Study population
This study has been approved by the Ethics Committee of Nanjing Drum Tower Hospital have therefore been performed in accordance with the Declaration of Helsinki and its later amendments. We enrolled 82 patients with ICM or DCM who received ICD implantation for primary prevention between January 2010 and August 2018 admitted in the Department of Cardiology of Nanjing Drum Towel Hospital. Among them, 26 were ICM and 56 were DCM. A total of 78 patients were followed up, including 25 patients with ICM and 53 patients with DCM. Clinical characteristics, medications, 24-h Holter electrocardiograms (ECGs) were recorded on admission.
Inclusion criteria
ICM patients: 1) Patients with chronic congestive heart failure; 2) Patients with definite myocardial infarction and who have received percutaneous coronary intervention (PCI) or surgical coronary artery bypass grafting (CABG); 3) Electrocardiogram, echocardiography or cardiac magnetic resonance show large-scale necrosis of myocardium or local dyskinesia of ventricular wall; 4) After 3 months of treatment with standard anti-heart failure drugs, echocardiography confirmed left ventricular ejection fraction (LVEF) ≤35%; 5) NYHA class II-III or IV patients considering CRT-D or NYHA class IV patients waiting for heart transplantation.[7]
DCM patients: 1) Patients with chronic congestive heart failure; 2) After 3 months of treatment with standard anti-heart failure drugs, echocardiography confirmed LVEF ≤35%, the whole heart is enlarged, and LVEDD (left ventricular end diastolic diameter) > 55mm in male or > 50mm in female, or the wall motion is weakened; 3) Exclude heart enlargement and EF reduction caused by other diseases (such as hypertrophic cardiomyopathy, alcoholic cardiomyopathy, valvular disease, cardiomyopathy caused by hyperthyroidism, etc.); 4) NYHA class II-III or IV patients considering CRT-D or NYHA class IV patients waiting for heart transplantation.[8]
Exclusion criteria
1) Suffering from heart disease other than ICM and DCM which leads to chronic heart failure; 2) Patients had acute left heart failure; 3) The life expectancy of the patient is less than 1 year; 4) Patient experienced cardiovascular events such as SCD, ventricular fibrillation, cardiopulmonary resuscitation or continuous ventricular tachycardia.