Plasma Levels Of B-Type And C-Type Natriuretic Peptide In Patients With Acute Coronary Syndrome And Its Clinical Significance

Aims: To explore the significance of plasma B-type natriuretic peptide(BNP) and C-type natriuretic peptide(CNP) levels in patients with acute coronary syndrome(ACS).Methods: Thirty-five patients with ACS and twenty healthy subjects as control were selected into this protocol. Blood samples of ACS patients were extracted from femoral vein on admission immediately and at 24 h after percutaneous coronary intervention (PCI). The plasma BNP and CNP were measured by a bedside rapid assay and radioimmunoassay, respectively. The plasma levels of BNP and CNP were compared among those of before and after PCI, ACS patients and healthy controls, and different conditions of heart function. The relationship between the plasma levels of BNP and CNP with Gensini scores was studied by correlation analysis.Results: The plasma levels of BNP and CNP were significantly increased in patients with ACS compared with those of the control subjects (112.9±80.3 pg/ml vs 9.1±3.5 pg/ml, P<0.001 and 6.8±1.4 pg/ml vs 5.1±1.6 pg/ml, P<0.01, respectively), but different change was found at 24 h after PCI compared to before PCI, BNP level was decreased (112.9±80.3 pg/ml vs 74.7±59.5 pg/ml, P=0.027) and CNP was increased (6.8±1.4 pg/ml vs 10.9±2.9 pg/ml, P<0.001). Compared to ACS group with LVEF>50%, the plasma CNP were significantly increased in ACS patients with LVEF<50% (7.8±1.1 pg/ml vs 6.1±1.2 pg/ml, P<0.001), the similar result was found in BNP (174.4±75.2 pg/ml vs 66.9±46.5 pg/ml, P<0.001), and the plasma levels of BNP was negatively correlated with LVEF (r= -0.88, P<0.001), but there was no significant relationship among different NYHA with CNP levels (P>0.05). Coronary Gensini scores were correlated with the plasma levels of CNP in ACS group (r=0.76, P<0.001), not with BNP.Conclusions: It was found that plasma levels of BNP and CNP were increased significantly in ACS patients. The plasma level of BNP was correlated with classification of heart function. The plasma level of CNP was increased further after PCI. The pathological role of CNP during process of ACS remains to be investigated.