Prediction of response to cardiac resynchronization therapy: the selection of candidates for CRT (SCART) study.
BACKGROUND
The aim of this study was to evaluate the ability of baseline clinical and echocardiographic parameters to predict a positive response to CRT.


METHODS
We analyzed 6-month data from the first 133 consecutive patients enrolled in a multicenter prospective study. These patients had symptomatic heart failure (HF) refractory to pharmacological therapy (NYHA class II-IV), left ventricular ejection fraction (LVEF) < or =35%, and prespecified electrocardiographic, echocardiographic or tissue Doppler imaging markers of left ventricular (LV) dyssynchrony.


RESULTS
After a follow-up period of 6 months, 1 patient died and 13 were hospitalized for worsening HF. There were significant (P < 0.01) clinical, functional, and echocardiographic improvements that included: New York heart Association Class, Quality-of-Life Score, QRS duration, LVEF, LV end-diastolic and end-systolic diameter (LVESD), and severity of mitral regurgitation A positive response was documented in 90/133 (68%) patients who presented an improved clinical composite score associated to an increase in LVEF > or = 5 units. A multivariate analysis identified that a smaller LVESD (OR = 0.957, 95% CI 0.920-0.996; P = 0.030) and longer interventricular mechanical delay (IVMD) (OR = 1.017, 95% CI 1.005-1.029, P = 0.007) as independent predictors of a positive response. Receiver-operating curve analysis showed that a positive response to CRT may be predicted in patients with IVMD > 44 ms (with a sensitivity of 66% and a specificity of 55%) or with LVESD < 60 mm (with a sensitivity of 66% and a specificity of 61%).


CONCLUSIONS
Our results confirm the limited value of QRS duration in the selection of patients for CRT. A less-advanced stage of disease and echocardiographic evidence of interventricular dyssynchrony demonstrated to predict response to CRT, while intraventricular dyssynchrony did not predict response.
Achilli
Augusto
A
Belcolle Hospital, Viterbo, Italy. a_achilli@virgilio.it
Peraldo
Carlo
C
Sassara
Massimo
M
Orazi
Serafino
S
Bianchi
Stefano
S
Laurenzi
Francesco
F
Donati
Roberto
R
Perego
Giovanni B
GB
Spampinato
Andrea
A
Valsecchi
Sergio
S
Denaro
Alessandra
A
Puglisi
Andrea
A
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D018579:Patient Selection; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D014463:Ultrasonography / Q000706:statistics & numerical data*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000517:prevention & control