Correspondence

Low procedure-related mortality achieved with alcohol septal ablation in European patients☆

Treatment of left ventricular outflow-obstruction (LVOTO) in hypertrophic obstructive cardiomyopathy (HOCM) by short atrio-ventricular delay pacing has long-term hemodynamic results that are not inferior to myectomy, but publications comparing long-term morbidity following those treatments are lacking.

A search for HOCM-patients attending all ten hospitals in the West Götaland Region, Sweden, from 2002 through 2013, identified 251 patients (42 treated with myectomy, 88 with pacing and 121 conservatively). As the age at procedure was significantly lower in the myectomy-group compared to the pacing-group, morbidity was compared by case-control methodology, matching patients for age, maximal wall thickness and LVOT-gradient. We found 31 pairs who constituted the comparison-groups. Post-intervention median follow-up was 15.4 and 10.4 years in pacing- and myectomy-group, respectively. Post-procedural and long-term complications and re-interventions, length of stay, and cost of hospitalization were documented.

Both treatments improved New York Heart Association class and LVOT-gradients significantly. There were fewer peri-procedural complications in the pacing-group compared to myectomy-group (3.2% and 35.5% p < 0.001). During follow-up pacemaker was implanted in 35.5% of myectomy-group for atrio-ventricular block, 9.7% peri-operatively, and 25.8% during late-follow-up. Furthermore, the pacing group had a superior freedom from all re-interventions, 90.3% versus 61.3% in myectomy-group (p = 0.003). Pacing patients had a shorter in-hospital stay (median 4 [IQR = 2] days) compared to myectomy 11 [7] days; P < 0.001). The mean cost of hospitalization was 74,000 ± 16,000 SEK for pacing and 310,000 ± 180,000 SEK for myectomy, p < 0.001.

Pacing is a simple and reliable treatment for drug-refractory HOCM-patients with low rate of complications and costs.

Hypertrophic cardiomyopathy is the leading cause of sudden death in young individuals and an important cause of heart failure at any age. In this review we discuss advances in investigation and management of this heterogenous disease. Improved cardiac imaging has allowed us to detail many of the structural abnormalities whereas the use of new techniques, predominantly in cardiac magnetic resonance imaging, has given us a greater insight in to tissue architecture, mechanism of contractile abnormalities, and function. Risk stratification remains challenging because of the low event rate in clinical studies. Multicentre registries have improved risk stratification for sudden cardiac death and multiple models can be used to aid decision-making for implantable defibrillator therapy. We discuss the current state of nonsurgical septal reduction therapy and results of multicentre registries. New approaches to septal reduction therapy including refinement of alcohol ablation and noncoronary interventions such as radiofrequency ablation of the septum show great promise. Surgical myectomy remains a major part of treatment; a greater recognition of abnormalities of the mitral valve apparatus can allow improved surgical options. Myocardial perfusion abnormalities are known to predict adverse outcome in hypertrophic cardiomyopathy and we discuss underlying mechanisms and relevance to management. The off-label use of currently licensed medicines such as ranolazine, perhexiline, calcium channel blockers, and renin-angiotensin system antagonists are discussed. A novel approach to medical treatment of the underlying sarcomeric disorder has been investigated and shows great potential.

La cardiomyopathie hypertrophique est la principale cause de mort subite chez les jeunes et une cause importante d'insuffisance cardiaque, quel que soit l’âge. Dans cette analyse, nous traitons des avancées liées à la compréhension et à la prise en charge de cette maladie hétérogène. L'amélioration de l'imagerie cardiaque nous a permis de préciser plusieurs des anomalies structurelles tandis que le recours à de nouvelles techniques, surtout en matière d'imagerie cardiaque par résonnance magnétique, nous a permis de mieux définir la structure tissulaire, les anomalies du mécanisme de contraction ainsi que le fonctionnement. La stratification du risque demeure complexe en raison du faible taux d'incidence de la maladie lors des études cliniques. Des registres multicentriques ont permis d'améliorer la stratification du risque en ce qui concerne la mort subite d'origine cardiaque, et divers modèles peuvent faciliter la prise de décision liée à l'implantation d'un défibrillateur. Nous discutons de la situation actuelle entourant l'ablation septale non chirurgicale et des résultats consignés dans des registres multicentriques. De nouvelles stratégies du côté de l'ablation septale s'avèrent très prometteuses, notamment le perfectionnement de la technique d'ablation septale à l'alcool et des interventions non coronariennes comme l'ablation septale par radiofréquence. La myectomie représente toujours la majeure partie du traitement; une meilleure détection des anomalies de la valve mitrale permet d'améliorer les options chirurgicales. Des anomalies de la perfusion myocardique sont des indicateurs connus permettant d'anticiper les effets néfastes d'une cardiomyopathie hypertrophique; nous abordons les mécanismes sous-jacents et leur pertinence à l’égard de la prise en charge. Il est également question de l'utilisation de médicaments homologués à l'heure actuelle, mais à des fins non approuvées (p. ex., la ranolazine, la perhexiline, les inhibiteurs calciques et les antagonistes du système rénine-angiotensine). Une nouvelle manière d'aborder le traitement médical d'un trouble sarcomérique sous-jacent a été étudiée et démontre un grand potentiel.

Hypertrophic obstructive cardiomyopathy is an inherited myocardial disease defined by cardiac hypertrophy (wall thickness ≥15 mm) that is not explained by abnormal loading conditions, and left ventricular obstruction greater than or equal to 30 mm Hg. Typical symptoms include dyspnoea, chest pain, palpitations, and syncope. The diagnosis is usually suspected on clinical examination and confirmed by imaging. Some patients are at increased risk of sudden cardiac death, heart failure, and atrial fibrillation. Patients with an increased risk of sudden cardiac death undergo cardioverter-defibrillator implantation; in patients with severe symptoms related to ventricular obstruction, septal reduction therapy (myectomy or alcohol septal ablation) is recommended. Life-long anticoagulation is indicated after the first episode of atrial fibrillation.