Associations Between Multiple Circulating Biomarkers and the Presence of Atrial Fibrillation in Hypertrophic Cardiomyopathy with or Without Left Ventricular Outflow Tract Obstruction

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Data regarding the correlations of biomarkers and AF in HCM patients are rather limited. We sought to explore the associations between the presence of AF and circulating biomarkers reflecting cardiovascular function (N-terminal pro-brain natriuretic peptide, NT-pro BNP), endothelial function (big endothelin-1, big ET-1), inflammation (high-sensitivity C-reactive protein), and myocardial damage (cardiac troponin I, cTnI) in HCM patients with and without left ventricular outflow tract obstruction (LVOTO).In all, 375 consecutive HCM in-hospital patients were divided into an AF group (n = 90) and a sinus rhythm (SR) group (n = 285) according to their medical history and electrocardiogram results.In comparison with the SR group, peripheral concentrations of big ET-1, NT-pro BNP, and cTnI were significantly higher in patients with AF. Only the biomarker of big ET-1, together with palpitation and left atrial diameter (LAD), was independently associated with AF in HCM patients. Ln big ET-1 was positively related to Ln NT-pro BNP, LAD, and heart rate, but negatively related to left ventricular ejection fraction. Combined measurements of big ET-1 ≥ 0.285 pmol/L and LAD ≥ 44.5 mm indicated good predictive values in the presence of AF, with a specificity of 94% and a sensitivity of 85% in HCM patients.Big ET-1 has been identified as an independent determinant of AF, regardless of LVOTO, and is significantly related to parameters representing cardiac function and remodeling in HCM. Big ET-1 might be a valuable index to evaluate the clinical status of AF in HCM patients.