title: New insights in the pathophysiology of acute myocardial infarction detectable by a contemporary troponin assay.
abstract: OBJECTIVE
  ST-elevation and non-ST-elevation myocardial infarction (STEMI, NSTEMI) are considered two distinct pathophysiologic entities. We evaluated cardiac troponin I (cTnI) release in STEMI and NSTEMI using a "contemporary" (CV>10 to 20% at the 99th percentile concentration) cTnI assay for patients undergoing early percutaneous coronary intervention (PCI).
  
  
  METHODS
  856 patients with suspected acute coronary syndrome consecutively admitted to the Emergency Department of the Maggiore Hospital of Novara (225 STEMI and 135 NSTEMI) were selected according to: 1) early (≤ 4 h from admission) and successful PCI; and 2) cTnI measurements at ED presentation and within 24h. The influence of the MI type on cTnI concentrations at baseline and after PCI as well as the velocity of cTnI [cTnI V=absolute increase (after log conversion of cTnI measurements)/delay between the two measurements] was studied by multiple regression analysis, adjusting for patient parameters.
  
  
  RESULTS
  A statistically significant interaction between MI type and time from symptoms was reported on cTnI concentrations (p<0.0001): STEMI and NSTEMI differed for cTnI releases at admission and after revascularization. Higher cTnI V in STEMI was detectable in patients admitted within 6h from symptoms. Baseline cTnI concentrations were lower in patients with a history of coronary artery disease (CAD) and increased with aging (p<0.0001). In the elderly (>75 years), the cTnI V was significantly increased.
  
  
  CONCLUSIONS
  STEMI and NSTEMI patients have different patterns and dynamics of cTnI release influenced by the interaction with time from symptoms, by aging and history of CAD.
authors.affiliation: Laboratorio Analisi Chimico-Cliniche, A.O. 'Luigi Sacco', and Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Università degli Studi, Milano, Italy; SCDO Cardiologia, Ospedale Maggiore, Novara, Italy. Electronic address: ferraro.simona@hsacco.it.
authors.forename: Simona
authors.initials: S
authors.lastname: Ferraro
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics "Giulio A. Maccacaro", Department of Clinical Sciences and Community Health, University of Milan, Italy; Campus Cascina Rosa, Fondazione IRCCS Istituto Nazionale Tumori Milano, Italy.
authors.forename: Elia
authors.initials: E
authors.lastname: Biganzoli
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics "Giulio A. Maccacaro", Department of Clinical Sciences and Community Health, University of Milan, Italy; Campus Cascina Rosa, Fondazione IRCCS Istituto Nazionale Tumori Milano, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Marano
authors.affiliation: SCDO Cardiologia, Ospedale Maggiore, Novara, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Santagostino
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics "Giulio A. Maccacaro", Department of Clinical Sciences and Community Health, University of Milan, Italy; Campus Cascina Rosa, Fondazione IRCCS Istituto Nazionale Tumori Milano, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Boracchi
authors.affiliation: Laboratorio Analisi Chimico-Cliniche, A.O. 'Luigi Sacco', and Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Università degli Studi, Milano, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Panteghini
authors.affiliation: SCDO Cardiologia, Ospedale Maggiore, Novara, Italy.
authors.forename: Angelo S
authors.initials: AS
authors.lastname: Bongo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002624:Chemistry, Clinical / Q000379:methods*; D004636:Emergency Service, Hospital; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism; D062645:Percutaneous Coronary Intervention; D013997:Time Factors; D019210:Troponin I / Q000097:blood*; D014463:Ultrasonography
chemical_list: D019210:Troponin I
keywords: ACS; Analytical sensitivity; Assay; Biological interaction; CAD; CCU; CI; CK-MB; CVa; Cardiac Care Unit; ECG; ED; Emergency Department; LoD; MI; Myocardial pathophysiology; NSTEMI; PCI; ST-elevation myocardial infarction; STEMI; Troponin; acute coronary syndrome; acute myocardial infarction; analytical coefficient of variation; cTnI; cTnI V; cardiac troponin I; confidence interval; coronary artery disease; creatine kinase MB isoenzyme; electrocardiogram; limit of detection; no ST-elevation at electrocardiogram myocardial infarction; percutaneous coronary intervention; velocity of cTnI release