title: Relation between strain dyssynchrony index determined by comprehensive assessment using speckle-tracking imaging and long-term outcome after cardiac resynchronization therapy for patients with heart failure.
abstract: Strain dyssynchrony index (SDI), which was a marker of dyssynchrony and residual myocardial contractility, can predict left ventricular reverse remodeling short-term after cardiac resynchronization therapy (CRT). We investigated SDI-predicted long-term outcome after CRT in patients with heart failure (HF). We studied 74 patients with HF who underwent CRT. SDI was calculated as the average difference between peak and end-systolic strain from 6 segments for radial and circumferential SDIs and 18 segments for longitudinal SDI using 2-dimensional speckle-tracking strain. Based on our previous findings, the predefined cutoff for significant dyssynchrony and residual myocardial contractility was a radial SDI ≥6.5%, a circumferential SDI ≥3.2%, and a longitudinal SDI ≥3.6%. The predefined principal outcome variable was the combined end point of death or hospitalization owing to deteriorating HF. Long-term follow-up after CRT was tracked over 4 years. The primary end point of prespecified events occurred in 14 patients (19%). An association with a favorable long-term outcome after CRT was observed in patients with significant radial, circumferential, and longitudinal SDIs (p <0.001, <0.005, and 0.010 vs patients without significant SDIs, respectively). Furthermore, cardiovascular event-free rate after CRT in patients with positivity of 3 for the 3 SDIs was 100% better than that in patients with positivity of 1 (52%, p <0.005) or 0 (31%, p <0.001) for the 3 SDIs. In conclusion, SDIs can successfully predict long-term outcome after CRT in patients with HF. Moreover, the approach combining the 3 types of SDI leads to a more accurate prediction than the use of individual parameters. These findings may have clinical implications in patients with CRT.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Kensuke
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kaneko
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tsuji
authors.forename: Keiko
authors.initials: K
authors.lastname: Ryo
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Kazuko
authors.initials: K
authors.lastname: Norisada
authors.forename: Tetsuari
authors.initials: T
authors.lastname: Onishi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kawai
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D018619:Echocardiography, Doppler, Pulsed; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D016016:Proportional Hazards Models; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*