Outcome-targeted Therapy: Principle and Outcome Evaluation: Clinical Study and Phenotype-genotype Correlation

Inclusion criteria Patients diagnosed as dilated cardiomyopathy, classified as NYHA functional class II or III and still have a low left ventricular ejection fraction (LVEF) (LVEF \< 45% and the Z score of the LV end-diastolic diameter \> 2.0) will be enrolled, if they have normal or high level of cholesterol and triglyceride and fulfill any of the following criteria: 1. Patients who have already received anti-congestive medications for at least three months and still have poor LV function (LVEF \< 45% and the Z score of the LV end-diastolic diameter \> 2.0). 2. Patients who have persistent or even worsening heart failure after one month of anti-congestive medications. 3. Patients who have positive family history of dilated cardiomyopathy and have received anti-congestive medications for one month. 4. Patients or their parents must sign an informed consent form. Exclusion criteria Patients who fulfill any of the following criteria will be excluded from the trial: 1. Patients who underwent prior cardiac surgery. Those who received DCM related surgery, such as mitral valve plasy, for longer than a year are not subject to this restriction. 2. Patients who had active liver / renal dysfunction. 3. Concomitant use with gemfibrozil, cyclosporine, danazol, strong CYP3A4 inhibitors (eg, boceprevir, clarithromycin, erythromycin, HIV protease inhibitors, itraconazole, ketoconazole, nefazodone, posaconazole, telaprevir, telithromycin, voriconazole), or cobicistat-containing products 4. Patients who are pregnant or plan to pregnancy in the period of study. 5. Patients who are intolerance to simvastatin therapy.