Meta-analysis of the effectiveness and safety of catheter ablation of atrial fibrillation in patients with versus without left ventricular systolic dysfunction

Left Atrium Volume Measured with Multislice Computed Tomography as a Prognostic Predictor for Atrial Fibrillation Catheter Ablation Outcomes

Background: Current guidelines consider atrial fibrillation (AF) type as the prognostic factor for a recommendation of catheter ablation. We aimed to determine whether LA and LA appendage (LAA) volumes measured using multislice computed tomography (MSCT) were related to long-term outcomes in AF following radiofrequency catheter ablation (RFCA). Methods: We evaluated 152 consecutive patients with drug-refractory AF (median age, 55.8 ± 9.6 years), including 110 male patients, who underwent RFCA in a single center. All patients underwent MSCT imaging for anatomical assessment. The endpoint of this study was documented AF recurrence after RFCA. Results: The overall procedure success rate was 77.6% (n = 118) during a mean follow-up period of 12.6 months. The LA volume was significantly larger for those who experienced AF recurrence after RFCA than for the patients without recurrent AF after the procedure (153.8 ± 29.9 mL vs. 139.2 ± 34.1 mL, p = 0.025). However, LAA volumes were nearly equivalent between the patients with and without AF recurrence after RFCA (16.2 ± 6.3 mL and 14.7 ± 6.5 mL, respectively; p = 0.235). LA volume ≥ 153.2 mL was the optimal cutoff value for estimating AF recurrence after RFCA, with 94% sensitivity and 66% specificity. LA volume remained an independent predictor of both AF recurrence and permanent AF. Conclusions: LA volume as assessed by MSCT might be helpful for identifying patients likely to achieve successful AF ablation. LA volume ≥ 153.2 mL, but not LAA volume, showed good accuracy in predicting AF recurrence after RFCA.

Catheter ablation vs. drug therapy in the treatment of atrial fibrillation patients with heart failure: An update meta-analysis for randomized controlled trials

Background

Atrial fibrillation (AF) and heart failure (HF) often coexist. The treatment of AF in patients with HF has been challenging because of the ongoing debate about the merits of catheter ablation vs. drug therapy.

Methods

The Cochrane Library, PubMed, and www.clinicaltrials.gov were searched until June 14, 2022. Inclusion criteria were catheter ablation compared with drug therapy in adults with AF and HF in randomized controlled trials (RCTs). Primary outcomes consisted of all-cause mortality, re-hospitalization, change in left ventricular ejection fraction (LVEF), and AF recurrence. Secondary outcomes referred to quality of life [QoL; measured by the Minnesota Living with Heart Failure Questionnaire (MLHFQ)], six-minute walk distance (6MWD), and adverse events. The PROSPERO registration ID was CRD42022344208.

Findings

In total, nine RCTs with 2,100 patients met the inclusion criteria, with 1,062 for catheter ablation and 1,038 for medication. According to the meta-analysis, catheter ablation significantly reduced all-cause mortality compared with drug therapy [9.2% vs. 14.1%, OR: 0.62, (95% CI: 0.47-0.82), P = 0.0007, I 2   = 0%], improved LVEF [MD: 5.65%, (95% CI: 3.32-7.98), P < 0.00001, I 2   = 86%], reduced AF recurrence [41.6% vs. 61.9%, OR: 0.23, (95% CI: 0.11-0.48), P < 0.0001, I 2   = 82%], decreased the MLHFQ score [MD: -6.38, (95% CI: -11.09 to -1.67), P = 0.008, I2  = 64%] and increased 6MWD [MD: 17.55, (95% CI: 15.77-19.33), P < 0.0001, I 2   = 37%]. Catheter ablation did not increase the re-hospitalization [30.4% vs. 35.5%, OR: 0.68, (95% CI: 0.42-1.10), P = 0.12, I 2   = 73%] and adverse events [31.5% vs. 30.9%, OR: 1.06, (95% CI: 0.83-1.35), P = 0.66, I 2   = 48%].

Interpretation

In AF patients with HF, catheter ablation improves exercise tolerance, QoL, and LVEF and significantly reduced all-cause mortality and AF recurrence. Although the differences were not statistically significant, the study found lower re-hospitalization and approximate adverse events with improved catheter ablation tendency.

PROSPERO registration ID

CRD42022344208.

Randomized Ablation-Based Rhythm-Control Versus Rate-Control Trial in Patients with Heart Failure and Atrial Fibrillation: Results from the RAFT-AF trial

Background: Atrial fibrillation (AF) and heart failure (HF) frequently coexist and can be challenging to treat. Pharmacologic based rhythm-control of AF has not proven to be superior to rate-control. Ablation-based rhythm-control was compared to rate-control to evaluate if clinical outcomes in patients with HF and AF could be improved. Methods: This was a multicenter, open-label trial with blinded outcome evaluation using a central adjudication committee. Patients with high burden paroxysmal (>4 episodes in six months) or persistent (duration < three years) AF, New York Heart Association class II-III HF, and elevated NT-proBNP were randomized to ablation-based rhythm-control or rate-control. The primary outcome was a composite of all-cause mortality and all HF events, with a minimum follow up of two years. Secondary outcomes included left ventricular ejection fraction (LVEF), six-minute walk test and NT-proBNP. Quality of life was measured using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the AF Effect on quality of life (AFEQT). The primary analysis was time-to-event using Cox proportional hazards modeling. The trial was stopped early due to a determination of apparent futility by the Data Safety Monitoring Committee. Results: From December 1, 2011, to January 20, 2018, 411 patients were randomized to ablation-based rhythm-control (n=214) or rate-control (n=197). The primary outcome occurred in 50 (23.4%) patients in the ablation-based rhythm-control group and 64 (32.5%) patients in the rate-control group (hazard ratio 0.71 95% CI (0.49, 1.03), p=0.066). LVEF increased in the ablation-based group (10.1±1.2% vs 3.8±1.2%, p=0.017); six-minute walk distance improved (44.9±9.1 meters 27.5±9.7 meters, p=0.025) and NT-proBNP demonstrated a decrease (mean change -77.1% vs -39.2%, p<0.0001). MLHFQ demonstrated greater improvement in the ablation-based rhythm-control group (LSMD of -5.4, 95%CI (-10.5, -0.3), p=0.0036), as did the AFEQT score (LSMD of 6.2, 95%CI (1.7, 10.7), p=0.0005). Serious adverse events were observed in 50% of patients in both treatment groups. Conclusions: In patients with high burden AF and HF, there was no statistical difference in all-cause mortality or HF events with ablation-based rhythm-control versus rate-control, however, there was a non-significant trend for improved outcomes with ablation-based rhythm control over rate-control.

The Critical Roles of Proteostasis and Endoplasmic Reticulum Stress in Atrial Fibrillation

Atrial fibrillation (AF) remains the most common arrhythmia seen clinically. The incidence of AF is increasing due to the aging population. AF is associated with a significant increase in morbidity and mortality, yet current treatment paradigms have proven largely inadequate. Therefore, there is an urgent need to develop new effective therapeutic strategies for AF. The endoplasmic reticulum (ER) in the heart plays critical roles in the regulation of excitation-contraction coupling and cardiac function. Perturbation in the ER homeostasis due to intrinsic and extrinsic factors, such as inflammation, oxidative stress, and ischemia, leads to ER stress that has been linked to multiple conditions including diabetes mellitus, neurodegeneration, cancer, heart disease, and cardiac arrhythmias. Recent studies have documented the critical roles of ER stress in the pathophysiological basis of AF. Using an animal model of chronic pressure overload, we demonstrate a significant increase in ER stress in atrial tissues. Moreover, we demonstrate that treatment with a small molecule inhibitor to inhibit the soluble epoxide hydrolase enzyme in the arachidonic acid metabolism significantly reduces ER stress as well as atrial electrical and structural remodeling. The current review article will attempt to provide a perspective on our recent understandings and current knowledge gaps on the critical roles of proteostasis and ER stress in AF progression.

Atrial fibrillation ablation in heart failure: What do we know? What can we do?

Atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) are two conditions that frequently impact reciprocally on each other. Patients with HFrEF have an increased risk of stroke, hospitalization and mortality after they develop AF and vice versa, AF causing deterioration of the ejection fraction is also associated to increased mortality. Catheter ablation has emerged as an effective alternative to antiarrhythmic drug treatment to maintain sinus rhythm and some randomized trials have shown a potential benefit in terms of mortality and hospitalization. This review discusses the available evidence regarding catheter ablation treatment in this specific patient group.

Atrial fibrillation in patients with systolic heart failure: pathophysiology mechanisms and management

Heart failure (HF) and atrial fibrillation (AF) demonstrate a constantly increasing prevalence during the 21^st century worldwide, as a result of the aging population and the successful interventions of the clinical practice in the deterioration of adverse cardiovascular outcomes. HF and AF share common risk factors and pathophysiological mechanisms, creating the base of a constant interrelation. AF impairs systolic and diastolic function, resulting in the increasing incidence of HF, whereas the structural and neurohormonal changes in HF with preserved or reduced ejection fraction increase the possibility of the AF development. The temporal relationship of the development of either condition affects the diagnostic algorithms, the prognosis and the ideal therapeutic strategy that leads to euvolaemia, management of non-cardiovascular comorbidities, control of heart rate or restoration of sinus rate, ventricular synchronization, prevention of sudden death, stroke, embolism, or major bleeding and maintenance of a sustainable quality of life. The indicated treatment for the concomitant HF and AF includes rate or/and rhythm control as well as thromboembolism prophylaxis, while the progress in the understanding of their pathophysiological interdependence and the introduction of the genetic profiling, create new paths in the diagnosis, the prognosis and the prevention of these diseases.

A randomized ablation-based atrial fibrillation rhythm control versus rate control trial in patients with heart failure and high burden atrial fibrillation: The RAFT-AF trial rationale and design

Heart failure (HF) and atrial fibrillation (AF) are 2 cardiac conditions that are increasing in prevalence and incidence. The 2 conditions frequently coexist, and are associated with increased morbidity and mortality. Catheter ablation of AF has been successfully performed in patients with HF, with an improvement in HF and AF, when compared to amiodarone, but further data is required to compare this to rate control. OBJECTIVES: The primary objective is to determine whether AF treated by catheter ablation, with or without antiarrhythmic drugs reduces all-cause mortality and hospitalizations for HF as compared with rate control in patients with HF and a high burden AF. METHODS: This is a multi-center prospective randomized open blinded endpoint (PROBE) study. Patients with NYHA class II-III HF (HF with reduced ejection fraction (<35%) or HF with preserved ejection fraction), and high burden AF are included in the trial. Patients are randomized to either rate control or catheter ablation-based AF rhythm control in a 1:1 ratio. Patients in the rate control group receive optimal HF therapy and rate control measures to achieve a resting hazard ratio (HR) < 80 bpm and 6-minute walk HR < 110 bpm. Patients randomized to catheter ablation-based AF rhythm control group receive optimal HF therapy and one or more aggressive catheter ablation, which include PV antral ablation and LA substrate ablation with or without adjunctive antiarrhythmic drug. The primary outcome is a composite of all-cause mortality and hospitalization for heart failure defined as an admission to a health care facility. The sample size is 600. Enrolment has been completed.

Catheter ablation for non-paroxysmal atrial fibrillation accompanied by heart failure with preserved ejection fraction: feasibility and benefits in functions and B-type natriuretic peptide

AIMS

We aimed to examine the benefits of catheter ablation in patients with non-paroxysmal atrial fibrillation (AF) accompanied by heart failure (HF) with preserved ejection fraction (HFpEF), in comparison with the benefits in patients with AF accompanied by HF with reduced ejection fraction (HFrEF) or patients with no HF.

METHODS AND RESULTS

From 1173 consecutive patients undergoing catheter ablation, 502 with non-paroxysmal AF were divided into three groups: no history of HF [plasma B-type natriuretic peptide (BNP) <100 pg/mL and no HF hospitalization; n = 125], HFpEF [left ventricular (LV) EF ≥50%; n = 293], and HF with midrange EF (HFmrEF) + HFrEF (LVEF <50%; n = 84) groups. The endpoints were AF recurrence at 1 year, changes in symptomatic and image-based functional status, and changes in BNP levels from baseline to 1 year. In the HFpEF group, AF recurred in 48 patients (16.4%) and 278 patients (94.8%) had sinus rhythm at 1 year; these values were comparable with those in the other groups. Significant improvement was observed in the left atrial diameter, LVEF, and New York Heart Association functional class in the HFpEF and HFmrEF + HFrEF groups. The BNP level significantly decreased irrespective of the index rate control status, and freedom from AF recurrence was an independent predictor of HF remission, defined as BNP <100 pg/mL at 1 year, in the HFpEF group.

CONCLUSION

Catheter ablation is highly feasible for restoring sinus rhythm in non-paroxysmal AF with coexisting HFpEF, thereby improving cardiac function and BNP levels. Catheter ablation for AF may be an optional management strategy.

A Meta-Regression Analysis of Atrial Fibrillation Ablation in Patients with Systolic Heart Failure

Background

Meta-analyses of randomized controlled trials comparing atrial fibrillation (AF) ablation to medical therapy in patients with heart failure (HF) reported improvement in left ventricular ejection fraction (LVEF), quality of life using the Minnesota Living with HF Questionnaire (MLWHFQ), and 6-minute walk test (6MWT). Nonetheless, there was significant heterogeneity not accounted for suggesting that not all HF patients derive the same effect from AF ablation.

Objectives

To evaluate if baseline LVEF or the etiology of the cardiomyopathy would moderate the efficacy of AF ablation.

Methods

We performed random effects meta-regression using the mean baseline LVEF and total percentage of patients with non-ischemic cardiomyopathy (NICMP) in the placebo arms as moderator variables.

Results

Six trials with a total of 687 patients were included. The baseline LVEF in the control arm of trials ranged from 25% - 42.9%, and the percentage of patients with NICMP within each trial varied from 35% to 100%. When baseline LVEF was used as the moderator variable, no significant change in heterogeneity was observed for any of the outcomes of interest (R2 0.00 - 0.02). However, when controlling for NICMP, heterogeneity dropped substantially for the outcomes of LVEF (I2 44.7%, R2 0.91), and MLWHFQ (I2 0.00%, R2 1.00) but not 6MWT (I2 67.4%, R2 0.00). This indicates that improvement in LVEF and MLWHFQ was greater in the AF ablation group when more patients with NICMP were included in the trials.

Conclusions

In patients with systolic HF, AF ablation may be more beneficial in patients with NICMP.

Safety and efficacy of catheter ablation in atrial fibrillation patients with left ventricular dysfunction

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) in heart failure (HF) patients reduced the mortality but may increase complications and raise the safety concern.

HYPOTHESIS

CA for AF in HF patients may not increase the complications vs medical treatment, and it may reduce hospitalizations and mortality and improve heart function.

METHODS

Three groups of AF patients were included in the study: 120 congestive HF for their first CA (AFHF-CA), 150 congestive HF who were undergoing medical therapy (AFHF-Med), and 150 patients with normal left ventricular (LV) ejection fraction (LVEF) (AF-CA).

RESULTS

After 30 ± 6 months of follow up, 45.8% of patients in the AFHF-CA and 61.3% of patients in the AF-CA groups maintained sinus rhythm (SR) in comparison with 2.7% in AFHF-Med (P < .01). Hospitalization for HF was significantly lower in AFHF-CA than in AFHF-Med groups (P < .01). Death occurred in 7.5% of patients in the AFHF-CA group, which was lower than 18% in the AFHF-Med group (P < .01). Significant improvements in heart function were shown in the AFHF-CA group compared to the AFHF-Med group, including LVEF (P < .01), LV end-diastolic diameter (P < .01), and New York Heart Association classification (P < .01), as well as the left atrial diameter (P < .01). AFHF-CA patients required additional ablation more often (P < .05). CA had a better prognosis in paroxysmal AF and tachycardia-related diseases.

CONCLUSION

CA for AF reduced hospitalizations and mortality and improved heart function, vs medical treatment, and was as safe as CA in those with normal heart function.

Methodological and Clinical Heterogeneity and Extraction Errors in Meta-Analyses of Catheter Ablation for Atrial Fibrillation in Heart Failure

Background

Meta‐analyses are expected to follow a standardized process, and thus, they have become highly formulaic, although there is little evidence that such regimentation yields high‐quality results.

Methods and Results

This article describes the results of a critical examination of 14 published meta‐analyses of catheter ablation for atrial fibrillation in heart failure that were based on a nearly identical core set of 4 to 6 primary trials. Methodological issues included (1) the neglect of primary data or the failure to report any primary data; (2) the inaccurate recording of the number of randomized patients; (3) the lack of attention to data missingness or baseline imbalances; (4) the failure to contact investigators of primary trials for additional data; (5) the incorrect extraction of data, the misidentification of events, and the assignment of events to the wrong treatment groups; (6) the calculation of summary estimates based on demonstrably heterogenous data, methods of differing reliability, or unrelated end points; and (7) the development of conclusions based on sparse numbers of events or overly reliant on the results of 1 dominant trial.

Conclusions

These findings reinforce existing concerns about the methodological validity of meta‐analyses and their current status in the hierarchy of medical evidence, and they raise new questions about the process by which meta‐analyses undergo peer review by medical journals.

Cryoballoon Ablation in Patients With Paroxysmal Atrial Fibrillation: An Evaluation of Cohorts With and Without Structural Heart Disease

BACKGROUND

Pulmonary vein isolation (PVI) is the most widely adopted strategy for paroxysmal atrial fibrillation (PAF) ablation. Limited evidence on acute results and late outcomes of cryoballoon (CB)-PVI in patients with structural heart disease (SHD) exist. The aim of this analysis was to compare acute procedural results and the 1-year recurrence rate of a single CB-PVI procedure in a PAF population with and without SHD.

METHOD

From April 2012 to May 2017, a total of 2,031 patients with AF underwent CB-PVI and were followed prospectively in the framework of the One Shot TO Pulmonary vein isolation (1STOP) ClinicalService project, involving 36 Italian cardiology centres. We identified patients with SHD according to criteria proposed by current ESC guidelines: left ventricular (LV) systolic or diastolic dysfunction, long-standing hypertension with LV hypertrophy, and/or other structural heart disease. Data on procedural outcomes and long-term freedom from AF recurrence were evaluated.

RESULTS

Our population consisted of 1,452 patients, of whom 282 (19.4%) were classified as having SHD. Compared to non-SHD patients, the SHD cohort was older (mean ± standard deviation, 62.9 ± 9.0 vs 58.2 ± 11.4 years; p < 0.001), was more frequently male (79.1% vs 69.8%; p < 0.002), had a higher thrombo-embolic risk (CHA₂DS₂VASc ≥2: 63.4% vs 40.2%; p < 0.001), had a higher body mass index (27.7 ± 3.9 vs 26.4 ± 3.9 kg/m²; p < 0.001), had a larger atrial diameter (43.8 ± 7.0 vs 40.2 ± 5.8 mm; p < 0.001), and had a lower LV ejection fraction (57.2 ± 7.7% vs 60.7 ± 6.0%; p < 0.001). At the time of ablation, 73% of patients were on class Ic or III anti-arrhythmic drugs. Procedure time (106.9 ± 41.5 vs 112.1 ± 46.8 min; p = 0.248), fluoroscopic time (28.7 ± 14.7 vs 28.6 ± 15.2 min; p = 0.819), and complication rate (3.9% vs 4.8%; p = 0.525) were not different between the SHD and non-SHD cohorts. However, the acute success rate (98.9% vs 97.7%; p = 0.016) was higher in patients with SHD. After a follow-up of 13.4 ± 12.8 months, freedom from symptomatic recurrence was 78.0% for SHD and 78.4% for non-SHD (p = 0.895). Recurrence rate was not related to either left atrial size or LVEF. In the SHD cohort, Class Ic or III anti-arrhythmic drugs treatment decreased from 70.7% of patients before ablation to 28.7% of patients after CB-PVI (p = 0.001).

CONCLUSIONS

CB-PVI was extensively applied to treat patients with PAF. Unlike previous PVI experiences, the acute success and recurrence rate after a single procedure was not related to the presence of SHD or to the degree of cardiac remodelling. Further studies are required to define whether CB-PVI has a useful role in patients with a significantly reduced ejection fraction as those patients were under-represented in the current population.

Individualised Approaches for Catheter Ablation of AF: Patient Selection and Procedural Endpoints

Pulmonary vein isolation (PVI) is the cornerstone of AF ablation, but studies have reported improved efficacy with high rates of repeat procedures. Because of the large interindividual variability in the underlying electrical and anatomical substrate, achieving optimal outcomes requires an individualised approach. This includes optimal candidate selection as well as defined ablation strategies with objective procedure endpoints beyond PVI. Candidate selection is traditionally based on coarse and sometimes arbitrary clinical stratification such as AF type, but finer predictors of treatment efficacy including biomarkers, advanced imaging and electrocardiographic parameters have shown promise. Numerous ancillary ablation strategies beyond PVI have been investigated, but the absence of a clear mechanistic and evidence-based endpoint, unlike in other arrhythmias, has remained a universal limitation. Potential endpoints include functional ones such as AF termination or non-inducibility and substrate-based endpoints such as isolation of low-voltage areas. This review summarises the relevant literature and proposes guidance for clinical practice and future research.

Should His Bundle Pacing Be Preferred over Cardiac Resynchronization Therapy Following Atrioventricular Junction Ablation?

Atrial fibrillation (AF) and heart failure (HF) are associated with high morbidity and mortality, which is particularly detrimental when patients develop rapid ventricular rates (RVR). Atrioventricular junction (AVJ) ablation with pacemaker implantation has been used as a method of achieving rate control in patients with incessant AF with RVR. Right ventricular only pacing is known to be harmful in the setting of HF. His bundle pacing (HBP) and biventricular (BiV) pacing both offer durable pacing solutions that offer more physiologic activation. This review describes the benefits and drawbacks of HBP and BiV pacing in HF patients after AVJ ablation.

Prediction and Management of Recurrences after Catheter Ablation in Atrial Fibrillation and Heart Failure

Catheter ablation is recommended in patients with symptomatic atrial fibrillation (AF) refractory to pharmacologic therapy. AF recurrence is common postablation, particularly in patients with heart failure, because of multiple structural and functional changes that can occur. Determining predictors of AF recurrence has become increasingly important. These include increased left atrial volume, termination of AF during the index ablation, electrocardiogram parameters, and serum biomarkers. Cardiac MRI can also determine the degree of scarring and left atrial sphericity, which is used in risk prediction scores. In patients with recurrence, further treatment options include pharmacologic therapy and atrioventricular nodal ablation with pacing.

Meta-Analysis of Atrial Fibrillation Ablation in Patients with Systolic Heart Failure

Atrial fibrillation (AF) and heart failure (HF) are two common conditions that often coexist and predispose each to one another. AF increases hospitalization rates and overall mortality in patients with HF. The current available therapeutic options for AF in patients with HF are diverse and guidelines do not provide a clear consensus regarding the best management approach. To determine if catheter ablation for AF is superior to medical therapy alone in patients with coexisting HF, we conducted this systematic review and meta-analysis. The primary outcomes evaluated are left ventricular ejection fraction (LVEF), Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores, 6-minute walk test (6MWT) distance, heart failure hospitalizations, and mortality. The results are presented as a mean difference for continuous outcome measures and odds ratios for dichotomous outcomes (using Mantel-Haenszel random effects model). 7 full texts met inclusion criteria, including 856 patients. AF catheter ablation was associated with a significant increase in LVEF (mean difference 6.8%; 95% CI: 3.5 – 10.1; P<0.001) and 6MWT (mean difference 29.3; 95% CI: 11.8 – 46.8; P = 0.001), and improvement in MLWHFQ (mean difference -12.1; 95% CI: -20.9 – -3.3; P = 0.007). The risk of all-cause mortality was significantly lower in the AF ablation arm (OR 0.49; 95% CI: 0.31 – 0.77; P = 0.002). In conclusion, atrial fibrillation ablation in patients with systolic heart failure is associated with significant improvement in LVEF, quality of life, 6MWT, and overall mortality.

Catheter Ablation for Atrial Fibrillation in Systolic Heart Failure Patients: Stone by Stone, a CASTLE

Heart failure (HF) and AF frequently coexist and are involved in a vicious cycle of adverse pathophysiologic interactions. Applying treatment algorithms that have been validated in the general AF population to patients with AF and HF may be fraught with risks and lack effectiveness. While firm recommendations on using catheter ablation for AF do exist, the subset of patients also suffering from HF needs to be further evaluated. Observational data indicate that a significant number of ablation procedures are performed in patients with coexistent HF. Initial randomised data on outcomes are encouraging. Apart from sinus rhythm maintenance, benefits have been observed in terms of other significant endpoints, including left ventricular ejection fraction, quality of life, exercise capacity and hospital readmissions for HF. Limited existing data on survival are also promising. In the present article, observational and randomised studies along with current practice guidelines are summarised.

Coronary Sinus Electrograms May Predict New-onset Atrial Fibrillation After Typical Atrial Flutter Radiofrequency Ablation (CSE-AF)

Background

Complex fractionated electrograms (EGMs) of the coronary sinus electrograms (CSEs) are employed as a target during radiofrequency ablations (RFA) of atrial fibrillation (AF). Anatomically, CSEs includes both of left atrium (LA), coronary sinus musculature and right atrium (RA) electrograms.

Aim

To determine the significance of fractionated CSE and delayed potentials as a predictor of new-onset AF after radiofrequency ablation (RFA) of isolated atrial flutter (AFL).

Methods

Consecutive patients underwent AFL ablation. Fractionated and/or continuous discrete activities were recorded from coronary sinus electrograms during sinus rhythm and during pacing. Earliest CSE to the S nadir or peak R in milliseconds was recorded and considered as propagation delay for EGMs.

Results

Forty patients were included during a mean follow-up period of 55.1± 15.8 months. Twenty patients (50 %) developed AF while the remaining 20 patients maintained sinus rhythm(SR) during the follow-up period. Proximal and mid CSEs were significantly fractionated in AF group compared to group with no AF development (65 % and 60% Vs. 35 % and 30 %, p = 0.03, respectively). However, during pacing from distal duo-decapolar catheter (pole 1-2), distal CSEs alone were significantly fractionated (p < 0.05) compared to SR group. Significant delayed propagation of proximal CSE during pacing and in sinus rhythm were observed in AF group (12.3 ± 9.2 ms vs 7.1 ± 3.6 ms, p = 0.03) and (7.2 ± 2.9 ms Vs 8.1 ± 4.6 ms, p= 0.02) in the same order.

Conclusion

Incidence of AF is associated with fractionated proximal and mid CSE in sinus rhythm and distal CSE during paced rhythm after isolated AFL ablation. Delayed proximal CSE propagation is correlated with AF incidence.

Meta-analysis of randomized controlled trials on atrial fibrillation ablation in patients with heart failure with reduced ejection fraction

BACKGROUND

The role of catheter ablation (CA) is increasingly recognized as a reasonable therapeutic option in patients with atrial fibrillation (AF) and heart failure (HF).

HYPOTHESIS

We aimed to compare CA to medical therapy in AF patients with HF with reduced ejection fraction (HFrEF).

METHODS

We searched the literature for randomized clinical trials comparing CA to medical therapy in this population.

RESULTS

Six trials with a total of 775 patients were included. AF was persistent in 95% of patients with a mean duration of 18.5 ± 23 months prior enrollment. The mean age was 62.2 ± 7.8 years, mostly males (83%) with mean left ventricular ejection fraction (LVEF) of 31.2 ± 6.7%. Compared to medical therapy, CA has significantly improved LVEF by 5.9% (Mean difference [MD] 5.93, confidence interval [CI] 3.59-8.27, P < 0.00001, I²  = 87%), quality of life, (MD -9.01, CI -15.56, -2.45, P = 0.007, I² = 47%), and functional capacity (MD 25.82, CI 5.46-46.18, P = 0.01, I² = 90%). CA has less HF hospital readmissions (odds ratio [OR] 0.5, CI 0.32-0.78, P = 0.002, I² = 0%) and death from any cause (OR 0.46, CI 0.29-0.73, P = 0.0009, I² = 0%). Freedom from AF during follow-up was higher in patients who had CA (OR 24.2, CI 6.94-84.41, P < 0.00001, I² = 81%.

CONCLUSION

CA was superior to medical therapy in patients with AF and HFrEF in terms of symptoms, hemodynamic response, and clinical outcomes by reducing AF burden. However, these findings are applicable to the very specific patients enrolled in these trials.

Treatment Strategies for Atrial Fibrillation With Left Ventricular Systolic Dysfunction - Meta-Analysis

BACKGROUND

Atrial fibrillation (AF) frequently coexists with heart failure (HF) with reduced ejection fraction (EF). This meta-analysis compared AF control strategies, that is, rhythm vs. rate, and catheter ablation (CA) vs. anti-arrhythmic drugs (AAD) in patients with AF combined with HF.Methods and Results:The MEDLINE, EMBASE, and CENTRAL databases were searched, and 13 articles from 11 randomized controlled trials with 5,256 patients were included in this meta-analysis. The outcomes were echocardiographic parameters (left ventricular EF, LVEF), left atrial (LA) size, and left ventricular end-systolic volume, LVESV), clinical outcomes (mortality, hospitalization, and thromboembolism), exercise capacity, and quality of life (QOL). In a random effects model, rhythm control was associated with higher LVEF, better exercise capacity, and better QOL than the rate control. When the 2 different rhythm control strategies were compared (CA vs. AAD), the CA group had significantly decreased LA size and LVESV, and improved LVEF and 6-min walk distance, but mortality, hospitalization, and thromboembolism rates were not different between the rhythm and rate control groups.

CONCLUSIONS

In AF combined with HF, even though mortality, hospitalization and thromboembolism rates were similar, a rhythm control strategy was superior to rate control in terms of improvement in LVEF, exercise capacity, and QOL. In particular, the CA group was superior to the AAD group for reversal of cardiac remodeling.

Ablation for Atrial Fibrillation in Heart Failure with Reduced Ejection Fraction

AF and heart failure with reduced ejection fraction (HFrEF) frequently coexist. Catheter ablation is an increasingly utilised treatment strategy for patients with AF and can be safely performed and is effective in achieving sinus rhythm for patients with HFrEF. Successful ablation may result in improved LV function, clinical heart failure status, quality of life and possibly even mortality. This review summarises the literature analysing efficacy, safety and outcomes of AF ablation for patients with HFrEF.

Predictors of arrhythmia recurrence in patients with heart failure undergoing left atrial ablation for atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) ablation is increasingly used in patients with reduced left ventricular ejection fraction (LVEF). The aim of the present study was to evaluate the long-term results of a single radiofrequency catheter ablation procedure in heart failure (HF) patients with AF.

HYPOTHESIS

We tested the hypothesis that left atrial ablation is an effective therapeutic modality in patients with heart failure.

METHODS

Our study included HF patients with LVEF <50% who underwent catheter ablation for AF at our department between January 2010 and March 2017. All patients underwent our institution's protocol for follow-up post-ablation.

RESULTS

The study enrolled a total of 38 patients (mean age, 54.1 ± 12.2 years; 28 [73.7%] males; mean LVEF, 38.2% ± 6.3%). After a mean follow-up period of 38.2 months (range, 5-92 months), 28 patients (73.7%) were free from arrhythmia recurrence. In multivariate analysis, early arrhythmia recurrence (P = 0.03) and amiodarone antiarrhythmic drug administration (P = 0.003) remained independent predictors of arrhythmia recurrence.

CONCLUSIONS

The main findings of this study are that (1) a single radiofrequency catheter ablation procedure is an effective and safe modality for AF in patients with concomitant HF; (2) after a mean 3.3 years of follow-up, 73.7% of HF patients remained in sinus rhythm; and (3) early arrhythmia recurrence was a significant predictor of arrhythmia recurrence after the blanking period.

Catheter ablation of atrial fibrillation in patients with heart failure and preserved ejection fraction

BACKGROUND

Few studies have examined outcomes of catheter ablation for atrial fibrillation (AF) in patients with heart failure (HF) with preserved ejection fraction (HFpEF).

OBJECTIVE

The purpose of this study was to compare outcomes of AF ablation in patients with HFpEF vs HF with reduced ejection fraction (HFrEF).

METHODS

We performed a retrospective study of 230 patients with HF who underwent AF ablation, including 97 (42.2%) with HFrEF and 133 (57.8%) with HFpEF. Outcomes included adverse events, symptoms (Mayo AF Symptom Inventory [MAFSI]), New York Heart Association (NYHA) functional class, and freedom from recurrent atrial arrhythmia at 12 months.

RESULTS

Overall, 150 of 230 patients had nonparoxysmal AF (62.8% HFpEF vs 63.0% HFrEF). Patients with HFpEF had a smaller mean left atrial diameter (4.4 ± 0.8 cm vs 4.7 ± 0.7 cm; P = .013) and were less likely to be taking a beta-blocker at baseline (72.9% vs 85.6%; P = .022). Median (Q1, Q3) procedure times (233 minutes [192, 290] vs 233.5 minutes [193.0, 297.5]; P = .780) and adverse events such as acute HF (3.8% vs 6.2%; P = .395) were similar between HFpEF and HFrEF patients. Freedom from recurrent atrial arrhythmia was not significantly different in HFpEF vs HFrEF patients (33.9% vs 32.6%; adjusted hazard ratio 1.47; 95% confidence interval 0.72-3.01), with similar improvements in NYHA functional class (-0.32 vs -0.19; P = .135) and MAFSI symptom severity (-0.23 vs -0.09; P = .116) after ablation.

CONCLUSION

Catheter ablation of AF seems to have similar effectiveness in patients with HF, regardless of presence of systolic dysfunction. There were no significant differences in procedural characteristics, arrhythmia-free recurrence, or functional improvements between patients with HFpEF and those with HFrEF.

Treatment of Patients With Atrial Fibrillation and Heart Failure With Reduced Ejection Fraction

Atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) frequently coexist, and each complicates the course and treatment of the other. Recent population-based studies have demonstrated that the 2 conditions together increase the risk of stroke, heart failure hospitalization, and all-cause mortality, especially soon after the clinical onset of AF. Guideline-directed pharmacological therapy for HFrEF is important; however, although there are various treatment modalities for AF, there is no clear consensus on how best to treat AF with concomitant HFrEF. This in-depth review discusses the available data for the treatment of AF in the setting of HFrEF, focuses on areas where more investigation is necessary, examines the clinical implications of randomized and observational clinical trials, and presents suggestions for individualized treatment strategies for specific patient groups.

Who Needs Catheter Ablation And Which Approach?

Catheter ablation therapy for atrial fibrillation (AF) has gained a significant role during maintenance of sinus rhythm compared to anti-arrhythmic medication. Catheter ablation techniques are also improved and progressed over years in parallel to better understanding of disease mechanisms and technological advancements. However, due to invasive nature of the therapy with its pertinent procedural risks, both appropriate patient selection and use of relevant approach should be considered by all electrophysiologists before decide to perform catheter ablation.

How to Improve Cardiac Resynchronization Therapy Benefit in Atrial Fibrillation Patients: Pulmonary Vein Isolation (and Beyond)

Although cardiac resynchronization therapy (CRT) is an important treatment of symptomatic heart failure patients in sinus rhythm with low left ventricular ejection fraction and ventricular dyssynchrony, its role is not well defined in patients with atrial fibrillation (AF). CRT is not as effective in patients with AF because of inadequate biventricular capture and loss of atrioventricular synchrony. Both can be addressed with catheter ablation of AF. It is still unclear if these therapies offer additive benefits in patients with ventricular dyssynchrony. This article discusses the role and techniques of catheter ablation of AF in patients with heart failure, and its application in CRT recipients.

The Right to Left Atrial Volume Ratio Predicts Outcomes after Circumferential Pulmonary Vein Isolation of Longstanding Persistent Atrial Fibrillation

BACKGROUND

We aimed to identify the predictors of clinical outcomes after circumferential pulmonary vein isolation (CPVI) without any substrate modification for longstanding persistent atrial fibrillation (LSP-AF).

METHODS

This study retrospectively analyzed 70 consecutive LSP-AF patients who underwent an initial CPVI and were followed-up for more than 1 year. The right and left atrial volumes indexed to the body surface areas (right atrial volume index [RAVI] and left atrial volume index [LAVI]) were determined by preacquired contrast-enhanced computed tomography (CT). The %RAVI/LAVI was obtained as 100 × RAVI/LAVI.

RESULTS

During a median follow-up period of 15 months (interquartile range, 13-19 months), 21 patients (30%) had arrhythmia recurrences after the CPVI. Antiarrhythmic drugs were continued in 34 patients (48%). In the Cox proportional hazard model, the %RAVI/LAVI was a significant positive predictor of arrhythmia recurrences (hazard ratio, 1.048; P = 0.039). A receiver-operating characteristic analysis demonstrated that at an optimal cutoff of 100.1 for the %RAVI/LAVI, the sensitivity and specificity for predicting arrhythmia recurrences were 85.7% and 71.4%, respectively. The Kaplan-Meier analysis showed that arrhythmia recurrences were less frequent in patients with a %RAVI/LAVI of <100.1 than in those with a %RAVI/LAVI of ≥100.1 (P < 0.0001), and the arrhythmia-free survival rate at 12 months was 89.7% and 45.2%, respectively.

CONCLUSIONS

The ratio of the RAVI to LAVI on CT may be a useful predictor of clinical outcomes after CPVI of LSP-AF. LSP-AF patients with a less predominant right atrial enlargement relative to the left atrial enlargement may be good candidates for successful treatment with CPVI alone as the ablation strategy for LSP-AF.

Molecular Mechanisms and New Treatment Paradigm for Atrial Fibrillation

BACKGROUND

Atrial fibrillation represents the most common arrhythmia leading to increased morbidity and mortality, yet, current treatment strategies have proven inadequate. Conventional treatment with antiarrhythmic drugs carries a high risk for proarrhythmias. The soluble epoxide hydrolase enzyme catalyzes the hydrolysis of anti-inflammatory epoxy fatty acids, including epoxyeicosatrienoic acids from arachidonic acid to the corresponding proinflammatory diols. Therefore, the goal of the study is to directly test the hypotheses that inhibition of the soluble epoxide hydrolase enzyme can result in an increase in the levels of epoxyeicosatrienoic acids, leading to the attenuation of atrial structural and electric remodeling and the prevention of atrial fibrillation.

METHODS AND RESULTS

For the first time, we report findings that inhibition of soluble epoxide hydrolase reduces inflammation, oxidative stress, atrial structural, and electric remodeling. Treatment with soluble epoxide hydrolase inhibitor significantly reduces the activation of key inflammatory signaling molecules, including the transcription factor nuclear factor κ-light-chain-enhancer, mitogen-activated protein kinase, and transforming growth factor-β.

CONCLUSIONS

This study provides insights into the underlying molecular mechanisms leading to atrial fibrillation by inflammation and represents a paradigm shift from conventional antiarrhythmic drugs, which block downstream events to a novel upstream therapeutic target by counteracting the inflammatory processes in atrial fibrillation.

Constitutive Expression of a Dominant-Negative TGF-β Type II Receptor in the Posterior Left Atrium Leads to Beneficial Remodeling of Atrial Fibrillation Substrate

RATIONALE

Fibrosis is an important structural contributor to formation of atrial fibrillation (AF) substrate in heart failure. Transforming growth factor-β (TGF-β) signaling is thought to be intricately involved in creation of atrial fibrosis.

OBJECTIVE

We hypothesized that gene-based expression of dominant-negative type II TGF-β receptor (TGF-β-RII-DN) in the posterior left atrium in a canine heart failure model will sufficiently attenuate fibrosis-induced changes in atrial conduction and restitution to decrease AF. Because AF electrograms are thought to reflect AF substrate, we further hypothesized that TGF-β-RII-DN would lead to increased fractionation and decreased organization of AF electrograms.

METHODS AND RESULTS

Twenty-one dogs underwent injection+electroporation in the posterior left atrium of plasmid expressing a dominant-negative TGF-β type II receptor (pUBc-TGFβ-DN-RII; n=9) or control vector (pUBc-LacZ; n=12), followed by 3 to 4 weeks of right ventricular tachypacing (240 bpm). Compared with controls, dogs treated with pUBC-TGFβ-DN-RII demonstrated an attenuated increase in conduction inhomogeneity, flattening of restitution slope and decreased duration of induced AF, with AF electrograms being more fractionated and less organized in pUBc-TGFβ-DN-RII versus pUBc-LacZ dogs. Tissue analysis revealed a significant decrease in replacement/interstitial fibrosis, p-SMAD2/3 and p-ERK1/2.

CONCLUSIONS

Targeted gene-based reduction of TGF-β signaling in the posterior left atrium-with resulting decrease in replacement fibrosis-led to beneficial remodeling of both conduction and restitution characteristics of the posterior left atrium, translating into a decrease in AF and increased complexity of AF electrograms. In addition to providing mechanistic insights, this data may have important diagnostic and therapeutic implications for AF.

Ablation Versus Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device

Background—

Whether catheter ablation (CA) is superior to amiodarone (AMIO) for the treatment of persistent atrial fibrillation (AF) in patients with heart failure is unknown.

Methods and Results—

This was an open-label, randomized, parallel-group, multicenter study. Patients with persistent AF, dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, New York Heart Association II to III, and left ventricular ejection fraction <40% within the past 6 months were randomly assigned (1:1 ratio) to undergo CA for AF (group 1, n=102) or receive AMIO (group 2, n=101). Recurrence of AF was the primary end point. All-cause mortality and unplanned hospitalization were the secondary end points. Patients were followed up for a minimum of 24 months. At the end of follow-up, 71 (70%; 95% confidence interval, 60%–78%) patients in group 1 were recurrence free after an average of 1.4±0.6 procedures in comparison with 34 (34%; 95% confidence interval, 25%–44%) in group 2 (log-rank P <0.001). The success rate of CA in the different centers after a single procedure ranged from 29% to 61%. After adjusting for covariates in the multivariable model, AMIO therapy was found to be significantly more likely to fail (hazard ratio, 2.5; 95% confidence interval, 1.5–4.3; P <0.001) than CA. Over the 2-year follow-up, the unplanned hospitalization rate was (32 [31%] in group 1 and 58 [57%] in group 2; P <0.001), showing 45% relative risk reduction (relative risk, 0.55; 95% confidence interval, 0.39–0.76). A significantly lower mortality was observed in CA (8 [8%] versus AMIO (18 [18%]; P =0.037).

Conclusions—

This multicenter randomized study shows that CA of AF is superior to AMIO in achieving freedom from AF at long-term follow-up and reducing unplanned hospitalization and mortality in patients with heart failure and persistent AF.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00729911.

Atrial fibrillation ablation and left appendage closure in heart failure patients

PURPOSE OF REVIEW

Patients with atrial fibrillation and heart failure experience an increased morbidity and mortality from the hemodynamic consequences of atrial fibrillation and an increased stroke risk. Consequently, there has been increased attention to procedural alternatives to pharmacologic rhythm control and anticoagulation for stroke prevention. This review aims to evaluate the evidence for atrial fibrillation ablation and left atrial appendage closure in heart failure patients.

RECENT FINDINGS

Several randomized control trials and systematic reviews demonstrate the safety and efficacy of atrial fibrillation ablation in patients with heart failure and left ventricular systolic dysfunction. In multiple trials, these patients have shown clinical benefit from atrial fibrillation ablation including improved left ventricular systolic function, quality of life, and clinical heart failure symptoms. The evidence of clinical benefit of atrial fibrillation ablation in heart failure patients with preserved ejection fraction remains limited. Only a handful of randomized controlled trials have been performed evaluating left atrial appendage closure, and there is insufficient data regarding the safety and efficacy of these procedures in heart failure patients.

SUMMARY

Atrial fibrillation ablation in heart failure patients remains well tolerated with an overall efficacy comparable to atrial fibrillation ablation in patients without heart failure. There is consistent evidence for the clinical benefit of atrial fibrillation ablation in heart failure patients with left ventricular systolic dysfunction and limited evidence for atrial fibrillation ablation in heart failure patients with preserved ejection fraction. Currently, there is insufficient data regarding the safety and efficacy of left atrial appendage closure devices in heart failure patients.

Atrial fibrillation in heart failure: what should we do?

Heart failure (HF) and atrial fibrillation (AF) are two conditions that are likely to dominate the next 50 years of cardiovascular (CV) care. Both are increasingly prevalent and associated with high morbidity, mortality, and healthcare cost. They are closely inter-related with similar risk factors and shared pathophysiology. Patients with concomitant HF and AF suffer from even worse symptoms and poorer prognosis, yet evidence-based evaluation and management of this group of patients is lacking. In this review, we evaluate the common mechanisms for the development of AF in HF patients and vice versa, focusing on the evidence for potential treatment strategies. Recent data have suggested that these patients may respond differently than those with HF or AF alone. These results highlight the clear clinical need to identify and treat according to best evidence, in order to prevent adverse outcomes and reduce the huge burden that HF and AF are expected to have on global healthcare systems in the future. We propose an easy-to-use clinical mnemonic to aid the initial management of newly discovered concomitant HF and AF, the CAN-TREAT HFrEF + AF algorithm (Cardioversion if compromised; Anticoagulation unless contraindication; Normalize fluid balance; Target initial heart rate <110 b.p.m.; Renin-angiotensin-aldosterone modification; Early consideration of rhythm control; Advanced HF therapies; Treatment of other CV disease).

How to Improve Cardiac Resynchronization Therapy Benefit in Atrial Fibrillation Patients: Pulmonary Vein Isolation (and Beyond)

Although cardiac resynchronization therapy (CRT) is an important treatment of symptomatic heart failure patients in sinus rhythm with low left ventricular ejection fraction and ventricular dyssynchrony, its role is not well defined in patients with atrial fibrillation (AF). CRT is not as effective in patients with AF because of inadequate biventricular capture and loss of atrioventricular synchrony. Both can be addressed with catheter ablation of AF. It is still unclear if these therapies offer additive benefits in patients with ventricular dyssynchrony. This article discusses the role and techniques of catheter ablation of AF in patients with heart failure, and its application in CRT recipients.

Efficacy and safety of catheter ablation vs. rate control of atrial fibrillation in systolic left ventricular dysfunction : A meta-analysis and systematic review

PURPOSE

It is unclear what constitutes the optimal strategy for management of atrial fibrillation (AF) in patients with systolic left ventricular (LV) dysfunction. We hypothesized that catheter ablation of AF had benefits compared with rate control in patients with systolic LV dysfunction.

METHODS

PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials and nonrandomized, observational studies. Weighted mean differences (WMD) and 95 % confidence intervals (CIs) were calculated to compare the improvement of left ventricular ejection fraction (LVEF), functional capacity, and quality of life between a catheter ablation group and a rate control group.

RESULTS

Six trials with 324 patients were included in the analysis. Patients in the catheter ablation group had greater improvement of LVEF (WMD: 8.89; 95 % CI: 6.93-10.86; p < 0.001), 6-min walk distance (WMD: 46.9; 95 % CI: 28.5-65.4; p < 0.001), and lower Minnesota Living With Heart Failure Questionnaire (MLHFQ) scores (WMD: - 19.6; 95 % CI: - 23.6-- 15.7; p < 0.001) compared with patients in the rate control group. Overall, there were only ten procedure-related events and the procedure-related events rate was 4.9 % per procedure and 5.6 % per patient.

CONCLUSION

The present analysis suggests that catheter ablation of AF has benefits in terms of an improvement in LVEF, in functional capacity, and in quality of life compared with rate control in patients with systolic LV dysfunction, and the risk of complications related to procedures is acceptable.