[One-year follow-up after echocardiographically-guided percutaneous septal ablation in hypertrophic obstructive cardiomyopathy]

A modified endocardial radiofrequency ablation approach for hypertrophic obstructive cardiomyopathy guided by transthoracic echocardiography: a case series

Background

A series of studies showed that endocardial radiofrequency ablation (ERFA) could reduce the left ventricular outflow tract (LVOT) gradient in patients with septal hypertrophy. This study aimed to determine the safety and efficacy of a modified ERFA approach guided by transthoracic echocardiography (TTE) as an alternative to ablation performed under a three-dimensional (3D) electroanatomical system or intracardiac echocardiography (ICE).

Methods

Twenty-five patients with hypertrophic obstructive cardiomyopathy (HOCM) underwent ERFA of septal hypertrophy, guided by echocardiography. The LVOT gradient, left ventricular ejection fraction (LVEF), LV thickness, New York Heart Association (NYHA) class, and biochemical laboratory values were recorded before ablation and during follow-up.

Results

The patients’ peak and stress-induced LVOT gradients were significantly reduced after 12 months of follow-up (resting gradient: from 123.2±17.7 to 15.7±7.8 mmHg, P<0.05; provocative gradient: from 140.2±20.8 to 18.4±8.0 mmHg, P<0.05). Compared with baseline, the septal diameter was reduced slightly after 12 months, but the difference was not significant (24.8±3.5 vs. 24.2±3.4 mm, P>0.05). The reduction in LVOT gradient was associated with an improvement in NYHA functional classification (from 3.0±0.0 to 1.6±0.7, P<0.05), the 6-minute walking distance (413±129 m at baseline; 458±108 m immediately after ERFA; 471±139 m after 12 months, P<0.05), and pro B-type natriuretic peptide levels (from 924.00±139 to 137.45 ±75.73 pg/mL, P<0.05). After the procedure, the patients showed no worsening of LVEF compared with baseline (64%±5.3%), and no cases of bundle branch block nor complete heart block occurred.

Conclusions

ERFA guided by TTE provides a new treatment option for HOCM which can achieve symptomatic improvement as well as a significant and sustained reduction of the LVOT gradient. Moreover, by avoiding the use of the 3D electroanatomical system or ICE, this treatment has an acceptable cost.

[Syncope in hypertrophic (obstructive) cardiomyopathy]

Hypertrophic cardiomyopathy is the most common genetic cardiac disease. The most important pathophysiological finding is dynamic (outflow tract) obstruction of the left ventricle in about 70% of affected patients. Especially in younger patients, an increased risk of sudden cardiac death has been observed. Syncope and presyncope-in addition to extremely variable cardiac symptoms (dyspnea and angina)-are common. The etiology of syncope is complex. The most important aspect for diagnosis is a detailed history regarding the accompanying circumstances of the syncope. In principle, an attempt must be made to distinguish between rhythmogenic and hemodynamic causes. Diagnostic work-up should be performed under the criteria of a possible prognostic-with implantation of an implantable cardioverter-defibrillator (ICD) in patients at increased risk of sudden cardiac death-and symptomatic therapy. Depending on the underlying morphology and the experience of the surgeon, percutaneous septal ablation and operative myectomy are complementary options for symptomatic treatment if medical therapy with beta-blockers and/or verapamil is inadequate.

Twenty Years of Alcohol Septal Ablation in Hypertrophic Obstructive Cardiomyopathy

Hypertrophic obstructive cardiomyopathy is the most common genetic cardiac disease and is generally characterised by asymmetric septal hypertrophy and intraventricular obstruction. Patients with severe obstruction and significant symptoms that persist despite optimal medical treatment are candidates for an invasive septal reduction therapy. Twenty years after its introduction, percutaneous transluminal alcohol septal ablation has been increasingly preferred for septal reduction in patients with drug refractory hypertrophic obstructive cardiomyopathy. Myocardial contrast echocardiography and injection of reduced alcohol volumes have increased safety, while efficacy is comparable to the surgical alternative, septal myectomy, which has for decades been regarded as the 'gold standard' treatment. Data on medium- and long-term survival show improved prognosis with survival being similar to the general population. Current guidelines have supported its use by experienced operators in centres specialised in the treatment of patients with hypertrophic obstructive cardiomyopathy.

Current status and future perspectives on alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. Patients may present with a wide variety of symptoms, ranging from relatively asymptomatic to heart failure, recurrent syncope, angina, or sudden death. Once diagnosed, a thorough clinical, anatomic and physiologic assessment should be undertaken. Treatment options include both pharmacologic and invasive therapies, with a goal to reduce symptoms and possibly extend longevity. Traditionally, the "gold standard" for treating severe obstructive HCM has been ventricular septal myotomy-myomectomy. Since its introduction in 1994, alcohol septal ablation (ASA) has emerged as an acceptable alternative in patients who meet strict anatomic criteria, and has been supported in recent guidelines. We review the indications, technique, competency requirements, alternatives, outcomes, complications, and future directions of ASA.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: a systematic review of published studies

OBJECTIVE

Alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM) has emerged as a lesser invasive alternative to surgical myectomy over the past decade. The purpose of this study is to analyze all the published literature on outcomes and complications after ASA.

METHODS

MEDLINE and PubMed were searched for all available published literature on ASA (June 1996-June 2005) using the terms hypertrophic obstructive cardiomyopathy (HOCM), alcohol septal ablation for hypertrophic obstructive cardiomyopathy, alcohol septal ablation for HOCM, alcohol septal ablation (ASA), transcoronary alcohol septal ablation for hypertrophic obstructive cardiomyopathy (TASH), transcoronary alcohol septal ablation for HOCM, nonsurgical septal reduction therapy (NSRT), and percutaneous transcoronary septal myocardial ablation (PTSMA).

RESULTS

A total of 42 published studies (2,959 patients) were analyzed. Mean age was 53.5 (35.4-72) years with a mean male to female ratio of 1.17. Mean follow-up was 12.7 +/- 0.3 months (1.5-43.2). Absolute ethanol (3 mL) was injected in 1.2 septal perforator arteries. On average, serum CK peaked at 964 units. At 12 months, there was a sustained decrease in resting and provoked LVOT gradient (65.3-15.8 and 125.4-31.5 mmHg, respectively) accompanied by reduction in basal septal diameter (20.9-13.9 mm), improvement in NYHA Class (2.9-1.2), and increase in exercise capacity (325.3-437.5 seconds). Early mortality (within 30 days) was 1.5% (0.0-5.0%) and late mortality (beyond 30 days) was 0.5% (0.0-9.3%). Other complications include ventricular fibrillation (2.2%), LAD dissection (1.8%), complete heart block requiring permanent pacemaker (10.5%), and pericardial effusion (0.6%). A repeat ASA was performed on 6.6% of patients and 1.9% of patients underwent surgical myomectomy with resolution of symptoms.

CONCLUSIONS

Literature to date suggests that ASA results in acute and intermediate-term favorable clinical and echocardiographic outcomes. A randomized controlled trial is needed to compare ASA and myomectomy in order to determine which technique provides maximal benefit.