The natriuretic peptides and their role in disorders of right heart dysfunction and pulmonary hypertension.

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are increased in conditions with cardiac ventricular volume and pressure overload. The general physiological and potential therapeutic roles of natriuretic peptides in respiratory disease, right ventricular (RV) dysfunction, and pulmonary arterial hypertension (PAH) are reviewed. BNP levels can be used to differentiate between dyspneic patients with a pure respiratory defect and those with RV dysfunction. BNP levels also correlate with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with PAH (atrial septal defect, chronic thromboembolic disease, and scleroderma). BNP is a predictor of mortality in patients with primary pulmonary hypertension (PPH). These are important clinical implications in that a noninvasive blood test may be used to identify high-risk patients for more invasive procedures such as cardiac catheterization. BNP or NT-proBNP measurements may also be used to guide therapy (e.g., pulmonary vasorelaxants) in PAH since upregulation of the natriuretic peptide pathway has been shown to reduce cardiac hypertrophy and PAH. Additionally, there may be therapeutic potential via recombinant BNP or neutral endopeptidase inhibitors in RV dysfunction and PAH.