Prevalence of transthyretin amyloid cardiomyopathy in an unselected cohort with heart failure with preserved ejection fraction

Introduction: Heart failure with preserved ejection fraction (HFpEF) represents a heterogeneous syndrome characterised by various underlying aetiologies, such as transthyretin amyloid cardiomyopathy (ATTR-CM). The aim of this study was to determine the true prevalence of ATTR-CM in a Dutch all-comers cohort of HFpEF patients. Methods: From 2018 to 2023, all patients diagnosed with HFpEF underwent prospective screening for ATTR-CM. Diagnosis of ATTR-CM was made in accordance with guideline recommendations. Results: Of the 202 HFpEF patients included (mean ± standard deviation age: 76 ± 7 years; 64% female), 9 (5%) showed cardiac uptake on scintigraphy, of whom 6 (3%) were subsequently diagnosed with wild-type ATTR-CM. Left ventricular wall thickness (LVWT) was significantly higher in ATTR-CM patients than non-amyloid HFpEF patients (median interventricular septum diameter: 15 mm; interquartile range (IQR): 11–17 vs 10 mm; IQR: 9–11; p < 0.001). Interestingly, 2 ATTR-CM patients (33%) did not have increased LVWT at the time of diagnosis. These 2 patients were in a less advanced prognostic stage. Conclusion : This study revealed a low prevalence of ATTR-CM (3%) in an unselected HFpEF cohort. We identified ATTR-CM patients without increased LVWT (33%), who presented at an earlier disease stage. Hence, relying exclusively on LVWT for the diagnosis of ATTR-CM may result in delayed and/or missed diagnoses.