LAUSR

We thank dr. Lucas for her comments regarding our article in which we described patients with heart failure with preserved ejection fraction (HFpEF) and low levels of natriuretic peptides. In this article [1], we described that HFpEF patients with relatively low B-type natriuretic peptide (BNP) levels have strikingly similar clinical characteristics as HFpEF patients with elevated BNP levels, except for BMI, which was significantly higher in the first group. Clinicians might expect that low BNP levels are associated with low risk of adverse events, but, as recently observed in another study [2], NP-proBNP and BNP are not the ideal markers to identify low-risk patients. The hypothesis, shared by dr. Lucas, that the stiff left atrial syndrome might explain the low BNP levels observed in HFpEF patients is interesting. The stiff left atrium has mostly been described after ablation therapy for atrial fibrillation (AF) [3, 4]. However, we agree that also in heart failure, atrial tissue may remodel and become stiff. It has indeed been suggested that heart failure patients with a longer duration of AF exhibit advanced remodelling of the atrial tissue, in which atrial cardiomyocytes are replaced by fibrotic tissue, a hallmark of remodelling [5]. The remaining atrial tissue no longer produces natriuretic peptides, with pseudo-low natriuretic peptide levels as a result [6].