Neutrophil to Lymphocyte Ratio in Acute ST-Segment Elevation Myocardial Infarction

Background: Spontaneous early patency of infarct-related artery (IRA) on arrival for primary percutaneous coronary intervention is associated with better short-and long-term prognosis in patients with ST-segment elevation myocardial infarction (STEMI). We aimed to investigate whether the hemographic parameters on admission are associated with spontaneous IRA patency. Methods: This was a retrospective study of 1,625 patients with acute STEMI who underwent primary percutaneous coronary intervention <12 hours after the onset of symptoms. Results: Angiography showed patent IRA (prethrombolysis in myocardial infarction [TIMI] grade 3 flow) in 160 (9.8%) patients. Neutrophil count on admission (7.8 +/- 2.4 x 10(3)/mu L versus 9.7 +/- 3.8 x 10(3)/mu L; P < 0.001) was significantly lower and lymphocyte count (2.4 +/- 1.0 x 10(3)/mu L versus 1.9 +/- 1.1 x 10(3)/mu L; P < 0.001) on admission was significantly higher in the patent IRA group. Neutrophil to lymphocyte ratio (NLR) was significantly lower in the patent IRA group (4.1 +/- 3.2 versus 6.9 +/- 5.5; P < 0.001). Admission leukocyte counts (13 +/- 4.0 x 10(3)/mu L versus 12 +/- 3.4 x 10(3)/mu L; P < 0.001) and NLR (7.2 +/- 5.8 versus 5.5 +/- 4.4; P < 0.001) of the patients with TIMI thrombus score >= 4 were significantly higher than patients with TIMI thrombus score <4. In the multivariate analysis, NLR >= 4.5 (3.17 [95% confidence interval: 2.04-4.92]; P < 0.001) was found to be independently predicting an occluded IRA on initial angiography with a sensitivity of 62.7% and a specificity of 70%. Conclusions: NLR on admission is significantly related to angiographic thrombus burden and spontaneous early IRA patency in patients with acute STEMI.