Aims
Heart failure (HF) is frequently caused by an ischaemic event (e.g. myocardial infarction) but might also be caused by a primary disease of the myocardium (cardiomyopathy). In order to identify targeted therapies specific for either ischaemic or nonâischaemic HF, it is important to better understand differences in underlying molecular mechanisms.
Methods and results
We performed a biological physical proteinâprotein interaction network analysis to identify pathophysiological pathways distinguishing ischaemic from nonâischaemic HF. First, differentially expressed plasma protein biomarkers were identified in 1160 patients enrolled in the BIOSTATâCHF study, 715 of whom had ischaemic HF and 445 had nonâischaemic HF. Second, we constructed an enriched physical proteinâprotein interaction network, followed by a pathway overârepresentation analysis. Finally, we identified key network proteins. Data were validated in an independent HF cohort comprised of 765 ischaemic and 100 nonâischaemic HF patients. We found 21/92 proteins to be upâregulated and 2/92 downâregulated in ischaemic relative to nonâischaemic HF patients. An enriched network of 18 proteins that were specific for ischaemic heart disease yielded six pathways, which are related to inflammation, endothelial dysfunction superoxide production, coagulation, and atherosclerosis. We identified five key network proteins: acid phosphatase 5, epidermal growth factor receptor, insulinâlike growth factor binding proteinâ1, plasminogen activator urokinase receptor, and secreted phosphoprotein 1. Similar results were observed in the independent validation cohort.
Conclusions
Pathophysiological pathways distinguishing patients with ischaemic HF from those with nonâischaemic HF were related to inflammation, endothelial dysfunction superoxide production, coagulation, and atherosclerosis. The five key pathway proteins identified are potential treatment targets specifically for patients with ischaemic
HF.