Abstract 3473: Identification of Plasma Soluble Corin as a Novel Biomarker for Heart Failure
Background: Brain natriuretic peptide (BNP) and its derivatives are current diagnostic biomarkers for heart failure (HF). Corin is a membrane protease that processes natriuretic peptides in cardiomyocytes. Many membrane proteins are shed from the cell surface in a regulated manner and can be detected in plasma. We hypothesize that similar shedding of corin may occur and that levels of plasma corin may reflect the cellular homeostasis in the heart. In this study, we examined plasma corin levels in HF patients.
Methods and Results: We developed an ELISA and measured corin levels in human plasma. In healthy adults (n=217), plasma corin levels were 691±282 pg/mL. In HF patients, plasma corin levels were significantly lower (386±280 pg/mL, n=317, p<0.001 vs. controls). Moreover, the reduction in plasma corin levels directly correlated with the severity of the disease. In contrast, plasma corin levels in patients with acute myocardial infarction (AMI) were similar to that of controls (690±260 pg/mL, n=73, p>0.05), suggesting that the reduction of plasma corin levels was closely related to HF but not AMI. We then compared the diagnostic value of plasma corin with that of BNP (Biosite Triage) in a study with 40 normal controls and 179 HF patients. With a cutoff value of ≤462 pg/mL based on receiver-operating-characteristic curve analysis, the corin assay had 78% sensitivity, 88% specificity and 80% accuracy for identifying the disease. Similar results were found for the BNP test with corresponding values of 76%, 100% and 80% (p values >0.4 vs. corin assay). Importantly, the corin assay detected HF patients who were missed by the BNP test. When both assays were used, the values for sensitivity, specificity and accuracy were 96% (p<0.0001, vs. corin or BNP), 100% and 97% (p<0.0001 vs. corin or BNP), respectively.
Conclusions: Our results show that plasma soluble corin is a novel biomarker for HF. When used in conjunction with BNP measurement, a plasma corin assay significantly improves the sensitivity and accuracy of HF diagnosis.