Interpreting tafamidis effectiveness within the evolving phenotype of contemporary ATTRwt cardiomyopathy

The study by Porcari et al.1 provides valuable real-world data on tafamidis-treated wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM).1 Their findings merit further reflection when anchored to methodological considerations and placed within the broader context of disease natural history, diagnostic evolution, and contemporary evidence generation. At the methodological level, the authors appropriately used propensity matching to balance key baseline characteristics, yet their cohort retains features that distinguish it from both ATTR-ACT trial populations and several recent real-world registries. This distinction is important, because survival differences observed across ATTRwt-CM studies are shaped not only by treatment effects but also by shifts in diagnosis era, disease stage, and clinical phenotype at presentation—factors repeatedly shown to influence tafamidis effectiveness.2,3,4 Long-term analyses of ATTR-ACT demonstrate that tafamidis reduces mortality, with sustained benefit over a 5-year horizon; however, the magnitude of benefit is highly dependent on disease severity at initiation (Elliott et al., Circ Heart Fail 2022).3 Patients with milder symptoms and earlier NAC stages exhibit the most pronounced survival advantage, while those with advanced heart failure derive attenuated or heterogeneous benefit (Elliott et al., Eur J Heart Fail 2023).2 Contemporary real-world studies reinforce this stage-dependence. In the multinational THAOS registry, the expanding population of NAC stage 1 and NYHA I–II patients shows substantially better survival than historical cohorts, reflecting earlier diagnosis enabled by technetium-labeled bone scintigraphy, cardiac MRI, and strain imaging (Garcia-Pavia et al., J Card Fail 2025).4 Similarly, analyses from the TriNetX network indicate that even before the widespread uptake of tafamidis, baseline survival for ATTRwt-CM had improved, consistent with evolving recognition and referral patterns (Ghoneem et al., Curr Probl Cardiol 2023).5 These data contextualize the high 30-month survival reported by Porcari et al.,1 suggesting that the favourable outcomes align with the emerging natural history of earlier-stage, newly diagnosed ATTRwt-CM rather than a treatment effect isolated from changes in disease detection.