Potassium level related to myocardial reperfusion injury following percutaneous coronary intervention in delayed STEMI presentation

BACKGROUND: Impaired reperfusion following percutaneous coronary intervention (PCI) in patients with delayed hospitalization for STEMI is not fully clarified. The aim of our study was to analyze the role of electrolyte levels associated with unsuccessful reperfusion in these patients.METHODS: This was a prospective study with 103 consecutive patients with the following inclusion criteria: total ischemic time >120 minutes and ≤12 hours; persistent ST-segment elevation; high cardiac biomarkers; patients who underwent PCI. Patients were divided in TIMI flow 3 and TIMI flow ≤2 group (myocardial reperfusion injury).RESULTS: The difference between TIMI flow ≤2 group (39 patients) and TIMI flow 3 group (64 patients) regarding electrolytes was: the mean sodium (Na+) level was 137.66±2.80 vs. 138.57±3.26 mmol/L, potassium (K+) 3.88±0.55 vs. 3.61±0.49 mmol/L, and the median calcium (Ca++) level 1 (0.41-1.15) vs. 1.03 (0.27-1.23) mmol/L. The difference between potassium levels in the two groups was statistically significant (P=0.016). Based on ROC analysis a cut-off value of 3.6 mmol/L for potassium is defined.CONCLUSIONS: Low potassium level, within the reference range, has an encouraging effect on myocardial reperfusion following PCI in delayed STEMI patients.