Response to preventive cardiac resynchronization therapy in patients with ischaemic and nonischaemic cardiomyopathy...

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Cardiac resynchronization therapy with a defibrillator (CRT-D) is a key treatment for heart failure.
• Limited data exist on how cardiomyopathy aetiology affects CRT-D response in mildly symptomatic patients.

Purpose of the Study:

• To evaluate the differential outcomes of CRT-D based on ischaemic (ICM) versus non-ischaemic (non-ICM) cardiomyopathy aetiology.
• To identify specific patient subsets within each aetiology that benefit most from CRT-D.

Main Methods:

• Analysis of patients from the MADIT-CRT trial with ICM (n=1046) and non-ICM (n=774) aetiologies.
• Assessment of clinical response (heart failure/death) and echocardiographic response (ventricular volumes) over 2.4 years and 1 year, respectively.

Main Results:

• Both ICM and non-ICM groups showed significant risk reduction for heart failure/death with CRT-D.
• Non-ICM patients exhibited greater reductions in left ventricular volumes compared to ICM patients.
• Favorable clinical response subsets differed, including QRS duration and LBBB in ICM, and female sex and diabetes in non-ICM.

Conclusions:

• Mildly symptomatic patients with ICM and non-ICM cardiomyopathies demonstrate distinct echocardiographic and clinical responses to CRT-D.
• Risk stratification for CRT-D therapy in this population should consider the specific aetiology of cardiomyopathy.