Early phosphatemia changes in acute cardiac care patients

IntroductionThe significance of inorganic serum phosphate levels (Pi) in patients with acute coronary syndromes (ACS) in the reperfusion era is unknown, as well as its relation to biomarkers of myocardial necrosis. Our aim was to assess admission Pi and its dynamics in patients admitted to the intensive cardiac care unit (ICCU), with emphasis on patients with ST segment elevation myocardial infarction (STEMI).MethodsWe studied 192 patients admitted to the ICCU during a 4-month period. The first group included 92 patients with STEMI (STEMI group) treated by primary percutaneous coronary intervention (PCI). The second group consisted of 100 patients without ACS (non-ACS group). Normophosphatemia was defined as Pi 0.7–1.6 mmol/l. Phosphatemia was measured at admission and then 6 h and 12 h later as well as troponin I.ResultsAdmission phosphatemia was lower in the STEMI group as compared to the non-ACS group (Pi 0.95 mmol/l vs. 1.18 mmol/l, p<0.001). Admission hypophosphatemia (Pi<0.7 mmol/l) was more often present in the STEMI group than in the non-ACS group (21% vs. 4%, p=0.001). In all hypophosphatemic STEMI patients, serum Pi normalized itself within 6 h without substitution. Admission hyperphosphatemia (Pi>1.6 mmol/l) was more frequent in non-ACS group (6.5% STEMI pts. vs. 13% non-ACS pts.). In the STEMI group, admission phosphatemia did not correlate with peak troponin I.ConclusionWe conclude that patients with STEMI treated by primary PCI have lower Pi and more frequent transient hypophosphatemia at admission than acute cardiac care patients without acute coronary syndrome.