American College of Cardiology/European Society of Cardiology Clinical Expert Consensus Document on Hypertrophic Cardiomyopathy A report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines

Abstract

Preamble Introduction Organization of committee and evidence review Purpose of this Expert Consensus Document General considerations and perspectives Nomenclature, definitions, and clinical diagnosis Obstruction to LV Outflow Genetics and molecular diagnosis General considerations for natural history, and clinical course Symptoms and pharmacological managementstrategies Beta-adrenergic blocking agents Verapamil Disopyramide Drugs in end-stage phase Asymptomatic patients Infective endocarditis prophylaxis Pregnancy Treatment options for drug-refractory patients Additional approaches to relieve outflowobstruction and symptoms Dual-chamber pacing Percutaneous alcohol septal ablation Sudden Cardiac Death Risk stratification Prevention Athlete recommendations Atrial Fibrillation References This document has been developed as a Clinical Expert Consensus Document (CECD), combining the resources of the American College of Cardiology Foundation (ACCF) and the European Society of Cardiology (ESC). It is intended to provide a perspective on the current state of management of patients with hypertrophic cardiomyopathy. Clinical Expert Consensus Documents are intended to inform practitioners, payers, and other interested parties of the opinion of the ACCF and the ESC concerning evolving areas of clinical practice and/or technologies that are widely available or new to the practice community. Topics chosen for coverage by expert consensus documents are so designed because the evidence base, the experience with technology, and/or the clinical practice are not considered sufficiently well developed to be evaluated by the formal American College of Cardiology/American Heart Association (ACC/AHA) Practice Guidelines process. Often the topic is the subject of considerable ongoing investigation. Thus, the reader should view the CECD as the best attempt of the ACC and the ESC to inform and guide clinical practice in areas where rigorous evidence may not yet be available or the evidence to date is not widely accepted. When feasible, CECDs include indications or contraindications. Some topics covered by CECDs will be addressed subsequently by the ACC/AHA Practice Guidelines Committee. The Task Force on Clinical Expert Consensus Documents makes every effort to avoid any actual or potential conflicts of interest that might arise as a result of an outside relationship or personal interest of a member of the writing panel. Specifically, all members of the writing panel are asked to provide disclosure statements of all such relationships that might be perceived as real or potential conflicts of interest to inform the writing effort. These statements are reviewed by the parent task force, reported orally to all members of the writing panel at the first meeting, and updated as changes occur. Robert A. Vogel, MD, FACC, Chair, ACCF Task Force on Clinical Expert Consensus DocumentsWerner W. Klein, MD, FACC, FESC Chair, ESC Committee for Practice Guidelines The Writing Committee consisted of acknowledged experts in hypertrophic cardiomyopathy (HCM) representing the American College of Cardiology Foundation and the European Society of Cardiology. Both theacademic and private practice sectors were represented. The document was reviewed by 2 official reviewers nominated by the ACCF, 3 official reviewers were nominated by the ESC, 12 members of the ACCF Clinical Electrophysiology Committee, and 4 additional content reviewers nominated by the Writing Committee. The document was approved for publication by the ACCF Board of Trustees in August 2003 and the Board of ESC in July 2003. This document will be considered current until the Task Force on Clinical Expert Consensus Documents revises or withdraws it from distribution. In addition to the references cited as part of this document, a comprehensive bibliography including relevant, supplementary references is available on the ACCF and ESC websites. Hypertrophic cardiomyopathy is a complex and relatively common genetic cardiac disorder (about 1:500 in the general adult population)1that has been the subject of intense scrutiny and investigation for over 40 years.2–15Hypertrophic cardiomyopathy affects men and women equally and occurs in many races and countries, although it appears to be under-diagnosed in women, minorities, and under-served populations.16–20 Hypertrophic cardiomyopathy is a particularly common cause of sudden cardiac death (SCD) in young people (including trained athletes)21–29and may cause death and disability in patients of all ages, although it is also frequently compatible with normal longevity.30–35Because of its heterogeneous clinical course and expression,7,36–42HCM frequently presents uncertainty and represents a management dilemma to cardiovascular specialists and other practitioners, particularly those infrequently engaged in the evaluation of patients with this disease. Furthermore, with the recent introduction of novel treatment strategies targeting subgroups of patient