Abstract 5608: Prognostic Impact of the Baseline White Blood Cell Count in Patients with Acute Myocardial Infarction Undergoing Primary PCI: Results from the HORIZONS-AMI trial
Background: Inflammation plays a crucial role in atherosclerosis. Previous studies have suggested an association between elevated white blood cell (WBC) and adverse outcomes in patients with ST-elevation acute myocardial infarction (STEMI). We sought to determine the relationship between admission WBC count and mortality in patients with STEMI in the HORIZONS-AMI trial.
Methods: HORIZONS-AMI enrolled 3602 patients with STEMI undergoing primary PCI. We compared rates of 30-day major adverse cardiac events (MACE: death, reinfarction, target vessel revascularization for ischemia, or stroke), non-CABG major bleeding, and net adverse clinical events (NACE: MACE or major bleeding) in patients with baseline WBC count >12,000 cells/mm3 vs ≤12,000 cells/mm3.
Results: Of the 3497 patients with baseline WBC data, 2206 (63.1%) had a WBC count of ≤12,000 and 1291 (38.9%) had a WBC of >12,000 (median 10,800 mm3, mean 11,700 mm3). Patients with WBC ≤12,000 were older, had more hypertension, hyperlipidemia, diabetes, prior MI, and prior CABG. Compared to patients with WBC ≤12,000, those with WBC >12,000 had significantly higher rates of 30-day adverse outcomes (Table⇓). By multivariate analyses, WBC >12,000 was an independent predictor of 30-day mortality (HR [95% CI] = 2.51 [1.61–3.91], p30.001), MACE (1.82 [1.36, 2.44], p<0.0001), and major bleeding (1.52 [1.16 –1.99], p=0.003).
Conclusions: In patients presenting with STEMI undergoing primary PCI, an elevated WBC count identifies a high risk cohort with significantly higher mortality, MACE and major bleeding at 30-days. These results further support the pivotal role of inflammation in ACS/AMI.