Abstract MP24: Contemporary Trends in Incident Ischemic Stroke, Intracranial Hemorrhage, and Mortality in Individuals With Atrial Fibrillation

Background: The prognosis for atrial fibrillation (AF) patients is based on data that is decades old. Given evolving standards of clinical practice that may now include lifestyle factor modification, catheter ablation, and DOACs, we evaluated temporal trends in clinically important outcomes among patients with AF. Methods: California’s Department of Health Care Access and Information databases were used to identify adults aged ≥18 years with AF receiving hospital-based care in California. We compared 3 time-periods in this population-based cohort corresponding to 2005-2009, 2010-2014, and 2015-2019. The outcomes were incident ischemic stroke, intracranial hemorrhage, and mortality. Results: We included 1,859,901 patients with AF (52.7% males, 71.0% Whites, and mean age of 74.8 years), divided in 3 cohorts: 2005-2009 (n=680,872), 2010-2014 (n=558,365), and 2015-2019 (n=620,664). Each of these outcomes became substantially less common with time: compared to 2005-2009 ( Figure 1A ), AF patients diagnosed in 2015-2019 experienced a 42% (adjusted hazard ratio HR 0.58, 95% CI 0.57-0.60), 17% (HR 0.83, 95% CI 0.80-0.88), and 28% (HR 0.72, 95% CI 0.71-0.73) reduction in risk of incident ischemic stroke, intracranial hemorrhage, and mortality, respectively. Between 2005-2009 and 2015-2019, the decline in the incidence rate of adverse outcomes was greater in patients aged ≥65 years (p<.001), females (p=.02), and Whites (p<.001) for ischemic stroke; more pronounced in patients aged ≥65 years (p=.008), females (p=.02), and Whites and Asians (p=.005) for intracranial hemorrhage; and greater in patients aged ≥65 years (p<.001), in males (p=.04), and in Whites (p<.001) for mortality ( Figure 1B ). Conclusion: The risk of stroke, intracranial hemorrhage, and mortality have significantly declined among AF patients, although significant disparities in the magnitude of improvement of these outcomes by demographic groups were observed. Estimates of the prognosis for AF patients should be updated to reflect contemporary care.