Catheter ablation of atrial fibrillation in patients with hypertrophic cardiomyopathy: a European observational multicentre study

Percutaneous endocardial septal radiofrequency ablation on syncope in patients with hypertrophic obstructive cardiomyopathy: a short-term safety and efficacy study

Background

Syncope is a serious consequence in patients with hypertrophic obstructive cardiomyopathy (HOCM). Percutaneous endocardial septal radiofrequency ablation (PESA) has emerged as a promising intervention to alleviate symptoms and enhance the quality of life for HOCM patients. However, little is known about the effects of PESA on syncope in HOCM. The authors aimed to study the effects of PESA on syncope in patients with HOCM.

Materials and methods

Nineteen patients with HOCM and syncope were enrolled. The left ventricular outflow tract gradient (LVOTG) of the patients was more than 50 mmHg despite medication. The participants underwent PESA under the guidance of intracardiac echocardiography (ICE) combined with a three-dimensional electrophysiological mapping system. The patients were followed for 3 (3-5.5) months.

Results

The mean age of the patients was 54.8±13.7 years. Out of the 19 participants, 7 (37%) were females. During the follow-up, the syncope was completely alleviated in 14 patients (73.7%) or the syncope episodes were reduced greater than or equal to 80% in 16 patients (84.2%). The mean NYHA functional class significantly improved from 2.2±0.7 at baseline to 1.7±0.6 during follow-up (P=0.002). The LVOTG and septal thickness showed a decreasing trend from baseline to follow-up (LVOTG: P=0.083, septal thickness: P=0.086).

Conclusion

The authors' investigation provides evidence supporting the effectiveness of PESA in reducing syncope episodes in patients with HOCM.

Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation

Background

Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes and those without HCM at AF catheter ablation (AFCA) and analyzed post-AFCA reverse remodeling and AF recurrence based on HCM presence and subtype.

Methods

Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age-, gender-, and AF type-matched. Between AF-HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1-year follow-up, and procedural outcomes over the course of follow-up between two groups.

Results

A total of 122 AF-HCM patients and 318 control patients were included. AF-HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p < .001). However, LAWT did not differ from control group. A year after AFCA, degree of LA reverse remodeling was significantly lower in AF-HCM than in control group (ΔLA dimension, p = .025). Nonapical HCM (HR 1.71; 95% CI 1.05-2.80), persistent AF (HR 1.46; 95% CI 1.05-2.04), and LA dimension (HR 1.04; 95% CI 1.01-1.06) were independent risk factors for AF recurrence. During 78.0 months of follow-up, nonapical HCM patients showed higher AF recurrence rate than both apical HCM (log-rank p = .005) and control patients (log-rank p = .002).

Conclusions

The presence of HCM, particularly nonapical HCM, displayed increased LA hemodynamic loading with diastolic dysfunction and had poorer rhythm outcomes after AFCA compared to both apical HCM and control group.

Comparing cryoballoon and contact-force guided radiofrequency ablation in pulmonary vein isolation for atrial fibrillation in patients with hypertrophic cardiomyopathy

BACKGROUND

Pulmonary vein isolation (PVI) employing cryoballoon (CB) or contact force-guided radiofrequency (CF-RF) catheter ablation has been established as an effective strategy for managing atrial fibrillation (AF). However, its efficacy in hypertrophic cardiomyopathy (HCM) remains to be further explored.

METHODS

This retrospective study analyzed 60 consecutive AF patients with HCM (average age 67 ± 10 years; 41 men) who were consecutively admitted to our hospital from January 2014 to December 2022 and underwent initial PVI.

RESULTS

The patients were treated with CB (26 patients) or CF-RF (34 patients). Successful PVI was achieved in both groups without significant complications. In the CF-RF group, additional ablations were performed on the cavotricuspid isthmus (14.7% of patients) and the anterior line (2.9%). The CB group benefited from reduced procedural times (93 ± 31 vs. 165 ± 60 min, p < 0.05) and decreased saline irrigation requirements (77.5 ± 31.4 vs. 870 ± 281.9 mL, p < 0.0001). Using a contrast medium was exclusive to the CB group (33.8 ± 4.2 mL). In a 12-month follow-up, the atrial tachyarrhythmia recurrence-free rates in the CB and CF-RF groups were comparable (77% and 76%, respectively; p = 0.63 according to the log-rank test). Notably, pulmonary vein reconnection was prevalent in most (7 out of 8) patients requiring a secondary ablation procedure.

CONCLUSION

PVI is feasible as a strategy for AF in patients with HCM employing either CB or CF-RF techniques. While the recurrence-free rates were comparable in both groups, differences were noted in procedure duration, saline usage, and the need for a contrast medium.

Atrial Fibrillation Substrate and Catheter Ablation Outcomes in MYBPC3- and MYH7-Mediated Hypertrophic Cardiomyopathy

BACKGROUND

The effects of disease-causing MYBPC3 or MYH7 genetic variants on atrial myopathy, atrial fibrillation (AF) clinical course, and catheter ablation efficacy remain unclear.

OBJECTIVES

The aim of this study was to characterize the atrial substrate of patients with MYBPC3- or MYH7-mediated hypertrophic cardiomyopathy (HCM) and its impact on catheter ablation outcomes.

METHODS

A retrospective single-center study of patients with HCM who underwent genetic testing and catheter ablation for AF was performed. Patients with MYBPC3- or MYH7-mediated HCM formed the gene-positive cohort; those without disease-causative genetic variants formed the control cohort. High-density electroanatomical mapping was performed using a 3-dimensional mapping system, followed by radiofrequency ablation.

RESULTS

Twelve patients were included in the gene-positive cohort (mean age 55.6 ± 9.9 years, 83% men, 50% MYBPC3, 50% MYH7, mean ejection fraction 59.3% ± 13.7%, mean left atrial [LA] volume index 51.7 ± 13.1 mL/m2, mean LA pressure 20.2 ± 5.4 mm Hg) and 15 patients in the control arm (mean age 61.5 ± 12.6 years, 60% men, mean ejection fraction 64.9% ± 5.1%, mean LA volume index 54.1 ± 12.8 mL/m2, mean LA pressure 19.6 ± 5.41 mm Hg). Electroanatomical mapping demonstrated normal voltage in 87.7% ± 5.03% of the LA in the gene-positive cohort and 94.3% ± 3.58% of the LA in the control cohort (P < 0.001). Of the abnormal regions, intermediate scar (0.1-0.5 mV) accounted for 6.33% ± 1.97% in the gene-positive cohort and 3.07% ± 2.46% in the control cohort (P < 0.01). Dense scar (<0.1 mV) accounted for 5.93% ± 3.20% in the gene-positive cohort and 2.61% ± 2.19% in the control cohort (P < 0.01). Freedom from AF at 12 months was similar between the gene-positive (75%) and control (73%) cohorts (P = 0.92), though a greater number of procedures were required in the gene-positive cohort.

CONCLUSIONS

Patients with MYBPC3- or MYH7-mediated HCM undergoing AF ablation have appreciably more low-amplitude LA signals, suggestive of fibrosis. However, catheter ablation remains an effective rhythm-control strategy.

From Atrial Fibrillation Management to Atrial Myopathy Assessment: The Evolving Concept of Left Atrium Disease in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetically inherited cardiovascular disorder in adults and a significant cause of heart failure and sudden cardiac death. Historically, atrial fibrillation (AF) has been considered as a critical aspect in HCM patients as it is considered to be a marker of disease progression, escalates the frequency of heart failure hospitalisations, increases the risk of thromboembolic events, and worsens quality of life and outcome. Increasing evidence suggests that AF is the result of a subtle long-standing process that starts early in the history of HCM. The process of left atrial dilation accompanied by morphologic and functional remodelling is the quintessential prerequisite for the onset of AF. This review aims to describe the current understanding of AF pathophysiology in HCM, emphasising the role of left atrial myopathy in its development. In addition, we discuss risk factors and management strategies specific to AF in the context of HCM, providing insights into the complexities and challenges of treating this specific patient population.

Transcatheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy: A Multicenter Propensity Score-Based Analysis

Background

The prognostic impact of catheter ablation (CA) of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients has not yet been satisfactorily elucidated.

Objectives

The aim of the study was to assess the impact of CA of AF on clinical outcomes in a large cohort of HCM patients.

Methods

In this retrospective multicenter study, 555 HCM patients with AF were enrolled, 140 undergoing CA and 415 receiving medical therapy. 1:1 propensity score matching led to the inclusion of 226 patients (113 medical group, 113 intervention group) in the final analysis. The primary outcome was a composite of all-cause mortality, heart transplant and acute heart failure exacerbations. Secondary outcomes included AF recurrence and transition to permanent AF. Additionally, an inverse probability weighted (IPW) model was examined.

Results

At propensity score matching analysis, after a median follow-up of 58.1 months, the primary endpoint occurred in 29 (25.7%) patients in intervention group vs 42 (37.2%) in medical group (P = 0.9). Thromboembolic strokes and major arrhythmic events in intervention vs medical group were 9.7% vs 7.1% (P = 0.144) and 4.4 vs 8.0% (P = 0.779), respectively. Fewer patients in intervention vs medical group experienced AF recurrences (63.7% vs 84.1%, P = 0.001) and transition to permanent AF pattern (20.4% vs 33.6%, P = 0.026). IPW analysis showed consistent results. Severe complications related to CA were uncommon (0.7%).

Conclusions

After 5 years of follow-up, CA did not improve major adverse cardiac outcomes in a large cohort of patients with HCM and AF. Nevertheless, CA seems to facilitate the maintenance of sinus rhythm and slow the progression to permanent AF, without significant safety concerns.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

Assessing the impact of atrial fibrillation on symptoms and quality of life in hypertrophic cardiomyopathy

INTRODUCTION

In hypertrophic cardiomyopathy (HCM), atrial fibrillation (AF) has historically been regarded to have a deleterious impact on clinical course, strongly associated with progressive heart failure (HF) symptoms. However, there is a paucity of information regarding the impact of AF on HCM employing validated quality of life (QoL) surveys. Therefore, we evaluated the impact of AF on QoL utilizing patient reported outcome measures (PROMs).

METHODS

218 consecutive HCM patients with or without AF at the Lahey HCM center in 2022 completed PROMs at their most recent visit evaluating HF (Kansas City Cardiomyopathy Questionnaire [KCCQ]) and AF symptoms (AF Effect on QoL [AFEQT]).

RESULTS

Among the 218 patients, 50 (23%) had a history of AF and comprise the primary study cohort. AF was diagnosed at 55 ± 10 years of age, median of 5.5 years before PROM, with 66% of patients treated with a rhythm control strategy with antiarrhythmic drug and/or AF ablation. AFEQT indicated that 52% of patients experienced no or minimal AF-related disability, mild to moderate in 22%, and severe in 26%. There was no substantial difference in HCM phenotype in patients with no or minimal AF disability compared to those with severe disability. HF symptoms for most HCM patients with prior AF history was consistent with no or minimal (59%) or only mild (27%) disability as measured by KCCQ overall summary scores. In addition, with multivariate analysis, AF history was associated with less HF symptoms and improved QoL (OR 0.4, p = 0.02).

CONCLUSION

In contrast to prior perceptions, HCM patients with prior AF history were less likely to incur HF symptoms impairing QoL compared to HCM patients without AF. After treatment, prior history of AF did not substantially impact current QoL. These data provide a realistic appraisal for the impact that AF has on HCM patients and also offers a measure of reassurance for this patient subgroup.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Atrioventricular nodal ablation is an effective management strategy for atrial fibrillation in patients with hypertrophic cardiomyopathy

BACKGROUND

Atrial fibrillation (AF) is common in patients with hypertrophic cardiomyopathy (HCM) and can be challenging to manage. Atrioventricular nodal (AVN) ablation may be an effective management strategy for AF in these patients.

OBJECTIVE

The purpose of this study was to assess the efficacy of AVN ablation in HCM patients who have failed medical therapy and/or catheter ablation for AF.

METHODS

A multicenter study with retrospective analysis of a prospectively collated HCM registry was performed. AVN ablation patients were identified. Baseline characteristics and device and procedural indications were collected. Symptoms defined by New York Heart Association and European Heart Rhythm Association classification and echocardiographic findings during follow-up were assessed.

RESULTS

Fifty-nine patients were included in the study. Indications for AVN ablation were 6 (10.2%) inappropriate implantable cardioverter-defibrillator shock, 35 (59.3%) ineffective rate control, and 18 (30.5%) to regularize rhythm for symptom improvement. During post-AVN ablation follow-up of 79.4 ± 61.1 months, left ventricular ejection fraction (LVEF) remained stable (pre-LVEF 48.9% ± 12.6% vs post-LVEF 50.1% ± 10.1%; P = .29), even in those without a cardiac resynchronization therapy (CRT) device (pre-LVEF 54.3% ± 8.0% vs post-LVEF 53.8% ± 8.0%; P = .65). Forty-nine patients (83.1%) reported an improvement in symptoms regardless of AF type (17/21 [81.0%] paroxysmal vs 32/38 [84.2%] persistent; P = 1.00), presence of baseline left ventricular impairment (22/26 [84.6%] LVEF ≤50% vs 27/33 [81.8%] LVEF ≥50%; P = 1.00) or CRT device (27/32 [84.4%] CRT vs 22/27 [81.5%] no CRT; P = 1.00). Symptoms improved in 16 patients (89.0%) who underwent AVN ablation to regularize rhythm.

CONCLUSION

AVN ablation improved symptoms without impacting left ventricular function in the majority of patients. The data suggest that AVN ablation is an effective and safe management approach for AF in HCM and should be further evaluated in larger prospective studies.

Evolving Contemporary Management of Atrial Fibrillation in Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) is the most common sustained arrhythmia in hypertrophic cardiomyopathy (HCM) with clinical and subclinical episodes occurring in nearly one-half of patients. AF in HCM historically has been characterized as a decisive disease complication associated with substantial risk for thromboembolic stroke and increased morbidity and mortality. However, there have been many advances in treatment strategy resulting in improved outcomes for this patient group. For example, stroke risk in HCM has been greatly reduced by using systemic oral anticoagulation initiated after the first clinical (symptomatic) AF episode, usually with preference given to direct anticoagulants over warfarin. In contrast, stroke risk scoring systems (such as CHA2DS2-VASc score) are not informative in HCM given the substantial potential for stroke events in patients with low scores, and therefore should not be used for anticoagulation decisions in this disease. A novel risk score specifically designed for HCM (HCM-AF score) can reliably identify most patients with HCM at risk for future AF. Although a strategy focused on controlling ventricular rate is effective in asymptomatic (or minimally symptomatic) patients with AF, restoring and maintaining sinus rhythm is required for most patients with marked AF symptom burden and impaired quality of life. Several antiarrhythmic drugs such as sotalol, disopyramide, and amiodarone, can be effective in suppressing AF episodes; albeit safe, long-term efficacy is supported by only limited data. Catheter AF ablation has emerged as an important treatment option for some patients, although freedom from AF after a single ablation is relatively low (35% at 3 years), multiple ablations and the concomitant use of antiarrhythmic drugs can control AF with more than two-thirds of patients maintaining sinus rhythm at 5 years. Surgical AF ablation with biatrial Cox-Maze IV performed as an adjunctive procedure during myectomy can reduce symptomatic AF episodes (70% of patients free from AF at 5 years). For the vast majority of patients who have HCM with AF, the implementation of contemporary therapies has allowed for improved quality of life and low HCM-related mortality.

State-of-the-art document on optimal contemporary management of cardiomyopathies

Cardiomyopathies represent significant contributors to cardiovascular morbidity and mortality. Over the past decades, a progress has occurred in characterization of the genetic background and major pathophysiological mechanisms, which has been incorporated into a more nuanced diagnostic approach and risk stratification. Furthermore, medications targeting core disease processes and/or their downstream adverse effects have been introduced for several cardiomyopathies. Combined with standard care and prevention of sudden cardiac death, these novel and emerging targeted therapies offer a possibility of improving the outcomes in several cardiomyopathies. Therefore, the aim of this document is to summarize practical approaches to the treatment of cardiomyopathies, which includes the evidence-based novel therapeutic concepts and established principles of care, tailored to the individual patient aetiology and clinical presentation of the cardiomyopathy. The scope of the document encompasses contemporary treatment of dilated, hypertrophic, restrictive and arrhythmogenic cardiomyopathy. It was based on an expert consensus reached at the Heart Failure Association online Workshop, held on 18 March 2021.

Catheter ablation of atrial fibrillation in patients with and without hypertrophic cardiomyopathy: systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM). There is limited data regarding the outcomes of AF catheter ablation in HCM patients. In this study, we aimed to synthesize all available evidence on the effectiveness of ablation of AF in patients with HCM compared to those without HCM.

METHODS AND RESULTS

We systematically reviewed bibliographic databases to identify studies published through February 2023. We included cohort studies with available quantitative information on rates of recurrent atrial arrhythmias, anti-arrhythmic drug (AAD) therapy, and repeat ablation procedures after initial AF ablation in patients with vs without HCM. Estimates were combined using random-effects meta-analysis models and reported as risk ratios (RR) and 95% confidence intervals (CI). Eight studies were included in quantitative synthesis (262 HCM and 642 non-HCM patients). During median follow-up 13-54 months across studies, AF recurrence rates ranged from 13.3% to 92.9% in HCM and 7.6% to 58.8% in non-HCM patients. The pooled RR for recurrent atrial arrhythmia after the first AF ablation in HCM patients compared to non-HCM controls was 1.498 (95% CI = 1.305-1.720; P < 0.001). During follow-up, HCM patients more often required AAD therapy (RR = 2.844; 95% CI = 1.713-4.856; P < 0.001) and repeat AF ablation (RR = 1.544; 95% CI = 1.070-2.228; P = 0.02). The pooled RR for recurrent atrial arrhythmias after the last AF ablation was higher in patients with HCM than those without HCM (RR = 1.607; 95% CI = 1.235-2.090; P < 0.001).

CONCLUSIONS

Compared to non-HCM patients, those with HCM had higher rates of recurrent atrial arrhythmias, AAD use, and need for repeat AF ablation after initial ablation of AF.

Efficacy of Catheter Ablation for Atrial Fibrillation in Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) has emerged as an effective therapy for AF. We conducted a meta-analysis to update the current clinical evidence on the efficacy of CA for AF in patients with HCM. We searched PubMed, Embase, Cochrane and Clinicaltrials.gov for interventional and observational studies assessing single and multiple procedure success rate of CA in HCM patients. Our meta-analysis included 25 studies involving 1817 patients. Success rate following single procedure was 40.4% (95% CI 33.1 to 48.0%) at latest follow-up. The pooled success rate following multiple procedures was 51.4% (95% CI 42.9% to 60.0%) at latest follow-up. In the subgroup analysis for AF subtype, TCA was more successful for paroxysmal AF compared to non-paroxysmal AF. For the subset of studies reporting drug-free success rate, single and multiple procedures had a success rate of 33.4% (95% CI 19.3 to 49.1%) and 51.8% (95% CI 41.3 to 62.2%) at latest follow-up, respectively. CA is a suitable option for AF in patients with HCM. Success rate is greater in paroxysmal AF, after multiple procedures and with antiarrhythmic drugs.

Catheter Ablation for Atrial Fibrillation in Structural Heart Disease: A Review

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Patients with structural heart disease (SHD) are at an increased risk of developing this arrhythmia and are particularly susceptible to the deleterious hemodynamic effects it carries. In the last two decades, catheter ablation (CA) has emerged as a valuable strategy for rhythm control and is currently part of the standard care for symptomatic relief in patients with AF. Growing evidence suggests that CA of AF may have potential benefits that extend beyond symptoms. In this review, we summarize the current knowledge of this intervention on SHD patients.

Catheter Ablation of Atrial Fibrillation in Hypertrophic Cardiomyopathy: A Proportional Meta-Analysis and Systematic Review of Single Arm Studies

Background

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Limited data exists about the efficacy and clinical outcomes of AF ablation in HCM.

Objective

The purpose of this meta-analysis was to evaluate the role of catheter-based ablation for treatment of AF in patients with HCM.

Methods

PubMed, SCOPUS, Web of Science, Embase, Cochrane library, and ClinicalTrials.gov were searched for studies discussing outcomes of catheter-based ablation for AF in patients with HCM. Two reviewers independently screened studies and extracted relevant data. Incidence rate estimates from individual studies underwent logit transformation to calculate the weighted summary proportion under the random effect model.

Results

A total of 19 reports met the inclusion criteria (1183 patients). The single ablation procedure was successful in 39% patients. Up to 34% patients underwent a repeat ablation. About 41% patients in normal sinus rhythm after successful AF ablation received postprocedure antiarrhythmic drug (AAD) therapy. Patients undergoing successful AF ablation experienced a significant improvement in the New York Heart Association functional class (standardized mean difference -1.03; 95% confidence interval -1.23 to -0.83; P < .00001).

Conclusion

AF ablation appears to be safe and feasible in patients with HCM. Freedom from AF after undergoing successful ablation is associated with significant improvement in heart failure symptoms.

Radiofrequency ablation in patients with obstructive hypertrophic cardiomyopathy: A systematic review and meta-analysis

Study objective

Hypertrophic cardiomyopathy (HCM) is a genetic disease that can cause left ventricular outflow tract (LVOT) obstruction. This study analyzed the efficacy of radiofrequency ablation (RA) in improving clinical and hemodynamic factors in patients receiving obstructive HCM refractory treatment. This evaluation was necessary because of the small number of studies on the effectiveness of this technique for obstructive HCM in the existing literature.

Design

We used the PubMed, Embase, and Science Direct databases to identify randomized clinical trials and observational studies addressing the clinical and hemodynamic outcomes before and after RA in patients with HCM.

Participants

We selected six articles published between 2011 and 2022, comprising 304 patients (mean age: 45 years).

Interventions

We performed a bias assessment using the ROBINS I tool, and meta-analysis processing was performed using the STATA program (v.16.0).

Results

The left ventricular outflow tract (LVOT) gradient at rest and with stimulation decreased by 58.78 mmHg (p = 0.001) and 70.38 mmHg (total effect Z = 21.62; p < 0.0001), respectively. Additionally, the New York Heart Association (NYHA) functional class decreased by 0.43 (p = 0.001), indicating symptomatic and hemodynamic improvements. Furthermore, we observed a significant reduction in septal thickness (by 4 mm; p = 0.001).

Conclusions

RA improved the NYHA functional class and LVOT gradient at rest and with stimulation and reduced septal thickness. These results suggest that RA is effective in patients refractory to pharmacological therapy and unsuitable for alcohol septal ablation or myectomy. However, more studies, including randomized clinical trials, should be conducted to define the role of RA in interventional therapies.

State-of-the-Art Treatments for Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM) are two very common clinical entities, which often occur simultaneously, giving a hard time to both patients and cardiologists. Myocyte hypertrophy, myocyte disarray and interstitial fibrosis in the left atrium (LA) predisposes to atrial arrhythmias due to modifications of the substrate that promote re-entry. AF is usually poorly tolerated due to the shortening of the diastolic time with rapid heart rates and the lack of the atrial contribution to the diastolic filling in patients who often have a previous diastolic dysfunction. AF onset frequently results in exercise intolerance and recurrent heart failure admissions and also has prognostic implications. Early maintenance of sinus rhythm appears as a worthy approach in these patients, especially when started early in the course of the disease. However, treatment with antiarrhythmic (AA) agents in HCM patients is less effective than in patients without the disease, and concerns regarding safety frequently limit the long-term adherence. Catheter ablation has limited efficacy in patients with persistent AF but can play an important role in patients with paroxysmal AF, emphasizing the importance of an accurate patient selection. The aim of this review is to provide an overview of the pathophysiology of combined HCM and AF and the principal pharmacological and non-pharmacological treatments recommended in this complex clinical scenario.

Characteristics of left atrial remodeling in patients with atrial fibrillation and hypertrophic cardiomyopathy in comparison to patients without hypertrophy

Atrial fibrillation (AF) leads to remodeling characterized by changes in both size and shape of the left atrium (LA). Here we aimed to study the effect of hypertrophic cardiomyopathy (HCM) on the pattern of LA remodeling in AF-patients. HCM-patients (n = 23) undergoing AF ablation (2009–2012) were matched and compared with 125 Non-HCM patients from our prospective registry. Pre-procedural CT data were analyzed (EnSite Verismo, SJM, MN) to determine the maximal sagittal (anterior–posterior, AP), coronal (superior-inferior, SI and transversal, TV) dimensions and the sphericity index (LAS). Volume (LAV) was rendered after appendage (LAA) and pulmonary vein (PV) exclusion. A cutting plane, between PV ostia/LAA and parallel to the posterior wall, divided LAV into anterior- (LA­A) and posterior-LA (LA­P) parts. The ratio LA-A/LAV was defined as asymmetry index (ASI). HCM patients had a wider inter-ventricular septum and a smaller LV than Non-HCM patients. LA volume (LAV 166 ± 72 vs. 130 ± 36 ml, p = 0.03) and LA diameters were significantly larger in HCM patients. Anterior volume (LA-A: 112 ± 48 vs. 83 ± 26 ml, p < 0.001) differed significantly between groups, whereas the posterior volume LA-P (55 ± 28 vs. 47 ± 13 ml, p = 0.23) and LAS (75% vs. 78%, p = 0.089) was similar in both groups. As a result, ASI was significantly higher (67 ± 6 vs. 63 ± 6%, p = 0.01) in HCM than in Non-HCM patients. In conclusion, LA remodeling in patients with AF and HCM is characterized by asymmetric dilatation, driven by an anterior rather than a posterior dilatation. This can be characterized by three-dimensional imaging and could be used as surrogate of advanced atrial remodeling.

First experience of POLARx™ versus Arctic Front Advance™: An early technology comparison

INTRODUCTION

Cryoballoon ablation is an established technique to achieve pulmonary vein isolation in patients with atrial fibrillation (AF). Recently, a new manufacturer of cryoballoon achieved regulatory CE marking (POLARx™; Boston Scientific). We describe our early experience of using this new market entrant of the technology and describe procedural aspects in comparison to the incumbent Medtronic Arctic Front Advance™.

METHODS

We assessed the first 40 AF ablations performed with the POLARx catheter at the Barts Heart Centre. These patients were compared with a contemporaneous series of patients undergoing ablation by the same operators using the Arctic Front Advance. Procedural metrics were prospectively recorded.

RESULTS

A total of four operators undertook 40 cases using the POLARx catheter, compared with 40 cases using the Arctic Front Advance. Procedure times (60.0 vs. 60.0 min) were similar between the two technologies, however left atrial dwell time (35.0 vs 39.0 min) and fluoroscopy times (3.3 vs. 5.2 min) were higher with the POLARx. Measured nadir and isolation balloon temperatures were significantly lower with POLARx. Almost all veins were isolated with a median freezing time of 16.0 (POLARx) versus 15.0 (Arctic Front Advance) min. The rate of procedural complications was low in both groups.

CONCLUSION

The POLARx cryoballoon is effective for pulmonary vein isolation. Measured isolation and nadir temperatures are lower compared with the predicate Arctic Front Advance catheter. The technology appears similar in acute efficacy and has a short learning curve, but formal dosing studies may be required to prove equivalence of efficacy.