Myocardial fibrosis, is a key HFpEF disease mechanism and represents an important therapeutic target.~Myocardial fibrosis is caused by excess secretion of collagen and other large molecules within the heart. Several of these molecules can be detected and measure in blood serum, thereby acting as non-invasive markers of myocardial fibrosis. Examples include, but are not limited to, precursors of type I and type 3 collagen.~In addition, gut microorganisms produce imidazole propionate (ImP), which can be detected in blood samples. This molecule has previously been associated with cardiovascular disease and heart failure and the investigators hypothesise that it may also be associated with myocardial fibrosis.~These circulating biomarkers of fibrosis are a cheaper and more accessible alternative for measurement of cardiac fibrosis compared to cardiovascular MRI ECV technique.~This study will investigate the association between circulating biomarkers of fibrosis, gut microbiome function and cardiovascular disease in samples from PIROUETTE.
Heart failure with preserved ejection fraction (HFpEF) represents one of the largest unmet needs in cardiovascular medicine. Heart muscle scarring (myocardial fibrosis) is a key HFpEF disease mechanism and represents an important therapeutic target.~Myocardial fibrosis can be measured non-invasively using the cardiovascular magnetic resonance imaging (MRI) extracellular volume (ECV) technique. However, some patients cannot undergo MRI scanning, and it is expensive. Circulating biomarkers in the blood that are sensitive to changes in myocardial fibrosis would represent an attractive cheaper and accessible alternative.~This study aims to assess baseline levels of, and longitudinal change in, circulating biomarkers relating to fibrosis and cardiovascular disease in gifted samples from PIROUETTE trial participants, and evaluate the relationship between the biomarkers, anti-fibrotic treatment response and other study measurements.