Outcomes in Cardiac Transthyretin Amyloidosis and Association With New York Heart Association Class: Real-World Data.

Background: Results from ATTR-ACT (Safety and Efficacy of Tafamidis in Patients With Transthyretin Cardiomyopathy) indicate that tafamidis prolongs survival and reduces cardiovascular hospitalizations in cardiac transthyretin amyloidosis (ATTR-CA). However, real-world data supporting these findings are scarce. Thus, we sought to characterize the clinical outcome of patients with ATTR-CA treated with tafamidis in a real-world setting and assess the prognostic role of the New York Heart Association (NYHA) classification.

Methods And Results: We conducted a retrospective observational study, enrolling a consecutive sample of patients with ATTR-CA (wild-type or variant) treated with tafamidis. Clinical outcome was tracked through follow-up visits or phone calls. Primary outcomes were death and major adverse cardiac events (MACE), a composite end point of death and hospitalizations for acute cardiac decompensation, myocardial infarction, severe arrythmias, or stroke. Kaplan-Meier analysis estimated overall and MACE-free survival including NYHA subgroups (NYHA I/II versus NYHA III). One hundred sixty-seven patients with ATTR-CA (94.6% wild-type) were enrolled and followed for a median of 539 [323-869] days. Median overall survival was not reached. Estimated 1-year, 2-year, and 5-year overall survival among the whole cohort was 93.5%, 85.9%, and 70.2%, respectively. Overall survival was higher in the NYHA I/II subgroup (=0.002). Median MACE-free survival time was 1082 (95% CI, 962-1202) days. MACE-free survival was higher in the NYHA I/II subgroup (<0.001). With respective hazard ratios of 5.85 (95% CI, 1.48-23.18; =0.012) and 3.95 (95% CI, 1.99-7.84; <0.001), NYHA III was an independent predictor of death and MACE.

Conclusions: Treatment of ATTR-CA with tafamidis led to substantial improvements of clinical outcome. NYHA classification at treatment initiation is a reliable tool to provide patients with individualized prognostic information.