Abstract 15077: Serum-transthyretin: Does it Predict Ablation Outcome in Patients With Atrial Fibrillation?

Abstract

Background: Transthyretin (TTR), a transport protein produced by liver, is closely associated with amyloidosis. Tetramers of TTR circulating in blood can dissociate to monomers that misassemble into amyloid fibrils. Although amyloidosis is a frequent finding in aged atrial fibrillation (AF) patients, the relevance of serum-TTR in AF is unknown. Objective: We evaluated if post-ablation change in serum-TTR level has any prognostic association with long-term ablation outcome in AF patients. Methods: One-hundred-forty-five patients (age: 62.8 ± 6.2years, male 69%, non-paroxysmal AF 41%, BMI : 30.8 ± 6.3) were included in this prospective study. Patients with chronic inflammatory conditions or taking anti-inflammatory drugs were excluded. All patients received pulmonary vein isolation plus isolation of left atrial posterior wall and superior vena cava. In non-paroxysmal AF, non-PV triggers identified by isoproterenol challenge were ablated. Fasting blood samples were collected at baseline and 24-hours post-ablation. Samples were tested for TTR using an automated quantitative test. Results: Mean TTR concentration was 27.94±6.5 mg/dL at baseline and 26.33±9.2 mg/dL at 24-hour post ablation (p<0.001). Of the 145 patients, post-ablation TTR remained unchanged or increased in 65 (44.8%) and decreased in 80 (55.2%) patients at 24-hour post-ablation. Mean decrease in the serum TTR in these 80 patients was 7.9± 4.38 mg/dL. At 3 years of follow-up, the recurrence rate was 28/80 (35%) in the group with decreased-serum TTR and 11/65 (17%) in the population with unchanged/increased TTR (p=0.01). Post-ablation decrease in TTR was found to be an independent predictor of recurrence (OR 2.64 (1.19-5.85), p=0.01). Conclusion: Our findings demonstrated significant association of higher recurrence rate with decreased serum-TTR tetramer level at 24-hour post-ablation.