MAGNITUDE is a study exploring how safe and effective a drug called NTLA-2001 is for people with Transthyretin Amyloidosis with Cardiomyopathy (ATTR-CM). ATTR-CM is a condition where abnormal proteins build up in the heart, making it hard for the heart to work properly. This study compares a single dose of NTLA-2001 to a placebo, which is a harmless substance that doesn't have any active medicine. The study includes about 765 participants from different countries, and it's designed so that neither the participants nor the researchers know who receives NTLA-2001 or the placebo, keeping it double-blind.

• Participants will receive one infusion of either NTLA-2001 or a placebo.
• Eligibility includes having heart failure symptoms that are stable and managed.
• Participants must be willing to take vitamin A supplements during the study.

If you have this heart condition and meet the criteria, you might consider joining, but ensure you are aware of any risks and the need for regular check-ins throughout the study.