Circulating N-terminal atrial natriuretic peptide as a marker for symptomless left-ventricular dysfunction

Area of Science:

• Cardiology
• Biochemistry
• Medical Diagnostics

Background:

• Early identification of symptomless left-ventricular dysfunction is crucial for managing heart failure.
• Atrial natriuretic peptide (ANP) exists as N-terminal (N-ANP) and C-terminal (C-ANP) forms.
• N-ANP has higher circulating concentrations due to slower clearance compared to C-ANP.

Purpose of the Study:

• To prospectively evaluate N-ANP levels in relation to left-ventricular function.
• To assess the role of plasma N-ANP as an early diagnostic marker for heart failure.
• To compare N-ANP profiles in subjects with and without heart failure.

Main Methods:

• 180 patients undergoing radionuclide angiography for left-ventricular function assessment were studied.
• Blood samples were collected for C-ANP and N-ANP measurement prior to angiography.
• Patients were classified based on New York Heart Association (NYHA) heart failure classification and left-ventricular function.

Main Results:

• Plasma N-ANP concentrations were significantly higher in patients with symptomless left-ventricular dysfunction (NYHA class I) compared to controls (243 vs. 28 pmol/L, p < 0.001).
• A threshold of 54 pmol/L for plasma N-ANP demonstrated 90% sensitivity and 92% specificity for detecting symptomless left-ventricular dysfunction.
• Elevated N-ANP levels were observed even in patients without overt heart failure symptoms.

Conclusions:

• Plasma N-ANP concentrations are significantly elevated in individuals with symptomless left-ventricular dysfunction.
• N-ANP serves as a valuable and sensitive biomarker for the early diagnosis of left-ventricular dysfunction.
• This finding supports the potential for early pharmacologic intervention in asymptomatic patients.