Abstract Body: Introduction: Atrial fibrillation (AF) is the most common arrhythmia worldwide. Although it was recently identified as a risk factor for coronary heart disease (CHD), the underlying pathophysiology is not well understood. Initial studies suggested an embolic mechanism when compared to those without AF. We studied several biomarkers to understand possible mechanisms and identify potential predictors of CHD in this population.

Methods: The REGARDS cohort study enrolled 30,239 White and Black adults aged 45 and older in 2003-7. We included those with baseline AF and no history of stroke, myocardial infarction (MI), or coronary revascularization. We calculated hazard ratios (HR) for incident CHD, defined as definite or probable MI, per 1 SD increment of each biomarker using Cox models adjusted for CHD risk factors and medications.

Results: The 1,807 participants had mean age 66 years; 33% were Black, 57% female, 76% had hypertension, and 21% diabetes. Incident CHD was seen in 201 participants (39.8% fatal) over a mean follow-up of 9 years. Among the 14 biomarkers (figure), significant associations were seen with cholesterol (HR 2.9; 1.4-6.2), cystatin C (HR 2.6; 1.6-4.2), GDF15 (HR 2.0; 1.5-2.9), serum creatinine (HR 1.8; 1.1-2.9) NTproBNP (HR 1.4; 1.3-1.6), D-dimer (HR 1.4; 1.2-1.7), IL6 (HR 1.3; 1.2-1.5), CRP (HR 1.3; 1.1-1.5), GGT (HR 1.25; 1.02-1.54), and LP(a) (HR 1.22; 1.05-1.41).


Conclusions:
Total cholesterol, LP(a), D-dimer, GGT, and biomarkers of kidney function (cystatin C, creatinine), myocardial strain (NTproBNP), and inflammation (IL6, CRP, GDF15) were associated with incident CHD in AF. These findings lay the groundwork for further research to determine potential therapeutic targets to prevent CHD in people with AF.