From the Guidelines
ANP levels in the blood can indicate cardiac stress or volume overload, and elevated levels may suggest heart failure, as the heart produces more ANP when struggling to pump efficiently. Atrial Natriuretic Peptide (ANP) is a hormone secreted by cardiac muscle cells in the atria of the heart in response to high blood pressure or stretching of the atrial walls. It functions as a natural diuretic by promoting sodium and water excretion through the kidneys, which helps reduce blood volume and lower blood pressure. According to the 2017 study by the American Heart Association 1, natriuretic peptides have led the way as a diagnostic and prognostic tool for the diagnosis and management of heart failure (HF). The hormone works by relaxing vascular smooth muscle, increasing glomerular filtration rate, and inhibiting sodium reabsorption in the kidneys, all of which contribute to its blood pressure-lowering effects.
Some key points to consider when interpreting ANP levels include:
- Elevated ANP levels may suggest heart failure, as the heart produces more ANP when struggling to pump efficiently 1
- ANP levels can be used to help diagnose heart failure, monitor treatment effectiveness, and assess prognosis in cardiac patients 1
- The diagnostic ranges for ANP levels may be different in the ambulatory care setting compared to the acute setting 1
- Careful prospective evaluation of the utility of blood natriuretic peptide testing has not been conducted in the non-acute ambulatory care setting 1
Overall, ANP is an important biomarker for cardiac health, and its levels can provide valuable information for diagnosing and managing heart failure. Clinicians should consider ANP levels in conjunction with other clinical and laboratory variables to provide optimal care for patients with heart failure. As noted in the 2016 ESC guidelines 1, natriuretic peptides are semi-quantitative markers of cardiac stress and HF, and thus related to the extent of atrial, ventricular, and valvular dysfunction.
From the Research
Definition and Function of ANP
- Atrial Natriuretic Peptide (ANP) is a cardiac hormone that regulates salt-water balance and blood pressure by promoting renal sodium and water excretion and stimulating vasodilation 2.
- ANP has an anti-hypertrophic function in the heart, which is independent of its systemic blood pressure-lowering effect 2.
- ANP plays an important role in regulating vascular remodeling and energy metabolism 2.
Physiological Effects of ANP
- ANP exhibits antagonistic effects against angiotensin II via diuretic/natriuretic actions, vasodilatory actions, and inhibition of aldosterone secretion 3.
- ANP is involved in the regulation of vascular tone and blood pressure 3, 4.
- ANP has a role in maintaining cardiovascular homeostasis and disease, and its levels are increased in patients with heart failure 3, 4.
Clinical Significance of ANP
- ANP and related peptides are used as biomarkers for heart disease 2, 4.
- ANP levels could serve as a potential biomarker for the diagnosis of acute stages of heart failure 4.
- ANP infusion could have a role in the management of acute or chronic heart failure 4.
- ANP has potent effects in experimental dilated cardiomyopathy that reduce the development of heart failure, prevent pathological remodeling, preserve systolic function, and reduce mortality 5.
Therapeutic Implications of ANP
- ANP may represent an optimal therapeutic agent in cardiovascular diseases 6.
- The potential use of ANP analogues, neutral endopeptidase (NEP) inhibitors, ACE/NEP inhibitors, angiotensin receptor blocker (ARB)/NEP inhibitors, the new dual endothelin-converting enzyme (ECE)/NEP inhibitors and ANP-based gene therapy are being explored 6.