I want to know that is accupuncture useful of heart disease like dilated cardiomyopathy.
The way to answer this question for yourself is two fold. First, can the body heal this condition ever on it's own - i.e. are there cases of lower stage cardio myopathies that people have resolved or experienced minimal symptoms via lifestyle change, etc. And/or are there any studies for related conditions using Chinese Medicine that are applicable. The answer to both is yes. An example of a study showing benefit is "Effect of auriculo-acupuncture... on dilated cardiomyopathy." Another one, an example of celiac disease contributing to cardiomyopathy - "A Bad Heart From A Stomachache".
Secondly, Chinese Medicine is far more concerned generally with the causes and conditions for a particular western medical condition to arise in the first place than symptomatically treating the condition overall (see "What Does Acupuncture Treat?"). From this, then, what does it even mean to "treat" cardiomyopathy. As there are multiple causes from lifestyle related causes to thyroid conditions to drug and alcohol abuse - treatment is often more about resolving the underlying causes and conditions properly using TCM than something specific to their heart vessel per se. In this case the answer is also, yes, but you need to properly diagnose and treat the patient in a complete way instead of going after the symptoms.