PAPP-A as a marker of increased long-term risk in patients with chest pain

Objectives: Long-term risk stratification in patients presenting with acute coronary syndromes (ACS) is possible by measuring cardiac troponin (cTn). The present study examined whether PAPP-A measured in an emergency department (ED) chest pain population ill association with conventional and novel high sensitivity cTn (hs-cTnI) assays can predict long-term mortality. Methods: In 320 patients with cTn measurements the earliest heparinized plasma PAPP-A concentration after presentation was used for risk stratification for death by Kaplan-Meier and Cox analyses. Subgroup analyses using the earliest PAPP-A concentrations were also performed in a cohort of subjects with presentation cTnI <= 99th percentile but with significantly changing cardiac troponin concentrations as measured by the AccuTnI assay and the hs-cTnI assay (n=45 and 120 subjects, respectively). Results: Subjects with PAPP-A concentrations in the highest tertile were at higher risk for death (HR > 2.00; p <= 0.05 at 2 years) even after adjusting for cTnI at presentation. In the cohort with cTnI <= 99th percentile but with changing hs-cTnI concentrations, subjects in the top PAPP-A tertile had a higher probability for death (p=0.02). Conclusion: Early measurement of PAPP-A may identify chest pain patients at higher risk for long-term death. Additional prospective ACS studies are required to fully elucidate PAPP-A's role. (c) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.