Comparative Outcomes of a Transthyretin Amyloid Cardiomyopathy Cohort Versus Patients With Heart Failure With Preserved Ejection Fraction Enrolled in the TOPCAT Trial

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CM), found in 6% to 15% of cohorts with heart failure with preserved ejection fraction, has long been considered a rare disease with poor prognosis. New treatments have made it one of the few directly treatable causes of heart failure. This study sought to determine whether patients with ATTR-CM, particularly those treated with tafamidis, have comparable survival to an unselected cohort with heart failure with preserved ejection fraction. METHODS AND RESULTS: We compared the clinical characteristics and outcomes between a single-center cohort of patients with ATTR-CM (n=114) and patients with heart failure with preserved ejection fraction enrolled in the TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist) trial (n=1761, excluding Russia and Georgia). The primary outcome was a composite of all-cause death, heart failure hospitalization, myocardial infarction, and stroke. Subgroup analysis of patients with ATTR-CM treated with tafamidis was also performed. Patients with ATTR-CM had higher rates of the primary composite outcome compared with patients enrolled in the TOPCAT trial (hazard ratio [HR], 1.44 [95% CI, 1.09–1.91]; P=0.01), with similar rates of all-cause death (HR, 1.43 [95% CI, 0.99–2.06]; P=0.06) but higher rates of heart failure hospitalizations (HR, 1.62 [95% CI, 1.15–2.28]; P<0.01). Compared with patients enrolled in TOPCAT, patients with ATTR-CM treated with tafamidis had similar rates of the primary composite outcome (HR, 1.30 [95% CI, 0.86–1.96]; P=0.21) and all-cause death (HR, 1.10 [95% CI, 0.57–2.14]; P=0.78) but higher rates of heart failure hospitalizations (HR, 1.96 [95% CI, 1.27–3.02]; P<0.01). CONCLUSIONS: Patients with ATTR-CM treated with tafamidis have similar rates of all-cause death compared with patients with heart failure with preserved ejection fraction, with higher rates of heart failure hospitalizations.