Effect of SGLT-2 inhibitors on arrhythmia events: insight from an updated secondary analysis of > 80,000 patients (the SGLT2i-Arrhythmias and Sudden Cardiac Death).

OBJECTIVE: We aimed to assess the effect of SGLT2i on arrhythmias by conducting a meta-analysis using data from randomized controlled trials(RCTs). BACKGROUND: Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have shown cardioprotective effects via multiple mechanisms that may also contribute to decrease arrhythmias risk. METHODS: We searched in databases (PubMed, Embase, Cochrane Library, and clinicaltrials.gov) up to April 2023. RCTs comparing SGLT2i with placebo were included. The effects of SGLT2i on atrial fibrillation(AF), atrial flutter(AFL), composite AF/AFL, ventricular fibrillation(VF), ventricular tachycardia(VT), ventricular extrasystoles(VES), sudden cardiac death(SCD) and composite VF/VT/SCD were evaluated. RESULTS: 33 placebo-controlled RCTs were included, comprising 88,098 patients (48,585 in SGLT2i vs. 39,513 in placebo). The mean age was 64.9 ± 9.4 years, 63.0% were male. The mean follow-up was 1.4 ± 1.1 years. The pooled-results showed that SGLT2i was associated with a significantly lower risk of AF [risk ratio(RR): 0.88, 95% confidence interval(CI) 0.78-1.00, P = 0.04] and composite AF/AFL (RR: 0.86, 95%CI 0.77-0.96, P = 0.01). This favorable effect appeared to be substantially pronounced in patients with HFrEF, male gender, dapagliflozin, and > 1 year follow-up. For SCD, only in heart failure patients, SGLT2i were found to be associated with a borderline lower risk of SCD (RR: 0.67, P = 0.05). No significant effects of SGLT2i on other ventricular arrhythmic outcomes were found. CONCLUSIONS: SGLT2i lowers the risks of AF and AF/AFL, and this favorable effect appeared to be particularly pronounced in patients with HFrEF, male gender, dapagliflozin, and longer follow-up (> 1 year). SGLT2i lowers the risk of SCD only in heart failure patients.

Catheter ablation vs. antiarrhythmic drugs as 'first-line' initial therapy for atrial fibrillation: a pooled analysis of randomized data.

AIMS: Catheter ablation (CA) is recommended for patients with atrial fibrillation (AF) after failure of antiarrhythmic drugs (AADs). The role of CA as 'initial therapy' for AF is to be determined. METHODS AND RESULTS: Following PRISMA guideline an up-to-date pooled analysis of randomized data comparing ablation vs. AADs as first-line therapy for symptomatic AF was performed. The primary outcome was recurrence of atrial tachyarrhythmia. The secondary outcomes were improvement in quality-of-life (QoL) and major adverse events. A total of 997 patients from five randomized trials were enrolled (mean age 57.4 years, 68.6% male patients, 98% paroxysmal AF, mean follow-up 1.4 years). The baseline characteristics were similar between the ablation and AADs group. Overall pooled analysis showed that, as compared with AADs, CA as first-line therapy was associated with significantly higher freedom from arrhythmia recurrence (69% vs. 48%, odds ratio: 0.36, 95% confidence interval: 0.27-0.48, P < 0.001). This significance was maintained in subgroup analyses of 1- and 2-year follow-up (P < 0.001). Catheter ablation was associated with significantly greater improvement in QoL regarding AFEQT score and 36-Item Short-Form Health Survey score. The incidence of serious adverse events between ablation and AADs group (5.6% vs. 4.9%, P = 0.62) was similar. CONCLUSIONS: Catheter ablation as 'initial therapy' was superior to AADs in maintenance of sinus rhythm and improving QoL for patients with symptomatic paroxysmal AF, without increasing risk of serious adverse events.

Rhythm control for patients with atrial fibrillation complicated with heart failure in the contemporary era of catheter ablation: a stratified pooled analysis of randomized data.

AIMS: The optimal treatment for patients with atrial fibrillation (AF) and heart failure (HF) has been a subject of debate for years. We aimed to evaluate the efficacy and safety of rhythm control strategy in patients with AF complicated with HF regarding hard clinical endpoints. METHODS AND RESULTS: Up-to-date randomized data comparing rhythm control using antiarrhythmic drugs (AADs) vs. rate control (Subset A) or rhythm control using catheter ablation vs. medical therapy (Subset B) in AF and HF patients were pooled. The primary outcomes were all-cause mortality, re-hospitalization, stroke, and thromboembolic events. A total of 11 studies involving 3598 patients were enrolled (Subset A: 2486; Subset B: 1112). As compared with medical rate control, the AADs rhythm control was associated with similar all-cause mortality [odds ratio (OR): 0.96, P = 0.65], significantly higher rate of re-hospitalization (OR: 1.25, P = 0.01), and similar rate of stroke and thromboembolic events (OR: 0.91, P = 0.76,); however, as compared with medical therapy, catheter ablation rhythm control was associated with significantly lower all-cause mortality (OR: 0.51, P = 0.0003), reduced re-hospitalization rate (OR: 0.44, P = 0.003), similar rate of stroke events (OR: 0.59, P = 0.27), greater improvement in left ventricular ejection fraction [weighted mean difference (WMD): 6.8%, P = 0.0004], lower arrhythmia recurrence (29.6% vs. 80.1%, OR: 0.04, P < 0.00001), and greater improvement in quality of life (Minnesota Living with Heart Failure Questionnaire score) (WMD: -9.1, P = 0.007). CONCLUSION: Catheter ablation as rhythm control strategy substantially improves survival rate, reduces re-hospitalization, increases the maintenance rate of sinus rhythm, contributes to preserve cardiac function, and improves quality of life for AF patients complicated with HF.

Synergy of pulmonary vein isolation and catheter renal denervation in atrial fibrillation complicated with uncontrolled hypertension: Mapping the renal sympathetic nerve and pulmonary vein (the pulmonary vein isolation plus renal denervation strategy)?

INTRODUCTION: Disturbance of sympathetic and vagal nervous system participates in the pathogenesis of hypertension and atrial fibrillation (AF). Renal denervation (RDN) can modulate autonomic nervous activity and reduce blood pressure (BP) in hypertensive patients. We aimed to evaluate the effect of RDN combined with pulmonary vein isolation (PVI) in patients with AF and hypertension. METHODS: Clinical trials including randomized data comparing PVI plus RDN vs PVI alone were enrolled. Primary outcome was incidence of AF recurrence after procedure. RESULTS: A total of 387 patients, of them 252 were randomized and were enrolled. Mean age was 57 ± 10 years, 71% were male, and mean left ventricular ejection fraction was 57.4% ± 6.9%. Follow-up for randomized data was 12 months. Overall comparison for primary outcome showed that PVI + RDN was associated with significantly lower AF recurrence as compared with PVI alone (35.8% vs 55.4%, P < 0.0001). This advantageous effect was consistently maintained among randomized patients (37.3% vs 61.9%, odds ratio = 0.37, P = 0.0001), and among patients with implanted devices for detection of AF recurrence (38.9% vs 61.6%, P = 0.007). Post-hoc sensitivity and regression analysis demonstrated very good stability of this primary result. Pooled Kaplan-Meier analysis further showed that PVI + RDN was associated with significantly higher freedom from AF recurrence as compared with PVI alone (log-rank test, P = 0.001). Besides, RDN resulted in significant BP reduction without additionally increasing the risk of adverse events. CONCLUSIONS: RDN may provide synergetic effects with PVI to reduce the burden of AF and improve BP control in patients with AF and uncontrolled hypertension.

An apparent way of achieving proof of pulmonary vein disconnection during cryoballoon ablation.

Pulmonary vein isolation (PVI) has established itself as a standard therapy for paroxysmal atrial fibrillation (AF). Still, the most widely performed procedure of point-by-point distal-tip ablation using a 3-dimensional mapping system and a circular catheter to validate PVI remains a complex, elaborative, and time-consuming procedure. This explains the many efforts being made over the recent years to simplify and shorten PVI procedures without compromising the efficacy or the safety. The cryoballoon (Ablation Frontiers, Medtronic, Inc., Minneapolis, MN, USA) is a recently introduced "single shot ablation tool" to facilitate PVI. Initial studies on efficacy and safety of this device are encouraging in patients with paroxysmal AF. However, several controversies remain, such as the need for an additional circular mapping catheter to validate PVI and the lack of on-line PV recording during freezes. One of the most recent developments in this field is the Achieve circular mapping catheter (Ablation Frontiers, Medtronic, Inc.). We describe an apparent case in which this tool is used in conjunction with the cryoballoon.

Evolving Role of Catheter Ablation for Atrial Fibrillation: Early and Effective Rhythm Control.

Catheter Ablation (CA) is an effective therapeutic option in treating atrial fibrillation (AF). Importantly, recent data show that CA as a rhythm control strategy not only significantly reduces AF burden, but also substantially improves clinical hard endpoints. Since AF is a progressive disease, the time of Diagnosis-to-Intervention appears crucial. Recent evidence shows that earlier rhythm control is associated with a lower risk of adverse cardiovascular outcomes in patients with early AF. Particularly, CA as an initial first line rhythm control strategy is associated with significant reduction of arrhythmia recurrence and rehospitalization in patients with paroxysmal AF. CA is shown to significantly lower the risk of progression from paroxysmal AF to persistent AF. When treating persistent AF, the overall clinical success after ablation remains unsatisfactory, however the ablation outcome in patients with "early" persistent AF appears better than those with "late" persistent AF. "Adjunctive" ablation on top of pulmonary vein isolation (PVI), e.g., ablation of atrial low voltage area, left atrial posterior wall, vein of Marshall, left atrial appendage, etc., may further reduce arrhythmia recurrence in selected patient group. New ablation concepts or new ablation technologies have been developing to optimize therapeutic effects or safety profile and may ultimately improve the clinical outcome.

Adjunctive Left Atrial Posterior Wall Isolation in Treating Atrial Fibrillation: Insight From a Large Secondary Analysis.

OBJECTIVES: This study evaluated the role of adjunctive left atrium posterior wall isolation (PWI) in preventing atrial fibrillation (AF) recurrence. BACKGROUND: The left atrium posterior wall is an arrhythmogenic substrate that contributes to the development of AF. METHODS: This was an updated pooled analysis that included clinical data regarding PWI plus pulmonary vein isolation (PVI) in treating AF. The primary outcome was recurrence of atrial tachyarrhythmias. RESULTS: A total of 26 studies with 3,287 patients with AF (age 61.7 ± 10.8 years) were included. Mean follow-up was 15.2 ± 8.4 months. Procedural success to achieve PWI was 92.8%. In paroxysmal AF, adjunctive PWI did not reduce the recurrence of all atrial arrhythmias (P = 0.21) or AF (P = 0.37); however, in persistent AF, adjunctive PWI was associated with substantially lower recurrence of all atrial arrhythmias (risk ratio: 0.74; P < 0.001) and AF (risk ratio: 0.67; P = 0.01), particularly when randomized data were included. Subgroup analyses based on meta-regression demonstrated that patients with older age, a larger left atrial diameter, and persistent AF benefited more significantly from the adjunctive PWI. Adjunctive PWI using either radiofrequency or a cryoballoon reduced AF recurrence, whereas using radiofrequency seemed to be associated with higher recurrence rate of atrial tachycardias and/or atrial flutter. Non-BOX adjunctive PWI rather than BOX PWI was associated with significantly lower recurrence of AF. The incidence of procedural adverse events between the PVI+PWI (3.2%) and PVI (2.8%) groups was low and similar. PVI+PWI needed longer ablation and/or procedural time but had similar fluoroscopy time. CONCLUSIONS: Adjunctive PWI can be achieved in most patients without compromising safety. Patients with persistent AF appear to benefit from this approach. The ablation technology and/or approach may affect the clinical outcome of PWI.

Anticoagulation in atrial fibrillation and liver disease: a pooled-analysis of >20 000 patients.

AIMS: Anticoagulation for atrial fibrillation patients with liver disease represents a clinical dilemma. We sought to evaluate the efficacy/safety of different anticoagulation, i.e. vitamin K antagonist (VKA) and non-VKA oral anticoagulants (NOACs) in such patient group. METHODS AND RESULTS: This was a pooled-analysis enrolling up-to-date clinical data. Two subsets: subset A (VKA vs. Non-Anticoagulation) and subset B (NOACs vs. VKA) were pre-specified. The study outcomes were ischaemic stroke (IS)/thromboembolism (TE), major bleeding (MB), intracranial bleeding (ICB), gastrointestinal bleeding (GIB), and all-cause mortality. A total of 20 042 patients' data were analysed (subset A: N = 10 275, subset B: N = 9767). Overall mean age: 71 ± 11 years, mean CHA2DS2-VASc score: 4.0 ± 1.8, mean HAS-BLED score: 3.6 ± 1.2. The majority of the patients had Child-Pugh category (A-B). As compared with Non-Anticoagulation, VKA seemed to reduce the risk of IS/TE [odds ratio (OR): 0.60, P = 0.05], but heighten the risk of all-bleeding events including MB (OR: 2.81, P = 0.01), ICB (OR: 1.60, P = 0.01), and GIB (OR: 3.32, P = 0.01). When compared with VKA, NOACs had similar efficacy in reducing the risk of IS/TE (OR: 0.82, P = 0.64), significantly lower risk of MB (OR: 0.54, P = 0.0003) and ICB (OR: 0.35, P < 0.0001), and trend towards reduced risk of GIB (OR: 0.72, P = 0.12) and all-cause mortality (OR: 0.79, P = 0.35). The favourable effects were maintained in subgroups of individual NOAC. CONCLUSIONS: VKA appears to reduce the risk of IS/TE but increase all-bleeding events. NOACs have similar effect in reducing the risk of IS/TE and have significantly lower risk of MB and ICB as compared with VKA. NOACs seem to be associated with better clinical outcome than VKA in patients with mild-moderate liver disease.

Comparison of Left Atrial Appendage Occlusion versus Non-Vitamin-K Antagonist Oral Anticoagulation in High-Risk Atrial Fibrillation: An Update.

Transcatheter left atrial appendage occlusion (LAAO) is non-inferior to vitamin K antagonists (VKAs) in preventing thromboembolic events in atrial fibrillation (AF). Non-vitamin K antagonists (NOACs) have an improved safety profile over VKAs; however, evidence regarding their effect on cardiovascular and neurological outcomes relative to LAAO is limited. Up-to-date randomized trials or propensity-score-matched data comparing LAAO vs. NOACs in high-risk patients with AF were pooled in our study. A total of 2849 AF patients (LAAO: 1368, NOACs: 1481, mean age: 75 ± 7.5 yrs, 63.5% male) were enrolled. The mean CHA2DS2-VASc score was 4.3 ± 1.7, and the mean HAS-BLED score was 3.4 ± 1.2. The baseline characteristics were comparable between the two groups. In the LAAO group, the success rate of device implantation was 98.8%. During a mean follow-up of 2 years, as compared with NOACs, LAAO was associated with a significant reduction of ISTH major bleeding (p = 0.0002). There were no significant differences in terms of ischemic stroke (p = 0.61), ischemic stroke/thromboembolism (p = 0.63), ISTH major and clinically relevant minor bleeding (p = 0.73), cardiovascular death (p = 0.63), and all-cause mortality (p = 0.71). There was a trend toward reduction of combined major cardiovascular and neurological endpoints in the LAAO group (OR: 0.84, 95% CI: 0.64-1.11, p = 0.12). In conclusion, for high-risk AF patients, LAAO is associated with a significant reduction of ISTH major bleeding without increased ischemic events, as compared to "contemporary NOACs". The present data show the superior role of LAAO over NOACs among high-risk AF patients in terms of reduction of major bleeding; however, more randomized controlled trials are warranted.

Association of Preoperative Renin-Angiotensin System Inhibitors With Prevention of Postoperative Atrial Fibrillation and Adverse Events: A Systematic Review and Meta-analysis.

Importance: Postoperative atrial fibrillation (POAF) is a well-known complication after cardiac surgery. Renin-angiotensin system inhibitors (RASIs) have been suggested as an upstream therapy for selected patients with AF; however, evidence in the surgical setting is limited. Objective: To evaluate the role of preoperative RASIs in prevention of POAF and adverse events for patients undergoing cardiac surgery. Data Sources: The PubMed database and the Cochrane Library from inception until December 31, 2018, were searched by using the keywords renin-angiotensin system inhibitors OR angiotensin-converting enzyme inhibitors OR angiotensin receptor blocker OR aldosterone antagonist AND cardiac surgery. ClinicalTrials.gov was searched from inception until December 31, 2018, by using the keywords postoperative atrial fibrillation. Study Selection: Randomized clinical trials (RCTs) and observational studies comparing the association between preoperative RASI treatment vs no preoperative RASI treatment (control group) and the incidence of POAF were identified. Eleven unique studies met the selection criteria. Data Extraction and Synthesis: Pooled analysis was performed using a random-effects model. Sensitivity and subgroup analyses of RCTs were performed to test the stability of the overall effect. Metaregression was conducted to explore potential risk of bias. Main Outcomes and Measures: The primary outcome was POAF, and the secondary outcomes included rates of stroke and mortality and duration of hospitalization. Results: Eleven unique studies involving 27 885 unique patients (74.4% male; median age, 65 years [range, 58.5-74.5 years]) were included. Compared with the control group, the RASI group did not have a significantly reduced risk of POAF (odds ratio [OR], 1.04; 95% CI, 0.91-1.19; P = .55; z = 0.60), stroke (OR, 0.86; 95% CI, 0.62-1.19; P = .37; z = 0.90; without significant heterogeneity, P = .11), death (OR, 1.07; 95% CI, 0.85-1.35; P = .56; z = 0.59; without significant heterogeneity, P = .12), composite adverse cardiac events (OR, 1.04; 95% CI, 0.91-1.18; P = .58; z = 0.56), or a reduced hospital stay (weighted mean difference, -0.04; 95% CI, -1.05 to 0.98; P = .94; z = 0.07) using a random-effects model. Pooled analysis focusing on RCTs showed consistent results. The primary overall effect was maintained in sensitivity and subgroup analyses. Metaregression showed that male sex was significantly associated with POAF (τ2 = 0.0065; z = 3.47; Q = 12.047; P < .001) and that use of ß-blockers was associated with a significantly reduced risk in developing POAF (τ2 = 0.018; z = -2.24; Q = 5.0091; P = .03). Conclusions and Relevance: The findings from this study suggest that preoperative RASI treatment does not offer additional benefit in reducing the risk of POAF, stroke, death, and hospitalization in the setting of cardiac surgery. The results provide no support for conventional use of RASIs for the possible prevention of POAF and adverse events in patients undergoing cardiac surgery; further randomized data, particularly among those patients with heart failure, are needed.

Feasibility of catheter ablation renal denervation in "mild" resistant hypertension.

Renal denervation (RDN) has been proposed as a novel interventional antihypertensive technique. However, existing evidence was mainly from patients with severe resistant hypertension. The authors aimed to evaluate the efficacy of RDN in patients with resistant hypertension with mildly elevated blood pressure (BP). Studies of RDN in patients with mild resistant hypertension (systolic office BP 140-160 mm Hg despite treatment with three antihypertensive drugs including one diuretic, or mean systolic BP by 24-hour ambulatory BP measurement [ABPM] 135-150 mm Hg) were included. Two observational and one randomized cohort were identified (109 patients in the RDN group and 36 patients in the control group). Overall, the mean age of patients was 62±10 years, and 69.7% were male. Before-after comparison showed that RDN significantly reduced ABPM as compared with the baseline systolic ABPM, from 146.3±13 mm Hg at baseline to 134.6±14.7 mm Hg at 6-month follow-up and diastolic ABPM from 80.8±9.4 mm Hg at baseline to 75.5±9.8 mm Hg at 6-month follow up (both P<.001). This significant effect was not observed in the control group. Between-group comparison showed a greater change in ABPM in the RDN group as compared with that in the control group (change in systolic ABPM: -11.7±9.9 mm Hg in RDN vs -3.5±9.6 mm Hg in controls [P<.001]; change in diastolic ABPM: -5.3±6.3 mm Hg in RDN vs -2.1±5.5 mm Hg in control [P=.007]). RDN was also associated with a significantly decreased office systolic/diastolic BP and reduced number of antihypertensive medications. No severe adverse events were found during follow-up. RDN seems feasible to treat patients with mild resistant hypertension.

Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach.

BACKGROUND: Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG. OBJECTIVE: The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study. METHODS: We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19). RESULTS: Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin. CONCLUSION: A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.

Prospective, multicenter validation of a clinical risk score for left atrial arrhythmogenic substrate based on voltage analysis: DR-FLASH score.

BACKGROUND: Left atrial (LA) low-voltage areas (LVAs) are frequently observed in patients with atrial fibrillation (AF) and may predict AF recurrence after catheter ablation. OBJECTIVE: The aim of this study was to develop and validate a clinical tool to identify LVAs that are associated with AF recurrence after pulmonary vein isolation (PVI). METHODS: In a cohort of 238 patients, voltage maps were created during LA procedures. LVAs were defined as areas with electrogram amplitudes <0.5 mV. On the basis of regression analysis, predictors of LA substrate were identified. These parameters were used to establish a dedicated risk score (DR-FLASH score, based on diabetes mellitus, renal dysfunction, persistent form of AF, LA diameter >45 mm, age >65 years, female sex, and hypertension). This risk score was then prospectively validated in a multicenter cohort of 180 patients. The association of the score with long-term recurrence of atrial arrhythmias after circumferential PVI was tested in a retrospective cohort of 484 patients. RESULTS: The DR-FLASH score effectively identified LVA substrate (C statistic = 0.801, P < .001). In the prospective multicenter validation cohort, the predictive value of the DR-FLASH score was confirmed (C statistic = 0.767, P < .001). The probability for the presence of LA substrate increased by a factor of 2.2 (95% confidence interval [CI] 1.6-2.9, P < .001) with each point scored. Furthermore, the risk of AF recurrence after PVI increased by a factor of 1.3 (95% CI 1.1-1.5, P < .001) with every additional point and was almost 2 times higher in patients with a DR-FLASH score >3 (odds ratio 1.7, 95% CI 1.1-2.8, P = .026). CONCLUSION: The DR-FLASH score may be useful to identify patients who may require extensive substrate modification instead of PVI alone.

Impact of metabolic syndrome on left atrial electroanatomical remodeling and outcomes after radiofrequency ablation of nonvalvular atrial fibrillation.

BACKGROUND: Recent studies reported worse outcomes after atrial fibrillation (AF) ablation in patients with metabolic syndrome (MetS). However, mechanisms of AF recurrence in MetS remain unclear. METHOD AND RESULTS: We performed pulmonary vein isolation and voltage mapping in 236 patients with AF (age 61±9.6 years; persistent AF 64%; MetS 54%). Left atrial (LA) low voltage areas were semiquantitatively estimated and presented as low voltage index. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III. Follow-up for AF recurrence ≤12 months was performed. LA low voltage areas were observed in 46% of patients with MetS versus 8.2% patients without MetS ; P<0.0001. MetS was an independent predictor of LA low voltage areas: odds ratio, 11.64; 95% confidence interval, 4.381-30.903; P<0.0001. Observed AF recurrence at 12 months was 42.7% in MetS versus 36.1% in the non-MetS group (P=0.303). The presence of LA low voltage areas was a predictor of 12-month AF recurrence: odds ratio, 2.99; 95% confidence interval, 1.36-6.56; P=0.006. Probability of 12-month AF recurrence increased with 84.5% for every unit of low voltage Index. CONCLUSIONS: MetS was not associated with worse outcomes after radiofrequency catheter ablation of AF, but LA low voltage areas were more frequently observed in patients with MetS. The presence and extent of LA low voltage areas may influence the long-term outcomes after catheter ablation.