Frequency and causes of implantable cardioverter-defibrillator therapies: is device therapy proarrhythmic?

Area of Science:

• Cardiology
• Biomedical Engineering
• Clinical Trials

Background:

• Implantable cardioverter-defibrillator (ICD) shocks negatively impact patient quality of life and increase healthcare costs.
• Optimizing patient outcomes requires a deeper understanding of factors leading to ICD therapies and strategies to prevent unnecessary shocks.

Purpose of the Study:

• To review data from major randomized clinical trials on ICDs and cardiac resynchronization therapy-defibrillator devices.
• To determine control group mortality and sudden death rates.
• To assess the frequency of appropriate and inappropriate ICD therapies.

Main Methods:

• Systematic review of data from major randomized clinical trials involving ICDs and CRT-D devices.
• Analysis of control group mortality and sudden death rates.
• Evaluation of appropriate and inappropriate ICD therapy frequencies.

Main Results:

• Appropriate ICD therapies occurred 2 to 3 times more frequently than sudden cardiac deaths in control groups across studies.
• Factors contributing to frequent therapies include device programming, treatment of non-sustained tachycardias, and misclassification of episodes.
• The potential proarrhythmic effect of ICD therapy is an underexplored factor.

Conclusions:

• Frequent ICD therapies, including appropriate and potentially inappropriate shocks, impact the overall benefit of device therapy.
• Strategies to prevent unnecessary therapies and address device proarrhythmia are critical for optimizing patient management.
• Further research is needed to mitigate the adverse effects of ICD shocks and improve patient outcomes.