Leukocyte Count as Predictor of Angiographic Findings and Clinical Events in Non-ST-Segment Elevation Acute Coronary Syndromes. Sub-analysis of the PACS Angiographic Study

Abstract

BackgroundPrevious studies have analyzed the relationship between inflammatory markers andacute coronary syndromes. Prognosis in Acute Coronary Syndromes (PACS) was aprospective, multicentric study conducted between January 2000 and May 2002 in11 coronary care units of Argentina. It determined the prognostic value of differentbiomarkers, alone or in combination, to stratify risk in patients with non-STsegmentelevation acute coronary syndromes (NSTEACS). However, there are fewstudies on the relationship of increased leukocyte levels with angiographic findingsand mid-term events.ObjectiveThe aim of the study was to establish whether leukocyte count at admission is associatedwith complex coronary disease and adverse prognosis at 6-month follow-upin patients with NSTEACS.MethodsThe angiographic PACS substudy was conducted in 1253 patients from the corePACS study cohort (with a total population of 1500 patients) and it included centerswith coronary angiography facilities (CA). Out of the 1253 substudy patients, CA wasperformed in 633 patients (50.5%) (mean of 48 hours after admission, percentiles25-75, 24-72 hours).To perform the sub-analysis, complete data were obtained from 580 patients (46.2%).In this group, leukocyte count within 24 hours of admission was analyzed in additionto tests performed in the biomarker PACS protocol. The population was divided inpercentiles according to admission leukocyte count. Patients with initial leukocytes< 7700/mm 3 were included in the lower percentile, patients with leukocyte count between7700 and 11500/mm 3 in the middle percentile and those with leukocyte count> 11500/mm 3 in the higher percentile.ResultsMost of the 580 patients were men (72.9%), and mean age was 66±12 years. Amongthese patients, 64.4% had history of hypertension, 17.9% of diabetes, 22.2% of previousinfarction, 60% presented high clinical risk (ACC/AHA) and 61.1% had ECG atadmission with ST-segment or T wave alterations. Leukocyte count > 11500/mm 3was associated with higher rate of visible thrombus, presence of complicated plaqueand more extensive coronary disease (p = 0.019, 0.033 and 0.07, respectively). At the6-month follow-up, patients in the higher percentile had greater tendency of death orinfarction than patients in the lower percentile (14.2% vs. 7.5%; p = 0.026).ConclusionIn patients with NSTEACS, a high leukocyte count at admission is associated withcomplex coronary disease and worse prognosis at 6 months.