Heart failure & cardiomyopathies
Definition and Prognosis of Mitral Regurgitation in Transthyretin Amyloid Cardiomyopathy: A Multicenter International Cohort Study
Authors' conclusion
Quantitative MR thresholds in transthyretin amyloid cardiomyopathy are substantially lower than current guideline cutoffs. A validated, risk-based composite MR grading scheme improves prediction of both mortality and HFH, better reflecting the restrictive low-flow pathophysiology of transthyretin amyloid cardiomyopathy and supporting disease-specific MR grading.
Study context
- Population
- Patients with newly diagnosed transthyretin amyloid cardiomyopathyderivation 722 · validation 379
- Participants
- 1,101 patients
- Exposure
- Disease-specific composite Mitral Regurgitation (MR) grading scheme vs American Heart Association/American College of Cardiology, European Society of Cardiology/European Association for Cardiothoracic Surgery, and American Society of Echocardiography definitions
Methodological details8 centers, 4 countries, blinded core laboratory analysis, external validation
- 8 centers, 4 countries
- Blinded core laboratory analysis
- External validation
Main finding
As reported in the abstract
Died
314 patients
28.5%
Experienced heart failure hospitalization (HFH)
244
22.2%
Observational data: associations, not effects.
Further findings
MR metrics as predictors of mortality and HFH
- All MR metrics independently predicted mortality and HFH
- all P <0.05
Spline-derived MR risk thresholds
- Intermediate risk: vena contracta width
- ≥3.0 mm
- Intermediate risk: effective regurgitant orifice area
- ≥0.10 cm 2
- Intermediate risk: regurgitant volume
- ≥15 mL
- Intermediate risk: regurgitant fraction
- ≥20%
- High risk: effective regurgitant orifice area
- >0.25 cm 2
- High risk: regurgitant volume
- >38 mL
- High risk: regurgitant fraction
- >35%
Proportion classified as severe MR
- Guideline grading
- ≈12%-13%
- Composite MR grading scheme
- 21%
- Composite scheme provided superior discrimination for clinical outcomes at 12 and 24 months in both the derivation and validation cohort
Composite MR grading scheme, multivariable adjusted
- Mortality hazard ratio
- 1.20 [1.07-1.36]
- HFH hazard ratio
- 1.21 [1.05-1.38]
- After multivariable adjustment, only the composite MR grading scheme remained strongly predictive
Original publication
Summarised from the published abstract; every number is checked against it