Sorry for late reply, long story!
Firstly heart failure is not the end of the world, there are 4 classes of heart failure as per NHS page and I was class 3 when diagnosed in 2010 with myocardial fibrosis, diastolic and systolic dysfunction, heart failure class 3 and ejection fraction 32% with normal being 55-60%. At that time I had about 2 years to live. I had both right and left heart catheterisation and heart MRI and eventually implantation of a biventricular implantable cardioverter defibrillator (ICD) and now have a normal ejection fraction BUT technically I will always be in heart failure because without my device my heart would no longer function and I would die.
So you see as scary as these terms can be, heart failure, dysfunction, fibrosis, the heart is the only organ with the ability to repair itself as it did in my case thanks to my device.
I had all my diagnosis and treatment under the Royal Free and hopefully you will be treated by Dr Benji Schreiber Pulmonary Hypertension (PH) clinic as he is the bestest doctor! I initially refused to have the MRI as I am claustrophobic so he rang the Royal Brompton, (which is where you will have the MRI and it's a marvellous place to have it as well!) and found out that there are ways of overcoming this problem.
The PH clinic at the Royal Free deals with scleroderma patients with heart involvement and its held in the same dingy, small corridor as the rheumatology clinic! The doctors are excellent though and you will get the best care possible. I believe that Dr Coghlan will see you with regards to the catheterisation and again he is excellent. I can't say enough about the cardiac team at the Royal Free so you are in good hands.
As scary as heart involvement sounds it can be tested for and treated and the heart can repair itself so try not to worry.