Elsevier

Resuscitation

Volume 133, December 2018, Pages 33-39
Resuscitation

Clinical paper
Long-term neurological outcomes in out-of-hospital cardiac arrest patients treated with targeted-temperature management

https://doi.org/10.1016/j.resuscitation.2018.09.015Get rights and content

Abstract

Background

This study aimed to assess long-term cognitive and functional outcomes in out-of-hospital cardiac arrest (OHCA) patients treated with targeted-temperature management, investigate the existence of prognostic factors that could be assessed during initial admission and evaluate the usefulness of classic neurological scales in this clinical scenario.

Methods

Patients admitted due to OHCA from August 2007 to November 2015 and surviving at least one year were included. Each patient completed a structured interview focused on the collection of clinical, social and demographic data. All available information in clinical records was reviewed and a battery of neurocognitive and psychometric tests was performed.

Results

Seventy-nine patients were finally included in the analysis. Forty-three patients (54.4%) scored below the usual cut-off points for the diagnosis of mild cognitive impairment, even though most of these deficits went unnoticed when patients were assessed using CPC and modified Rankin scale. Nineteen (24%) developed certain degree of impairment in their attention capacity and executive functions. A significant proportion developed new memory-related disorders (43%), depressive symptoms (17.7%), aggressive/uninhibited behavior (12.7%) and emotional lability (8.9%). A greater number of weekly hours of intellectual activity and a qualified job were independent protective factors for the development of cognitive impairment. However, being older at the time of the cardiac arrest was identified as a poor prognostic factor.

Conclusions

There is a high prevalence of long-term cognitive deficits and functional limitations in OHCA survivors. Most commonly used clinical scales in clinical practice are crude and lack sensitivity to detect most of these deficits.

Introduction

Hypoxic-ischemic brain injury encompasses a whole spectrum of lesions after out-of-hospital cardiac arrest (OHCA) [1]. In order to improve the neurological prognosis of OHCA patients, clinical guidelines recommend the use of targeted temperature management (TTM) after return of spontaneous circulation (ROSC) [2].

Ultimate assessment of neurological and functional outcomes in OHCA patients is usually based on simple scales, such as CPC or modified Rankin scale (mRS), which are not able to discriminate situations of mild or moderate cognitive impairment [3,4]. Therefore, these prognostic tools dichotomize the overall result of a given patient into two large groups: those who have suffered very serious sequelae and those who have not [5].

Few studies have focused on cognitive and functional outcomes of OHCA survivors, and clinical data are especially lacking of long-term prognosis information [6,7] even though some studies suggest that there may be a slowly progressive improvement after hospital discharge [[7], [8], [9]].

This study aimed to assess long-term cognitive and functional outcomes in OHCA patients treated with TTM surviving at least one year after the index event. The secondary objective was to investigate the relationship between these long-term outcomes and baseline characteristics, in order to identify the existence of prognostic factors that could be assessed during initial admission.

Section snippets

Patients

Patients admitted to the Coronary Unit due to OHCA with a Glasgow Coma Scale ≤8 after ROSC, from August 2007 to November 2015 and surviving at least one year after cardiac arrest were included. All patients received TTM according to the current protocol in our center. The targeted temperature (32–34 °C) was either selected at discretion of the treating physician or assigned by randomization as part of a clinical trial [10,11]. Those with a score equal to or greater than 3 in the CPC scale prior

Patients and baseline characteristics

During the study period, a total of 124 patients admitted after OHCA and surviving at least 1 year after the event, were identified. Finally, 79 patients were included in the study after being assessed through the corresponding structured interview (Flow chart is shown in Ref. [17]). The median follow-up time was 3.1 years (interquartile range 1.7–4.4 years). No significant correlations were observed between the quantitative results of cognitive assessment tests and this follow-up time.

The

Discussion

Mortality after OHCA remains very high, with a survival rate at hospital discharge of 11.4% [21]. Even among those patients who achieve ROSC, in-hospital mortality ranges from 20% to 50% depending on the study population (i.e. rate of bystander cardiopulmonary resuscitation, use of automated external defibrillators) [22,23], being hypoxic-ischemic brain injury the leading cause of death [24,25]. Post-cardiac arrest care includes a combination of strategies, including TTM, aimed to assess and

Conclusions

There is a high prevalence of long-term cognitive deficits in OHCA survivors. Even in a selected population, more than half of the patients experienced some degree of cognitive impairment, in addition to other functional and psychosocial limitations.

The cognitive scales most commonly used in clinical practice to assess the neurological outcomes after cardiac arrest (CPC and mRS) are crude and lack sensitivity to detect most of these deficits, occasionally subtle and difficult to appreciate on

Conflicts of interests

All the authors wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.

Acknowledgment

The authors thank Jesús Díez Sebastían M.D. Ph.D., from the Biostatistics Department at Hospital Universitario La Paz, for assistance with statistical analysis.

References (37)

  • G. Lilja et al.

    Anxiety and depression among out-of-hospital cardiac arrest survivors

    Resuscitation

    (2015)
  • M.S. Sekhon et al.

    Clinical pathophysiology of hypoxic ischemic brain injury after cardiac arrest: a “two-hit” model

    Crit Care

    (2017)
  • C.W. Callaway et al.

    Part 8: post-cardiac arrest care: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care

    Circulation

    (2015)
  • B. Farrell et al.

    The United Kingdom transient ischaemic attack (UK-TIA) aspirin trial: final results

    J Neurol Neurosurg Psychiatry

    (1991)
  • C. Sandroni et al.

    Neurological prognostication after cardiac arrest

    Curr Opin Crit Care

    (2015)
  • M. Tiainen et al.

    Surviving out-of-hospital cardiac arrest: the neurological and functional outcome and health-related quality of life one year later

    Resuscitation

    (2018)
  • K.E. Polanowska et al.

    A neuropsychological and neurological sequelae of out-of-hospital cardiac arrest and the estimated need for neurorehabilitation: a prospective pilot study

    Kardiol Pol

    (2014)
  • E. Lopez-De-Sa et al.

    Hypothermia in comatose survivors from out-of-hospital cardiac arrest: pilot trial comparing 2 levels of target temperature

    Circulation

    (2012)
  • Cited by (0)

    A Spanish translated version of the abstract of this article appears as Appendix in the final online version at https://doi.org/10.1016/j.resuscitation.2018.09.015.

    1

    These authors contributed equally to this paper.

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