Definition and Prognosis of Mitral Regurgitation in Transthyretin Amyloid Cardiomyopathy: A Multicenter International Cohort Study.

Quantitative mitral regurgitation thresholds in transthyretin amyloid cardiomyopathy are substantially lower than current guidelines, improving outcome prediction.

• Why it matters: Accurate assessment of mitral regurgitation severity is crucial for prognosis in transthyretin amyloid cardiomyopathy, but conventional criteria may underestimate severity due to restrictive low-flow hemodynamics. Addressing this gap can enhance risk stratification and management.
• What they did: A multicenter cohort study analyzed 1101 patients with transthyretin amyloid cardiomyopathy, using standardized echocardiography to derive and validate disease-specific MR thresholds and compare them with existing guideline definitions.
• The result: The study found that a composite MR grading scheme based on lower thresholds better predicted mortality and heart failure hospitalization than guideline-based grading, with hazard ratios of 1.20 and 1.21, respectively, supporting disease-specific MR assessment.