The objective of this prospective registry study is to comprehensively characterize the prevalence, (semi-) quantitative parameters, and associated clinical outcomes of mitral (MR) and tricuspid regurgitation (TR) in patients diagnosed with transthyretin amyloid cardiomyopathy (ATTR-CM). The study further aims to develop and implement new grading standards for the quantitative assessment of regurgitation severity, tailored to the distinct hemodynamic profile of ATTR-CM. This approach seeks to address the limitations of current regurgitation severity classifications, which do not adequately reflect the unique pathophysiology of a restrictive phenotype as seen in ATTR-CM.

Inclusion Criteria:

• Diagnosis of ATTR-CM according to current diagnostic criteria
• Comprehensive baseline echocardiographic assessment, including (semi-)quantitative mitral and tricuspid regurgitation (MR/TR) parameters, performed within ±6 months of diagnosis
• Age ≥ 18 years
• Willingness to participate in the study and provide informed consent

Exclusion Criteria:

• Severe aortic valve disease requiring intervention
• Inability to provide informed consent or participate in study follow-up

This observational study will include patients diagnosed with transthyretin amyloid cardiomyopathy (ATTR-CM) from international specialized cardiac amyloidosis referral centers. The study population will encompass both wild-type and hereditary ATTR-CM patients, ensuring representation of diverse disease phenotypes. Data collection will be standardized across centers, with echocardiographic assessments performed in accordance with the dedicated study protocol. The inclusion of multiple international centers will enhance the generalizability of findings across different healthcare systems and patient populations.