Prognostic Factors in Patients with Acute Coronary Syndrome without ST-segment Elevation

Dear Editor, We read the article, Prognostic factors in patients with acute coronary syndrome without ST-segment written by Santos JC1. The authors concluded that the assessment of renal function and lymphocyte count provide potentially useful information for the prognostic stratification of patients with non-ST elevation ACS. We know that patients with end-stage renal disease have a higher risk for and a worse outcome after myocardial infarction. However, lesser degrees of renal dysfunction also predict an adverse prognosis in patients with acute MI. Several studies have shown the magnitude of this effect2. We also know that patients with a higher white blood cell (WBC) count - which is a marker of inflammation, have an increased risk for adverse events, in-hospital mortality, and short- and long-term mortality after a non-ST elevation ACS, as well as for acute ST-elevation MI3. The value of the baseline WBC in patients with non-ST-elevation MI or unstable angina was evaluated in the TACTICS-TIMI 18 trial4, which concluded that higher WBC was associated with significantly lower TIMI flow grades, myocardial perfusion grades and more extensive coronary disease. This was found in relation to WBC but not to lymphocytes, because many factors in the ICU environment may lead to lymphocytopenia (trauma, hemorrhage, viral infections, etc.). Therefore, in order to establish a relationship between lymphocyte count and prognosis, further evaluation and objective evidence are needed.