Association of a Cancer Diagnosis and Mortality After Ischemic and Hemorrhagic Stroke and Myocardial Infarction

BACKGROUND AND OBJECTIVES: Previous studies have indicated an increased risk of cerebrovascular and coronary events shortly after cancer diagnosis. However, whether cancer affects mortality outcomes after stroke and myocardial infarction (MI) remains unclear. We aimed to investigate the relationship between cancer diagnosis and mortality after stroke and MI. METHODS: Using linked nationwide databases from Taiwan, we conducted a population-based cohort study including 3 cohorts of patients with first-time ischemic stroke, hemorrhagic stroke, and MI between 2011 and 2019. The primary outcome was 90-day mortality, with follow-up beginning at the index stroke (for ischemic and hemorrhagic stroke cohorts) and MI (for the MI cohort) event date for all patients. Odds ratios (ORs) of 90-day mortality associated with all cancers combined and 15 cancer types were estimated through propensity score matching for potential confounding variables. Excess mortality rates (between patients with cancer and matched controls) were analyzed across time intervals after cancer diagnosis, stratified by age group, cancer stage, and cancer type. RESULTS: Overall, 440,664, 159,606, and 228,993 patients were included in ischemic stroke (mean age, 70.1 years; 40.7% female), hemorrhagic stroke (mean age, 65.4 years; 36.5% female), and MI (mean age, 67.8 years; 29.7% female) cohorts, respectively. Compared with matched controls, patients with cancer had higher risks of 90-day mortality in ischemic stroke (OR 2.71, 95% CI 2.63-2.79), hemorrhagic stroke (OR 2.20, 95% CI 2.11-2.29), and MI (OR 1.63, 95% CI 1.57-1.69). Across 3 cohorts, substantial variations existed among cancer types, with aggressive malignancies (e.g., pancreatic cancer) consistently presenting the highest risks. Excess mortality rates were highest during the first postdiagnosis year and declined progressively thereafter. This temporal pattern was consistent across age groups and cancer stages, with excess mortality rates highest among patients aged 18-59 years and those with stage 4 disease. Despite variability among cancer types, excess mortality typically peaked within 2 years. DISCUSSION: This population-based study showed that patients with cancer had higher risks of mortality after stroke and MI, with substantial variations by cancer type, although cause-specific mortality data were lacking. Excess mortality rates peaked shortly after diagnosis, particularly for early-onset cancer and advanced disease.