Cardiac Resynchronization in Different Age Groups: A MADIT-CRT Long-Term Follow-Up Substudy

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Cardiac resynchronization therapy with a defibrillator (CRT-D) improves outcomes in heart failure patients.
• The impact of CRT-D across different age groups remains incompletely understood.

Purpose of the Study:

• To evaluate the association of age with the effectiveness of CRT-D in reducing heart failure (HF) and mortality events.
• To compare CRT-D versus defibrillators alone across distinct age strata.

Main Methods:

• Post hoc analysis of the MADIT-CRT follow-up study involving 1,281 patients with Class I/II HF.
• Patients were randomized to CRT-D or implantable cardioverter-defibrillators alone.
• Multivariate regression analysis assessed outcomes in age groups: <60, 60-74, and ≥75 years over 7 years.

Main Results:

• CRT-D significantly reduced the composite of HF or death in all age groups (<60: 36% RRR; 60-74: 61% RRR; ≥75: 56% RRR).
• CRT-D significantly reduced HF events across all age groups (<60: 49% RRR; 60-74: 62% RRR; ≥75: 74% RRR).
• Mortality reduction was significant only in the 60-74 age group (59% RRR).

Conclusions:

• CRT-D effectively reduces heart failure events and the combined endpoint of mortality or HF events in all studied age groups.
• The mortality benefit of CRT-D was specifically observed in patients aged 60-74 years.