Indeed, median circulating GDF-15 in our cohort (∼2600 ng/L) was higher compared to patients with chronic coronary artery disease or atrial fibrillation (∼1000–2000 ng/L) or healthy controls (<1000 ng/L) but similar to patients with chronic heart failure (median ∼2000–3000 ng/L) [8]. Here, GDF15 is linked to atrial fibrillation.