Dyssynchrony by speckle-tracking echocardiography and response to cardiac resynchronization therapy: results of the Speckle Tracking and Resynchronization (STAR) study.
OBJECTIVE
The Speckle Tracking and Resynchronization (STAR) study used a prospective multi-centre design to test the hypothesis that speckle-tracking echocardiography can predict response to cardiac resynchronization therapy (CRT).


RESULTS
We studied 132 consecutive CRT patients with class III and IV heart failure, ejection fraction (EF) < or =35%, and QRS > or =120 ms from three international centres. Baseline dyssynchrony was evaluated by four speckle tracking strain methods; radial, circumferential, transverse, and longitudinal (> or =130 ms opposing wall delay for each). Pre-specified outcome variables were EF response and three serious long-term events: death, transplant, or left ventricular assist device. Of 120 patients (91%) with baseline dyssynchrony data, both short-axis radial strain and transverse strain from apical views were associated with favourable EF response 7 +/- 4 months and long-term outcome over 3.5 years (P < 0.01). Radial strain had the highest sensitivity at 86% for predicting EF response with a specificity of 67%. Serious long-term unfavourable events occurred in 20 patients after CRT, and happened three times more frequently in those who lacked baseline radial or transverse dyssynchrony than in patients with dyssynchrony (P < 0.01). Patients who lacked both radial and transverse dyssynchrony had unfavourable clinical events occur in 53%, in contrast to events occurring in 12% if baseline dyssynchrony was present (P < 0.01). Circumferential and longitudinal strains predicted response when dyssynchrony was detected, but failed to identify dyssynchrony in one-third of patients who responded to CRT.


CONCLUSIONS
Dyssynchrony by speckle-tracking echocardiography using radial and transverse strains is associated with EF response and long-term outcome following CRT.
University of Pittsburgh, Scaife Hall 564, 200 Lothrop Street, Pittsburgh, PA 15213-2582, USA.
Hidekazu
H
Tanaka
Hans-Joachim
HJ
Nesser
Thomas
T
Buck
Olusegun
O
Oyenuga
Rolf Alexander
RA
Jánosi
Siegmund
S
Winter
Samir
S
Saba
John
J
Gorcsan
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016896:Treatment Outcome