Coordinated expression of BMP10/ALK1/endoglin-proteins that drive embryonic cardiac and vascular morphogenesis-in...

Bone morphogenetic protein 10 (BMP10), activin receptor-like kinase 1 (ALK1) and endoglin form a single transforming growth factor-β family signalling complex that is the principal driver of cardiac and vascular morphogenesis and maturation during hypoxic embryonic development. These proteins are down-regulated with the onset of normoxia at birth, but are up-regulated following experimental cardiac injury. Yet, little is known about the expression of this protein complex in patients with heart failure.

In the EMPEROR Program, we measured serum levels of BMP10 by electrochemiluminescence immunoassay in 1127 patients in Cohort 1 (n = 1127) and plasma levels of BMP10, ALK1 and endoglin by proximity extension assay in a distinct Cohort 2 (n = 1120). In both cohorts, patients were characterized at baseline and were followed for the occurrence of major adverse heart failure events. Levels of BMP10, ALK1 and endoglin at baseline and changes in these levels during follow-up were closely correlated with each other. Higher levels of BMP10, ALK1 and endoglin were associated with worse functional class, higher likelihood of atrial fibrillation and higher levels of natriuretic peptides and troponin T (p for trend <0.001 for all). Increasing levels of BMP10, ALK1 and endoglin were associated with progressively higher risks of major adverse outcomes (p for trend <0.001 for all three proteins and for all heart failure endpoints). The hazard ratios for the risks associated with tertiles of the three proteins in Cohort 2 were remarkably similar to those seen with BMP10 in Cohort 1. Treatment with empagliflozin had a modest effect to reduce BMP10 in both cohorts.

The coordinated circulating expression of proteins critical to foetal cardiac and vascular development tracks closely with the severity of heart failure, as reflected by symptoms, cardiac injury and stress, prevalence of atrial fibrillation and other comorbidities, and prognosis, suggesting a role of BMP10/ALK1/endoglin signalling in the progression of heart failure.