Applicability of phase 3 trial selection criteria to real-world transthyretin amyloid cardiomyopathy patients

Several randomized, double-blind, placebo-controlled trials (RCT) explore disease-modifying therapeutics in transthyretin amyloid cardiomyopathy (ATTR-CM). However, it is currently unclear whether patients eligible to participate in the RCT are representative of real-world patients. ATTR-CM patients presenting to a tertiary referral center for cardiac amyloidosis at the Medical University of Vienna between March 2012 and May 2024 were included in a prospective registry. Inclusion and exclusion criteria of the ATTRACT, ATTRIBUTE, HELIOS-B, CARDIO-TTRANSFORM, and the DEPLETTR-CM trial were applied, and the baseline characteristics of the hypothetical trial cohorts as well as their survival were compared. 353 patients (80.3 years, IQR: 75.5-84.2, 17.6% female) were included, and 192 (57.8%) patients would have been eligible to participate in ATTRIBUTE, ATTRACT would have recruited 163 (49.1%) patients, HELIOS-B 105 (31.6%) patients, CARDIO-TTRANSFORM 80 (24.1%) subjects, and 71 (21.4%) patients would have been eligible for DEPLETTR-CM. Hypothetical ATTRIBUTE, ATTRACT, HELIOS-B, and CARDIO-TTRANSFORM patients demonstrated only minor differences regarding baseline characteristics, both among each other and compared to the real-world cohort. However, DEPLETTR-CM eligible patients exhibited more severely elevated biomarkers of heart failure (NT-proBNP: 2590pg/mL, IQR: 1614-4423, vs. 2339pg/mL, IQR: 1154-4250; p < 0.001) and more advanced National Amyloidosis Centre stage (p < 0.001). Patients who could have been included in DEPLETTR-CM also showed significantly worse survival. Applied to our real-world ATTR-CM cohort, RCT inclusion and exclusion criteria would have selected patients comparable to the real-world cohort. Only the DEPLETTR-CM trial would have selected patients with more advanced disease and worse prognosis.