Bioactive adrenomedullin as a marker of congestion and disease progression in patients with a systemic right ventricle

Background:
Adults with a systemic right ventricle (sRV) are at a high risk for heart failure (HF) hospitalization and mortality. Bioactive adrenomedullin (bio-ADM) has been proposed as a marker of congestion and prognosis in patients with cardiovascular disease. We aimed to evaluate the association between bio-ADM and mortality and HF events in sRV patients.

Methods:
Plasma bio-ADM was measured by a novel immunoassay in plasma of 85 sRV patients. A composite endpoint of all-cause mortality and HF events was used as outcome. HF events were defined as onset or progression of HF signs or symptoms requiring hospitalization, initiation or intensification of therapy. Multivariable Cox regression analyses were performed to evaluate the association between bio-ADM and outcome.

Results:
The mean age of the patients was 37 ± 9 years and 65% were male. Patients with higher plasma bio-ADM concentrations were more often treated with diuretics (p = 0.007), possibly because of signs and/or symptoms of congestion. During a median follow-up of 10.2 years, 33.7% of the patients reached the endpoint. After adjustment for age and N-terminal pro B-type natriuretic peptide (NT-pro BNP), higher bio-ADM levels were associated with a higher risk of the composite endpoint (hazard ratio: 2.09 [95%-confidence interval: 1.15–3.78]). Bio-ADM improved risk prediction when added to NT-proBNP and age (C-statistic improved from 0.748 to 0.776 [p = 0.03]).

Conclusions:
Bio-ADM can be considered as a marker of congestion and independent predictor of death and HF events in adult patients with a sRV. Moreover, in terms of risk prediction, it has added value to NT-proBNP.