NPPB and pulmonary arterial hypertension: In-depth investigation into HFpEF clinical presentations has led to the identification and stratification in three distinct phenogroups that include: (1) elderly patients with moderate diastolic dysfunction, hypertension, and relatively preserved brain natriuretic peptide (BNP), (2) obese, diabetic patients with significantly impaired left ventricular relaxation, and (3) older patients with chronic kidney disease, pulmonary hypertension, and right ventricular dysfunction.