In a contemporary population of patients with transthyretin amyloid cardiomyopathy (ATTR-CM) treated with tafamidis, long-term mortality was relatively high, according to a multicenter study published Feb. 11 in JACC: CardioOncology.

The observational study included 624 patients from five amyloidosis centers in the U.S. who were diagnosed with ATTR-CM and received at least one daily dose of tafamidis between 2018 and 2021. Baseline demographics, cardiac and amyloidosis history, treatment history, and outcomes were collected using prespecified definitions for each variable to homogenize data collection.

The mean age of the study population was 76.9 years, 12.5% were female, 17.5% Black and 17.5% had variant ATTR-CM. When treatment with tafamidis started, 52% had NYHA class II heart failure and 34% had NYHA class III. Moreover, the National Amyloidosis Center Stage was ≥II in 40% and Columbia Stage was ≥II in 38%. The median (Q1-Q3) NT-proBNP level was 1,914 (957-3914) pg/mL.

Results showed that the primary outcome of all-cause mortality was 38.6% (241 patients) over the median follow-up of 43.2 months. The survival probability at 65 months was 54.1%. Of note, similar results were found in an analysis of the 397 patients (63.6%) who received tafamidis treatment within six months of ATTR-CM diagnosis: 49.6% survival probability at 65 months.

Ahmad Masri, MD, FACC, et al., report that predictors of all-cause mortality were age, male sex, Black race, variant ATTR-CM, Columbia Stage and time from diagnosis to tafamidis treatment.

"Ongoing assessment of the changing natural history and outcomes of ATTR-CM is vital to progress in this field. Further work is needed to improve the understanding of ATTR-CM burden, its natural history and how to improve outcomes beyond currently available therapies," write the authors.

In an accompanying editorial comment, Nowell M. Fine, MD, SM, FACC, discusses ways to improve long-term outcomes in ATTR-CM and how advancements are "aiming at a moving target." The author writes that the current study helps to contextualize the questions that should be asked. "By looking back and comparing where we have come from, we may be able to better anticipate where we are going and what knowledge and care gaps we need to focus on to continue to improve outcomes," he writes.