title: Additive Prognostic Value of Echocardiographic Global Longitudinal and Global Circumferential Strain to Electrocardiographic Criteria in Patients With Heart Failure Undergoing Cardiac Resynchronization Therapy.
abstract: BACKGROUND
  Response to cardiac resynchronization therapy is most favorable in patients with heart failure with QRS duration ≥150 ms and left bundle branch block and less predictable in those with QRS width 120 to 149 ms or non-left bundle branch block.
  
  
  RESULTS
  We studied 205 patients with heart failure referred for cardiac resynchronization therapy with QRS ≥120 ms and ejection fraction ≤35%. We tested the hypothesis that contractile function using speckle-tracking echocardiographic global circumferential strain (GCS) from 2 short-axis views and global longitudinal strain (GLS) from 3 apical views add prognostic value to electrocardiographic criteria. There were 112 patients (55%) with GLS >-9% and 136 patients (66%) with GCS >-9%. During 4 years, 81 patients reached the combined primary end point (death, circulatory support, or transplant) and 120 reached the secondary end point (heart failure hospitalization or death). Both GLS >-9% and GCS >-9% were associated with increased risk of unfavorable events as follows: for the primary end point (hazard ratio=2.91; 95% confidence interval, 1.88-4.49; P<0.001) and (hazard ratio=3.73; 95% confidence interval, 2.39-5.82; P<0.001) for the secondary end point (hazard ratio=2.10; 95% confidence interval, 1.45-3.05; P<0.001) and (hazard ratio=3.25; 95% confidence interval, 2.23-4.75; P<0.001). In a prespecified subgroup of 120 patients with QRS 120 to 149 ms or non-left bundle branch block, significant associations of baseline GLS and GCS and outcomes remained: P=0.014 and P=0.002 for the primary end point and P=0.049 and P=0.001 for the secondary end point. Global strain measures had additive prognostic value to routine clinical or electrocardiographic parameters (P<0.001).
  
  
  CONCLUSIONS
  Baseline GCS and GLS were significantly associated with long-term outcome after cardiac resynchronization therapy and had additive prognostic value to routine clinical and electrocardiographic selection criteria for cardiac resynchronization therapy.
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Antonia
authors.initials: A
authors.lastname: Delgado-Montero
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Bhupendar
authors.initials: B
authors.lastname: Tayal
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Akiko
authors.initials: A
authors.lastname: Goda
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Keiko
authors.initials: K
authors.lastname: Ryo
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Josef J
authors.initials: JJ
authors.lastname: Marek
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Masataka
authors.initials: M
authors.lastname: Sugahara
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Qi
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Althouse
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: Samir
authors.initials: S
authors.lastname: Saba
authors.affiliation: From the University of Pittsburgh, PA.
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
authors.affiliation: From the University of Pittsburgh, PA. gorcsanj@upmc.edu.
authors.forename: John
authors.initials: J
authors.lastname: Gorcsan
mesh_terms: D000200:Action Potentials; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D001696:Biomechanical Phenomena; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D010359:Patient Readmission; D010414:Pennsylvania; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D019233:Retreatment; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
keywords: cardiac resynchronization therapy; cardiomyopathy; echocardiography; heart failure; hospitalization; prognosis