New-onset atrial fibrillation, cardiovascular outcomes and all-cause mortality in patients with newly diagnosed cancer: A large population-based matched cohort study.

11184 Background: Studies have shown an association between atrial fibrillation (AF) and cancer, but the relationship is incompletely studied. there is also a paucity of data regarding the specific association between cancer type and AF risk . Notably, the longitudinal associations of new-onset AF with adverse cardiovascular (ACV) outcomes in Newly Diagnosed Cancer Patients remain unclear. Thus, through a comprehensive nationwide population-based study, we assessed the associations between new-onset AF and subsequent risks of ACV events and all-cause mortality. Methods: This large retrospective cohort study was conducted using the TriNetX database and included adults (>18 years) with any new cancer diagnoses. We performed 1:1 propensity score matching (PSM) for demographics, BMI, nicotine dependence, comorbidities, cancer type, and medications to similar controls as cancer patients without AF. The primary outcome was new ACV events like heart failure (HF), major adverse cardiovascular events (MACE; coronary artery intervention myocardial infarction, or unstable angina), ischemic heart disease (IHD), and cerebrovascular events (CVE; cerebral infarction, carotid intervention, stroke, transient ischemic attack. The secondary outcome was all-cause mortality. Sensitivity analysis assessed statistical robustness. Hazard ratios (HR) were calculated to compare group outcomes. Results: Among the new diagnoses, 52,606 developed AF, and 374,959 remained AF free during the follow-up. After PSM, both cohorts (51,567 each) were well-matched. The mean follow-up duration was 4.8 (± 2.7) years. Among newly diagnosed cancer patients, those with incident AF had higher risk of MACE (HR 1.56; 95% CI 1.49–2.16), HF (HR 3.10; 95% CI 2.76–4.36), IHD (HR 1.68; 95% CI 1.41–2.01), CVE (HR 2.93; 95% CI 2.13–4.04), and all-cause mortality (HR 2.56; 95% CI 1.89–3.78) compared with those without incident AF. We noted a higher incidence rate during the initial months after the diagnosis of AF for both sexes. During the first year, the association with any ACV events (men: HR 2.78, 95% CI, 1.85–3.20; women: HR 1.81, 95% CI, 1.31–2.67) was more substantial than that following AF diagnosis for both sexes. New ‐onset AF was strongly associated with metastatic cancer. In sensitivity analysis, we excluded individuals with <1 year of follow-up results were consistent, and all statistically significant associations remained unchanged. Conclusions: cancer patients who developed AF had significantly higher risks of subsequent adverse cardiovascular events and greater all-cause mortality. AF was strongly associated with metastatic disease. Our findings highlight the importance of strategies for AF prevention to mitigate macrovascular complications in all newly diagnosed cancer patients.