New Automatic Tools to Identify Responders to Cardiac Resynchronization Therapy

Area of Science:

• Cardiology
• Echocardiography
• Medical Imaging

Background:

• Cardiac resynchronization therapy (CRT) response prediction relies on identifying specific echocardiographic patterns like apical rocking (AR) and septal flash (SF).
• Visual assessment of AR and SF requires significant expertise and training, limiting its widespread application.
• Speckle-tracking echocardiography offers a quantitative approach to assess these patterns using parameters like start systolic index (SSI) and peak longitudinal displacement (PLD).

Purpose of the Study:

• To evaluate the efficacy of novel speckle-tracking echocardiography parameters, SSI and PLD, in identifying patients who are potential responders to CRT.
• To compare the performance of quantitative SSI and PLD analysis with the traditional visual assessment of AR and SF by both expert and novice readers.

Main Methods:

• Retrospective analysis of echocardiograms from 125 patients before and after CRT implantation.
• Generation of color-coded bull's-eye displays of SSI and PLD from baseline speckle-tracking images.
• Derivation of cutoff values for SSI and PLD in a subset of patients and application to the remaining cohort to define CRT response (≥15% decrease in end-systolic volume).

Main Results:

• Expert readers identified AR in 77 patients, achieving 85% sensitivity and 82% specificity for predicting CRT response.
• Novice readers demonstrated lower accuracy, with 74% sensitivity and 55% specificity.
• Quantitative SSI and PLD analysis showed comparable performance to expert readers, with SSI achieving 72% sensitivity and 84% specificity, and PLD achieving 80% sensitivity and 75% specificity.

Conclusions:

• Quantitative assessment of mechanical dyssynchrony using speckle-tracking parameters SSI and PLD is a reliable method for identifying CRT responders.
• This novel quantitative approach performs comparably to experienced clinicians' visual assessment.
• SSI and PLD offer a more objective and reproducible method for predicting CRT response compared to subjective visual interpretation by less experienced readers.