Total leucocyte count, but not C-reactive protein, predicts 1-year mortality in patients with acute coronary syndromes treated with percutaneous coronary intervention

Although an association between elevated leucocyte count and mortality in patients with ACS (acute coronary syndromes) has been established, the independence of this association from coronary risk factors and C-reactive protein has been inadequately studied. In the present study, this prospective registry included 4329 patients with ACS treated with PCI (percutaneous coronary intervention): 1059 patients with STEMI [ST-segment elevation MI (myocardial infarction)], 1753 patients with NSTEMI (non-STEMI) and 1517 patients with unstable angina. Blood samples were obtained before angiography for leucocyte count and C-reactive protein measurements. The primary outcome of this analysis was 1-year mortality. At 1 year, 345 patients (8%) had died: 45 patients in the 1st tertile, 93 patients in the 2nd tertile and 207 patients in the 3rd tertile of leucocyte count [Kaplan-Meier estimates of mortality, 3.2%, 6.4% and 14.1% with an OR (odds ratio)=2.42, 95% CI (confidence interval)1.78-3.12; P<0.001 for tertile 3 compared with tertile 2 and an OR=1.99, 95% CI 1.77-2.25; P<0.001 for tertile 2 compared with tertile 1]. The Cox proportional hazards model adjusting for coronary risk factors, ACS presentation, extent of coronary artery disease, C-reactive protein and other covariates identified leucocyte count with a HR (hazard ratio)=1.05 (95% CI 1.02-1.07; P<0.001 for 1000 cells/mm(3) increase in the leucocyte count), but not C-reactive protein (HR=1.13, 95% CI 0.95-1.34; P=0.15 for a 1 tertile increase in the C-reactive protein concentration) as an independent correlate of 1-year mortality. We conclude that elevated leucocyte count, but not C-reactive protein, predicts 1-year mortality independent of cardiovascular risk factors across the entire spectrum of patients with ACS treated with PCI.