Prognostic implications of troponin I elevation in emergency department patients with tachyarrhythmia

Clin Cardiol. 2019 May;42(5):546-552. doi: 10.1002/clc.23175. Epub 2019 Mar 26.

Abstract

Background: Tachyarrhythmias are very common in emergency medicine, and little is known about the long-term prognostic implications of troponin I levels in these patients.

Hypothesis: This study aimed to investigate the correlation of cardiac troponin I (cTnI) levels and long-term prognosis in patients admitted to the emergency department (ED) with a primary diagnosis of tachyarrhythmia.

Methods: A retrospective cohort study was conducted between January 2012 and December 2013, enrolling patients admitted to the ED with a primary diagnosis of tachyarrhythmia and having documented cTnI measurements. Clinical characteristics and 5-year all-cause mortality were analyzed.

Results: Of a total of 222 subjects with a primary diagnosis of tachyarrhythmia, 73 patients had elevated levels of cTnI (32.9%). Patients with elevated cTnI levels were older and presented significantly more cardiovascular risk factors. At the 5-year follow-up, mortality was higher among patients with elevated cTnI levels (log-rank test P < 0.001). In the multivariable Cox regression analysis, elevated cTnI was an independent predictor of all-cause death (hazard ratio, 1.95, 95% confidence interval: 1.08-3.50, P = 0.026), in addition to age and prior heart failure.

Conclusion: Patients admitted to the ED with a primary diagnosis of tachyarrhythmia and high cTnI levels have higher long-term mortality rates than patients with low cTnI levels. cTnI is thus a biomarker with predictive capacity for mortality in late follow-up, conferring utility in the risk stratification of this population.

Keywords: arrhythmia; cardiac troponin; emergency department.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Arrhythmias, Cardiac / blood*
  • Arrhythmias, Cardiac / diagnosis
  • Arrhythmias, Cardiac / mortality
  • Arrhythmias, Cardiac / physiopathology
  • Biomarkers / blood
  • Emergency Service, Hospital*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prognosis
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Troponin I / blood*
  • Up-Regulation

Substances

  • Biomarkers
  • Troponin I