Low-dose dobutamine test associated with interventricular dyssynchrony: A useful tool to identify cardiac resynchronization therapy responders: Data from the LOw dose DObutamine stress-echo test in Cardiac Resynchronization Therapy (LODO-CRT) phase 2 study

• Published in: The American heart journal Vol. 163; no. 3; pp. 422 - 429
• Main Authors: GASPARINI, Maurizio, MUTO, Carmine, MANGONI, Lorenza, DENARO, Alessandra, IACOPINO, Saverio, ZANON, Francesco, DICANDIA, Cosimo, DISTEFANO, Giuseppe, FAVALE, Stefano, PERALDO NEJA, Carlo, BRAGATO, Renato, DAVINELLI, Mario
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby 01.03.2012
• Subjects: Aged; Biological and medical sciences; Cardiac Resynchronization Therapy - methods; Cardiology. Vascular system; Cardiotonic Agents - administration & dosage; Dobutamine; Dose-Response Relationship, Drug; Echocardiography, Stress - methods; Female; Follow-Up Studies; Humans; Male; Medical sciences; Prospective Studies; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Sensitivity and Specificity; Severity of Illness Index; Stroke Volume - physiology; Tachycardia, Ventricular - diagnostic imaging; Tachycardia, Ventricular - physiopathology; Tachycardia, Ventricular - therapy; Time Factors; Ventricular Remodeling; Cardiac resynchronization; Pharmacologic test; Instrumental stimulation; Phase; Echo; Low dose; Dobutamine; Instrumentation therapy; Data; Circulatory system; Cardiology; Responder
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2011.11.015

Cardiac resynchronization therapy (CRT) is effective in patients with heart failure, but 30% to 50% of subjects are classified as nonresponders. Identifying responders remains a challenging task. The LODO-CRT trial investigated the association between left ventricular contractile reserve (LVCR) and clinical and echocardiographic long-term CRT response. This is a multicenter, prospective, observational study. Left ventricular contractile reserve was detected using a dobutamine stress echocardiography test, defined as an ejection fraction increase of >5 points. Clinical CRT response was defined as the absence of major cardiovascular events (ie, cardiovascular death or heart failure hospitalization). Echocardiographic response was defined as a left ventricle end-systolic volume reduction of >10%. A total of 221 CRT-indicated patients were studied (80% presented LVCR). During a mean follow-up of 15 ± 5 months, 17 patients died and 16 were hospitalized due to heart failure. The proportion of clinical responders was 155 (88%) of 177 and 33 (75%) of 44 (P = .036) in the groups with and without LVCR, respectively. Kaplan-Meier analysis showed a significant difference in cardiac survival/hospitalization between patients with and without LVCR. The proportion of echocardiographic responders was 144 (87%) of 166 and 16 (42%) of 38 in the groups with and without LVCR (P < .001), respectively; LVCR showed 90% sensitivity and 87% positive predictive value to prefigure echocardiographic CRT responders. Multivariable analysis identified LVCR and interventricular dyssynchrony as independent predictors of CRT response. The concomitant presence of both factors showed 99% specificity and 83% sensitivity in detecting responders. The presence of LVCR helps in predicting a clinical and echocardiographic CRT response. Concomitant assessment of LVCR and interventricular dyssynchrony accurately stratifies responder and nonresponder patients.