Microvascular Dysfunction Assessment to Predict Left Ventricular Reverse Remodeling

This study looks at whether measuring how well the tiny blood vessels in the heart work (microvascular function) can predict which patients with a weakened heart (dilated cardiomyopathy) will improve their heart's pumping ability after treatment. Currently it's hard to predict who will recover — this test could help. **You may be eligible if...** - You are 18 or older (any gender) - You have been newly diagnosed with dilated cardiomyopathy (a weakened, enlarged heart) with a reduced pumping strength (ejection fraction of 40% or less) - Your doctors have recommended coronary angiography (a heart artery imaging test) to rule out blockages - You are willing and able to give informed consent **You may NOT be eligible if...** - You have significant blockages in your heart arteries - You have had a previous heart attack, stent placement, or bypass surgery - You have significant valve disease (such as severe aortic stenosis or mitral regurgitation) - You have had a heart infection, inflammation (myocarditis), or congenital heart disease - You have severely reduced kidney function or a contrast dye allergy - You drink more than 80 grams of alcohol per day - You have received high-dose chemotherapy (anthracyclines) Talk to your doctor to see if this trial is right for you.