Abstract 12013: Procollagen Type 1 N-terminal Propeptide, a Collagen Synthesis Biomarker, is Associated With Adverse Clinical Outcome in Patients With Suspected Acute Coronary Syndrome

Abstract

Introduction: Procollagen type 1 N-terminal Propeptide (P1NP) is a precursor protein of collagen type 1, a major component of cardiac extracellular matrix. The association of P1NP to clinical outcome in patients with suspected acute coronary syndrome (ACS) has so far not been investigated. The objective of the present study was to assess the predictive value of P1NP concerning adverse clinical outcome in patients admitted for suspected ACS. Methods: Plasma P1NP was measured with an enzyme immune assay in samples taken upon admission from patients enrolled in the Risk markers in Acute Coronary Syndrome (RACS) study (NCT00521976), a Norwegian single center study including patients with suspected ACS from November 2002 to September 2003. The primary endpoint was a composite of all-cause mortality, myocardial infarction (MI), or stroke within 1 year. Additional analyzes included the composite and its individual components at 1, 2, and 7 years, and cardiac death at 1 and 2 years. Associations between quartiles of P1NP and the endpoints were assessed in both univariate analyzes and in stepwise multivariable Cox regression analyzes fitted with significant clinical variables, past medical history, medication, TnT, BNP, and eGFR before P1NP was introduced. Results: Samples were available from 813 patients (Mean age 69.6 years, 61.4 % males, 52.9% elevated TnT). Mean P1NP levels was 46.2 ng/mL (CI 44.8-47.6). In multivariable Cox analyzes, P1NP was found to be significantly associated with the composite of all-cause mortality, MI, or stroke at 1 year (HR [Q4vsQ1] 1.82, CI 1.12-2.98; p=0.017). This association did not remain significant beyond 1 year. No association was seen for any of the individual components, or cardiac death, at any timepoint, or in patients with elevated TNT (p>0.05 for all). Conclusions: This first study on P1NP in suspected ACS revealed a significant association with adverse clinical outcome (all-cause death, MI, or stroke) at 1 year. However, no predictive value was found concerning outcome for the individual components of the primary endpoint, or cardiac death, at any timepoint, or in patients with elevated TNT.