Association between baseline neutrophil count, clopidogrel therapy, and clinical and angiographic outcomes in patients with ST-elevation myocardial infarction receiving fibrinolytic therapy.

Author(s): O'Donoghue M, Morrow DA, Cannon CP, Guo W, Murphy SA, Gibson CM, Sabatine MS

Affiliation(s): TIMI Study Group, Cardiovascular Division, Brigham and Women's Hospital, 350 Longwood Avenue, 1st Floor, Boston, MA 02115, USA. modonoghue@partners.org

Publication date & source: 2008-04, Eur Heart J., 29(8):984-91. Epub 2008 Mar 16.

Publication type: Multicenter Study; Randomized Controlled Trial; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

AIMS: To investigate the association between neutrophil count, outcomes, and benefit of clopidogrel therapy in ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: Baseline neutrophil count was measured in 2865 patients in CLARITY-TIMI 28, a randomized trial of clopidogrel vs. placebo in STEMI patients undergoing fibrinolysis. Angiography was performed at 2-8 days following enrollment. Analyses were adjusted for demographics, time from symptom onset, Killip class, peak CK-MB, and therapies received. A baseline neutrophil count in the highest quartile was independently associated with the risk of cardiovascular (CV) death [adj (adjusted) OR (odds ratio) 5.8, P < 0.001] and congestive heart failure (adj OR 3.0, P = 0.009) at 30 days. Patients with higher neutrophil counts were less likely to achieve complete ST-segment resolution (adj OR 0.76, P = 0.03) or TIMI myocardial perfusion grade 2/3 (adj OR 0.71, P = 0.017). Clopidogrel had a lesser effect on reducing the odds of a closed infarct-related artery, or death or MI before angiography, in patients with a neutrophil count above the median (adjusted OR 0.83, 0.61-1.13) vs. in those below the median (adjusted OR 0.46, 0.33-0.64) (Pinteraction = 0.008). CONCLUSION: In patients with STEMI, higher baseline neutrophil count is associated with worse angiographic findings and increased CV mortality, as well as a diminished benefit of clopidogrel.