Abstract 12143: Association of Biomarkers with Pre-Existent Left Atrial Myocardial Scar in Atrial Fibrillation Patients Undergoing Catheter Ablation
Introduction: Inflammatory mediators are known to play a key causative role in atrial structural remodeling that leads to myocardial scar formation. This study aims to examine possible association of inflammatory biomarkers such as C-reactive protein (CRP), total white blood cell (TWBC) count and B-type Natriuretic Peptide (BNP) with long-term outcome after catheter ablation of atrial fibrillation (AF), with or without pre-existent severe myocardial scar.
Method: In this prospective study, 1665 consecutive AF patients undergoing first-time pulmonary vein antrum isolation (PVAI) were enrolled. Detail voltage mapping of the left atrium was done in all patients using CARTO system (Biosense Webster Inc). Scar was defined as absence of voltage or a bipolar voltage amplitude ≤ 0.05 mV indistinguishable from noise and classified as mild (<20%), moderate (20-50%) or severe (>50%) depending on the percentage of the estimated LA area involved. Of the 1665 patients, 70(4.2%) had severe scar (72±8 years, 68% male, LVEF 55±8) and 1461(88%) had no scar (64±10 years, 73% male, LVEF 60±11). For the purpose of this study, patients with severe scar or no pre-existing scar were only included. Baseline blood sample was drawn for WBC count and assessment of CRP and BNP. Event-recorder and 7-day Holter monitors were used at 3, 6, 9 and 12-month follow-up to assess AF recurrence.
Result: Median CRP, BNP and TWBC values were significantly higher in severe-scar group [3.42 mg/L (IQR 1.2-6.1) vs. 1.4 mg/L (IQR 0.46-3.98), p=0.016; 226 pg/ml (IQR 79-438) vs. 86 pg/ml (IQR 34-166) p=0.034; 6837mm3 (IQR 5197-8177) vs. 6279mm3 (IQR 5119-7267), p=0.043 respectively]. At 18±6 months of follow-up, the success rate was higher in no-scar group [1067(73%) vs. 38(54%), log-rank p = 0.030). In a multivariable Cox model, baseline BNP (HR 1.41, 95% CI 1.032-1.781; p =0.024) and CRP (HR 2.14, 95% CI 1.200-4.968; p =0.014) were independent predictors of recurrence in patients presenting with severe scar at the time of first PVAI. No significant association was observed in the no-scar population.
Conclusion: Elevated levels of CRP and BNP in association with severe left atrial scar did predict poor ablation-outcome of AF with a single procedure.
- © 2011 by American Heart Association, Inc.