Prevalence of transthyretin cardiac amyloidosis in patients hospitalized for heart failure with preserved ejection fraction and septal thickness.

Introduction: Transthyretin cardiac amyloidosis (ATTR-CM) usually presents as heart failure with preserved ejection fraction. Its diagnosis has a significant clinical impact, as specific treatment is currently available. The aim of this study is to assess the prevalence of ATTR-CM in patients hospitalized for heart failure with preserved ejection fraction and septal thickness in our region. Methods: Cross-sectional study. Patients over 18 years old hospitalized for heart failure with preserved ejection fraction (greater than 50%) and septal thickness greater than or equal to 12 mm during the period from 8/2019 to 1/2023 were prospectively included. A pyrophosphate bone scintigraphy (PYP) was planned to assess cardiac involvement. The prevalence of ATTR-CM and its 95% confidence interval were calculated. Results: A PYP was performed in 59/82 patients. The median age was 85 [IQR 78-88] years old, 54% women. On admission, 61% had atrial fibrillation/flutter rhythm and the median NT-Pro-Bnp was 3536 [IQR 1700-7748] pg/nl. The mean ejection fraction was 57% (+/- 5). The prevalence of ATTR-CM diagnosed by bone scintigraphy with PYP was 19% (95%CI 9.7-30.1). No differences were found compared with those patients who did not perform a PYP. Conclusion: In patients admitted for heart failure with preserved ejection fraction and septal thickness, the diagnosis of ATTR-CM was relatively common (1/5). We believe that it should be routinely explored.