Associated diseases and diuretic dosage to predict mortality in transthyretin amyloid cardiomyopathy

BACKGROUND: Transthyretin amyloidosis can lead to transthyretin amyloid cardiomyopathy (ATTR-CM) and heart failure. AIMS: To describe the prevalence of cardiac and extracardiac diseases in patients with ATTR-CM and examine mortality predictors, including diuretic dosage, using the French National Health Database. METHODS: Patients with ATTR-CM and their medical characteristics were identified from the French database from 2011 to 2019. Diuretic doses were categorized into four classes (furosemide dose: level 1<20mg; level 2 20 to <60mg; level 3 60 to<120mg; level 4 ≥120mg). Predictive factors for mortality were examined. RESULTS: Of 7804 patients with ATTR-CM, 33.0% were on level 1 diuretics, 25.8% on level 2, 15.8% on level 3 and 25.3% on level 4 at diagnosis. Leading extracardiac conditions included kidney disease (37.0%), diabetes (29.5%), neurologic disorders (17.9%), gastrointestinal disorders (15.7%) and musculoskeletal conditions (11.8%). Median (95% confidence interval [CI]) survival was 3.1 (3.0-3.3) years. Multivariable analysis identified age at diagnosis (hazard ratio [HR] 1.482, 95% CI 1.400-1.558), male sex (HR 1.258, 95% CI 1.125-1.406), diuretic dose (HR 1.380, 95% CI 1.315-1.449), heart failure (HR 1.251, 95% CI 1.090-1.437), arrhythmia/conduction disorder (HR 1.143, 95% CI 1.001-1.306), kidney disease (HR 1.224, 95% CI 1.104-1.358), gastrointestinal disorder (HR 1.143, 95% CI 1.000-1.307) and diabetes (HR 1.192, 95% CI 1.071-1.326) as significantly associated with mortality. CONCLUSION: Patients with ATTR-CM face a significant burden of associated diseases requiring comprehensive management alongside their ATTR-CM treatment. Beyond addressing these comorbidities, diuretic dosage emerges as a pivotal prognostic indicator.