The presence of HF symptoms with a LVEF ≥ 50% at time of inclusion, combined with significant cardiac structural [increased left atrial volume index (LAVI > 34 ml/m2) or left ventricular mass index (LVMI ≥ 115 g/m2 for men or ≥95 g/m2 for women)] or functional abnormalities (mean E/e′ ≥ 13 and/or mean e′ septal and lateral wall <9 cm/s) with additional increased levels of NT-proBNP; or not have increased NT-proBNP but have a previous HF hospitalization or clinical signs of congestion with positive response to diuretic therapy. This evidence concerns the gene NPPB and hydrops fetalis.