Responders to cardiac resynchronization therapy with narrow or intermediate QRS complexes identified by simple echocardiographic indices of dyssynchrony: the DESIRE study.
BACKGROUND
Cardiac resynchronization therapy (CRT) is recommended for patients with NYHA class III-IV refractory heart failure (HF), ejection fraction <35% and a QRS >120 ms. We attempted to identify responders to CRT from echocardiographic (echo) indices of mechanical dyssynchrony in patients with QRS<150 ms.


RESULTS
The study enrolled 51 men and 9 women (mean age: 64.5 years) in NYHA class III (n=54) or IV (n=6) presenting with a mean ejection fraction: 25.7%, LV end-diastolic diameter: 69.1 mm, and QRS=121+/-19 ms. All patients were implanted with a CRT system and followed for 1 year. Implantation was preceded and followed by clinical, functional and Doppler (D)-echo evaluation. The primary combined endpoint included 1) death from any cause, 2) HF-related hospitalisations, and 3) NYHA class at 6 months. Before implant, 27 patients had > or =1 echo criterion of mechanical dyssynchrony (DES+ group) and 33 had no evidence of dyssynchrony (DES- group). At 12 months, 8 patients (4 per group) had died, 7 from HF. As regards the primary endpoint at 6 months, 33 patients (55%) had improved, 10 (16%) were unchanged, and 17 (29%) had deteriorated. Clinical improvement was observed in 19 of 27 DES+ (70%), versus 14 of 33 DES- (42%) patients (P<0.04). Baseline QRS duration did not predict response to CRT.


CONCLUSIONS
In this population of HF patients with QRS<150 ms, the presence of mechanical dyssynchrony at baseline D-echo examination, but not the QRS width, predicted 6-month clinical response to CRT.
Cazeau
Serge J
SJ
Inparys Clinical Research Group, 12 rue Pasteur, 92210 - St. Cloud, France. SergeCaz@aol.com
Daubert
J-Claude
JC
Tavazzi
Luigi
L
Frohlig
Gerd
G
Paul
Vince
V
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging*; D002304:Cardiac Pacing, Artificial; D015897:Comorbidity; D005260:Female; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006333:Heart Failure / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D013318:Stroke Volume; D016896:Treatment Outcome; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology / Q000503:physiopathology