title: Prevalence and prognostic value of subclinical left ventricular systolic dysfunction by global longitudinal strain in a community-based cohort.
abstract: OBJECTIVE
  Global longitudinal strain (GLS) assessed by speckle-tracking echocardiography has been proposed as a parameter able to reflect early changes in left ventricular systolic function at a stage when left ventricular ejection fraction (LVEF) is still normal. This study aimed at assessing prevalence and prognostic value of left ventricular systolic dysfunction (LVSD) assessed by echocardiographic speckle-tracking GLS in a community-based cohort.
  
  
  RESULTS
  Participants from the community-based prospective Northern Manhattan Study underwent two-dimensional transthoracic echocardiography as part of the Cardiovascular Abnormalities and Brain Lesions study. Left ventricular systolic function was assessed by LVEF and speckle-tracking GLS. Subjects were followed annually (mean = 4.8 ± 1.5 years) and incident vascular events (ischaemic stroke, myocardial infarction, and vascular death) were reviewed and adjudicated. Of the 708 study participants, 114 (16.1%) had abnormal GLS but normal LVEF (GLS-LVSD), 30 (4.2%) had abnormal LVEF (LVEF-LVSD), and 564 (79.7%) had normal GLS and LVEF (no-LVSD). In multivariate analysis, risk of events was significantly greater in GLS-LVSD [adjusted hazard ratio (HR) = 2.39, 95% confidence interval (CI) = 1.20-4.77] and in LVEF-LVSD (adjusted HR = 3.51, 95% CI = 1.25-9.88) compared with no-LVSD. Among participants with normal LVEF, lower GLS was significantly associated with events (adjusted HR/unit decrease = 1.15, 95% CI = 1.03-1.28) whereas LVEF was not (adjusted HR/unit decrease = 1.01, 95% CI = 0.94-1.07). The GLS prognostic value was incremental to risk factors and LVEF both in the overall population (chi-square change = 7.406, P = 0.006) and in participants with normal LVEF (chi-square change = 6.357, P = 0.012).
  
  
  CONCLUSIONS
  In a community-based cohort, GLS-LVSD was four times more frequent than LVEF-LVSD. GLS-LVSD was a powerful and independent predictor of cardiovascular events. Left ventricular function assessment by GLS may improve cardiovascular risk stratification in subjects with normal LVEF.
authors.affiliation: Department of Medicine, Division of Cardiology, Columbia University Medical Center, 630 West 168th Street, New York, NY, 10032, USA.
authors.forename: Cesare
authors.initials: C
authors.lastname: Russo
authors.forename: Zhezhen
authors.initials: Z
authors.lastname: Jin
authors.forename: Mitchell S V
authors.initials: MS
authors.lastname: Elkind
authors.forename: Tatjana
authors.initials: T
authors.lastname: Rundek
authors.forename: Shunichi
authors.initials: S
authors.lastname: Homma
authors.forename: Ralph L
authors.initials: RL
authors.lastname: Sacco
authors.forename: Marco R
authors.initials: MR
authors.lastname: Di Tullio
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology
keywords: Ejection fraction; Global longitudinal strain; Left ventricular systolic dysfunction; Outcome