Blood Biomarkers and the Risk of Coronary Disease in Atrial Fibrillation

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia. Although it was recently identified as a risk factor for coronary heart disease (CHD), the underlying pathophysiology is not well understood. Biomarkers could provide insights on underlying mechanisms and identify potential predictors of CHD among people with AF. METHODS: The REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort study enrolled 30 239 White and Black adults aged 45 and older in 2003 to 2007. Among those with baseline AF and no history of stroke or CHD, 13 cardiovascular risk biomarkers were measured at baseline. We calculated hazard ratios (HR) for incident CHD by biomarkers using Cox proportional hazards model adjusting for risk factors and use of statins, aspirin, and anticoagulants. RESULTS: Among 1818 participants with prevalent AF mean age was 69 years (SD 10 years). There were 201 (11%) cases of incident CHD over 9 years. Several biomarkers were associated with incident CHD: NT-proBNP (N-terminal pro-B-type natriuretic peptide), GDF-15 (growth differentiation factor 15), C-reactive protein, interleukin-6, D-dimer, cholesterol, lipoprotein(a), triglycerides, low-density lipoprotein, and gamma-glutamyl transferase, with HRs 1.17 to 1.69 per SD increment. There were no associations for Factor VIII, galectin 3, and high-density lipoprotein. The largest associations were for NT-proBNP and GDF-15 with respective HRs per SD 1.69 (95% CI, 1.42-2.01) and 1.45 (95% CI, 1.21-1.74). Comparing the top versus bottom tertile, the largest associations were NT-proBNP (HR 3.14 [95% CI 2.03-4.84]), interleukin-6 (HR, 2.69 [95% CI, 1.78-4.06]), and GDF-15 (HR, 2.20 [95% CI, 1.38-3.51]). CONCLUSIONS: Multiple biomarkers were associated with incident CHD in AF with the largest associations being myocardial strain and inflammation.