MFAP4 and atrial fibrillation: In pre‐clinical studies, MFAP4 has been implicated in remodelling and myocardial fibrosis28, 29 and MFAP4 levels have previously been associated with risk of cardiovascular diseases relevant to HFpEF pathophysiology, including atrial fibrosis, atrial fibrillation, and pulmonary hypertension.30