NPPB and Left ventricular diastolic dysfunction: However, all enrolled patients with HFpEF had objective evidence of left ventricular diastolic dysfunction or increased left ventricular filling pressure (e.g., E/e′ ratio ≥ 13, E/A ratio < 1, estimated pulmonary artery systolic pressure > 35 mm Hg, tricuspid regurgitation velocity > 2.8 m/s, elevated NT-proBNP level, or pulmonary congestion).