Chitinase-3-like protein-1 (YKL-40) before and after therapy in supraventricular arrhythmias

BACKGROUND: The inflammatory glycoprotein chitinase-3-like protein 1 or YKL-40 has emerged as a potential biomarker of cardiovascular diseases, including atrial fibrillation (AFib). We sought to assess YKL-40 in a wide spectrum of supraventricular arrhythmias besides AFib in comparison with other inflammatory markers. METHODS: We determined serum levels of YKL-40, C-reactive protein (CRP) and IL-6 in 70 patients with AFib, atrial flutter, atrioventricular node reentry tachycardia or other supraventricular tachycardias before, immediately after therapy and 1 week after therapy; 20 healthy patients served as controls. Patients were subsequently followed for 6 months for arrhythmia recurrence. RESULTS: Baseline YKL-40 was significantly elevated in AFib patients [99.5 (65.5,194) ng/ml versus 47.2 (38.9,51.6) ng/ml in controls, P < 0.001], but not in patients with other arrhythmias. YKL-40 levels correlated positively with left atrial volume index (Spearman's rho = 0.853, P < 0.001). Its levels dropped significantly 1 week posttreatment only in AFib (P = 0.009 versus baseline); CRP and IL-6 remained practically stable throughout the study. Arrhythmia recurrence at 6 months occurred in 13 patients (19%), including 11 with AFib and 2 with atrial flutter. Baseline YKL-40 was independently associated with AFib recurrence (adjusted odds ratio = 1.02, 95% confidence interval = 1.00-1.04, P = 0.016). Neither CRP nor IL-6 was associated with AFib recurrence. CONCLUSION: Serum YKL-40 was elevated only in AFib and not in other supraventricular arrhythmias. In AFib, YKL-40 levels were responsive to therapy and predicted long-term recurrence.