Acute-Phase Inflammatory Reaction Predicts CMR Myocardial Scar Pattern and 2-Year Mortality in STEMI Patients Undergoing Primary PCI

(1) Background: The inflammatory response following MI plays an important role in the healing, scar formation, and left ventricle (LV) remodeling. Cardiac magnetic resonance (CMR) imaging can accurately quantify the extent of myocardial scarring. The study aimed to investigate: (a) the relationship between acute inflammatory response and the CMR parameters of the scarring extent, and (b) the predictive power of inflammatory biomarkers and myocardial scarring for 2-year mortality. (2) Methods: The study included 202 STEMI patients, who underwent pPCI. Serum hs-CRP, IL-6, P-selectin, E-selectin, I-CAM, and V-CAM levels were determined at admission, and hs-CRP on the fifth day. Patients underwent LGE-CMR after 1 month, for LV volumes, ejection fraction (EF), infarct size (IS), and transmurality. Subjects were divided into tertiles according to the IS, and 2-year all-cause mortality was determined. (3) Results: IL-6 was associated with IS (r = 0.324, p = 0.01), increased transmurality index (r = 0.3, p = 0.01), and lower LVEF (r = −0.3, p = 0.02). Admission hs-CRP levels were not associated with IS, transmurality, or mortality, while hs-CRP at day 5 was a significant predictor for IS (AUC = 0.635, p = 0.05) as well as IL-6 levels (AUC = 0.685, p < 0.001). Mortality was significantly higher in the upper IS tertiles (6% vs. 8.7% vs. 24.52%, p = 0.005). IS was a significant predictor of 2-year mortality (AUC = 0.673, p = 0.002), with a cut-off value of 28.81 g, as well as high transmurality (AUC = 0.641, p = 0.013), with a cut off value of 18.38 g. (4) Conclusions: The serum levels of IL-6 and day-5 hs-CRP predict IS and transmurality, and day-5 hs-CRP levels are independent predictors of 2-year mortality in STEMI patients treated with pPCI. The CMR pattern of myocardial scarring after 1 month, as expressed by the magnitude of IS and transmurality, is a significant predictor for 2-year mortality after revascularized STEMI.