title: Left ventricular outflow tract obstruction as a risk factor for sudden cardiac death in hypertrophic cardiomyopathy.
abstract: The effect of left ventricular outflow tract obstruction (LVOTO) at rest on the incidence of sudden death (SD) in patients with hypertrophic cardiomyopathy is rather conflicting. The aim of this study was the evaluation of LVOTO at rest as a new potential risk factor for SD in hypertrophic cardiomyopathy. A total of 166 patients (112 men, 51.8 +/- 15.6 years) were studied; 50 patients (30.1%) had peak instantaneous LVOTO gradients of > or = 30 mm Hg at rest. During the follow-up period (median 32.4 months, range 1 to 209), 13 patients either died suddenly, or had cardiac arrest, documented sustained ventricular tachycardia, or implantable cardioverter defibrillator discharge. The cumulative event-free survival rate was 92% in patients with LVOTO, and 92% in patients without obstruction (p = NS). LVOTO at rest was associated with a particularly low positive predictive value for SD (8%), although a high negative predictive value (92%) was recorded. Patients having syncope or presenting with a maximum wall thickness > or =3 cm in echocardiography were more sensitive to SD emergence because they had a 13.07 (95% confidence interval 4.00 to 46.95, p <0.0001) and a 10.07 (95% confidence interval 2.92 to 34.79, p = 0.003) greater relative risk, respectively. In conclusion, our cohort study results do not support LVOTO as an independent risk factor for SD in patients with hypertrophic cardiomyopathy.
authors.affiliation: First Cardiology Department, Cardiomyopathies Laboratory, Aristotle University of Thessaloniki Medical School, AHEPA Hospital, Thessaloniki, Greece. efthymos@med.auth.gr
authors.forename: Georgios K
authors.initials: GK
authors.lastname: Efthimiadis
authors.forename: Despina G
authors.initials: DG
authors.lastname: Parcharidou
authors.forename: Georgios
authors.initials: G
authors.lastname: Giannakoulas
authors.forename: Efstathios D
authors.initials: ED
authors.lastname: Pagourelias
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Charalampidis
authors.forename: Gregorios
authors.initials: G
authors.lastname: Savvopoulos
authors.forename: Antonios
authors.initials: A
authors.lastname: Ziakas
authors.forename: Haralambos
authors.initials: H
authors.lastname: Karvounis
authors.forename: Ioannis H
authors.initials: IH
authors.lastname: Styliadis
authors.forename: Georgios E
authors.initials: GE
authors.lastname: Parcharidis
mesh_terms: D000328:Adult; D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000453:epidemiology*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D014694:Ventricular Outflow Obstruction / Q000453:epidemiology*