Inside ST-elevation myocardial infarction by monitoring concentrations of cardio- vascular risk biomarkers in blood Simona Ferraro a, b, ⁎, Ilaria Ardoino c , Patrizia Boracchi c , Matteo Santagostino a , Laura Ciardi d , Giuseppina Antonini d , Federica Braga b, e , Elia Biganzoli c , Mauro Panteghini b, e , Angelo S. Bongo a a SCDO Cardiologia, Ospedale Maggiore, Novara, Italy b Laboratorio Analisi Chimico-Cliniche, A.O. ‘Luigi Sacco’, Università degli Studi, Milano, Italy c Dipartimento di Medicina del Lavoro L. Devoto Sezione di Statistica Medica e Biometria G.A. Maccacaro, Università degli Studi, Milano, Italy d Laboratorio di Ricerche Chimico Cliniche, Ospedale Maggiore della Carità, Novara, Italy e Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Università degli Studi, Milano, Italy abstract article info Article history: Received 19 December 2011 Received in revised form 30 January 2012 Accepted 30 January 2012 Available online 7 February 2012 Keywords: Biomarker ST-elevation myocardial infarction Kinetic Serum Interaction Background: No information is available on the optimal sampling time to catch the highest increase for biomarkers whose elevation after ST-elevation myocardial infarction (STEMI) is prognostic for adverse events. This study aimed to investigate release kinetics and peak times of cardiac troponin I (cTnI), C-reactive protein (CRP), B-type natriuretic peptide (BNP), chromogranin A (CgA) and cystatin C (CyC) in STEMI patients undergo- ing primary percutaneous coronary intervention (PPCI). Methods: Blood concentrations of cTnI, CRP, BNP, CgA and CyC were measured before and 6 h, 24 h, and 48 h after PPCI in 84 STEMI patients. The averaged trajectory of marker kinetics was estimated by multivariable regression models adjusted for patient characteristics and orthogonal polynomials were used to describe related releases. Results: From the estimated kinetics cTnI peaked at 10 h from symptoms, BNP at 28 h and CRP within 30 h. CyC concentrations did not change, whereas CgA concentrations increased from 6 to 48 h after PPCI. The amount of BNP release was found to be affected by the interaction between gender and age: females b 75 years had BNP concentrations fourfold higher than males. Conclusions: According to different release kinetics a single blood sampling for measuring all biomarkers is not recommended. © 2012 Elsevier B.V. All rights reserved. 1. Introduction The risk assessment of ST-elevation myocardial infarction (STEMI 1 ) patients is critical to set up an effective secondary prevention after hospitalization. Several circulating biomarkers released after myocardi- al infarction (MI) have been reported to contribute an additional prog- nostic value to commonly employed clinical risk scores [1]. Cardiac troponin (cTn) has emerged as the main prognostic marker in STEMI for its significant correlation with the infarct size [2–4]. In addition, high concentrations of C-reactive protein (CRP) and cystatin C (CyC) in serum have shown independent predictive value for major adverse events in MI patients [5,6]. The B-type natriuretic peptide (BNP) has also been largely investigated as prognostic marker in MI patients reflecting both the hemodynamic stress and the degree of ischemic insult [7]. Another neurohormonal biomarker, the chromogranin A (CgA), co-released with BNP under conditions of pressure or volume overload and known to modulate the activity of sympathetic system, has been recognized as a potential prognostic indicator [8]. Despite growing evidence on the prognostic value of these bio- markers no definitive information is available on the optimal sampling time suitable to gather the most reliable prognostic data. As shown for cTn [3], other biomarkers may display a typical release kinetic in the evolving acute event and their peak concentrations might contribute the strongest prognostic information. Aim of present study was to care- fully investigate release kinetics and the time of peak of cardiac tropo- nin I (cTnI), CRP, BNP, CgA, and CyC in STEMI patients undergoing primary percutaneous coronary intervention (PPCI) by collecting blood samples in the first 48 h from revascularization therapy. Clinica Chimica Acta 413 (2012) 888–893 ⁎ Corresponding author at: Laboratorio Analisi, Ospedale ‘Luigi Sacco’, via G.B. Grassi, Milano, Italy. Tel.: + 39 239042743. E-mail address: ferraro.simona@hsacco.it (S. Ferraro). 1 Nonstandard abbreviations: STEMI, ST-elevation myocardial infarction; MI, myocardi- al infarction; cTn, cardiac troponin; CRP, C-reactive protein; CyC, cystatin C; BNP, B-type natriuretic peptide; CgA, chromogranin A; cTnI, cardiac troponin I; PPCI, primary percuta- neous coronary intervention; LoD, limit of detection; CVa, analytical coefficient of varia- tion; RCV, reference change value; CVi, within-subject biological variation; LVEF, left ventricular ejection fraction; NSTEMI, non ST-elevation myocardial infarction. 0009-8981/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.cca.2012.01.034 Contents lists available at SciVerse ScienceDirect Clinica Chimica Acta journal homepage: www.elsevier.com/locate/clinchim