Background. Acute myocardial infarction is associated with a local and systemic inflammatory response which may result in the healing of necrotic myocardium to preserve left ventricular systolic function (LVSF).

Aim. To assess the course of inflammatory activation during hospitalisation and at one month after discharge in patients with preserved global LVSF in six month follow-up after a first acute ST-elevation myocardial infarction (STEMI), treated with primary percutaneous coronary intervention (pPCI).

Material and methods. The study group consisted of 199 patients with STEMI treated with pPCI. The following LVSF echocardiographic parameters were assessed before hospital discharge and at six months after STEMI: left ventricular ejection fraction, wall motion score index and average peak systolic mitral annular velocity. C-reactive protein (CRP) plasma concentrations were measured with an ultra-sensitive latex immunoassay on admission, 24 hours after admission, at discharge and one month after STEMI.

Results. Preserved global LVSF (LVEF > 50%) was present in 24.0% of patients at discharge and in 35.2% of patients at six months after STEMI (p < 0.001). Plasma CRP concentration steeply rose in study participants during the first 24 h of hospitalisation (p < 0.001) and persisted elevated at discharge. CRP concentrations 24 h after admission, at discharge and at one month after STEMI were lower in patients with preserved global LVSF at six month follow-up compared to patients with LVEF ≤ 50%. Normalisation of CRP concentration after one month occurred exclusively in patients with preserved LVSF at six months. Patients with preserved global LVSF at six months had a lower prevalence of anterior STEMI, diabetes mellitus and symptomatic heart failure at discharge, lower body mass index, more favourable pre-pPCI angiographic flow indices, better final angiographic outcome of pPCI with complete microvascular reperfusion in 57.1%of cases, lower values of myocardial necrosis indices, admission glycaemia, glycated haemoglobin, B-type natriuretic peptide plasma concentration; lower left ventricular volumes and mass and less impaired regional and longitudinal LVSF both at discharge and after six months than patients without preserved global LVSF at six months after STEMI.

Conclusions. Patients with preserved global LVSF at six months after a first STEMI treated with pPCI have a lower intensity of inflammatory response, as assessed by plasma CRP concentration measured during the acute phase, than patients presenting with LVEF ≤ 50% at six month follow-up.