European Heart Journal Advance Access originally published online on March 16, 2008
European Heart Journal 2008 29(8):984-991; doi:10.1093/eurheartj/ehn112
Association between baseline neutrophil count, clopidogrel therapy, and clinical and angiographic outcomes in patients with ST-elevation myocardial infarction receiving fibrinolytic therapy
1 TIMI Study Group, Cardiovascular Division, Brigham and Women’s Hospital, 350 Longwood Avenue, 1st Floor, Boston, MA 02115, USA
2 Harvard Clinical Research Institute, Boston, MA, USA
3 Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
Received 29 August 2007; revised 13 February 2008; accepted 21 February 2008; online publish-ahead-of-print 16 March 2008.
* Corresponding author. Tel: +1 617 278 0145, Fax: +1 617 734 7329. Email: modonoghue{at}partners.org
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 enrolment. 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.
Key Words: Acute coronary syndrome • ST-elevation myocardial infarction • Fibrinolysis • White blood cell • Clopidogrel