Heart failure severity, inappropriate ICD therapy, and novel ICD programming: a MADIT-RIT substudy

Area of Science:

• Cardiology
• Medical Devices
• Electrophysiology

Background:

• Heart failure (HF) severity's impact on inappropriate implantable cardioverter-defibrillator (ICD) therapy risk is not well-established.
• The Multicenter Automatic Defibrillator Trial with ICD Pacing (MADIT-RIT) provides a platform to investigate this association.

Purpose of the Study:

• To assess the relationship between HF severity (NYHA class III vs. I-II) and the risk of inappropriate ICD therapy.
• To evaluate the effectiveness of novel ICD programming strategies in mitigating inappropriate therapies based on HF severity.

Main Methods:

• The MADIT-RIT trial randomized 1,500 patients into three ICD programming arms: conventional, high-rate cut-off, and delayed therapy.
• Analysis focused on patients with NYHA class III versus class I-II HF, comparing inappropriate ICD therapy rates between conventional and novel programming arms.

Main Results:

• In the conventional programming arm, NYHA class III patients had a significantly higher risk of inappropriate therapy compared to NYHA class I-II patients (HR=2.55 for ICD, HR=3.73 for CRT-D).
• Novel ICD programming (high-rate cut-off or delayed detection) substantially reduced inappropriate therapies in both NYHA III and NYHA I-II patients.
• The benefit of novel programming was observed for inappropriate anti-tachycardia pacing (ATP) and therapies below 200 beats/min, but not for inappropriate shocks.

Conclusions:

• Increased HF severity is linked to a higher risk of inappropriate ICD therapy, particularly ATP from arrhythmias below 200 beats/min.
• Advanced ICD programming, including high-rate cut-off and delayed detection, effectively lowers inappropriate ICD therapies in patients with both mild and moderate HF.