Introduction:
The level of electrolytes is an important predictor in acute myocardial infarction (AMI). It is interesting whether the baseline sodilevel influences prognosis in patients with AMI treated with percutaneous coronary intervention (PCI).

Material and methods:
The aim of this study was to compare the results of treatment and prognosis according to the baseline sodilevel in AMI treated with PCI. We examined 2556 consecutive patients with AMI treated with PCI, admitted to III Chair and Department of Cardiology, Silesian Medical University, Silesian Center for Hart Diseases in Zabrze, Poland between 1998 and 2006. Patients were divided into three groups according to the baseline sersodilevel: I group-
patients with sodilevel<135 mmol/l, II group-patients with sodilevel.135 mmol/l but<145 mmol/l, III group-patients with sodilevel .145 mmol/l. For the purpose of this study selected parameters were compared during inhospital and one-year observation.

Results:
There were 236 patients in I group, 2235 in II and 85 in III group. Patients with hyponatraemia were older, more often female and more often had diabetes. They also more often presented cardiogenic shock (18,95%vs8,59%vs10,59%;p=0.0002), multivessel CAD and stroke (4,66%vs1,92%vs0,0%;p=0,0081).Patients with hypernatraemia were more often treated with fibrynolysis and more often presented final TIMI 3 flow. Hypernatraemia was connected with the highest inhospital mortality (9,41%vs4,07%vs7,20%;p=0,008) whereas hyponatraemia was connected with the highest one-year mortality (15,38%vs9,16%vs10,59%;p= 0,0091). In multivariate analysis independent factors influencing one-year mortality were: cardiogenic shock [HR=4,99 (3,76-6,63);p<0,0001], diabetes [HR=1,69 (1,29–2,22);p=0,0002], anterior wall MI [HR=1,49 (1,14–
1,95);p=0,0036], age[HR=1,03 (1,02–1,04);p<0,0001], LVEF [HR=0,96 (0,95–,97);p<0,0001] and final TIMI 3 flow[HR=0,63 (0,46–0,86);p= 0,041]. There was no statistical significance for hipo-and hipernatraemia in this analysis.

Conclusions:
Improper sersodilevel on admission is connected with higher in-hospital and one-year mortality in AMI treated with PCI. In multivariate analysis hiponatraemia and hipernatraemia are not independent factors influencing one-year mortality in MI.