Simple regional strain pattern analysis to predict response to cardiac resynchronization therapy: rationale, initial...

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• A specific strain pattern, characterized by early contraction in one wall and prestretching of the opposing wall, is linked to left bundle branch block (LBBB) and short-term response to cardiac resynchronization therapy (CRT).
• The study aimed to determine the long-term predictive value of this LBBB-related strain pattern and observe contraction pattern changes during CRT.

Purpose of the Study:

• To establish the long-term predictive value of an LBBB-related strain pattern for CRT response.
• To identify changes in myocardial contraction patterns during short-term and long-term CRT treatment.

Main Methods:

• Prospective enrollment of 67 patients meeting standard CRT criteria.
• Echocardiography with 2D speckle tracking for regional strain analysis performed pre-implantation, at day 1, and 6 months post-implantation.
• Comparison of the classical strain pattern's predictive ability against time-to-peak parameters.

Main Results:

• The classical strain pattern demonstrated high specificity (91%) and sensitivity (95%) for predicting CRT response, outperforming time-to-peak parameters.
• Forty-three patients (65%) were classified as responders, with the classical pattern being a superior predictor.
• In responders, CRT acutely improved septal longitudinal peak systolic strain, unlike in non-responders.

Conclusions:

• The classical strain pattern is a highly accurate predictor of CRT response, surpassing traditional time-to-peak methods.
• Long-term reverse remodeling in CRT patients correlates with the short-term reversal of the classical strain pattern.
• Identifying and recognizing reversible strain patterns is crucial for optimizing the selection of CRT candidates.