Combined electrical and global markers of dyssynchrony predict clinical response to cardiac resynchronization therapy

Area of Science:

• Cardiology
• Heart Failure Management
• Echocardiography

Background:

• Cardiac resynchronization therapy (CRT) is a key treatment for heart failure (HF) patients with ventricular dyssynchrony.
• Predicting CRT response remains challenging, necessitating improved diagnostic markers.
• Global left ventricular (LV) dyssynchrony assessment may offer additional predictive value.

Purpose of the Study:

• To evaluate the added value of global LV dyssynchrony markers in predicting CRT response in HF patients.
• To compare the predictive capabilities of total isovolumic time (t-IVT) and Tei index against conventional markers.
• To assess the utility of these markers, particularly in patients with atrial fibrillation (AF).

Main Methods:

• 103 HF patients meeting CRT criteria underwent clinical assessment, NT-proBNP, and echocardiography.
• Global LV dyssynchrony was quantified using total isovolumic time (t-IVT) and Tei index.
• Patients were classified as responders or non-responders based on NYHA class improvement post-CRT.

Main Results:

• Prolonged t-IVT, long QRS duration, and high tricuspid regurgitation pressure drop independently predicted CRT response.
• A t-IVT threshold of ≥ 11.6 s/min showed 67% sensitivity and 62% specificity (AUC 0.69).
• Combining t-IVT with QRS duration significantly increased specificity (88%) for predicting CRT response. In AF patients, only prolonged t-IVT was an independent predictor.

Conclusions:

• The combination of prolonged t-IVT and broad QRS duration enhances specificity in identifying CRT responders.
• Prolonged t-IVT is a significant independent predictor of CRT response, especially in HF patients with AF.
• Global LV dyssynchrony markers, particularly t-IVT, offer valuable additions to conventional criteria for CRT response prediction.