Changes of clinical characteristics, distribution of red flags and prognosis in contemporary patients with wild-type transthyretin amyloidosis cardiomyopathy.

Aim: Increased diagnostic awareness and specific disease treatments have changed the landscape of transthyretin cardiac amyloidosis (ATTR). Patients with wild-type ATTR (ATTRwt) are increasingly being diagnosed, potentially changing the clinical profile and prognosis compared with existing retrospective data. We aimed to study the clinical characteristics, distribution of red flags and prognosis of contemporary ATTRwt patients.

Methods: From January 1^st 2017, to December 31^st 2022, 213 consecutive patients were diagnosed with ATTRwt and prospectively followed up. Data on clinical characteristics, biomarkers, echocardiography findings, hospitalization due to worsening heart failure (WHF) and all-cause mortality were collected.

Results: A 37% increase in newly diagnosed patients from 2017-2019 (n = 90) vs. 2020-2022 (n = 123) was observed. The majority of patients presented with NAC disease stage I in the latter period (49% in 2017-2019 vs. 58% in 2020-2022, p = .16). Red flags were primarily cardiac-related, including elevated NT-proBNP, impaired left ventricular longitudinal systolic strain with an apical sparing pattern, heart failure with increased left ventricular wall thickness and elevated troponins. NAC disease stage I as well as low NT-proBNP levels (<1000 ng/L) were significantly associated with better survival (both p < .001). When compared with NAC disease stage II + III combined, patients with NAC disease stage I had a significantly lower risk of WHF hospitalization or death (log rank test: p = .0001). Independent predictors of the combined endpoint WHF hospitalization or death were NT-proBNP (HR 1.03 [95% CI 1.00-1.07], p < .049) and prior implantation of permanent pacemaker (HR 2.01 [1.30-3.11], p = .002).

Conclusion: Increased diagnostic awareness resulted in a 37% increase in newly diagnosed patients in 2020-2022 vs. 2017-2019. As expected all-cause mortality but also the morbidity in terms of risk of hospitalization with WHF were significantly lower in patients with NAC disease stage I, as well as in those with low NT-proBNP levels <1000 ng/L. These findings underline the importance of continuous attention to diagnostic awareness, as early diagnosis is critical for initiating both general and specific ATTR treatment, thus improving prognosis.