Biomarker Levels in Patients with Atrial Fibrillation Before and After Electrical Cardioversion

Background Biomarkers may help to improve our knowledge about the complex pathophysiology of atrial fibrillation (AF), the most common sustained cardiac arrhythmia. We aimed to identify significant changes in biomarkers and clinical measures in patients with and without AF recurrence after electrical cardioversion. Methods Patients with persistent AF undergoing elective electrical cardioversion were enrolled. We measured 21 conventional and new biomarkers before and 30 days after electrical cardioversion and assessed the associations of changes in biomarker levels with rhythm status at follow-up using multivariable logistic regression models. Results Of the 100 patients included (mean [SD] age 66 (10) years, 25% women), 28 (28%) had an AF recurrence. Of the 21 biomarkers assessed, 4 reached the predefined between group significance of p<0.01. The most significant ones were bone morphogenetic protein 10 (BMP10), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and total bilirubin. Their respective changes were -10.4%, -62.0% and -25.6% in patients with sinus rhythm, and 3.1%, 1.1% and -9.4% in patients with recurrent AF, for a between group difference of -13.5% (95% confidence interval [CI], -19.3% to -7.6%; P<0.001), -63.1% (95% CI, -76.6% to -49.6%; P<0.001) and -16.3 (95% CI, -27.9% to -4.7%; P=0.007). In age and sex adjusted models, reductions of BMP10 and NT-proBNP were significantly associated with rhythm status at follow-up (β coefficient per 1-SD decrease, -2.03; 95% CI, -3.06 to -1.00; P<0.001 and -3.98; 95% CI, -5.75 to -2.22; P<0.001, respectively). After additional adjustment for demographic characteristics, risk factors for AF, and changes in clinical measures, the β coefficients per 1-SD were -3.85 (95% CI, -6.34 to -1.35; P=0.003) for BMP10 and -5.84 (95% CI, -10.22 to -1.47; P=0.009) for NT-proBNP. Conclusions Changes in BMP10 und NT-proBNP levels were strongly associated with rhythm status after electrical cardioversion, suggesting that these markers may be dependent on the actual heart rhythm.