Survival of patients ≤ 50 years of age after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Looking Back at 30 Years of Alcohol Septal Ablation and Looking Forward to the Future

In the 30 years since Dr Sigwart's first pioneering procedures, alcohol septal ablation (ASA) has become the standard catheterisation procedure to reduce or eliminate obstruction in the left ventricular outflow tract. This procedure reduces the pressure gradient by 70%-80%, and only 10%-20% of patients have a residual gradient > 30 mm Hg after ASA. The mortality rate of the procedure is < 1%, and ∼ 10% of patients require permanent pacemaker implantation for higher degrees of atrioventricular block. Given the potential risks, ASA should be performed only in centres with extensive experience in the treatment of hypertrophic cardiomyopathy and with comprehensive therapeutic options, including myectomy. In the future, ASA is likely to be increasingly complemented by catheter-based mitral valve repair, which will increase its efficacy.

Invasive therapies for symptomatic obstructive hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic condition with multiple different genetic and clinical phenotypes. As awareness for HCM increases, it is important to also be familiar with potential treatment options for the disease. Treatment of HCM can be divided into two different categories, medical and interventional. Typically for obstructive forms of the disease, in which increased septal hypertrophy, abnormally placed papillary muscles, abnormalities in mitral valve or subvalvular apparatus, lead to dynamic left ventricular outflow tract (LVOT) obstruction, treatment is targeted at decreasing obstructive gradients and therefore symptoms. Medications like beta blockers, calcium channel blockers, disopyramide can often accomplish this. However, in patients with severe obstruction or symptoms refractory to medical therapy, either surgical correction of the LVOT obstruction or percutaneous via alcohol septal ablation, are treatment options. In this review, we will focus on the invasive treatment of hypertrophic obstructive cardiomyopathy.

Targeting Alcohol Septal Ablation in Patients with Obstructive Hypertrophic Cardiomyopathy Candidates for Surgical Myectomy: Added Value of Three-Dimensional Intracoronary Myocardial Contrast Echocardiography

Background: Myocardial contrast two-dimensional echocardiography (MC-2DE) is widely used to address alcohol septal ablation (ASA) in obstructive hypertrophic cardiomyopathy (HCM). Owing to its limited cut-planes, MC-2DE may inaccurately identify the contrast misplacement associated with an unsuccessful or complicated ASA outcome. Objective: The aim of this study was to assess the added value of myocardial contrast three-dimensional echocardiography (MC-3DE) compared with MC-2DE to identify the appropriate matching between the target septal zone (TSZ) and coronary artery branch for safe and long-term effective ASA in HCM patients. Methods: A consecutive series of 52 symptomatic obstructive HCM patients referred for isolated surgical myectomy (SM) was analyzed with MC-2DE and MC-3DE following injection of echocontrast into one or more septal branches. MC-2DE and MC-3DE patterns were categorized according to complete (Type 1) or incomplete (Type 2) TSZ covering, high-risk (Type 3) exceeding TSZ, or life-threatening outside TSZ distribution (Type 4). Results: MC-2DE per patient analysis showed a Type 1 pattern in 32 patients and Types 2–4 in the remaining 20 patients; subsequent MC-3DE analysis provided a re-phenotyping of MC-2DE findings in 22 of the 52 patients (42%), showing a high-risk Type 2 pattern in 17 of the 32 patients with Type 1, and a new life-threatening Type 4 in three patients with Type 2, respectively. All patients with MC-3DE Type 1 pattern underwent safe and effective ASA with a long-term uneventful follow-up, while the remaining patients underwent SM. Conclusions: Refining high risk or life-threatening contrast misplacement, MC-3DE is more accurate than conventional MC-2DE to target safe and long-term effective septal reduction with ASA in obstructive HCM patients referred for isolated SM.

Current state of the roles of alcohol septal ablation and surgical myectomy in the treatment of hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy is a genetically determined disorder resulting in left ventricular hypertrophy. In a majority of the estimated 20 million people affected worldwide, left ventricular outflow obstruction is present at rest or with provocation. The presence and degree of obstruction influence the symptomatic presentation, treatment strategies and prognosis of affected individuals. Pharmacologic therapy with beta-adrenergic blocking drugs and calcium channel blockers is the principal treatment strategy in symptomatic patients with left ventricular outflow obstruction but is ineffective in many patients. When symptoms of exertional shortness of breath, chest pain and/or syncope prove refractory to medical therapy and there is persisting left ventricular outflow obstruction, or when there is drug intolerance, septal reduction strategies (surgical myectomy and alcohol septal ablation) are quite effective. Selection of the optimal septal reduction strategy for a given patient has become controversial and is determined largely by the medical system providing treatment strategies for the patient. Regretably, there are no randomized trials comparing myectomy and ablation and none are anticipated. The comprehensive Hypertrophic Cardiomyopathy Guideline Statements published in 2011 and 2014 differ significantly with the earlier statement favoring surgical myectomy and the more recent statement giving equal class I status to the two septal reduction strategies in adult patients with drug-refractory symptoms. Recently published studies of long-term follow-up of patients after alcohol septal ablation in Europe, where surgical myectomy is rarely performed, confirm long-term safety and effectiveness with survival free of cardiac events exceeding 96% at 15 years. The lesser degree of discomfort and more rapid recovery associated with the minimally invasive catheter-based alcohol ablation procedure coupled with the recently published long-term safety data favor an increased use of this strategy in symptomatic adult patients with hypertrophic obstructive cardiomyopathy (HOCM).

Outcome of patients ≥ 60 years of age after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

INTRODUCTION

The outcome of patients ≥ 60 years of age after alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) remains unresolved. We sought to determine the long-term survival and the causes of death in this population.

MATERIAL AND METHODS

We enrolled 156 consecutive patients (69 ±6 years, 69% women, follow-up: 4.8 ±3.5 years) who underwent ASA at ≥ 60 years of age.

RESULTS

The 30-day mortality rate was 1.3%. At the last check-up, 81% of patients were in New York Heart Association class ≤ 2 and 76% had a left ventricular outflow tract gradient (LVOG) ≤ 30 mm Hg. A total of 39 patients died (51% of cardiovascular causes, 44% of non-cardiovascular causes, 5% of unknown causes) during the 734 patient-years. The annual sudden mortality, the sudden mortality and the all-cause mortality rates were 0.5%, 1.1%, and 4.8%, respectively. The all-cause mortality was higher compared to the age- and sex-matched general population (p = 0.002).

CONCLUSIONS

Alcohol septal ablation was safe and effective in the long-term follow-up. We observed a reduced life expectancy compared to the age- and sex-matched general population. Mortality was almost equally due to cardiovascular and non-cardiovascular causes of death.

Contemporary Septal Reduction Therapy in Drug-Refractory Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complex and relatively common genetic cardiac disease that has been the subject of intense investigation for over 50 years. Most patients with HCM are asymptomatic, but some develop symptoms, often many years after the appearance of electrocardiographic or echocardiographic evidence of left ventricular hypertrophy. Symptoms due to the left ventricular outflow tract obstruction frequently worsen over time, requiring septal reduction therapy (SRT) despite optimal medical therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) and surgical myectomy are collectively known as SRT. In this review, we will focus on the emerging concept and practical implication of SRT and the available evidence on either PTSMA or surgical myectomy in the literature.

Efficacy and safety of alcohol septal ablation in patients over 65 years old with obstructive hypertrophic cardiomyopathy

Background

The performance of alcohol septal ablation (ASA) in elderly symptomatic patients with drug-refractory obstructive hypertrophic cardiomyopathy is still to be confirmed. The objective of this study was to compare the efficacy and safety of ASA in patients under and over 65 years old.

Methods and results

Fifty-one consecutive patients with obstructive hypertrophic cardio-myopathy who underwent ASA were retrospectively included and reviewed for in-hospital major acute cardiac events and follow-up. Twenty-eight patients were over 65 years old. Left ventricular outflow tract obstruction at rest, use of diuretic and average dose of diuretic were higher in patients over 65 years old. There was no difference in hospital stay between patients under and over 65 years old. Among patients over 65 years old, 2 (7%) died before being discharged. Major acute cardiac events were more frequent in patients over 65 years old in comparison with younger patients (43% versus 9%, respectively, P=0.007). The average follow-up duration was 16±15 months. There was no difference between patients under and over 65 years old regarding the efficacy of the procedure with a decrease of the New York Heart Association class of 1.3±0.6 and 1.4±0.7 (P=0.510) and the maximum left ventricular outflow tract gradient of 86±57 and 81±36 mmHg (P=0.733), respectively.

Conclusion

Elderly patients have the same benefits as younger patients after ASA but have more complications including mortality events.

Long-Term Outcome of Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy in the Young and the Elderly

OBJECTIVES

The aim of this study was to compare outcomes of alcohol septal ablation (ASA) in young and elderly patients with obstructive hypertrophic cardiomyopathy (HCM).

BACKGROUND

The American College of Cardiology Foundation/American Heart Association guidelines reserve ASA for elderly patients and patients with serious comorbidities. Information on long-term age-specific outcomes after ASA is scarce.

METHODS

This cohort study included 217 HCM patients (age 54 ± 12 years) who underwent ASA because of symptomatic left ventricular outflow tract obstruction. Patients were divided into young (age ≤55 years) and elderly (age >55 years) groups and matched by age in a 1:1 fashion to nonobstructive HCM patients.

RESULTS

Atrioventricular block following ASA was more common in elderly patients (43% vs. 21%; p = 0.001), resulting in pacemaker implantation in 13% and 5%, respectively (p = 0.06). Residual left ventricular outflow tract gradient, post-procedural New York Heart Association functional class, and necessity for additional septal reduction therapy was comparable between age groups. During a follow-up of 7.6 ± 4.6 years, 54 patients died. The 5- and 10-year survival following ASA was 95% and 90% in patients age ≤55 years and 93% and 82% in patients age >55 years, which was comparable to their control groups. The annual adverse arrhythmic event rate following ASA was 0.7%/year in young patients and 1.4%/year in elderly patients, which was comparable to their control groups.

CONCLUSIONS

ASA is similarly effective for reduction of symptoms in young and elderly patients; however, younger patients have a lower risk of procedure-related atrioventricular conduction disturbances. The long-term mortality rate and risk of adverse arrhythmic events following ASA are low, both in young and elderly patients, and are comparable to age-matched nonobstructive HCM patients.

Ten-year Survival and Its Associated Factors in the Patients Undergoing Pacemaker Implantation in Hospitals Affiliated to Shiraz University of Medical Sciences During 2002 - 2012

Background:

Heart failure is a prevalent disease affecting about 4.9 million people in the U.S. and more than 22 million individuals worldwide. Using electric pacemaker is the most common treatment for the patients with heart conduction problems. The present study aimed to determine the factors affecting survival in the patients undergoing pacemaker implantation in the hospitals affiliated to Shiraz University of Medical Sciences.

Objectives:

The aim of the present study was to identify the factors affecting the survival of the patients suffering from arrhythmia.

Patients and Methods:

This retrospective survival analysis was conducted on all 1207 patients with heart failure who had undergone permanent pacemaker implantation in the hospitals affiliated to Shiraz University of Medical Sciences from 2002 to 2012. The data were analyzed using non-parametric methods such as Kaplan-Meier method, life table, and Cox regression model. The risk factors of mortality were determined using multivariate Cox proportional hazards method.

Results:

Survival data were available for 1030 (80%) patients (median age = 71 years [5th to 95th percentile range: 26 - 86 years]) and follow-up was completed for 84.28% of them. According to the results, 56% of the patients had received dual-chamber systems, while 44% had been implanted by single-chamber ventricular systems. Moreover, sick sinus syndrome and pacemaker mode were independent predictors of increased mortality.

Conclusions:

In this study, sick sinus syndrome and pacemaker mode followed by syncope were independently associated with increased mortality.

Intervention in HCM: patient selection, procedural approach and emerging techniques in alcohol septal ablation

Hypertrophic cardiomyopathy (HCM) is a highly heterogeneous disease with varied patterns of hypertrophy. Basal septal hypertrophy and systolic anterior motion (SAM) of the mitral valve (MV) are the key pathophysiological components to left ventricular outflow tract (LVOT) obstruction in HCM. LVOT is associated with higher morbidity and mortality in patients with HCM. Percutaneous septal reduction therapy with alcohol septal ablation (ASA) can lead to a significant improvement in left ventricle haemodynamics, patient symptoms and perhaps prognosis. ASA delivers pure alcohol to an area of myocardium via septal coronary arteries; this creates damage to tissue akin to a myocardial infarction. The basal septal myocardium involved in SAM-septal contact is the target for this iatrogenic infarct. Appropriate patient selection and accurate delivery of alcohol are critical to safe and effective ASA. Securing the correct diagnosis and ensuring suitable cardiac anatomy are essential before considering ASA. Pre-procedural planning and intra-procedural imaging guidance are important to delivering precise damage to the desired area. The procedure is performed worldwide and is generally safe; the need for a pacemaker is the most prominent complication. It is successful in the majority of patients but room for improvement exists. New techniques have been proposed to perform percutaneous septal reduction. We present a review of the relevant pathophysiology, current methods and a summary of available evidence for ASA. We also provide a glimpse into emerging techniques to deliver percutaneous septal reduction therapy.