Long Deyong

e0570 Can hatch score predict recurrence of atrial fibrillation after catheter ablation

Background HATCH score (1*hypertention+1*[age>75]+2*[stroke or transient ischaemic attack]+1*[chronic obstructive pulmonary disease]+2* [heart failure]) is an established predictor of progression from paroxysmal to persistent atrial fibrillation (AF). Whether atrial remodelling indexed by HATCH score could be a predictor of recurrence after catheter ablation of AF needs to be explored. Methods The data of 608 consecutive AF patients who underwent an index circumferential pulmonary veins ablation were retrospectively analysed. Of these patients, 313 (51.5%) patients had HATCH=0, 225 (37.0%) patients had HATCH=1, 70 (11.5%) patients had HATCH≥2. Results The patients with HATCH≥2 had significantly the largest left atrium size, the largest left ventricular end systolic diameter, and the lowest ejection fraction among the three HATCH categories. There were significant differences of the proportion of diabetes mellitus, statins medication, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers medications among the three HATCH categories. After a mean follow-up of 474±330 days, the recurrence rate were 36.4%, 38.7%, 34.3%, from HATCH=0 to HATCH≥2 categories (p=0.707). Univariate analysis revealed that nonparoxysmal AF, left atrium size, body mass index were predictors of AF recurrence. Multivariate analysis revealed that nonparoxysmal AF (HR=1.43, 95% CI 1.03 to 1.99, p =0.031) was the only independent predictor of AF recurrence. HATCH and left atrium size were not independent predictors of AF recurrence. Conclusion HATCH has no value in prediction of AF recurrence after catheter ablation.

e0573 Impact of ageing on the left atrium thrombus in patients with non-valvular atrial fibrillation

Objective This study sought to investigate the impact of ageing on left atrium thrombus in patients with non-valvular atrial fibrillation (AF). Methods Four hundred and twenty-one consecutive patients with AF underwent transesophageal echocardiography prior to AF ablation were included in a prospectively established database. The elderly group was defined as age more than 65 years old. Results In all the 421 patients, 108 (25.6%) were in the elderly group and 313 (74.4%) were in the young group, with the mean age 70.0±3.7, 52.1±8.5, respectively. There was no significant difference of left atrium thrombus between the elderly group and the young group (4.6% vs 6.7%, p=0.439). It was shown there is less value for age predicting left atrium thrombus, the area under the receptor-operating curve was 0.494. The mean age (56.7±9.9 vs 56.7±10.9, p=0.989) and the proportion of the elderly (19.2% vs 26.1%, p=0.439) did not differ significantly between the patients with left atrium thrombus and those without. After adjustment for ejection fraction, heart failure, hypertension, diabetes mellitus, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers medication in logistics multivariate analysis, left atrium diameter, non-paroxysmal AF, prior thromboembolic history were independent risk factors of left atrium thrombus. However, age was not an independent risk factor of left atrium thrombus. Conclusions Ageing itself was not a risk factor of left atrium thrombus in patients with non-vavular AF.

e0557 CARTO mapping to guide ablation of right ventricular outflow tract tachycardia ventricualr contraction

Objective The aim of this study was to determine whether CARTO mapping is feasible in the right ventricle and assess its utility in guiding ablation of right ventricular outflow tract (RVOT) ventricualr tachycardia (VT). Background In patients with RVOT VT; CARTO mapping permits ablation guided by a VT complex, which may facilitate ablation of VT cases. However, the mapping system may be geometry- dependent, and it has not been validated in the unique geometry of the RVOT. Methods 30 patients with left bundle branch block and right axis VT, no history of structurally cardiac disease and normal left ventricular function underwent CARTO guided ablation. Results The procedure was acutely successful in 27 of 30 patients, 3 had failed ablation. During a mean follow-up of 6 months, 26 of 30 patients remained arrhythmia-free. Conclusions In this study, CARTO mapping was safely and effectively used to guide ablation of patients with RVOT VT.

e0556 Catheter ablation of atrial tachycardia from the noncoronary cusp of the aortic valve

Objective In this study, we examine the characteristics of anteroseptal Atrial tachycardias (AT) originating from the Noncoronary Cusp (NCC) of the Aortic Valve, and demonstrate the long-term efficacy and safety of targeting the arrhythmias by Catheter Ablation. Methods From among a cohort of 43 patients with symptomatic focal AT undergoing electrophysiological evaluation, the point of earliest activation was at NCC region in 7 patients. Results The arrhythmia terminated with <10 seconds of radiofrequency delivery and was successfully eliminated in 7 patients. All patients have been arrhythmia free during follow-up (20±6) months. Conclusions Catheter ablation from the base of the NCC represents a safe and effective means to eliminate focal AT.

e0574 High-normal thyroid function and risk of recurrence of atrial fibrillation after catheter ablation

Background It has been shown that serum free thyroxine (FT4) concentration is independently associated with atrial fibrillation (AF) even in euthyroid persons. This study aimed to testify the impact of high-normal level of FT4 on recurrence after catheter ablation of AF. Methods Two hundred and forty-four consecutive patients with paroxysmal AF underwent circumferential pulmonary vein isolation (PVI) were prospectively enrolled. Exclusion criteria included prior or current thyroid dysfunction on admission, amiodarone medication for three months before admission. Results After a mean follow-up of 416±204 (91–856) days, the recurrence rates were 14.8%, 23.0%, 33.3%, 38.7% from the lowest FT4 quartile to the highest FT4 quartile, respectively (p=0.016). Adjustment for age, gender, left atrium diameter, PVI, there was an increased risk of recurrence in the subjects with the highest FT4 quartile compared with those with the lowest quartile (HR 3.31, 95% CI 1.45 to 7.54, p=0.004). As a continuous variable, FT4 was also an independent predictor of recurrence (HR 1.10, 95% CI 1.02 to 1.18, p=0.016). Conclusions Patients with high-normal thyroid function were at an increased risk of AF recurrence after catheter ablation.