title: Prognostic significance of left atrial size in patients with hypertrophic cardiomyopathy (from the Italian Registry for Hypertrophic Cardiomyopathy).
abstract: This study assessed left atrial (LA) dimension as a potential predictor of outcome in hypertrophic cardiomyopathy (HC). From the Italian Registry for Hypertrophic Cardiomyopathy, 1,491 patients (mean age 47 +/- 17 years; 61% men; 19% obstructive), followed for 9.4 +/- 7.4 years after the initial echocardiographic evaluation, constituted the study group. The mean LA transverse dimension was 43 +/- 9 mm and was larger in patients with severe symptoms (48 +/- 9 mm for New York Heart Association classes III and IV vs 42 +/- 9 mm for classes I and II, p <0.001), atrial fibrillation (47 +/- 9 vs 42 +/- 8 mm in sinus rhythm, p <0.001), and left ventricular outflow obstruction (46 +/- 9 mm for >or=30 mm Hg at rest vs 42 +/- 9 mm for <30 mm Hg at rest, p <0.001). On univariate analysis, each 5-mm increase in LA size was associated with a hazard ratio (HR) of 1.2 for all-cause mortality (p <0.0001). On multivariate analysis, a LA dimension >48 mm (the 75th percentile) had a HR of 1.9 for all-cause mortality (p = 0.008), 2.0 for cardiovascular death (p = 0.014), and 3.1 for death related to heart failure (p = 0.008) but was unassociated with sudden death (p = 0.81). Similar results were obtained after the exclusion of patients with atrial fibrillation (HR 1.7, p = 0.008) or outflow obstruction (HR 1.8, p = 0.003). The predictive power of LA dimension >48 mm was also validated in an independent HC cohort from the United States, with similar HRs (1.8 for all-cause mortality, p = 0.019). In conclusion, in a large cohort of patients with HC from a nationwide registry, a marked increase in LA dimension were predictive of long-term outcome, independent of co-existent atrial fibrillation or outflow obstruction. LA dimension is a novel and independent marker of prognosis in HC, particularly relevant to the identification of patients at risk for death related to heart failure.
authors.affiliation: Istituto Superiore di Sanità, Laboratory of Epidemiology and Biostatistics, Rome, Italy. snistr@tin.it <snistr@tin.it>
authors.forename: Stefano
authors.initials: S
authors.lastname: Nistri
authors.forename: Iacopo
authors.initials: I
authors.lastname: Olivotto
authors.forename: Sandro
authors.initials: S
authors.lastname: Betocchi
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Losi
authors.forename: Grazia
authors.initials: G
authors.lastname: Valsecchi
authors.forename: Bruno
authors.initials: B
authors.lastname: Pinamonti
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Conte
authors.forename: Franco
authors.initials: F
authors.lastname: Casazza
authors.forename: Maurizio
authors.initials: M
authors.lastname: Galderisi
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Maron
authors.forename: Franco
authors.initials: F
authors.lastname: Cecchi
mesh_terms: D000328:Adult; D000367:Age Factors; D001281:Atrial Fibrillation / Q000453:epidemiology; D015415:Biomarkers; D002312:Cardiomyopathy, Hypertrophic / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006333:Heart Failure / Q000401:mortality; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012042:Registries; D012720:Severity of Illness Index; D012737:Sex Factors; D014463:Ultrasonography; D014694:Ventricular Outflow Obstruction / Q000453:epidemiology
chemical_list: D015415:Biomarkers