Background: Neurohormonal activation has never been investigated in patients with cardiac amyloidosis (CA).
Methods: Forty-seven patients with amyloid light-chain (AL)-CA and 61 with transthyretin (ATTR)-CA were matched to non-amyloidotic heart failure (HF) patients based on age, sex, left ventricular ejection fraction ranges, renal function and HF therapies. N-terminal pro-B-type natriuretic peptide (NT-proBNP), norepinephrine and renin were dosed. The primary and secondary endpoints were 1-year cardiovascular death or HF hospitalisation, and 5-year cardiovascular death, respectively.
Results: Patients with AL-CA had a 10-fold higher NT-proBNP than HF patients (6548 ng/L [2059-15,097] vs. 692 [243-2241], p < 0.001), and slightly higher norepinephrine (595 ng/L [383-869] vs. 416 [250-693], p = 0.047). Patients with ATTR-CA had higher NT-proBNP (3984 ng/L [2275-9505] vs. 1751 [470-4768], p = 0.006), norepinephrine (552 ng/L [344-855] vs. 441 [323-601], p = 0.020), and renin (14 mU/L [8-80] vs. 10 [4-34], p = 0.017). Patients with AL- or ATTR-CA had more often 2 or 3 neurohormones above the corresponding upper reference limits than matched HF patients. NT-proBNP and aldosterone were univariate predictors of the primary endpoint in patients with ATTR-CA, but not in matched controls. NT-proBNP and renin predicted the secondary endpoint in patients with AL-CA, but not in matched controls.
Conclusions: Patients with CA display a neurohormonal activation, with some prognostic significance.
Keywords: RAAS; cardiac amyloidosis; neurohormones; sympathetic; therapies.