Implantable cardioverter defibrillators in patients with cardiac amyloidosis

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Cardiac amyloidosis (CA) increases sudden cardiac arrest risk.
• The efficacy of implantable cardioverter-defibrillator (ICD) therapy in CA patients remains uncertain due to limited data on sudden cardiac arrest mechanisms and patient selection.
• Understanding ICD benefits in CA is crucial for improving patient outcomes.

Purpose of the Study:

• To determine the benefit of ICD therapy in patients diagnosed with cardiac amyloidosis.
• To evaluate the effectiveness and outcomes of ICD implantation in a cohort of CA patients.

Main Methods:

• Retrospective review of 53 cardiac amyloidosis patients who underwent ICD implantation at Mayo Clinic between 2000 and 2009.
• Analysis of ICD implant indications, procedures, and therapies received.
• Categorization of CA subtypes including AL, senile, familial, and AA amyloidosis.

Main Results:

• The study included 53 CA patients (33 AL, 10 senile, 9 familial, 1 AA).
• Primary prevention was the indication for ICD implantation in 77% of patients.
• A 32% rate of appropriate ICD shocks was observed in the first year, predominantly in AL amyloidosis patients. Shocks were more frequent for secondary prevention indications and less frequent with decreased ejection fraction or syncope.

Conclusions:

• Cardiac amyloidosis patients, especially those with AL-type, experience a high rate of appropriate ICD shocks.
• Despite appropriate shocks, ICD therapy did not confer an overall survival benefit in this cohort.
• Current patient selection criteria for ICD implantation in cardiac amyloidosis appear imprecise, necessitating further research for optimized therapeutic strategies.