Heart failure and stroke risk in atrial fibrillation: temporal trends from a nationwide cohort study

Abstract Background Heart failure is a well-recognized risk factor for ischemic stroke (IS) in patients with atrial fibrillation (AF). Over the recent decades, advancements in medical research have markedly improved the detection and management of both AF and heart failure. However, there is limited data on whether the advances in treatment have modified the stroke risk related to heart failure in AF patients. Purpose To evaluate temporal trends in heart failure-related IS risk among patients with AF. Methods The Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) registry-linkage study includes all patients in Finland with incident AF from 2007 to 2018. Stroke rates and adjusted incidence rate ratios (IRRs) within one-year follow-up from AF diagnosis were calculated using Poisson regression models, with the study period divided into four-year intervals. The main analysis was performed with adjustments for anticoagulant use as a time-dependent variable, with a separate analysis covering only time without anticoagulation by censoring follow-up at treatment initiation. Results We identified 229 565 patients with incident AF (50.0% female; mean age 72.7 years), of whom 17.4% had heart failure at the time of AF diagnosis. The prevalence of heart failure decreased from 18.0% in 2007–2010 to 16.7% in 2015–2018, particularly among patients aged 75 and older. In contrast, among patients under 65 years, the prevalence slightly increased from 7.6% to 8.9%. Crude IS rates decreased both in patients with and without heart failure over the study period (Figure 1). Heart failure was independently associated with a 30–50% higher IS rate at the beginning of the study period, but this association attenuated to 10–15% in the last study period (Figure 2). This reduction in heart failure-related stroke risk was observed primarily in patients without a history of myocardial infarction (IRR with 95% CI in 2015-2018: 1.08 (0.95-1.22)), while stroke risk associated with heart failure remained unchanged in patients with prior myocardial infarction (IRR with 95% CI during the entire study period: 1.23 (1.07-1.41)). Conclusions Stroke risk associated with heart failure has decreased among patients with AF, driven by a decline in heart failure-related stroke risk in patients without a history of myocardial infarction. However, heart failure remains an important stroke risk factor in AF patients with a history of myocardial infarction.Figure 1 Figure 2