Presence of left ventricular contractile reserve, evaluated by means of dobutamine stress-echo test, is able to predict response to cardiac resynchronization therapy.
BACKGROUND
We evaluated whether the dobutamine stress-echo test can select responders to cardiac resynchronization therapy (CRT). Up to 50% of patients do not respond to CRT. Lack of response may be due to a significant amount of scar or fibrotic tissue at myocardial level.


RESULTS
We studied 42 CRT patients. After clinical and echocardiographic evaluation, all patients underwent a dobutamine stress-echo test to assess contractile reserve. Cut-off for the test was an increase of 25% of the left ventricular ejection fraction. Patients were implanted with a CRT-defibrillator and followed up at 6 months. Cut-off for CRT response was a reduction of 15% of left ventricular end-systolic volume. Twenty-five patients responded to CRT; all of them showed presence of contractile reserve. The test showed a sensitivity of 100% and a specificity of 88%.


CONCLUSIONS
Contractile reserve was a strong predictive factor of response to CRT in the studied population.
Tuccillo
Bernardino
B
Santa Maria di Loreto Mare Hospital, Naples, Italy.
Muto
Carmine
C
Iengo
Raffaele
R
Accadia
Maria
M
Rumolo
Salvatore
S
Canciello
Micheleangelo
M
Carreras
Giovanni
G
Calvanese
Raimondo
R
Celentano
Eduardo
E
Davinelli
Mario
M
Valsecchi
Sergio
S
Ascione
Luigi
L
D000368:Aged; D002304:Cardiac Pacing, Artificial; D002316:Cardiotonic Agents; D016009:Chi-Square Distribution; D004280:Dobutamine; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy
D002316:Cardiotonic Agents; D004280:Dobutamine