Paced left ventricular QRS width and ECG parameters predict outcomes after cardiac resynchronization therapy:...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Cardiac resynchronization therapy (CRT) is established for heart failure patients with specific criteria (NYHA class III-IV, EF ≤ 35%, QRS ≥ 130 ms).
• However, 30-45% of patients do not improve clinically or echocardiographically with current CRT implant criteria.
• Predictors of Response to CRT (PROSPECT)-ECG trial aimed to identify factors influencing CRT efficacy.

Purpose of the Study:

• To identify electrocardiogram (ECG) predictors of positive outcomes in cardiac resynchronization therapy (CRT).
• To explore novel intraprocedural methods for optimizing coronary sinus lead placement during CRT implantation.

Main Methods:

• Prospective observational study analyzing ECGs before, during, and after CRT implantation.
• Primary outcomes: clinical composite score improvement and >15% LVESV reduction at 6 months.
• Multivariable logistic regression analyzed numerous baseline and procedural ECG parameters, including QRS width and morphology.

Main Results:

• Left bundle branch block morphology on baseline ECG predicted both clinical composite score and LVESV response.
• LV-paced QRS width predicted LVESV reduction, with widths ≤ 200 ms being specific for nonischemic cardiomyopathy.
• The difference between biventricular (Bi-V) and preimplantation QRS width predicted clinical composite score improvement.

Conclusions:

• Baseline ECG features, specifically left bundle branch QRS morphology, are significant predictors of CRT response.
• LV-paced QRS width and the change in QRS width with Bi-V pacing offer valuable prognostic information.
• These ECG parameters may enable intraprocedural optimization of CRT lead placement for improved patient outcomes.