Predicting Ventricular Tachyarrhythmias in Patients With Left Ventricular Ejection Fraction Improvement Following...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Cardiac resynchronization therapy with a defibrillator (CRT-D) improves left ventricular ejection fraction (LVEF) in many patients.
• However, some patients remain at risk for ventricular tachyarrhythmias (VTA) even with significant LVEF improvement.

Purpose of the Study:

• To identify predictors of VTA in patients with CRT-D who achieved LVEF improvement exceeding guideline recommendations.
• To define a high-risk subgroup requiring closer surveillance.

Main Methods:

• Analysis of patients from the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT) trial.
• Inclusion criteria: CRT-D arm, LVEF >35% at 12 months post-implant (N=651).
• Cox proportional hazards regression used to evaluate predictors of appropriate implantable cardioverter-defibrillator (ICD) therapy for VTA.

Main Results:

• Three key predictors of VTA were identified: LVEF improvement in the 36%-40% range (HR 1.97), baseline non-Left Bundle Branch Block (LBBB) ECG morphology (HR 1.93), and VTA occurrence within the first year post-CRT-D (HR 4.91).
• Patients with these factors face significantly higher VTA risk despite improved LVEF.

Conclusions:

• A subset of patients on CRT-D remains at high risk for VTA despite substantial LVEF improvement.
• These patients necessitate vigilant monitoring, even when LVEF surpasses standard ICD guideline thresholds.