Long-term prognostic value of white blood cell count variation during hospital stay in patients with STEMI

Abstract

Abstract Background In patients with ST-elevation myocardial infarction (STEMI), white blood cell count (WBCC) is associated with infarct size and cardiovascular outcome. We sought to determine the impact of WBBC variation (∆WBCC) during hospital stay on the long-term outcome after STEMI. Methods From 06/2011 to 12/2019, consecutive patients referred for STEMI were enrolled. Those with at least two WBCC during hospitalization were included in this study. ∆WBCC was calculated as: [WBCC (admission) – WBCC (before discharge)]. The population was divided into 3 groups according to ∆WBCC tertiles. The primary outcome was all-cause mortality. Results A total of 1782 patients (mean age 64.5 ±14.1 years, 75.7% males), were included and divided in 3 groups: Group 1 (∆WBCC<880/mm3); Group 2 (∆WBCC 880-3265/mm3); and Group 3 (∆WBCC >3265/mm3). Patients in Group 1 were the oldest (67.9±13.8, vs. 65.1±13.9 and 60.5±13.7 years in Groups 2 and 3 respectively, p<0.001). Hypertension, prior coronary artery bypass and cancer were more prevalent in Groups 1 and 2. Troponin peak was the highest in Group 3 (3601±563, vs. 2810±439 and 2451±467 ng/ml in Groups 1 and 2, respectively; p<0.001). The 5-year survival was the lowest in Group 1 (78.5% vs. 87.4% and 87.5% in Group 2 and 3, respectively; p<0.001) (Figure). Adjusted to age, gender, cardiovascular risk factors, MI territory and left ventricular ejection fraction, ∆WBCC<0.880/mm3 was independently associated with all-cause mortality [HR 1.46; 95%CI 1.12-1.91; p=0.005]. Conclusion Low variation of WBCC (∆WBCC<880/mm3) is associated with increased mortality, and can represent an interesting prognostic tool in STEMI patients.