Related Experiment Video
Updated: Jul 11, 2026
Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Results of the SCART study: selection of candidates for cardiac resynchronisation therapy
Carlo Peraldo1, Augusto Achilli, Serafino Orazi
1Division of Cardiology, Fatebenefratelli Hospital, Isola Tiberina 39, Rome, Italy. c.p.neja@tiscali.it
Insights
Echocardiography effectively identifies patients likely to respond to cardiac resynchronisation therapy (CRT). Electrocardiographic and tissue Doppler imaging criteria did not predict CRT response in this study.
Area of Science:
- Cardiology
- Medical Imaging
- Heart Failure Management
Background:
- Cardiac resynchronisation therapy (CRT) is a treatment for heart failure.
- Predicting CRT response is crucial for patient selection.
- Current selection criteria include electrocardiographic, echocardiographic, and tissue Doppler imaging (TDI) parameters.
Purpose of the Study:
- To prospectively evaluate if prespecified electrocardiographic, echocardiographic, and TDI criteria can predict a positive response to CRT.
- To identify the most effective imaging modality for selecting CRT candidates.
Main Methods:
- A prospective, non-randomised study involving 96 heart failure patients (NYHA class III-IV, LVEF ≤35%) with ventricular dyssynchrony.
- Patients were assessed using electrocardiography, echocardiography, and TDI.
- The primary endpoint was an improved clinical composite score at 6 months.
Main Results:
- The overall CRT responder rate was 81%.
- Echocardiographic criteria for dyssynchrony significantly predicted a positive CRT response (88% vs. 53%, P=0.001).
- Neither electrocardiographic nor TDI criteria predicted CRT response.
Conclusions:
- Mechanical dyssynchrony assessed by echocardiography appears to identify CRT responders.
- TDI is useful for post-CRT dyssynchrony evaluation, but the study's TDI criteria did not enhance CRT response prediction.
Objective:
To prospectively determine whether prespecified electrocardiographic, echocardiographic and tissue Doppler imaging (TDI) selection criteria may predict a positive response to cardiac resynchronisation therapy (CRT).
Methods:
In this multicentre, prospective, non-randomised study, 96 heart failure patients with New York Heart Association class III-IV symptoms, an ejection fraction of < or =35%, and at least one marker of ventricular dyssynchrony according to prespecified electrocardiographic, echocardiographic or TDI criteria were enrolled. The primary endpoint was an improvement in the clinical composite score at 6 months.
Results:
At enrolment, 70 patients fulfilled the electrocardiographic criterion (QRS duration > or =150 ms), 77 patients showed echocardiographic signs of dyssynchrony, and 37 patients met the TDI dyssynchrony criteria. The overall responder rate was 78/96 (81%). In particular, the primary endpoint was reached in 68 patients who fulfilled the echocardiographic criteria as compared with 10 patients who did not (88 vs. 53%, P = 0.001). The patients who met the echocardiographic criteria showed a significant greater reduction in left ventricular end-systolic diameter (P = 0.029) and a higher improvement in quality of life (P = 0.017) than patients who did not. Neither electrocardiographic nor TDI criteria seemed to predict a positive response to CRT.
Conclusions:
In our patient population, mechanical indexes of dyssynchrony as assessed by echocardiography appeared to identify CRT responders. Although TDI is useful for evaluating ventricular dyssynchrony after CRT, the prespecified TDI inclusion criteria adopted in this investigation did not increase the number of CRT responders.
