Surgical ablation of atrial fibrillation in hypertrophic obstructive cardiomyopathy: Outcomes of a tailored surgical approach

Hemodynamics in Left-Sided Cardiomyopathies

Cardiomyopathies, historically regarded as rare, are increasingly recognized due to advances in imaging diagnostics and heightened clinical focus. These conditions, characterized by structural and functional abnormalities of the myocardium, pose significant challenges in both chronic and acute patient management. A thorough understanding of the hemodynamic properties, specifically the pressure-volume relationships, is essential. These relationships provide insights into cardiac function, including ventricular compliance, contractility, and overall cardiovascular performance. Despite their potential utility, pressure-volume curves are underutilized in clinical settings due to the invasive nature of traditional measurement techniques. Recognizing the dynamic nature of cardiomyopathies, with possible transitions between phenotypes, underscores the importance of continuous monitoring and adaptive therapeutic strategies. Enhanced hemodynamic evaluation can facilitate tailored treatment, potentially improving outcomes for patients with these complex cardiac conditions.

Percutaneous left atrial appendage closure for stroke prevention in hypertrophic cardiomyopathy patients with atrial fibrillation

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) is an effective alternative strategy for stroke prevention in patients with atrial fibrillation (AF) at high risk for bleeding with anticoagulation (AC). Efficacy of this strategy in hypertrophic cardiomyopathy (HCM) remains uncertain.

OBJECTIVE

The study aimed to compare risk of stroke in HCM-AF patients treated with LAAC with those treated with AC.

METHODS

By use of the TriNetX Global Research Network, HCM-AF patients from 2015 to 2024 were assigned to categories of treatment with LAAC and treatment solely with AC and observed for 3 years for ischemic stroke, systemic embolism, and all-cause mortality. Propensity score matching was used to limit confounders.

RESULTS

Of 14,867 HCM-AF patients identified, 364 (2.5%) were treated with LAAC vs 14,503 (97.5%) treated with AC. HCM LAAC patients were older (72 vs 67 years; P < .001) and had more comorbidities and more prior bleeding events, including higher rate of prior gastrointestinal bleeding (68% vs 18%; P < .001), compared with HCM patients treated solely with AC. After propensity score matching, there was no baseline difference between groups including prior bleeding events (P > .05). During follow-up, HCM patients treated with LAAC had higher rates of ischemic stroke (13% vs 8%; hazard ratio, 1.9; P = .006) and systemic embolism (14% vs 9%; hazard ratio, 1.8; P = .006) but no difference in mortality compared with matched HCM patients receiving AC.

CONCLUSION

These real-world data do not support percutaneous LAAC in HCM-AF patients as the primary treatment strategy during long-term AC to reduce stroke risk. However, LAAC may remain a reasonable option for HCM-AF patients who are unable to tolerate AC because of prohibitive bleeding risk.

Perioperative echocardiography in minimally invasive surgery for hypertrophic obstructive cardiomyopathy

BACKGROUND

Hypertrophic obstructive cardiomyopathy (HOCM) is clinically symptomatic and prone to malignant arrhythmias and sudden cardiac death (SCD). Currently, an effective treatment is surgical resection of the hypertrophic ventricular septum to relieve the left ventricular outflow tract (LVOT) obstruction and mitral insufficiency. Our center performs an innovative, minimally invasive right infra-axillary thoracotomy for transaortic septal myectomy. Minimally invasive procedures rely more on perioperative transesophageal echocardiography (TEE). This study aimed to explore the use of echocardiography during the perioperative period of surgical intervention for HOCM.

METHODS

Between August 2021 and April 2022, 27 patients with HOCM underwent cardiac surgery at our hospital. Minimally invasive transaortic septal resection (Morrow myectomy) was performed from the right axilla. The extent of myectomy and need for mitral valve repair were based on perioperative TEE assessment and surgical findings. The demographic parameters and clinical data of patients were recorded. The cardiopulmonary bypass time, aortic cross-clamp, and mechanical ventilation times were calculated. TEE was used to assess ventricular wall thickening and anatomical abnormalities of mitral regurgitation, assist in intravenous catheterization, and assess the postoperative gradients of the LVOT.

RESULTS

Among the 27 patients with HOCM who underwent transaortic septal myectomy by minimally invasive right infra-axillary thoracotomy, 16 had LVOT obstruction, 2 had mid-LV obstruction, and 9 had both LVOT and mid-LV involvement. TEE provides information about the fine structure of the LV cavity and the etiology of the obstruction. In all cases, LVOT obstruction and mitral valve systolic anterior motion were resolved postoperatively, and the degree of mitral regurgitation was significantly reduced.

CONCLUSION

Perioperative echocardiography provides valuable information regarding the complex etiology of LVOT obstruction during minimally invasive right infra-axillary thoracotomy for transaortic septal myectomy. It helps determine the extent of septal resection and assess the need for concomitant mitral valve repair.

Contemporary Surgical Management of Hypertrophic Cardiomyopathy

More than half of symptomatic patients with hypertrophic cardiomyopathy (HCM) have left ventricular outflow tract (LVOT) obstruction. Septal reduction therapy by septal myectomy can dramatically relieve exertional dyspnea, chest pain, and presyncope in properly selected patients and is an important management pathway for many patients. The distribution and degree of hypertrophy in patients with obstructive HCM are variable and, as discussed in this review, can influence clinical manifestations of the disease and surgical management. Subaortic septal hypertrophy is the most common phenotype of obstructive HCM associated with LVOT obstruction, but midventricular obstruction and apical hypertrophy may occur in isolation or in conjunction with subaortic septal hypertrophy. In many comprehensive HCM centers, transaortic septal myectomy is the preferred method of septal reduction therapy for symptomatic patients with obstructive HCM. Early surgical approaches aimed at alleviating left LVOT obstruction were hampered by a lack of understanding of the anatomy and pathophysiology of obstructive HCM. With the advent of Doppler echocardiography and, more recently, cardiac magnetic resonance imaging, surgeons can precisely assess the location and degree of obstruction, left ventricular size and function, and morphology and function of the mitral valve. This review discusses the current understanding of the role of septal myectomy in the management of patients with HCM and details contemporary operative methods.

Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy and Cardiac Amyloidosis: From Clinical Management to Catheter Ablation Indication

Atrial fibrillation (AF) is the most common arrhythmia in patients affected by cardiomyopathies. Reports estimate a prevalence of 27% in patients with hypertrophic cardiomyopathy (HCM) and 40% in patients with cardiac amyloidosis (CA). The presence of AF typically results in progressive functional decline, an increased frequency of hospitalizations for heart failure, and a higher thromboembolic risk. Medical management using mainly beta-blockers or amiodarone has produced variable outcomes and a high rate of recurrence. Catheter ablation reduces symptom burden and complications despite a moderate rate of recurrence. Recent evidence suggests that an early rhythm control strategy may lead to more favorable short- and long-term outcomes. In this review, we summarize contemporary data on the management of AF in patients with cardiomyopathy (HCM and CA) with particular reference to the timing and outcomes of ablation procedures.

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.

Outcomes of concomitant surgical ablation in patients undergoing surgical myectomy for hypertrophic obstructive cardiomyopathy: A systematic review and meta-analysis

OBJECTIVE

Studies investigating the efficacy of concomitant surgical atrial fibrillation (AF) ablation in hypertrophic obstructive cardiomyopathy (HOCM) patients undergoing myectomy are scarce and limited in terms of sample size. We aim to summarize current outcomes of concomitant surgical AF ablation in HOCM patients undergoing surgical myectomy.

METHODS

This systematic review and meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included all studies reporting any of the following outcomes of concomitant surgical AF ablation in HOCM patients: freedom from recurrence of AF, overall survival and complications. Outcomes were evaluated using traditional meta-analysis at given time-points and using pooled Kaplan-Meier curves.

RESULTS

A total of 13 studies were included, resulting in a total of 616 individual patients available for analysis. AF was paroxysmal in 68.1% of the patients (95% CI 56.0-78.2%; I2 = 87.1%; 8 studies, 583 participants). The majority of patients (86.2%) underwent either conventional Cox Maze III or IV (95% CI 39.7-98.3%; I2 = 92.4%; 8 studies, 616 patients) procedure. The incidence of early post-operative pacemaker implantation was 6.1% (95% CI 3.1-11.8%). Overall survival at 3, 5 and 7 years was 95.6% (95% CI 93.4-97.9%), 93.6% (95% CI 90.8-96.5%) and 90.5% (95% CI 86.5-94.6%), respectively. Freedom from recurrent AF at 3, 5 and 7 years was 77.6% (95% CI 73.7-81.7%), 70.6% (95% CI 65.8-75.7) and 63.2% (95% CI 56.2-73.8%), respectively.

CONCLUSION

This meta-analysis supports concomitant surgical AF ablation at the time of surgical myectomy in HOCM patients, as it seems to be safe and effective in terminating AF.

Patient-Reported Atrial Fibrillation Following Septal Myectomy for Hypertrophic Cardiomyopathy

BACKGROUND

Patient-reported outcomes are important metrics of medical and surgical care. In this study, we investigated the prevalence and risk factors of patient-reported postdischarge atrial fibrillation (AF) following septal myectomy for obstructive hypertrophic cardiomyopathy.

METHODS

Patients undergoing transaortic septal myectomy from August 2001 to January 2017 were contacted regarding postdischarge AF through questionnaire-based surveys sent at 3, 5, and 10 years post procedure. For each patient, the most recent survey response was analyzed.

RESULTS

Among 949 patients, 248 (26.1%) last responded at 3 years post procedure, 353 (37.2%) at 5 years, and 348 (36.7%) at 10 years. The overall incidence of patient-reported postdischarge AF was 34.4% (n=326), and at 3, 5, and 10 years, the incidences were 22.2%, 34.8%, and 42.5% (P<0.001). After multivariable adjustment, history of preoperative AF (OR 5.566, P<0.001), early postoperative AF within the first 30 days (OR 2.211, P<0.001), preoperative left atrial volume index (OR 1.014, P=0.005), postoperative right ventricular systolic pressure (OR 1.021, P=0.013), postoperative moderate or greater mitral valve regurgitation (OR 1.893, P=0.022), and preoperative septal thickness (OR 1.043, P=0.036) were independently associated with patient-reported postdischarge AF.

CONCLUSIONS

The incidence of patient-reported postdischarge AF increases with increasing length of follow-up after septal myectomy. We identified several risk factors for late postdischarge AF that were associated with chronicity of left ventricular outflow tract obstruction, and earlier intervention may mitigate late atrial arrhythmias.

Atrial fibrillation management during septal myectomy for hypertrophic cardiomyopathy: A systematic review

INTRODUCTION

Atrial fibrillation is common in patients with hypertrophic cardiomyopathy, and significantly impacts mortality and morbidity. In patients with atrial fibrillation undergoing septal myectomy, concomitant surgery for atrial fibrillation may improve outcomes.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies reporting the outcomes of combined septal myectomy and atrial fibrillation surgery were included.

RESULTS

A total of 10 observational studies were identified, including 644 patients. Most patients had paroxysmal atrial fibrillation. The proportion with prior unsuccessful ablation ranged from 0 to 19%, and preoperative left atrial diameter ranged from 44 ± 17 to 52 ± 8 mm. Cox-Maze IV (n = 311) was the most common technique used, followed by pulmonary vein isolation (n = 222) and Cox-Maze III (n = 98). Patients with persistent or longstanding atrial fibrillation more frequently received Cox-Maze III/IV. Ranges of early postoperative outcomes included: mortality 0 to 7%, recurrence of atrial tachyarrhythmias 4.4 to 48%, cerebrovascular events 0 to 1.5%, and pacemaker insertion 3 to 21%. Long-term data was limited. Freedom from atrial tachyarrhythmias at 1 year ranged from 74% to 96%, and at 5 years from 52% to 100%. Preoperative predictors of late atrial tachyarrhythmia recurrence included left atrial diameter >45 mm, persistent or longstanding preoperative atrial fibrillation and longer atrial fibrillation duration.

CONCLUSION

In patients with atrial fibrillation undergoing septal myectomy, the addition of ablation surgery adds low overall risk to the procedure, and likely reduces the risk of recurrent atrial fibrillation in the long term. Future randomised studies comparing septal myectomy with or without concomitant AF ablation are needed.