title: Serum tryptase detected during acute coronary syndrome is significantly related to the development of major adverse cardiovascular events after 2 years.
abstract: BACKGROUND
  One of the greatest challenges in cardiovascular medicine is to define the best tools for performing an accurate risk stratification for the recurrence of ischemic events in acute coronary syndrome (ACS) patients.
  
  
  METHODS
  We followed 65 ACS patients enrolled in a previous pilot study for 2 years after being discharged, focusing on the occurrence of major adverse cardiovascular events (MACE). The relationship between serum tryptase levels on admission, SYNergy between percutaneous coronary intervention with the TAXUS drug-eluting stent and the cardiac surgery score (SX-score), cardiovascular complexity and MACE at 2 years follow-up were analyzed.
  
  
  RESULTS
  The ACS population was divided in two groups: patients with MACE (n = 23) and patients without MACE (n = 42). The tryptase measurement at admission (T0) and at discharge (T3) and SX-score were higher in patients who experienced MACE than in those without (p = 0.0001, p < 0.0001 and p = 0.006, respectively). Conversely, we found no significant association between MACE and C-reactive protein (CRP), and between MACE and maximum level of high-sensitivity troponin (hs-Tn) values. Among all patients with MACE, 96% belonged to the group that presented with cardiovascular complexity at the beginning of ACS index admission (p < 0.0001). The predictive accuracy of serum tryptase for MACE at follow up set at the cut-off point of 4.95 ng/ml at T0 and of 5.2 ng/ml at T3. Interestingly, patients with both the above cut-off tryptase values at T0 and at T3 presented a 1320% increase in the odds of developing MACE (p < 0.0001).
  
  
  CONCLUSIONS
  In ACS patients, serum tryptase measured during index admission is significantly correlated to the development of MACE up to 2 years, demonstrating a possible long-term prognostic role of this biomarker.
authors.affiliation: The Department of Allergology and Immunology, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Elide Anna
authors.initials: EA
authors.lastname: Pastorello
authors.affiliation: The Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Farioli
authors.affiliation: The Department of Allergology and Immunology, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Laura Michelina
authors.initials: LM
authors.lastname: Losappio
authors.affiliation: The Department of Cardiology1-Emodinamic, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Nuccia
authors.initials: N
authors.lastname: Morici
authors.affiliation: The Department of Cardiology, University of Foggia, Foggia, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Di Biase
authors.affiliation: Service of Biostatistics, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Nichelatti
authors.affiliation: The Department of Allergology and Immunology, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Jan Walter
authors.initials: JW
authors.lastname: Schroeder
authors.affiliation: The Department of Allergology and Immunology, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Balossi
authors.affiliation: The Department of Cardiology1-Emodinamic, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Silvio
authors.initials: S
authors.lastname: Klugmann
keywords: Acute coronary syndrome; Biomarker; Major adverse cardiovascular events; Mast cell; Tryptase