Although the association of atrial fibrillation (AF) and coronary artery disease is a growing public health concern, data in patients with chronic coronary syndrome (CCS) is scarce. We aimed to describe the incidence rate and predictors of new-onset AF in CCS outpatients as well as its association with major adverse cardiovascular events (MACE) using a large-scale registry.

The international ProspeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease (CLARIFY), provides real-world data from 32,703 outpatients with CCS from 45 countries. Our analysis included 29,001 patients without prior AF at baseline. Over the median 5-year follow-up, 1453 (5%) had a new-onset AF diagnosed with an annual incidence rate of around 1%. Independent predictors of AF were increased age, treated hypertension, history of peripheral artery disease and an alcohol intake ≥1 drink per week. Left ventricular ejection fraction value and a high triglyceride level were independent predictors of lower new-onset AF rate. As rhythmic status was a variable that changed during follow-up, incident AF was included as a time-varying covariate in the Cox regression model. Compared to CCS patients without AF, those with new-onset AF had a higher rate of MACE, including the composite endpoint of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke, hazard ratio (HR) 2.52 (95% CI 2.11-3.01); cardiovascular death, HR 3.22 (2.63-3.94); stroke, HR 2.80 (2.01-3.91); all cause death, HR 2.64 (2.23-3.11); hospitalization for heart failure, HR 9.38 (8.02-10.97); major bleeding, HR 4.33 (2.94-6.39), P<0.001 for each and myocardial infarction, HR 1.55 (1.08-2.22), P<0.016 (Table 1, Figure 1).

New-onset AF is strongly associated with the risk of MACE and should be considered as a prognostic turning point in CCS patients. Many predictors have been identified which presence should lead to broader screening for arrhythmias in CCS patients.