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The dilemma of left ventricular outflow tract obstruction and sudden death in hypertrophic cardiomyopathy: do patients with gradients really deserve prophylactic defibrillators?
| Content Provider | Semantic Scholar |
|---|---|
| Author | Maron, Barry Joel Olivotto, Iacopo |
| Copyright Year | 2006 |
| Abstract | Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, as well as the most frequent cause of sudden cardiac death in young people including competitive athletes. The devastating consequence of sudden death has, in fact, been central to our perception of the natural history of HCM for almost 50 years, as its initial contemporary description by Teare in 1958. Now that HCM has assumed an important place in the implantable cardioverter-defibrillator (ICD) era, the issue of risk stratification and sudden death prevention has becomeamajor clinical consideration and central to the management of these patients, adding enormously to the complexity of the disease. Indeed, the ICD was initially promoted specifically for HCM in 2000, and subsequently thousands of young patients have been afforded this potentially life-saving therapy. The efficacy of the ICD in HCM, for both secondary and primary prevention, is now well established. Despite this encouraging development, a mismatch persists between the power of ICD technology to recognize and successfully abort potentially lethal ventricular tachyarrhythmias, and our ability to prospectively identify, with precision, each individual patient who may benefit from a prophylactically implanted device. Indeed, in a heterogeneous disease with a low cardiac event rate such as HCM, decisions regarding sudden death prevention are frequently encumbered by risk profiles of individual patients which fall into uncertain grey areas of ambiguity between high and low risk. At this point, six major risk factors for sudden death have been proposed in HCM, including prior cardiac arrest for which there is general agreement regarding the role of secondary prevention ICDs. The five traditional risk markers for primary prevention include: (1) sudden death due to HCM in one or more relatives; (2) massive left ventricular (LV) hypertrophy (wall thickness 30 mm); (3) nonsustained ventricular tachycardia on ambulatory Holter ECG, if repetitive on sequential recordings; (4) hypotensive or attenuated blood pressure during exercise; and (5) unexplained syncope, particularly if related to exertion. Because of the low annual event rate characteristic of HCM, all these primary prevention risk factors have low positive predictive value (about 20%), but very high negative predictive value (about 90–95%). Other small high-risk subgroups have emerged within this heterogeneous disease, including LV apical aneurysm associated with regional myocardial scarring and the end-stage phase with systolic dysfunction. Current US clinical practice for HCM involves full disclosure concerning the potential level of risk for sudden death to any patient with at least one of the aforementioned major risk markers (as judged with respect to the individual clinical profile), rather than rigid adherence to two or more risk factors. This strategy is supported by data from the largest HCM–ICD trial to date, an internationally assembled cohort of .500 high-risk patients, of whom 40% experienced an appropriate shock with only one primary prevention risk factor as justification for their prophylactic ICD. In the study by Elliott et al., which appears in this issue of the journal, LV outflow tract obstruction at rest (gradient 30 mmHg) is promoted as a novel risk factor in HCM. The data presented by Elliott et al. develop a linkage between LV outflow tract obstruction and sudden cardiac death in HCM. This important issue has been previously addressed in reports by Maki et al. from Japan and in a 2003 New England Journal of Medicine multicentre study co-authored |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/eurheartj/27/16/10.1093_eurheartj_ehl130/2/ehl130.pdf?Expires=1492463892&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q&Signature=KICBwg3c~daJQ3m8YqfJbEtIUVGB36uehMVBjphPDDie75fBb32Ff8Ct3~CzquWL~vqfjdiPu3mCBvYRWoSg7pmqp1HiGRbSbKWIdW3-uEfLxqalnq3ANCvhp8uTshr0BFt6oMHjHKbsREjMu-tZFSHLqZFv7fA9hBDw56j41K4bkISYok8q1~h9TFsG9LXkzZGVtKhnvcHaCjhJPUdv3ftqrrPuW1ClBSQNlxTb06tsQk22RJurzSg4fGbnA9Vjk-46mTiSmnQJvQOFOhGK9yCCZrmt-o3ypiUPamPC5m~UKNom1HF6VIkhSoXXQm6bjkBWzTUnsADlZ2ZSjkmA7g__ |
| PubMed reference number | 16818455v1 |
| Volume Number | 27 |
| Issue Number | 16 |
| Journal | European heart journal |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Aneurysm Assumed Cardiac Arrest Cardiomyopathies Cardiomyopathy, Dilated Cessation of life Condoms, Unspecified Defibrillators Genetic Heterogeneity Heart Diseases Hypertrophic Cardiomyopathy Hypertrophy Hypotensive Implantable defibrillator Implants Largest Left ventricular outflow tract obstruction Muscle Rigidity Natural History Negative Predictive Value of Diagnostic Test Patients Positive Predictive Value of Diagnostic Test Primary Prevention Secondary Prevention Shock Stratification Sudden Cardiac Death Sudden death Syncope Tachycardia Tachycardia, Ventricular Urinary tract infection Ventricular Fibrillation defibrillator/cardioverters physical hard work |
| Content Type | Text |
| Resource Type | Article |
