such as diabetes mellitus (14% of patients with solid tumors, 15% of patients with liquid tumors), dyslipidemia (33%, 31%), hypertension (50%, 49%), and smoking (35%, 32%) were common. The most frequent adverse outcomes were incident hypertension (26.8‐61.0 cases per 1000 person‐years, depending on the type of cancer), heart failure (9.4‐78.7), and acute coronary syndrome (2.6‐48.1). These event rates are high compared to what has been reported in prior KPNC cohort studies of patients without cancer. The rates of acute coronary syndrome, heart failure, and ischemic stroke increased with increasing numbers of cardiovascular risk factors. CONCLUSIONS: In a population of patients with cancer not exposed to TKIs, cardiovascular risk factors and outcomes are very common, regardless of cancer type. These data can inform the evaluation of potential excess cardiovascular risks from new interventions.