Prognostic importance of serum troponin concentration in patients with an implanted cardioverter‑defibrillator admitted to the emergency department due to electric shock

Abstract

Background: High-energy implantable cardioverter-defibrillator (ICD) therapy may increase serum troponin (cTnI) concentration.  

Aims: We aimed to assess an impact of cTnI concentration after ICD high-energy therapy on mortality.

Methods: A total of 150 patients aged 64.2 +/- 12.8 years admitted to the Emergency Departments (EDs) due to at least one electrical shock during the last 24 hours with measured serum cTnI concentration at admission were included. Age, gender, comorbidities, shocks’ numbers, therapy appropriateness, serum creatinine concentration, and left ventricular ejection fraction were noted for the retrospective analysis. Survival was obtained using the personal identification numbers (PESEL), on November 2018 until death or a period of three years had elapsed (1057 days).

Results: cTnI concentration was increased in 92 (61.3%) patients. The mortality rate was related to age – HR: 1.04, 95% CI: 1.01-1.08, p = 0.026; increased cTnI concentration – HR: 2.88, 95% CI: 1.30-6.37, p = 0.009; diabetes – HR: 2.19, 95% CI: 1.09-4.39, p = 0.027; ischemic heart disease – HR: 2.96, 95% CI: 1.11-7.87, p = 0.030, serum creatinine concentration – HR: 2.17, 95% CI: 1.18-4.00, p = 0.013; LVEF (HR 0.95, 95% CI: 0.91-0.99, p = 0.009), and previous or current CABG or PCI (HR: 0.38, 95% CI: 0.15-0.96, p = 0.040 and HR: 0.29, 95% CI: 0.13-0.65, p = 0.003, respectively).

Conclusions: Increased mortality rate in patients with ICD shocks is multifactorial. Increased cTnI concentration at ED admission, but not the number of ICD shocks, is an independent marker of higher long-term mortality.