Introduction: The inflammatory response in the acu-te phase of a myocardial infarction, as well as in later phases contributes to the healing process and left ven-tricular remodeling. Improvement of LV function hi-ghly depends on the magnitude of scar formation. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) has been validated for an accurate deter-mination of the myocardial scar size and transmurality. The recovery of ST segment elevation is a liable marker of vessel patency following PCI.

Objective: The aim of the study was to validate a new integrated score of ST segment elevation score (ISSTE) as a new predictor of the myocardial scar tissue size, in relation with increased inflammatory biomarkers, with the extent of myocardial fibrosis at one month, assessed with LGE-CMR, after STEMI.

Methods: The study included 65 patients with STEMI who underwent urgent revascularization with PCI in the first 12 hours from the onset of symptoms. The ISSTE was determined by summing the ST segment elevation in all registered ECG leads at presentation (ISSTE-1) and at 2 hours (ISSTE-2) after primary PCI. Blood samples were also collected at baseline and day-5 for determination of serum hs-CRP levels. At 1-month follow-up all patients under LGE-CMR (1.5T scanner) for evaluation of the myocardial scar extent (volume, percentage, transmurality).

Results: ISSTE-2 was significantly correlated with day-5 hs-CRP serum levels (r=0.546, 95%CI: 0.030-0.832, p=0.037), although no significant correlations were noted with baseline hs-CRP levels (r=0.238, p=0.407). There were no significant correlations between ISSTE-1 score and the myocardial scar percentage (r=0.241, p=0.11) or high transmurality volume (r=0.194, p=0.21), while ISSTE-2 significantly correlated with myocardial scar mass (r=0.406, 95%CI: 0.107-0.637 p=0.007) and high transmurality volume (r=0.344, 95%CI: 0.0320-0.596, p=0.0273). The restoration of the ST segment, reflected by the difference between ISS-TE-1 and ISSTE -2 is correlated with the infarct size mass (r=0.336, 95%CI: 0.0307-0.584, p=0.027).

Conclusions: The magnitude of ST segment elevation determined at 2 hours after PCI was associated with the inflammatory response at day 5 after STEMI and it may serve as a predictor for the extent of the myocar-dial scar tissue determined with LGE-CMR at 1 month following STEMI. The ISSTE-1 score calculated at pre-sentation does not reflect extent of the affected myocar-dial tissue following PCI.