Risk factors and clinical outcomes in patients with newly diagnosed asymptomatic atrial fibrillation

Although asymptomatic atrial fibrillation (AF) is common, screening has not consistently improved outcomes, possibly owing to challenges identifying those most at risk of asymptomatic AF.

This study aimed to identify risk factors associated with increased likelihood of presenting with asymptomatic vs symptomatic AF and evaluate and compare subsequent cardiovascular and mortality outcomes across these patient groups.

In the VITAL Rhythm study (n = 25,114, free of baseline cardiovascular disease [CVD] and AF), time-updated multivariable Cox competing-risk models identified risk factors differentially associated with new-onset asymptomatic vs symptomatic AF. Additional models with time-dependent indicators for AF type and interim CVD events assessed the relative risks of subsequent CVD and mortality associated with asymptomatic and symptomatic AF.

Over a median of 7.3 years, 5.0% developed new-onset AF; of these, 29.3% were asymptomatic. Male sex, body mass index, and elevated systolic blood pressure were more strongly associated with asymptomatic than symptomatic AF (P differential < .04 for all). Both groups had similarly increased risks of stroke, myocardial infarction, and death after AF onset. However, the risk of heart failure was higher for symptomatic AF (P differential = .03). After adjusting for interim nonfatal CVD, mortality risk was completely attenuated in patients with asymptomatic AF (hazard ratio 0.98; 95% confidence interval 0.67-1.45), but not in symptomatic AF (hazard ratio 1.54; 95% confidence interval 1.19-1.98; P differential = .046).

Men and individuals with higher body mass index and systolic blood pressure are more likely to have asymptomatic AF. Mortality risk in these patients is largely driven by potentially preventable CVD events, emphasizing the importance of targeted screening and early cardiovascular risk management to improve outcomes.