N-terminal pro brain natriuretic peptide (NT proBNP) assay kit (quantum dot immunochromatography) NT proBNP clinical diagnostic significance BNP, also known as B-type natriuretic peptide, was first isolated from pig brain in 1988. However, it was soon discovered that the main source of BNP synthesis and secretion was ventricular muscle. BNP is synthesized as preproBNP in ventricular muscle cells. During the stretching process of ventricular muscle cells, preproBNP is enzymatically cleaved into proBNP, which is then proportionally cleaved into a biologically active 32 amino acid BNP (representing the C-terminal fragment) and an biologically inactive 76 amino acid N-terminal fragment (NT proBNP). Therefore, plasma levels of BNP and NT proBNP can be used as objective biomarkers for diagnosing chronic heart failure (CHF). High plasma BNP and NT proBNP not only provide significant prognostic indicators, but can also be used for the diagnosis of coronary artery disease (CAD) patients, such as acute coronary syndrome and stable angina. In addition, both BNP and NT proBNP are significantly affected by renal dysfunction, and NTproBNP seems to be more affected by renal function deterioration. In patients with renal function decline, BNP and NT proBNP values increase, showing a negative correlation with creatinine clearance rate. In addition to the decrease of renal clearance, the higher incidence of concomitant left ventricular changes such as left ventricular hypertrophy, diastolic and systolic dysfunction, and fluid overload may lead to the increase of BNP and NT proBNP concentrations. Research has shown that BNP and NTproBNP are also related to gender and age. Gender relationship is believed to be caused by metabolic differences, while age relationship may reflect preclinical structural and functional myocardial changes, as referenced in Weber  M,  Hamm  c.  Role  of  B-type  natriuretic  peptide  (BNP)  and  NT-proBNP  in  clinical  routine.[J].  Heart,  2006,  92(6):843.46(1):118.Sakai  H,  Tsutamoto  T  C,  Tanaka  T,  et  al.  Direc  comparison  of  brain  natriuretic  peptide  (BNP)  and  N-terminal  pro-BNp  secretion  and  extent  of  coronary  arterystenosis  in  patients  with  stable  coronary  artery  disease.[J].  Circulation  Journal,  2007,  71(4):499-505.Bibbins-Domingo  K,  Ansari  M,  Schiler  N  B,  et  al.ls  B-type  natiuretic  peptide  a  usefu  screening  test  for  systolic  or  diastolic  dysfunction  in  patients  with  coronarydisease?   Data  from  the  Heart  and  Soul  Study[J].  American  Journa  of  Medicine,  2004,  116(8):509-516.Torbjprn  Omland,  Anita  Persson,  eong  Ng.  N-Teminal  Pro-B-Type  Natriuretic  Peptide  and  Long-Term  Mortality  in  Acute  Coronary  Syndromesl.  Circulation,2002106(23):2913.