Super-response to cardiac resynchronization therapy reduces appropriate implantable cardioverter defibrillator...

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Cardiac resynchronization therapy with a defibrillator (CRT-D) is a key treatment for heart failure.
• Patient response to CRT-D varies, impacting long-term outcomes.
• Understanding factors influencing device therapy burden is crucial for patient management.

Purpose of the Study:

• To assess implantable cardioverter defibrillator (ICD) therapy frequency in super-responders versus non-super-responders after CRT-D implantation.
• To investigate the association between improved left ventricular (LV) function and reduced ICD therapy burden.

Main Methods:

• Retrospective, two-center study (2002-2011) of 629 CRT-D recipients.
• Patients categorized as super-responders (post-CRT ejection fraction [EF] ≥50%) or non-super-responders (post-CRT EF <50%).
• Analysis of 5-year rates of antitachycardia pacing (ATP) and appropriate ICD shocks, with multivariable risk factor analysis.

Main Results:

• Super-responders (5.9%) had significantly lower 5-year rates of ATP (2.7% vs. 22.1%) and appropriate ICD shocks (2.7% vs. 14.3%) compared to non-super-responders.
• Multivariable analysis identified male gender, secondary prevention, increased LV end-systolic diameter, and higher baseline EF as predictors of ICD therapy.
• Super-responder status was highly protective against appropriate ICD therapy (HR 0.13).

Conclusions:

• CRT-D recipients who normalize their ejection fraction demonstrate very low rates of ventricular arrhythmias.
• These findings highlight the importance of achieving significant LV function improvement post-CRT-D to reduce the need for ICD therapy.