Leukocyte and its Subtypes as Predictors of Short-Term Outcome in Cardiogenic Shock Complicating Acute Myocardial Infarction: A Cohort Study

Background: Patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) are at high risk of death. Inflammation is involved in both CS and AMI, and our present study aimed to investigate the changes of leukocyte and its subtypes as well as their prognostic value in patients with CS complicating AMI. Methods: Data of 217 consecutive patients with CS complicating AMI were analyzed. The primary endpoint was 30-day all-cause mortality. The secondary endpoint was the composite events of major adverse cardiovascular events (MACE) including 30-day all-cause mortality, ventricular tachycardia/ventricular fibrillation, atrioventricular block, gastrointestinal hemorrhage and nonfatal stroke. The association of leukocyte and its subtypes with the endpoints was analyzed by Cox regression analysis. Results: Leukocyte and its subtypes including neutrophil, eosinophil, lymphocyte, monocyte and basophil were all statistically significant between survivors and nonsurvivors (all P < 0.05). Among the leukocyte subtypes, eosinophil had the highest predictive value for 30-day all-cause mortality (AUC = 0.799) and the composite of leukocyte and its subtypes improved the predictive power (AUC = 0.834). The 30-day mortality and MACE K-M curves of leukocyte and its subtypes reveal a distinct trend based on the cut-off value determined by Youden Index (all log rank P < 0.001). After multivariable adjustment, high leukocyte (>11.6 x 10(9)/L) (HR 1.815; 95%CI 1.134, 2.903; P = 0.013), low eosinophil (<0.3%) (HR 2.562; 95%CI 1.412, 4.648; P = 0.002) and low basophil (<= 0.1%) (HR 1.694; 95%CI 1.106, 2.592; P = 0.015) were independently associated with increased risk of 30-day mortality. Similarly, high leukocyte (>11.6 x 10(9)/L) (HR 1.894; 95%CI 1.285, 2.791; P = 0.001), low eosinophil (<0.3%) (HR 1.729; 95%CI 1.119, 2.670; P = 0.014) and low basophil (<= 0.1%) (HR 1.560; 95%CI 1.101, 2.210; P = 0.012) were independently associated with increased risk of 30-day MACE. Conclusions: Leukocyte and its subtypes changed significantly in patients with CS complicating AMI. In addition to leukocyte, eosinophil and basophil also served as independent prognostic factors for 30-day outcomes. Moreover, as the composite of leukocyte and its subtypes increased the predictive power, thus leukocyte and its subtypes, especially eosinophil and basophil should be taken into consideration for the current risk stratification model.