Temporal Outcomes of Patients Diagnosed With Transthyretin Cardiac Amyloidosis

Background: Transthyretin cardiac amyloidosis (ATTR-CA) is increasingly recognized. Clinical outcomes have evolved over time amid changes in the diagnostic pathway and advances in therapeutics. We sought to evaluate clinical outcomes over time of patients with ATTR-CA with access to disease-modifying therapy.

Methods and results: This is a retrospective cohort study of 419 patients diagnosed with ATTR-CA during 2001-2021, comparing clinical characteristics across eras. The primary end point was composite all-cause mortality or orthotopic heart transplantation (OHT). Time-to-event analysis was performed using Cox proportional hazard modeling controlling for differences among cohorts. Patients diagnosed in the more recent years had higher median age (2017-2021, 78 years; 2014-2016, 75 years; 2001-2013, 74 years) and more often had wild-type ATTR (81.9% vs 82.5% vs 56.4%), but less severe phenotypes as evidenced by more individuals with Columbia stage I disease (47.6% vs 35.9% vs 22.4%), owing to lower biomarkers, more patients in New York Heart Association functional classes I and II (68.9% vs 47.6% vs 43.6%), and lower use of loop diuretics (67.0% vs 78.6% vs 89.1%). Over time, patients were treated more frequently with tafamidis (74% vs 37% vs 32%). On multivariable analysis, greater Columbia score (hazard ratio 1.42, 95% confidence interval 1.30-1.54, P < .001) was predictive of death or OHT, whereas tafamidis (hazard ratio 0.31, 95% confidence interval 0.22-0.44, P < .001) was associated with greater survival and freedom from OHT.

Conclusions: Patients recently diagnosed with ATTR-CA have earlier stage disease and substantially lower mortality. Tafamidis is associated with significantly improved survival and freedom from OHT.