Interatrial septal thickness as a marker of structural and functional remodeling of the left atrium in patients with atrial fibrillation.

BACKGROUND/AIMS: There have been reports that interatrial septal (IAS) thickness is increased in patients with atrial fibrillation (AF). This study was performed to investigate whether IAS thickness determined by transthoracic echocardiography (TTE) represents the amount of left atrium (LA) structural and functional remodeling. METHODS: The study population consisted of 104 consecutive patients who underwent catheter ablation (CA) for AF (paroxysmal atrial fibrillation [PAF], 82; persistent atrial fibrillation [PeAF], 22). IAS thickness and left atrium volume (LAV) using TTE, and LA voltage (LA(VOL)) using 3-dimensional electroanatomical mapping system were assessed during sinus rhythm. RESULTS: IAS thickness was significantly correlated with maximal LAV (LAV(max)) (r = 0.288, p = 0.003), mean LA(VOL) (r = -0.537, p < 0.001), total left atrium emptying fraction (LAEF(total); r = -0.213, p = 0.030), and active LAEF (LAEF(active); r = -0.249, p = 0.014). IAS thickness was greater in the high-risk group (≥ 2) compared to other groups according to CHA2DS2-VASc score (p = 0.019). During a follow-up of 19.6 months, 23 subjects (22.1%; PAF, 17; PeAF, 6) had recurrence of arrhythmia. Univariate analysis showed that LAV(max), minimal LAV, mean LA(VOL), LVEF(total), LVEF(active), and IAS thickness were associated with recurrence of arrhythmia. However, on multivariate analysis, only mean LA(VOL) and LAEF(active) were independent risk factors for recurrence. CONCLUSIONS: Although IAS thickness showed significant correlations with parameters for LA structural and functional remodeling, this parameter alone could not independently predict recurrence of arrhythmia after CA for AF.

Impact of low dose atorvastatin on development of new-onset diabetes mellitus in Asian population: Three-year clinical outcomes.

BACKGROUND: High dose atorvastatin is known to be associated with new onset diabetes mellitus (NODM) in patients with high risk for developing diabetes mellitus (DM). However, low dose atorvastatin is more commonly used as compared with high dose atorvastatin. The aim of this study is to investigate the impact of low dose atorvastatin (LDA, 10mg or 20mg) on the development of NODM up to three years in Asian patients. METHODS: From January 2004 to September 2009, we investigated a total of 3566 patients who did not have DM. To adjust for potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. After PSM (C-statistics: 0.851), a total of 818 patients (LDA group, n=409 patients and control group, n=409 patients) were enrolled for analysis. RESULTS: Before PSM, the cumulative incidence of NODM (5.8% vs. 2.1%, p<0.001), myocardial infarction (0.5% vs. 0.1%, p-value=0.007), and major adverse cardio-cerebral event (MACCE, 1.8% vs. 0.7%, p-value=0.012) at three-years were higher in the LAD group. However, after PSM, there was a trend toward higher incidence of NODM (5.9% vs. 3.2%, p=0.064) in the LDA group, but the incidence of MACCE (1.2% vs. 1.5%, p-value=1.000) was similar between the two groups. In multivariable analysis, the LDA administration was tended to be an independent predictor of NODM (OR: 1.99, 95% CI: 1.00-3.98, p-value 0.050). CONCLUSIONS: In this study, the use of LDA tended to be a risk factor for NODM in Asian patients and reduced clinical events similar to the control group. However, large-scale randomized controlled trials will be needed to get the final conclusion.

Does isolation of the left atrial posterior wall improve clinical outcomes after radiofrequency catheter ablation for persistent atrial fibrillation?: A prospective randomized clinical trial.

INTRODUCTION: Although posterior wall of left atrium (LA) is known to be arrhythmogenic focus, little is known about the effect of posterior wall isolation (PWI) in patients who undergo radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF). METHODS: We randomly assigned 120 consecutive PeAF patients to additional PWI [PWI (+), n=60] or control [PWI (-), n=60] groups. In all patients, linear ablation was performed after circumferential pulmonary vein isolation (PVI). Linear lesions included roof, anterior perimitral, and cavotricuspid isthmus lines with conduction block. In PWI (+) group, posterior inferior linear lesion was also conducted. Creatine kinase-MB (CK-MB) and troponin-T levels were measured 1day after RFCA. LA emptying fraction (LAEF) was assessed before and 12 months after RFCA. RESULTS: A total of 120 subjects were followed for 12 months after RFCA. There were no significant differences between two groups in baseline demographics and LA volume (LAV). The levels of CK-MB and troponin-T and procedure time were not significantly different between the groups. AF termination during RFCA was more frequently observed in PWI (+) than control (P=0.035). During follow-up period, recurrence occurred in 10 (16.7%) patients in PWI (+) and 22 (36.7%) in control (P=0.02). The change in LAEF was not significantly different between the groups. On multivariate analysis, smaller LAV and additional PWI were independently associated with procedure outcome. CONCLUSIONS: PWI in addition to PVI plus linear lesions was an efficient strategy without deterioration of LA pump function in patients who underwent RFCA for PeAF.

Does the amount of atrial mass reduction improve clinical outcomes after radiofrequency catheter ablation for long-standing persistent atrial fibrillation? Comparison between linear ablation and defragmentation.

BACKGROUND: Although a large isolated surface area of the left atrium (LA) may improve the success rate of catheter ablation (CA) for paroxysmal atrial fibrillation (AF), little is known about the relation between clinical outcomes and the amount of atrial mass reduction (AMR: ratio of total isolated and ablated areas to LA surface area) in different ablation strategies for patients with long-standing persistent AF (L-PeAF). METHODS: We randomly assigned 119 consecutive L-PeAF patients to adjunctive linear ablation (n=60) or complex fractionated atrial electrogram (CFAE)-guided ablation (n=59) after circumferential antral pulmonary vein isolation (PVI). Linear lesions included roof and anterior lines with conduction block. LA defragmentation was performed with an automated CFAE-detection algorithm. Cavotricuspid isthmus block was performed in all patients. Creatine kinase-MB (CK-MB) and troponin-T levels were measured 1 day post-CA. RESULTS: CK-MB and troponin-T levels were higher, ablation time was longer, and AMR was greater in the CFAE-guided ablation group than in the linear ablation group. AF termination during CA was more frequently observed in the linear ablation group than in the CFAE-guided ablation group (P=0.031). Twelve months after a single procedure, recurrence occurred in 16 (26.7%) patients with linear ablation and 27 (45.8%) patients with CFAE-guided ablation (P=0.023). On multivariate analysis, LA volume and ablation method were the only independent risk factors for arrhythmia recurrence. CONCLUSION: Conduction block through linear lines+PVI was an efficient ablation strategy for L-PeAF, whereas the AMR amount did not influence clinical outcomes.