title: Incremental Value of Speckle Tracking Echocardiography to Predict Cardiac Resynchronization Therapy (CRT) Responders.
abstract: Speckle tracking echocardiography (STE) is reported as a useful method to predict cardiac resynchronization therapy (CRT) responders. This study aimed to identify the incremental value of a STE parameter to predict CRT responders.
  
  
  
  We enrolled 171 patients from the Speckle Tracking imaging for the Assessment of cardiac Resynchronization Therapy (START) study. CRT responders were defined as patients with ≥15% reduction of left ventricular (LV) end-systolic volume at 6 months post-CRT. Based on multivariable logistic regression analysis, incremental values of STE were assessed by c-statistics, net reclassification improvement (NRI)/integrated discrimination improvement (IDI), and decision curve analysis. Six parameters (left bundle branch block or right ventricular pacing, use of beta-blocker, blood urea nitrogen ≤3.0 mg/dL, LV end-systolic diameter ≤50 mm, mitral regurgitation index ≤40%, and STE parameter standard deviation of time from QRS onset to first peak on the circumferential strain curves [TSD] ≥116 ms) were identified as the determinants. Compared to the multivariable logistic regression model without TSD(model 1), that with TSD(model 2) showed significant improvement to predict CRT responders: c-statistic (0.86 vs 0.77; P<0.001), NRI=0.19, P<0.001, and IDI=0.17, P<0.001. The decision curve of model 2 was higher than that of model 1 at threshold probabilities ≥0.2. Based on model 2, a START score was constructed. Compared to the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) score, the decision curve of the START score was higher than that of the MADIT-CRT score at threshold probabilities ≥0.2.
  
  
  
  Based on various statistical methods, this study revealed that STE had an incremental value to predict CRT responders.
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan yo-seo@md.tsukuba.ac.jp.
authors: Yoshihiro
authors: Y
authors: Seo
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Tomoko
authors: T
authors: Ishizu
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Tomoko
authors: T
authors: Machino-Ohtsuka
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Masayoshi
authors: M
authors: Yamamoto
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Takeshi
authors: T
authors: Machino
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Kenji
authors: K
authors: Kuroki
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Hiro
authors: H
authors: Yamasaki
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Yukio
authors: Y
authors: Sekiguchi
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Akihiko
authors: A
authors: Nogami
authors: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Japan.
authors: Kazutaka
authors: K
authors: Aonuma
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011446:Prospective Studies; D013318:Stroke Volume; D016896:Treatment Outcome
keywords: cardiac resynchronization therapy; heart failure; speckle training echocardiography; statistics