Cardiac troponin elevation predicts all-cause mortality in patients with acute exacerbation of chronic obstructive pulmonary disease: Systematic review and meta-analysis

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Abstract

Background

Cardiovascular disease, especially ischemic heart disease, is a major comorbidity in chronic obstructive pulmonary disease (COPD) patients. Several studies suggested that after acute exacerbation of COPD (AECOPD), there is a significant increase of mortality (cardiac and all-cause) and of myocardial infarction. Whether cardiac troponin (Tn) elevation during AECOPD could be considered a prognostic marker of all-cause mortality is still debated.

Methods

To assess the prognostic role of cardiac Tn elevation during AECOPD, we performed a systematic review and meta-analysis. We included studies with patients admitted to the hospital for AECOPD, with at least one Tn assessment and reporting the relationship (after multivariable analysis) between Tn elevation and all-cause mortality. Secondarily, studies were stratified according to: i) type of troponin (Tn I or Tn T), and ii) follow-up length (≤ 6 months vs. > 6 months).

Results

Ten studies were included in the systematic review and 8 in the meta-analysis. Cardiac Tn elevation ranges from 18% to 73%. We found that cardiac Tn elevation was significantly related to an increased risk for all-cause mortality (OR 1.69; 95% CI 1.25–2.29; I2 40%). This finding was independent to the follow-up length of studies (≤ 6 months: OR 3.22; 95% CI 1.31–7.91; > 6 months: OR 1.38; 95% CI 1.02–1.86). Finally, Tn T seems to be more helpful in predicting all-cause mortality as compared to Tn I (OR 1.54; 95% CI 1.2–1.96 vs. OR 3.39, 95% CI 0.86–13.36, respectively).

Conclusions

In patients admitted to the hospital for AECOPD, cardiac Tn elevation emerged as an independent predictor of increased risk of all-cause mortality.

Introduction

Comorbidities are common at any severity degree of chronic obstructive pulmonary disease (COPD) [1], [2]. Cardiovascular disease (CVD) is a major comorbidity in COPD patients [1], [2]. Particularly, ischemic heart disease (IHD) and COPD are among the principal causes of mortality and morbidity in western countries and are frequently associated [1], [2]. IHD as well as heart failure or pulmonary embolism (PE) are reported as the main causes of death for patients affected by COPD [2], [3]. The natural history of at least one third of COPD patients is characterized by recurrent episodes of acute exacerbation (AECOPD) [2]. These episodes of AECOPD increase the risk of mortality (cardiac and all-cause) and of myocardial infarction (MI) [2], [3], [4], [5]. Several authors attempted to understand whether elevation of cardiac troponin (Tn) during AECOPD, in the absence of signs and symptoms suggestive of concomitant MI, could discriminate patients at higher mortality risk [6], [7], [8], [9], [10], [11], [12], [13], [14], [15]. The results are conflicting and the prognostic role of Tn elevation in AECOPD is still uncertain. Differences in inclusion/exclusion criteria, sample size, type of Tn, follow-up and endpoint's definition between various studies may contribute to explain these discrepancies [6], [7], [8], [9], [10], [11], [12], [13], [14], [15]. Consequently, Tn measurements are not systematically used to manage AECOPD patients in daily clinical practice. Systematic reviews employing meta-analytic techniques provide quantitative and objective means to pool and assess available clinical evidence, emphasizing internal validity and homogeneity. Therefore, we performed a comprehensive systematic review and meta-analysis of available studies to assess the value of cardiac Tn elevation to predict all-cause mortality in patients admitted to the hospital for AECOPD.

Section snippets

Methods

We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) amendment to the Quality of Reporting of Meta-analyses (QUOROM) statement and the recommendations from The Cochrane Collaboration and Meta-analysis of Observational Studies in Epidemiology (MOOSE) [16], [17], [18], [19].

Search results and study selection

After removal of duplicates, 302 studies were analyzed with database search. 276 studies were excluded after the first evaluation of the title and abstract, as they did not meet pre-specified inclusion and exclusion criteria. Twenty-five reports were screened and analyzed. Fifteen studies were excluded from analysis: two were just abstracts, one was a comment on previous data, three included only patients with a stable phase of COPD, one failed to provide complete data on troponin, one was a

Discussion

The main finding of our meta-analysis is that cardiac Tn elevation in patients admitted to the hospital for AECOPD is associated with an increased risk for all-cause mortality. These findings are not influenced by the length of follow-up. There is just a slight discrepancy between Tn T and Tn I assays. Cardiac Tn I elevation failed to predict all-cause mortality, but this could be due to the limited number of studies (n = 3) and to degree of heterogeneity (I2 = 73%).

Cardiac Tn elevation during

Conclusions

Our meta-analysis shows that cardiac Tn elevation at the time of hospital admission for acute exacerbation of COPD is associated with an increased risk of all-cause mortality.

The following is the supplementary data related to this article.

. Funnel plot of standard error.

Conflict of interest

The authors report no relationships that could be construed as a conflict of interest.

Acknowledgment

This work was supported by the year 2014 grant from Fondazione Anna Maria Sechi per il Cuore (FASC), Italy. The funders had no role in the study design, data collection and analysis, decision to publish, or the preparation of the manuscript.

References (32)

  • P.H. Brekke et al.

    Troponin T elevation and long-term mortality after chronic obstructive pulmonary disease exacerbation

    Eur. Respir. J.

    (2008)
  • O. Fruchter et al.

    Cardiac troponin-I predicts long-term mortality in chronic obstructive pulmonary disease

    COPD

    (2009)
  • C.S. Martins et al.

    Prognostic value of cardiac troponin I in patients with COPD acute exacerbation

    Neth. J. Med.

    (2009)
  • C.L. Chang et al.

    Biochemical markers of cardiac dysfunction predict mortality in acute exacerbations of COPD

    Thorax

    (2011)
  • A.D. Hoiseth et al.

    Elevated high sensitivity cardiac troponin T is associated with increased mortality after acute exacerbation of chronic obstructive pulmonary disease

    Thorax

    (2011)
  • A.M. Kelly et al.

    Is elevated troponin associated with in-hospital mortality in emergency department patients admitted with chronic obstructive pulmonary disease?

    Eur. J. Emerg. Med.

    (2013)
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