This study is examining a device called the Carillon Mitral Contour System to help people with heart failure and a condition called functional mitral regurgitation (FMR). FMR is when the heart's mitral valve doesn't close properly, causing blood to leak backward. The study will involve 300 patients from different countries, who will be split into two groups: one group will get the device, and the other will not. Patients will be checked at several times over five years to see how they're doing.

Before joining, patients will need tests like a transthoracic echocardiogram (an ultrasound of the heart) and a coronary angiogram (a special X-ray of the heart's blood vessels). They'll also check the coronary sinus/great cardiac vein to see if the device can be placed.

Here are some key points to consider:

• The study lasts five years, with regular check-ups at various months.
• Patients may either receive the Carillon device or have a similar procedure without the device.
• Participants must have heart failure and meet specific health criteria to join.