Circulating Markers That Underlie the Transition From Compensated Hypertrophy to Heart Failure

This study is collecting blood samples from people with heart failure — both stable and those whose condition has worsened — to find biological markers in the blood that indicate when heart failure is getting worse. **You may be eligible if...** - You are over 18 years old - You have stable or worsening heart failure (any type, regardless of how well your heart pumps) - You have symptoms of worsening heart failure such as shortness of breath, fluid buildup, or swelling - You have imaging evidence of heart failure - Healthy individuals with no history of heart attack or heart failure are also welcome as controls **You may NOT be eligible if...** - You are unable to give informed consent - You have had heart or non-heart surgery in the 3 months before enrollment Talk to your doctor to see if this trial is right for you.