Heart failure (HF), a current worldwide pandemic with an unacceptable high level of morbidity and mortality, brings an enormous medical and societal burden. Chronic HF is characterized by progressive alteration of cardiac structure and function. But the molecular mechanism of these alterations is still not well-established and needs to be discussed further. HF is a highly heterogeneous disease that can be caused by a multiple of diseases. Dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) are the main causes of this syndrome. Although HF is the common manifestation of DCM and ICM, the etiology and pathogenesis are different. Understanding the different pathophysiological mechanisms will contribute to the prevention and individualized therapy of heart failure. Therefore, this study aims to observation the different characteristics of the molecular biology and clinical courses in DCM and ICM patients.

Inclusion Criteria:

• LVEF≤ 55%
• enlarged left ventricular end-diastolic dimension
• ICM group: with history of MI or revascularization; ≥ 75% stenosis of LM or proximal LAD; ≥ 75% stenosis of two or more epicardial vessels.
• symptomatic heart failure

Exclusion Criteria:

• Known malignant tumour diseases
• Pregnancy or lactation period；
• Investigators think not suitable to participate in this trial.

The inpatient in the department of cardiology of Zhongshan Hospital, Fudan University will be selected.