title: The prognostic value of standardized reference values for speckle-tracking global longitudinal strain in hypertrophic cardiomyopathy.
abstract: Speckle-tracking left ventricular global longitudinal strain (GLS) assessment may provide substantial prognostic information for hypertrophic cardiomyopathy (HCM) patients. Reference values for GLS have been recently published. We aimed to evaluate the prognostic value of standardized reference values for GLS in HCM patients. An analysis of HCM clinic patients who underwent GLS was performed. GLS was defined as normal (more negative or equal to -16%) and abnormal (less negative than -16%) based on recently published reference values. Patients were followed for a composite of events including heart failure hospitalization, sustained ventricular arrhythmia, and all-cause death. The power of GLS to predict outcomes was assessed relative to traditional clinical and echocardiographic variables present in HCM. 79 HCM patients were followed for a median of 22 months (interquartile range 9-30 months) after imaging. During follow-up, 15 patients (19%) met the primary outcome. Abnormal GLS was the only echocardiographic variable independently predictive of the primary outcome [multivariate Hazard ratio 5.05 (95% confidence interval 1.09-23.4, p = 0.038)]. When combined with traditional clinical variables, abnormal GLS remained independently predictive of the primary outcome [multivariate Hazard ratio 5.31 (95 % confidence interval 1.18-24, p = 0.030)]. In a model including the strongest clinical and echocardiographic predictors of the primary outcome, abnormal GLS demonstrated significant incremental benefit for risk stratification [net reclassification improvement 0.75 (95 % confidence interval 0.21-1.23, p < 0.0001)]. Abnormal GLS is an independent predictor of adverse outcomes in HCM patients. Standardized use of GLS may provide significant incremental value over traditional variables for risk stratification.
authors.affiliation: Division of Cardiology, Department of Medicine, Emory University School of Medicine, 1364 Clifton Rd NE Room 4D33, Atlanta, GA, 30322, USA, ghartlagemd@gmail.com.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Hartlage
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Kim
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Strickland
authors.forename: Alan C
authors.initials: AC
authors.lastname: Cheng
authors.forename: Nima
authors.initials: N
authors.lastname: Ghasemzadeh
authors.forename: Maria A
authors.initials: MA
authors.lastname: Pernetz
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Clements
authors.forename: B Robinson
authors.initials: BR
authors.lastname: Williams
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D002423:Cause of Death; D018450:Disease Progression; D018572:Disease-Free Survival; D018618:Echocardiography, Doppler, Color / Q000592:standards*; D018619:Echocardiography, Doppler, Pulsed / Q000592:standards*; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D012015:Reference Standards; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013314:Stress, Mechanical; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D016277:Ventricular Function, Left