Prevalence of transthyretin cardiac amyloidosis in patients with heart failure with preserved ejection fraction: the PRACTICA study.

Introduction and objectives: Transthyretin cardiac amyloidosis (ATTR-CA) is a frequent cause of heart failure with preserved ejection fraction (HFpEF). This study sought to determine the prevalence of ATTR-CA among HFpEF patients in a multicenter nationwide study.

Methods: Consecutive ambulatory or hospitalized patients aged ≥ 50 years with HFpEF and left ventricle hypertrophy ≥ 12mm were studied at 20 Spanish hospitals. Screening for cardiac amyloidosis was initiated according to the usual clinical practice of each center. Positive scintigraphs were centrally analyzed.

Results: 422 patients were included, of whom 387 underwent further screening for cardiac amyloidosis. A total of 65 patients (16.8%) were diagnosed with ATTR-CA, none below 75 years. There was an increase of prevalence with age. Of them, 60% were male, with a mean age of 85.3±5.2 years, mean left ventricle ejection fraction of 60.3±7.6% and a mean maximum left ventricle wall thickness of 17.2 [12-25] mm. Most of the patients were New York Heart Association class II (48.4%) or III (46.8%). Besides being older than non-ATTR-CA patients, ATTR-CA patients had higher median NT-proBNP levels (3801 [2266-7132] vs 2391 [1141-4796] pg/mL; P=.003). There was no statistical difference in the prevalence of ATTR-CA by sex (19.7% for men and 13.8% for women, P=.085). A ∼7% (4/56) of the patients exhibited a genetic variant (ATTRv).

Conclusions: This multicenter nationwide study found a prevalence of 16.8%, confirming that ATTR-CA is a significant contributor to HFpEF in male and female patients with left ventricle hypertrophy and more than 75 years.