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

Abstract

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 (P=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 (P<0.001). With respective hazard ratios of 5.85 (95% CI, 1.48–23.18; P=0.012) and 3.95 (95% CI, 1.99–7.84; P<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.

Keywords

• cardiac transthyretin amyloidosis
• NYHA
• tafamidis
• transthyretin amyloid cardiomyopathy
• transthyretin amyloidosis