title: Combined Global Longitudinal Strain and Intraventricular Mechanical Dyssynchrony Predicts Long-Term Outcome in Patients With Systolic Heart Failure.
abstract: BACKGROUND
  Left ventricular (LV) ejection fraction (EF) and QRS duration enable prediction of outcome in patients with systolic heart failure (SHF). We assessed the predictive value of global longitudinal strain (GLS) and mechanical dyssynchrony for prognosis in SHF patients.
  
  
  RESULTS
  Two-hundred and forty SHF patients with LVEF ≤40% were studied. Global LV function and intraventricular mechanical dyssynchrony were calculated as GLS and SD of the time to peak longitudinal strain (SDε) over 18 LV segments. The added value of GLS and SDε for outcome prediction was assessed using nested Cox models. Sixty-six patients (28%) reached the study endpoint of all-cause mortality/heart transplantation over a median follow-up period of 45 months. Baseline variables associated with adverse outcome were age, glomerular filtration rate, pulmonary artery systolic pressure, diabetes and LV end-systolic volume (model χ(2)=69.8). The predictive power of the clinical variables was greater with addition of GLS (χ(2)=81.1) or SDε (χ(2)=102.3) than with LVEF (χ(2)=73.9) or QRS duration (χ(2)=75.5; both P<0.005). GLS (HR, 1.88; P=0.03) and SDε (HR, 1.48; P=0.04) were independent predictors after adjustment for the baseline variables. Patients with impaired GLS (≥-7.8%) and mechanical dyssynchrony (SDε ≥72 ms) had poor outcome.
  
  
  CONCLUSIONS
  Combined assessment of global LV function and mechanical dyssynchrony using speckle-tracking strain enabled the prediction of long-term outcome in SHF patients.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital.
authors.forename: Yi-Hsin
authors.initials: YH
authors.lastname: Chan
authors.forename: Chi-Tai
authors.initials: CT
authors.lastname: Kuo
authors.forename: Lung-Sheng
authors.initials: LS
authors.lastname: Wu
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Wang
authors.forename: Yung-Hsin
authors.initials: YH
authors.lastname: Yeh
authors.forename: Lung-An
authors.initials: LA
authors.lastname: Hsu
authors.forename: Wan-Jing
authors.initials: WJ
authors.lastname: Ho
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005919:Glomerular Filtration Rate; D054143:Heart Failure, Systolic / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D015996:Survival Rate; D014463:Ultrasonography