Green tea extract as a treatment for patients with wild-type transthyretin amyloidosis: an observational study

BACKGROUND: Causative treatment of patients with wild-type transthyretin amyloid cardiomyopathy (wtATTR-CM) is lacking. Recent reports indicate the potential use of epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, to inhibit amyloid fibril formation. We sought to investigate changes of cardiac function and morphology in patients with wtATTR-CM after consumption of green tea extract (GTE). METHODS: Twenty-five male patients (71 [64; 80] years) with wtATTR-CM were submitted to clinical examination, echocardiography, cardiac magnetic resonance imaging (cMRI) (n=14), and laboratory testing before and after daily consumption of GTE capsules containing 600 mg epigallocatechin-3-gallate for at least 12 months. RESULTS: A significant decrease of left ventricular (LV) myocardial mass by 6% (196 [100; 247] vs 180 [85; 237] g; P=0.03) by cMRI and total cholesterol by 8.4% (191 [118; 267] vs 173 [106; 287] mg/dL; P=0.006) was observed after a 1-year period of GTE consumption. LV ejection fraction by cMRI (53% [33%; 69%] vs 54% [28%; 71%]; P=0.75), LV wall thickness (17 [13; 21] vs 18 [14; 25] mm; P=0.1), and mitral annular plane systolic excursion (10 [5; 23] vs 8 [4; 13] mm; P=0.3) by echocardiography remained unchanged. CONCLUSION: This study supports LV mass stabilization in patients with wtATTR-CM consuming GTE potentially indicating amyloid fibril reduction.