title: Validation of global longitudinal strain and strain rate as reliable markers of right ventricular dysfunction: comparison with cardiac magnetic resonance and outcome.
abstract: BACKGROUND
  Right ventricular (RV) dysfunction in ischemic cardiomyopathy (ICM) is associated with poor prognosis, but RV assessment by conventional echocardiography remains difficult. We sought to validate RV global longitudinal strain (RVGLS) and global longitudinal strain rate (RVGLSR) against cardiac magnetic resonance (CMR) and outcome in ICM.
  
  
  METHODS
  In 57 patients (43 men, 64 ± 12 years) with ICM who underwent conventional and strain echocardiography and CMR, RVGLS and RVGLSR were measured off-line. RV dysfunction was determined by CMR [RV ejection fraction (RVEF) < 50%]. Patients were followed over 15 ± 9 months for a composite of death and hospitalization for worsening heart failure.
  
  
  RESULTS
  RVGLS showed significant correlations with CMR RVEF (r = -0.797, p < 0.01), RV fractional area change (RVFAC, r = -0.530, p < 0.01), and tricuspid annular plane systolic excursion (TAPSE, r = -0.547, p < 0.01). RVGLSR showed significant correlations between CMR RVEF (r = -0.668, p < 0.01), RVFAC (r = -0.394, p < 0.01), and TAPSE (r = -0.435, p < 0.01). RVGLS and RVGLSR showed significant correlations with pulmonary vascular resistance (r = 0.527 and r = 0.500, p < 0.01, respectively). The best cutoff value of RVGLS for detection of RV dysfunction was -15.4% [areas under the curve (AUC) = 0.955, p < 0.01] with a sensitivity of 81% and specificity 95%. The best cutoff value for RVGLSR was -0.94 s(-1) (AUC = 0.871, p < 0.01), sensitivity 72%, specificity 86%. During follow-up, there were 12 adverse events. In Cox-proportional hazard regression analysis, impaired RVGLS [hazard ratio (HR) = 5.46, p = 0.030] and impaired RVGLSR (HR = 3.95, p = 0.044) were associated with adverse clinical outcome.
  
  
  CONCLUSIONS
  Compared with conventional echocardiographic parameters, RVGLS and RVGLSR correlate better with CMR RVEF and outcome.
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA. ; Cardiology Division of Internal Medicine, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Jae-Hyeong
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Negishi
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Deborah H
authors.initials: DH
authors.lastname: Kwon
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Zoran B
authors.initials: ZB
authors.lastname: Popovic
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Grimm
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA. ; Menzies Research Institute Tasmania, Hobart, Australia.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
keywords: Cardiac magnetic resonance image; Right ventricle; Strain echocardiography; Systolic dysfunction