• 1\. Age ≥ 18 years 2. Moderate-severe or severe mitral regurgitation (≥ 3+) 3. Patient has New York Heart Association (NYHA) Functional Class II, III or ambulatory IV 4. Patient is under guideline directed medical therapy, as reviewed and confirmed by the local multidisciplinary Heart Team, for at least one month 5. Patient is high-risk for open-heart surgery based on the assessment of the multidisciplinary Heart Team using standard scoring systems and consideration of co-morbidities, frailty, and disability 6. Patient meets the anatomical criteria for HighLife valve 7. Patient is willing to participate in the study and provides signed informed consent