Abstract 3536: Circulating Markers of Collagen Turnover Following ST-Segment Elevation Myocardial Infarction and Primary Percutaneous Coronary Intervention Predict Infarct Size and Left Ventricular Volumes, Estimated by Serial Cardiac Magnetic Resonance Imaging for up to 1 Year
We investigated the time profile and predictive value of circulating markers of collagen turnover (CTO) for infarct size (IS), ejection fraction (EF) and left ventricular (LV) volumes, determined by serial cardiac magnetic resonance imaging (cMRI) in patients undergoing primary percutaneous coronary angioplasty for ST-elevation myocardial infarction (STEMI).
Methods: Forty-two patients with first time STEMI, 1-vessel disease, and successful revascularization of the proximal occluded infarct related artery were included. Serum samples were obtained at admission, 2 days, 7 days, 2 months and 1 year post-STEMI. We analyzed CTO-markers of collagen synthesis: N-terminal procollagen type I (PINP), N-terminal procollagen type III (PIIINP), and collagen degradation: C-terminal telopeptide of type I collagen (ICTP); established markers of outcome: Troponin-T (TnT), C-reactive protein (CRP), and N-terminal pro brain natriuretic peptide (NT-proBNP). Late enhancement and cine cMRI was performed on day 2, day 7, 2 months and 1 year post-STEMI.
Results: Median time from symptom debut to admission was 145 minutes (range: 25–720). CTO-marker analyses from admission samples were available in 35 patients. Significant time-dependent changes occured for all 3 CTO-markers and the PINP/ICTP ratio (p<0.001 for trend for all markers). In multivariable analysis including markers of CTO, TnT, CRP and NT-proBNP at admission, PINP was the only independent predictor of IS, EF and LV volumes at all imaging time-points (R2 ranging from 0.17 for LV end systolic volume index at 2 months [p<0.05], to 0.36 for EF at 1 year [p<0.001]). For serum samples drawn at 2 days, a model containing PINP/ICTP ratio, CRP, TnT and NT-proBNP was highly predictive for LV volumes, infarct size and EF at all imaging time-points, explaining up to 80 % of the variance of cMRI findings (R2=0.80 for IS at 2 months, p<0.0001).
Conclusions: Following STEMI, PINP appears to be a very early predictor of infarct size and LV-volumes, while the combination of PINP/ICTP ratio, CRP, NT-proBNP and TnT at 2 days post-STEMI is highly predictive for cMRI findings for up to 1 year. Our findings support the potential role of circulating markers of CTO as surrogates for subsequent extracellular cardiac matrix remodeling.