Böhm A, Musil P, Urban L, Slezak P, Hatala R, Bacharova L, Cvicela M.
Introduction: Atrial fibrillation (AF) is the most common sustained arrhythmia, however in the case of paroxysmal type, its detection is often challenging. Apelin (Ap) is a peptide hormone that affects cardiovascular system mainly by countering the renin-angiotensin-aldosterone axis and stimulating cardiac contractility. Previous studies suggested that there might be a link between Ap and AF. If there is some association between Ap and the duration of AF is unknown.
Objectives: To study a relation between plasmatic Apelin levels and AF burden (defined as percentage of time spent in AF) before and after catheter ablation in patients with paroxysmal AF.
Methods: We designed a prospective cohort study. Nine consecutive patients with implanted loop recorders for continual ECG monitoring undergoing catheter ablation (CA) of paroxysmal AF were included. Their only cardiovascular comorbidity was arterial hypertension. Blood samples were taken one day before, 3 months after (92 days, ±9) and 9 months (280 days, ±43) after CA. AF burden was recorded for a period of 2 months (63 days, ±11) before CA and then in the same intervals as blood samples were taken after the CA.
Results: The relative reduction of AF burden 3 and 9 months after the CA was 82% and 78% respectively. There was a significant increase in Ap level 3 months and 9 months after the CA by 0,163ng/ml (p=0,03) and 0,266ng/ml (p=0,006), respectively. There was also a negative correlation (r= -0,4, p=0,06) between the levels of Ap and AF burdens before, 3 months after and 9 months after the CA, on the edge of statistical significance.
Conclusion: Our study demonstrated a significant increase in Ap levels related to AF burden decrease caused by CA. We even observed a negative correlation between Ap levels and AF burden, however larger cohort is needed to verify the statistical significance of this phenomenon. Our study suggests that Ap might be a sensitive biomarker of AF. Further studies are needed to show whether this peptide could be used for precise AF detection that would be of paramount importance in CA prognosis and cryptogenic stroke management.