Catheter-based septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: follow-up results of the TASH-registry of the German Cardiac Society

[Hypertrophic cardiomyopathy]

Hypertrophic cardiomyopathy is the most common genetically determined cardiac disease with a prevalence of 0.2-0.6%. The most important pathophysiological phenomenon is dynamic obstruction predominantly of the left ventricular outflow tract in 70% of the patients. Clinical symptoms (e.g. dyspnea, angina pectoris and syncope) are extremely variable depending on changes in preload and afterload and an increased risk of sudden cardiac death particularly in younger patients. The diagnostic measures should be carried out with respect to a prognostic and symptomatic treatment with implantation of an implantable cardioverter defibrillator (ICD) in cases of increased risk of sudden cardiac death. When medication treatment fails, first-line treatment consists of septal ablation and surgical myectomy as a supplementary measure, depending on the underlying morphology and experience of the surgeon.

Short- and long-term outcome after alcohol septal ablation in obstructive hypertrophic cardiomyopathy: Experience of a reference center

INTRODUCTION

In obstructive hypertrophic cardiomyopathy (HCM), alcohol septal ablation (ASA) can lead to gradient reduction and symptom improvement. We aimed to assess the efficacy and safety of ASA in a long-term outcome study.

METHODS

We analyzed patients who underwent ASA over a seven-year period in a tertiary center. The primary echocardiographic endpoint was >50% reduction in left ventricular outflow tract (LVOT) gradient within a year of the procedure. The primary clinical endpoints were improvement in functional capacity and a combined endpoint of cardiac death and rehospitalization for cardiac cause. The follow-up period was 4.17±2.13 years.

RESULTS

A total of 80 patients, mean age 63.9±12.3 years, 30.0% male, were analyzed. Baseline LVOT gradient was 96.3±34.6 mmHg and interventricular septal thickness was 21.6±3.1 mm. Minor complications were observed in 6.3% and major complications in 2.5%, and 8.8% received a permanent pacemaker. The primary echocardiographic endpoint was achieved by 85.7%. At three-month follow-up, LVOT gradient was 25.8±26.0 mmHg in the successful procedure group, compared to 69.2±35.6 mmHg in the other patients (p=0.001). At six months, LVOT gradient was 27.1±27.4 vs. 58.2±16.6 mmHg (p=0.024). Among 74 patients in NYHA class III/IV before the procedure, 57 (77%) improved to NHYA class I/II. The combined primary clinical endpoint (cardiac death and rehospitalization for cardiac cause) was observed in 27.5% (n=22). In the unsuccessful group, the combined endpoint was observed in 54.5%, compared to only 22.7% in the successful group. Only two patients died of cardiac causes.

CONCLUSION

ASA is a safe procedure with a high success rate. Patients who achieved significant reductions in LVOT gradient suffered less cardiac death and rehospitalization for cardiac cause.

Significant reduction of left atrial volume concomitant with clinical improvement after percutaneous transluminal septal myocardial ablation for drug-refractory hypertrophic obstructive cardiomyopathy, and its precise detection with multidetector CT

Objective

In patients with hypertrophic obstructive cardiomyopathy (HOCM), left atrial (LA) volume measurement is very important to provide prognostic information. Recent studies demonstrated that multidetector CT (MDCT) is useful to assess the changes in LA volume. Our aim was to examine the utility of a follow-up cardiac MDCT for long-term evaluation of the effect of percutaneous transluminal septal myocardial ablation (PTSMA) on LA volume.

Methods

We studied a consecutive cohort of 20 patients with drug-refractory symptomatic HOCM after PTSMA. We evaluated LA volume analyses with cardiac MDCT on patients who underwent PTSMA as compared to echocardiography.

Results

Before PTSMA, 75% of all patients had heart failure-associated symptoms in the New York Heart Association functional class III/IV. All patients experienced relief from heart failure-associated symptoms after PTSMA. Cardiac MDCT showed significant reduction in the index of maximum LA volume during follow-up compared to before PTSMA in the same way as in echocardiography (93.6±34.1 mL/m² vs 82.6±35.3 mL/m², p=0.035). A Bland-Altman plot showed small mean differences and limits of agreement in the measurements of the index of maximum LA volume before and after PTSMA between echocardiography and MDCT.

Conclusions

The follow-up cardiac MDCT was a useful tool to evaluate the effectiveness of PTSMA on reduction of LA volume. Cardiac MDCT might provide comparable measurements of the LA volume in patients with drug-refractory symptomatic HOCM before and after PTSMA compared to echocardiography.

Percutaneous Septal Ablation in Hypertrophic Obstructive Cardiomyopathy: From Experiment to Standard of Care

Hypertrophic cardiomyopathy (HCM) is one of the more common hereditary cardiac conditions. According to presence or absence of outflow obstruction at rest or with provocation, a more common (about 60-70%) obstructive type of the disease (HOCM) has to be distinguished from the less common (30-40%) nonobstructive phenotype (HNCM). Symptoms include exercise limitation due to dyspnea, angina pectoris, palpitations, or dizziness; occasionally syncope or sudden cardiac death occurs. Correct diagnosis and risk stratification with respect to prophylactic ICD implantation are essential in HCM patient management. Drug therapy in symptomatic patients can be characterized as treatment of heart failure with preserved ejection fraction (HFpEF) in HNCM, while symptoms and the obstructive gradient in HOCM can be addressed with beta-blockers, disopyramide, or verapamil. After a short overview on etiology, natural history, and diagnostics in hypertrophic cardiomyopathy, this paper reviews the current treatment options for HOCM with a special focus on percutaneous septal ablation. Literature data and the own series of about 600 cases are discussed, suggesting a largely comparable outcome with respect to procedural mortality, clinical efficacy, and long-term outcome.

Permanent pacing in patients with recurrence of symptoms and relapse of left ventricular obstruction at midcavity level after alcohol septal ablation

Treatment of symptom recurrence after initially successful alcohol septal ablation (ASA) in hypertrophic obstructive cardiomyopathy (HOCM) when accompanied by relapse of intracavitary left ventricular pressure gradient (LVG) is guided by the underlying mechanism. We describe our experience with permanent pacing in three patients with relapse of both LVG and symptoms 7 to 12 months after successful ASA. Even though pressure gradient recurrence was observed at midventricular level, we were able to achieve symptomatic improvement and LVG reduction after right ventricular apex pacing in all three cases. The effect on symptoms was long lasting-the 6-month followup echo-stress tests confirmed good exercise capacity and lack of provocable LVG. We found pacing to be a safe and effective treatment option in this clinical scenario. Based on our overall observations, we propose pacing as a niche treatment for patients with recurrence of LVG at midventricular level after ASA.

The diagnosis and treatment of hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common hereditary disease of the heart.

METHODS

In this article, we summarize the current state of the diagnosis and treatment of HCM on the basis of a selective review of recent publications with relevance to clinical practice.

RESULTS

Several hundred mutations in more than 27 genes, most of which encode sarcomeric structures, are associated with the HCM phenotype. Thus, HCM can be thought of as a sarcomeric disease, with myocardial fiber disarray as its histological hallmark. There are two types of HCM, a more common, obstructive type (HOCM, 70%) and a less common, non-obstructive type (HNCM; in all cases of HCM, testing should be performed to detect outflow obstruction at rest and/or on provocation, and to thereby determine whether HOCM or HNCM is present. The symptoms of HCM include dyspnea, angina pectoris, palpitations, dizziness, and occasionally syncope. Because sudden cardiac death is the most serious complication of HCM, particularly in young and asymptomatic patients, it follows that correct diagnosis, followed by risk stratification of patients with regard to the need for prophylactic implantation of an implantable cardiac defibrillator (ICD), can be of life-saving importance. The pharmacotherapy of symptomatic HNCM consists of the treatment of heart failure with a normal ejection fraction (HFNEF). In HOCM, the patient's symptoms and the obstructive gradient are the guide to treatment with beta-blockers or verapamil. For patients with drug-resistant disease, surgical myectomy and percutaneous septal ablation are now standard treatments.

CONCLUSION

A near-normal life expectancy and a highly satisfactory quality of life are now realistic treatment goals for patients with HCM.

Peak systolic longitudinal strain of the lateral left ventricular wall improves after septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: a follow-up study using speckle tracking echocardiography

Speckle tracking echocardiography (STE) or two-dimensional (2D) strain imaging is a novel ultrasound method to assess myocardial deformation. Peak systolic longitudinal strain (PSLS) of the basal septum (IVS) and the opposite lateral (LVFW) wall were measured in addition to standard echocardiography in 88 consecutive patients (pts) with obstructive hypertrophic cardiomyopathy (HOCM) who underwent a septal ablation procedure (PTSMA) and who were re-evaluated 12 ± 12 after months. At baseline, PSLS was substantially reduced both in basal regions. While PSLS remained unchanged in the basal IVS, i.e. the target region for PTSMA (baseline: -5.3 ± 4.1%; follow-up: -6.0 ± 4.3%; P=0.06), it improved in the opposite LVFW (from -9.4 ± 4.7 to -12.4 ± 4.8%; P<0.0001). Wall thickness decreased in both regions (Septum: from 20 ± 4 to 17 ± 4 mm; P<0.0001; LV free wall: from 13 ± 2 to 12 ± 2 mm; P=0.001). PSLS correlated significantly with wall thickness, both at baseline and at follow-up. NYHA functional class (from 2.9 ± 0.4 to 1.6 ± 0.6; P<0.0001) and objective exercise capacity (from 96 ± 42 to 114 ± 42 W; P=0.001) improved together with the reduction of outflow obstruction (LVOTO: from 62 ± 30 to 11 ± 19 mm Hg at rest, from 121 ± 26 to 43 ± 40 mm Hg with provocation; P<0.0001). During the 12 months of observation, no patient had a severe adverse event. Regional myocardial deformation can be assessed quantitatively by STE. Reduction of LV afterload by elimination of the outflow gradient following a successful PTSMA with low doses of alcohol results in improvement of systolic lateral longitudinal function.

Percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: managing the risk of procedure-related AV conduction disturbances

AIM

To provide tools for predicting the course of AV conduction disturbances after ethanol-induced septal ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM).

METHODS AND RESULTS

Based on a scoring system developed 1996-1998 and including parameters from baseline ECG, heart rate profile, severity of outflow obstruction (LVOTO), peri-interventional enzyme kinetics, and peri-interventional conduction problems, the risk of permanent AV block following PTSMA was assessed in 155 consecutive HOCM patients (pts.; mean age: 53+/-13 years) between 1999 and 2004. During PTSMA with 2.1+/-0.5 ml of ethanol, transient complete AV block occurred in 71 pts. (46%). Pts. were grouped into a low, intermediate, and high risk group for permanent conduction damage, and treated accordingly (early discharge from monitoring, prolonged monitoring, early DDD-PM implantation). Permanent pacing was necessary in 11 cases (7%), 0/116 of these (0%) in the low, 4/31 (13%) in the intermediate, and 7/8 (87%) in the high-risk group. While a new right bundle branch block was the most frequent ECG finding after PTSMA, a left bundle branch block at baseline was associated with 4 of the 11 DDD-PM implantations (p<0.0001). In-hospital mortality was 0%, short-term (3-months) follow up was complete. During follow-up, AV conduction recovered in 4 pts. (46%) with a DDD-PM. New onset AV blocks did not occur. Significant improvement of symptoms was reported by 141 pts. (91%).

CONCLUSIONS

Catheter-based septal ablation is an effective non-surgical technique for reducing symptoms and outflow gradients in HOCM. The proposed scoring system appears to reliably discriminate pts. with a high risk for permanent PM dependency from those with stable AV conduction after PTSMA. Pts. with left bundle branch block at baseline should undergo DDD-PM implantation prior to ablation.

Effect of transcoronary ablation of septal hypertrophy on clinical outcome in hypertrophic obstructive cardiomyopathy associated with atrial fibrillation

BACKGROUND

Relatively few reports on the clinical impact of atrial fibrillation (AF) in hypertrophic obstructive cardiomyopathy (HOCM) are available. The aims of our study are to report the effect of transcoronary ablation of septal hypertrophy (TASH) on clinical outcome in HOCM associated with AF and to evaluate the influence of AF on symptoms and quality of life in HOCM.

PATIENT AND METHODS

In 80 consecutive patients (38 f, mean age 56 +/- 17 years) with severely symptomatic HOCM referred for interventional treatment, we analyzed the prevalence of AF based on 240 Holter ECG recordings and patients' history, retrospectively. Symptoms, quality of life, number of hospital admissions and hemodynamic performance were obtained in all patients before and after TASH. Mortality was additionally investigated by letter and telephone contact.

RESULTS

The overall prevalence of AF was 29%. Paroxysmal AF was detected in 17 pts (21.3%), persistent AF in 5 pts (6.3%). Only 1 pt (1.3%) suffered from permanent AF. Symptoms due to AF were present in 52.6% of the AF patients. Quality of life score was markedly improved after TASH (15.9 +/- 3.8 vs. 20.7 +/- 3.8, p < 0.001) with no difference between sinus rhythm and atrial fibrillation. However, hospital admissions were more frequent in the AF group (0.85 +/- 1.84 vs. 0.28 +/- 0.81, p = 0.03) in 32 +/- 13 months. AF patients suffered more often from syncope before TASH (30 +/- 70% vs. 10 +/- 30%, p = 0.008). Two patients with sinus rhythm at baseline died after 32 +/- 13 months from cardiovascular cause.

CONCLUSIONS

Atrial fibrillation is the major cardiac arrhythmia in severe HOCM. The majority of AF patients demonstrate AF specific symptoms. The paroxysmal type of atrial fibrillation dominates by far. Both patients with and without atrial fibrillation showed similar quality of life with marked improvement after TASH.