I would suggest that this a question only your doctor should answer.
Certainly losing weight is good for your heart. Just a suggestion... have you talked to your doctor about bariatric surgery? If you have had difficulty losing weight, there are safe procedures now. I think I'd consider bariatric surgery before choosing such a controversial approach.
Please read this web site before considering HCG injections....
http://www.ehow.com/about_5444909_dangers-hcg-injections-weight-loss.html
The proven way to loose weight is through dieting, calorie reduction and exercise. Not easy but safe.