The impact of therapeutic hypothermia on neurological function and quality of life after cardiac arrest

Return to work after out of hospital cardiac arrest, insights from a prospective multicentric French cohort

RATIONALE

About 60 to 70% of out-of-hospital cardiac arrest (OHCA) survivors who worked before cardiac arrest return to work within one year but the precise conditions for this resumption of professional activity remain little known. The objective of this study was to assess components of return to work among OHCA survivors.

PATIENTS AND METHODS

We used the French national multicentric cohort AfterRosc to include OHCA survivors admitted between April 1st 2021 and March 31st 2022, discharged alive from the Intensive Care Unit (ICU), and who were less than 65 years old. A phone-call interview was performed one year after OHCA to assess return to work, level of education, former level of occupation as well as neurological recovery. Geographic and socio-economic data from the patient's residential neighborhoods were also collected. Comparisons were performed between patients who returned to work and those who did not, using non-parametric tests.

RESULTS

Of the 251 patients included in the registry, 86 were alive at ICU discharge and 31 patients that worked prior to the OHCA were included for analysis. Seventeen survivors returned to work after a median delay of 112 days [92-157] Among them, nine (53%) had required initial work adjustments. Overall, only 6 patients (19%) had returned to work ad integrum. Higher educational level, work which required higher competence-level, higher income, living in a better socio-economical neighborhood, as well as better scores on all three standardized MPAI-4 score components (abilities, adjustment and participation) were significantly associated with return to work. Participants that had not returned to work had a significant drop of income (p = 0.0025).

CONCLUSION

In this prospective study regarding French OHCA survivors, return to work is associated with better socio-economical individual and environmental status, as well as better scores on all MPAI-4 components.

State of the art post-cardiac arrest care: evolution and future of post cardiac arrest care

Out-of-hospital cardiac arrest is a leading cause of mortality. In the pre-hospital setting, bystander response with cardiopulmonary resuscitation and the use of publicly available automated external defibrillators have been associated with improved survival. Early in-hospital treatment still focuses on emergency coronary angiography for selected patients. For patients remaining comatose, temperature control to avoid fever is still recommended, but former hypothermic targets have been abandoned. For patients without spontaneous awakening, the use of a multimodal prognostication model is key. After discharge, follow-up with screening for cognitive and emotional disabilities is recommended. There has been an incredible evolution of research on cardiac arrest. Two decades ago, the largest trials include a few hundred patients. Today, undergoing studies are planning to include 10-20 times as many patients, with improved methodology. This article describes the evolution and perspectives for the future in post-cardiac arrest care.

Determinants of health-related quality of life after out-of-hospital cardiac arrest (OHCA): A systematic review

OBJECTIVE

With a growing number of out-of-hospital cardiac arrest (OHCA) survivors globally, the focus of OHCA management has now broadened to survivorship. An outcome central to survivorship is health-related quality of life (HRQoL). This systematic review aimed to synthesise evidence related to the determinants of HRQoL of OHCA survivors.

METHODS

We systematically searched MEDLINE, Embase, and Scopus from inception to 15 August 2022 to identify studies investigating the association of at least one determinant and HRQoL in adult OHCA survivors. All articles were independently reviewed by two investigators. We abstracted data pertaining to determinants and classified them using a well-established HRQoL theoretical framework - the Wilson and Cleary (revised) model.

RESULTS

31 articles assessing a total of 35 determinants were included. Determinants were classified into the five domains in the HRQoL model. 26 studies assessed determinants related to individual characteristics (n=3), 12 studied biological function (n=7), nine studied symptoms (n=3), 16 studied functioning (n=5), and 35 studied characteristics of the environment (n=17). In studies that included multivariable analyses, most reported that individual characteristics (older age, female sex), symptoms (anxiety, depression), and functioning (impaired neurocognitive function) were significantly associated with poorer HRQoL.

CONCLUSIONS

Individual characteristics, symptoms, and functioning played significant roles in explaining the variability in HRQoL. Significant non-modifiable determinants such as age and sex could be used to identify populations at risk of poorer HRQoL, while significant modifiable determinants such as psychological health and neurocognitive functioning could serve as targets for post-discharge screening and rehabilitation plans. PROSPERO registration number: CRD42022359303.

Association between inflammatory markers and survival in comatose, resuscitated out-of-hospital cardiac arrest patients

OBJECTIVES

Prognostication after out-of-hospital cardiac arrest (OHCA) remains challenging. The inflammatory response after OHCA has been associated with increased mortality. This study investigates the associations and predictive value between inflammatory markers and outcome in resuscitated OHCA patients.

DESIGN

The study is based on post hoc analyses of a double-blind controlled trial, where resuscitated OHCA patients were randomized to receive either exenatide or placebo. Blood was analyzed for levels of inflammatory markers the day following admission. Primary endpoint was time to death for up to 180 days. Secondary endpoints included 180-day mortality and poor neurological outcome after 180 days, defined as a cerebral performance category (CPC) of 3 to 5.

RESULTS

Among 110 included patients we found significant associations between higher leucocyte quartile and increasing mortality in univariable analysis (OR 2.6 (95%CI 1.6-4.2), p < .001), as well as in multivariable analysis (OR 2.1 (95%CI 1.1-4.0), p = .02). A significant association was found between higher neutrophil quartile and increasing mortality in univariable analysis (OR 3.0 (95%CI 1.8-5.0), p < .001) as well as multivariable analysis (OR 2.4 (95%CI 1.2-4.6), p = .01). Leucocyte and neutrophil levels were predictive of poor outcome after 180 days with area under the receiver operating characteristics curves of 0.79 and 0.81, respectively. We found no associations between CRP and lymphocyte levels versus outcome.

CONCLUSIONS

Total leucocyte count and neutrophil levels measured the first day following OHCA were significantly associated with 180-day all-cause mortality and may potentially act as early predictors of outcome.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, unique identifier: NCT02442791.

The “Blood pressure and oxygenation targets in post resuscitation care, a randomized clinical trial”: design and statistical analysis plan

Background

Comatose patients admitted after resuscitation from cardiac arrest have a significant risk of poor outcome due to hypoxic brain injury. While numerous studies have investigated and challenged the target temperature as the efficacious part of the guideline endorsed Targeted Temperature Management (TTM) protocols, our knowledge and how the remaining parts of the TTM are optimized remain sparse. The present randomized trial investigated two aspects of the TTM protocol: target blood pressure during the ICU stay and oxygenation during mechanical ventilation. Furthermore, the efficacy of device-based post-TTM fever management is addressed.

Methods

Investigator-initiated, dual-center, randomized clinical trial in comatose OHCA patients admitted to an intensive cardiac care unit. Patients are eligible for inclusion if unconscious, older than 18 years of age, and have return of spontaneous circulation for more than 20 min.

Intervention: allocation 1:1:1:1 into a group defined by (a) blood pressure targets in double-blind intervention targeting a mean arterial blood pressure of 63 or 77 mmHg and (b) restrictive (9–10 kPa) or liberal (13–14 kPa) of arterial oxygen concentration during mechanical ventilation. As a subordinate intervention, device-based active fever management is discontinued after 36 h or 72. Patients will otherwise receive protocolized standard of care according to international guidelines, including targeted temperature management at 36 °C for 24 h, sedation with fentanyl and propofol, and multimodal neuro-prognostication. Primary endpoint: Discharge from hospital in poor neurological status (Cerebral Performance category 3 or 4) or death, whichever comes first. Secondary outcomes: Time to initiation of renal replacement therapy or death, neuron-specific enolase (NSE) level at 48 h, MOCA score at day 90, Modified Ranking Scale (mRS) and CPC at 3 months, NT-pro-BNP at 90 days, eGFR and LVEF at 90 days, daily cumulated vasopressor requirement during ICU stay, and need for a combination of vasopressors and inotropic agents or mechanical circulatory support.

Discussion

We hypothesize that low or high target blood pressure and restrictive and liberal oxygen administration will have an impact on mortality by reducing the risk and degree of hypoxic brain injury. This will be assessment neurological outcome and biochemical and neuropsychological testing after 90 days.

Trial registration

ClinicalTrials.gov NCT03141099. Registered on May 2017 (retrospectively registered)

Neurocognitive function following out-of-hospital cardiac arrest: A systematic review

OBJECTIVES

The primary aim of this review was to investigate neurocognitive outcomes following out-of-hospital cardiac arrest (OHCA). Specifically, the focus was on identifying the different neurocognitive domains that are assessed, the measures used, and the level of, and criteria for, impairment.

DESIGN AND REVIEW METHODS

A systematic review of the literature from 2006 to 2021 was completed using Medline, Cinahl and Psychinfo. Criteria for inclusion were studies with participants over the age of 18, OHCA and at least one neurocognitive function measure. Qualitative and case studies were excluded. Reviewers assessed criteria and risk of bias using a modified version of Downs and Black.

RESULTS

Forty-three studies were identified. Most studies had a low risk of bias (n = 31) or moderate risk of bias (n = 11) and one had a high risk; however, only six reported effect sizes or power analyses. Multiple measures of neurocognitive outcomes were used (>50) and level of impairment criteria varied considerably. Memory impairments were frequently found and were also more likely to be impaired followed by executive function and processing speed.

DISCUSSION

This review highlights the heterogeneity of measures and approaches used to assess neurocognitive outcomes following OHCA as well as the need to improve risk of bias concerning generalizability. Improved understanding of the approaches used for assessment and the subsequent findings will facilitate a standardized evaluation of neurocognitive outcomes following OHCA.

Management of out-of hospital cardiac arrest patients with extracorporeal cardiopulmonary resuscitation in 2021

INTRODUCTION

Over the last decade, eCPR programs have become more and more popular, at least amongst high-volume centers. Despite its rise in popularity and promising outcome, strategies concerning pre- and post-implantation of VA-ECMO remain at least debatable. Besides, integrating the appropriate set-up, managing anticoagulation, implementing LV-venting, and predicting neurological outcome play important roles in caring for thise highly selective patient-collective. We sought to present our institutional´s techniques for establishing an eCPR program and managing patients peri- and post implantation in eCPR-runs.

AREAS COVERED

This manuscript covers the majority of clinical concerns and parameters for establishing an eCPR program and its recent advantages. We will describe a safe way of cannulation, setting anticoagulation goals, strategies for LV-venting and ICU-treatment. Also included, an elaboration on neurological and cardiac prognostication.

EXPERT OPINION

We advocate ultrasound-guided cannula placement in eCPR patients. Also, we emphasize the importance of using stiffer wires and smaller arterial cannula sizes due to the different physiological parameters of OHCA patients. After cannulation, we aim for lower flow goals, the concept of 'partial VA-ECMO,' and lower anticoagulatory targets. LV-venting with Impella should remain an individual case to case decision.

Myocardial Infarction and Cardiac Arrest in a Patient With Severe Undiagnosed Hypothyroidism During Bronchoscopy

Thyroid hormones have an integral role in cardiac homeostasis, and hypothyroidism may be associated with impaired myocardial contractility, altered endothelial function, and blunted response to catecholamines. Herein, the case of a patient with undiagnosed severe hypothyroidism, who developed an acute myocardial infarction and cardiac arrest during sedation for bronchoscopy, is described. He required prolonged resuscitation, which included coronary catheterization and placement of an intra-aortic balloon pump. The resuscitation was noteworthy for blunted physiologic responses to large doses of epinephrine; in particular, persistent bradycardia without evidence of conduction abnormalities. On admission to the intensive care unit, he was hypothermic (31.4°C), bradycardic, and hypotensive. Laboratory investigations revealed profound hypothyroidism, and thyroid hormone replacement was initiated. Within hours of initiation of thyroid hormone replacement, the need for vasopressor support was reduced. He had a complete recovery and was discharged home neurologically intact. The authors of the present report believe that this favorable neurologic outcome could be attributed to efficient resuscitation, prompt coronary revascularization, and profound hypothermia likely related to a hypothyroidism-associated hypometabolic state.

Review of Hypothermia Protocol and Timing of the Echocardiogram

Targeted temperature management, also known as therapeutic hypothermia (TH), is recommended for out-of-hospital cardiac arrest (OHCA). Both internal or external methods of cooling can be applied. Individuals resuscitated from OHCA frequently develop postarrest myocardial dysfunction resulting in decreased cardiac output and left ventricular systolic function. This dysfunction is usually transient and improves with spontaneous recovery over time. Echocardiogram (ECHO) can be a vital tool for the assessment and management of these patients. This manuscript reviewed methods available for TH after OHCA and reviews role of ECHO in the diagnosis and prognosis in this setting.

Hemodynamic and metabolic recovery in acute myocardial infarction-related cardiogenic shock is more rapid among patients presenting with out-of-hospital cardiac arrest

Background

Most studies in acute myocardial infarction complicated by cardiogenic shock (AMICS) include patients presenting with and without out-of-hospital cardiac arrest (OHCA). The aim was to compare OHCA and non-OHCA AMICS patients in terms of hemodynamics, management in the intensive care unit (ICU) and outcome.

Methods

From a cohort corresponding to two thirds of the Danish population, all patients with AMICS admitted from 2010–2017 were individually identified through patient records.

Results

A total of 1716 AMICS patients were identified of which 723 (42%) presented with OHCA. A total of 1532 patients survived to ICU admission. At the time of ICU arrival, there were no differences between OHCA and non-OHCA AMICS patients in variables commonly used in the AMICS definition (mean arterial pressure (MAP) (72mmHg vs 70mmHg, p = 0.12), lactate (4.3mmol/L vs 4.0mmol/L, p = 0.09) and cardiac output (CO) (4.6L/min vs 4.4L/min, p = 0.30)) were observed. However, during the initial days of ICU treatment OHCA patients had a higher MAP despite a lower need for vasoactive drugs, higher CO, SVO2 and lactate clearance compared to non-OHCA patients (p<0.05 for all). In multivariable analysis outcome was similar but cause of death differed significantly with hypoxic brain injury being leading cause in OHCA and cardiac failure in non-OHCA AMICS patients.

Conclusion

OHCA and non-OHCA AMICS patients initially have comparable metabolic and hemodynamic profiles, but marked differences develop between the groups during the first days of ICU treatment. Thus, pooling of OHCA and non-OHCA patients as one clinical entity in studies should be done with caution.

Prognostic value of automated pupillometry: an unselected cohort from a cardiac intensive care unit

Background:

Patients admitted to a cardiac intensive care unit are often unconscious with uncertain prognosis. Automated infrared pupillometry for neurological assessment in the intensive care unit may provide early prognostic information. This study aimed to determine the prognostic value of automated pupillometry in different subgroups of patients in a cardiac intensive care unit with 30-day mortality as the primary endpoint and neurological outcome as the secondary endpoint.

Methods:

A total of 221 comatose patients were divided into three groups: out-of-hospital cardiac arrest, in-hospital cardiac arrest and others (i.e. patients with cardiac diagnoses other than cardiac arrest). Automated pupillometry was serially performed until discharge or death and pupil measurements were analysed using the neurological pupil index algorithm. We applied receiver operating characteristic curves in univariable and multivariable logistic regression models and a calculated Youden index identified neurological pupil index cut-off values at different specificities.

Results:

In out-of-hospital cardiac arrest patients higher neurological pupil index values were independently associated with lower 30-day mortality. The univariable model for 30-day mortality had an area under the curve of 0.87 and the multivariable model achieved an area under the curve of 0.94. The Youden index identified a neurological pupil index cut-off in out-of-hospital cardiac arrest patients of 2.40 for a specificity of 100%. For patients with in-hospital cardiac arrest and other cardiac diagnoses, we found no association between neurological pupil index values and 30-day mortality, and the univariable models showed poor predictive values.

Conclusion:

Automated infrared pupillometry has promising predictive value after out-of-hospital cardiac arrest, but poor predictive value in patients with in-hospital cardiac arrest or cardiac diagnoses unrelated to cardiac arrest. Our data suggest a possible neurological pupil index cut-off of 2.40 for poor outcome in out-of-hospital cardiac arrest patients.

Targeted Temperature Management in Cardiac Arrest Patients With an Initial Non-Shockable Rhythm: A Systematic Review and Meta-Analysis

BACKGROUND

Targeted temperature management (TTM) is now recommended for patients presenting with an out-of-hospital cardiac arrest. However, there are limited data that support its use in patients with an initial non-shockable rhythm (NSR).

METHODS

A literature search of PubMed/MEDLINE, Cochrane Library, and Embase was conducted by two independent authors for studies that compared TTM along with standard care versus standard care alone in treating cardiac arrest with initial NSR. Outcomes were short-term and long-term survival, and a Cerebral Performance Category (CPC) score of 1 to 2 at the longest follow-up period. The Mantel-Haenszel random-effects model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Trial sequential analysis (TSA) was performed on the randomized controlled trials (RCTs).

RESULTS

Thirty studies were included in the final analysis: 25 observational and five RCTs, totalling 10,703 patients, 4,023 of whom received TTM and 6,680 received standard care alone. Compared with standard care, patients who presented with an initial NSR cardiac arrest and received TTM (target of 32°C -34°C) had a significantly higher short-term survival (OR 1.44 95% CI 1.15-1.81; P = 0.002), long-term survival (OR 1.52 95% CI 1.03-2.26; P = 0.04), and CPC score of 1 to 2 (OR 1.63 95% CI 1.22-2.17; P = 0.0010). Sensitivity analyses by including only RCTs showed a trend, although not significant, toward better short-term survival (OR 1.25 95% CI 0.82-1.89; P = 0.30), long-term survival (OR 1.15 95% CI 0.80-1.66; P = 0.46), and neurologic outcomes (OR 1.51 95% CI 0.81-2.80; P = 0.19). However, TSA performed on the RCTs revealed that the results were inconclusive.

CONCLUSION

Among patients who survived cardiac arrest with an initial NSR, TTM is associated with a higher rate of survival and favorable neurological outcomes compared with no TTM. However, analyses from the included RCTs did not support this conclusion.

Design paper of the "Blood pressure targets in post-resuscitation care and bedside monitoring of cerebral energy state: a randomized clinical trial"

BACKGROUND

Neurological injuries remain the leading cause of death in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA). Adequate blood pressure is of paramount importance to optimize cerebral perfusion and to minimize secondary brain injury. Markers measuring global cerebral ischemia caused by cardiac arrest and consecutive resuscitation and reflecting the metabolic variations after successful resuscitation are needed to assist a more individualized post-resuscitation care. Currently, no technique is available for bedside evaluation of global cerebral energy state, and until now blood pressure targets have been based on limited clinical evidence. Recent experimental and clinical studies indicate that it might be possible to evaluate cerebral oxidative metabolism from measuring the lactate-to-pyruvate (LP) ratio of the draining venous blood. In this study, jugular bulb microdialysis and immediate bedside biochemical analysis are introduced as new diagnostic tools to evaluate the effect of higher mean arterial blood pressure on global cerebral metabolism and the degree of cellular damage after OHCA.

METHODS/DESIGN

This is a single-center, randomized, double-blinded, superiority trial. Sixty unconscious patients with sustained return of spontaneous circulation after OHCA will be randomly assigned in a one-to-one fashion to low (63 mm Hg) or high (77 mm Hg) mean arterial blood pressure target. The primary end-point will be a difference in mean LP ratio within 48 h between blood pressure groups. Secondary end-points are (1) association between LP ratio and all-cause intensive care unit (ICU) mortality and (2) association between LP ratio and survival to hospital discharge with poor neurological function.

DISCUSSION

Markers measuring cerebral ischemia caused by cardiac arrest and consecutive resuscitation and reflecting the metabolic changes after successful resuscitation are urgently needed to enable a more personalized post-resuscitation care and prognostication. Jugular bulb microdialysis may provide a reliable global estimate of cerebral metabolic state and can be implemented as an entirely new and less invasive diagnostic tool for ICU patients after OHCA and has implications for early prognosis and treatment.

TRIAL REGISTRATION

ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT03095742 ). Registered March 30, 2017.

Long-term outcome of elderly out-of-hospital cardiac arrest survivors as compared with their younger counterparts and the general population

BACKGROUND:

Over the past decade, prehospital and in-hospital treatment for out-of-hospital cardiac arrest (OHCA) has improved considerably. There are sparse data on the long-term outcome, especially in elderly patients. We studied whether elderly patients benefit to the same extent compared with younger patients and at long-term follow up as compared with the general population.

METHODS:

Between 2001 and 2010, data from all patients presented to our hospital after OHCA were recorded. Elderly patients (⩾75 years) were compared with younger patients. Neurological outcome was classified as cerebral performance category (CPC) at hospital discharge and long-term survival was compared with younger patients and predicted survival rates of the general population.

RESULTS:

Of the 810 patients admitted after OHCA, a total of 551 patients (68%) achieved return of spontaneous circulation, including 125 (23%) elderly patients with a mean age of 81 ± 5 years. In-hospital survival was lower in elderly patients compared with younger patients with rates of 33% versus 57% ( p < 0.001). A CPC of 1 was present in 73% of the elderly patients versus 86% of the younger patients ( p = 0.031). In 7.3% of the elderly patients, a CPC >2 was observed versus 2.5% of their younger counterparts ( p = 0.103). Elderly patients had a median survival of 6.5 [95% confidence interval (CI) 2.0-7.9] years compared with 7.7 (95% CI 7.5-7.9) years of the general population ( p = 0.019).

CONCLUSIONS:

The survival rate after OHCA in elderly patients is approximately half that of younger patients. Elderly patients who survive to discharge frequently have favorable neurological outcomes and a long-term survival that approximates that of the general population.

Psychiatric sequelae of cardiac arrest

This manuscript summarizes the literature on mental health outcomes after cardiac arrest. Survivors of cardiac arrest show high rates of mental illness with more than 40% suffering from anxiety, 30% from depression, and 25% from posttraumatic stress disorder (PTSD). Mental health outcomes may differ depending on the setting in which the cardiac arrest occurred. A major problem is reduced neuropsychological functioning. Between 30% and 50% of survivors of cardiac arrest suffer from cognitive deficits. Deficits of attention, declarative memory, executive function, visual-spatial abilities, and verbal fluency have been observed. As a result of numerous psychopathological symptoms (depression in 14% to 45%, anxiety in 13% to 61%, and PTSD in 19% to 27%) and reduced cognitive functioning (about 20% to 60%), relevantly reduced quality of life is observed in about 20% of cardiac arrest survivors.

Detailed analysis of health-related quality of life after out-of-hospital cardiac arrest

AIM

To describe the detailed health-related quality of life (HRQoL) in survivors from the TTM-trial and to investigate potential differences related to sex and age.

METHODS

This is a cross-sectional study originating from a large prospective international, multicentre trial, including 442 respondents who answered the Short Form-36 item Questionnaire Health Survey version 2^® (SF-36v2^®) at a structured follow-up 6 months after out-of-hospital cardiac arrest (OHCA). Statistical analysis between independent groups were performed with Mann-Whitney U or Chi-square. Age was analysed primarily as a dichotomised variable.

RESULTS

Although overall physical and mental health were within the normal range, a substantial proportion of respondents had impaired function at domain-specific levels, particularly in Role-Physical (50%) and Role-Emotional (35%). Females scored significantly lower than males in; Physical Functioning (41.7 vs. 47.9, p < 0.001), Role-Physical (40.4 vs. 44.3, p = 0.02), General Health (47.0 vs. 50.5, p = 0.02), Vitality (47.2 vs. 52.7, p < 0.001), and Role-Emotional (41.5 vs. 46.2, p = 0.009). Those ≤65 years scored significantly better in Physical Functioning (47.9 vs. 44.1 p < 0.001), while those >65 years scored significantly better in Vitality (50.8 vs. 53.7, p = 0.006) and Mental Health (50.3 vs. 52.6, p = 0.04).

CONCLUSIONS

Many OHCA survivors demonstrated impaired function in HRQoL at a domain level, despite most patients reporting an acceptable general HRQoL. Females reported worse HRQoL than males. Older age was associated with a worse Physical Functioning but better Vitality and Mental Health. Role-Physical and Role-Emotional aspects of health were especially affected, even when effects of age and sex where accounted for.

The effect of different target temperatures in targeted temperature management on neurologically favorable outcome after out-of-hospital cardiac arrest: A nationwide multicenter observational study in Japan (the JAAM-OHCA registry)

BACKGROUND

It has been insufficiently investigated whether neurological function after out-of-hospital cardiac arrest (OHCA) would differ by 1 °C change in ordered target temperature of 33-36 °C among patients undergoing targeted temperature management (TTM) in the real-world setting.

METHODS

This nationwide hospital-based observational study (The Japanese Association for Acute Medicine-OHCA Registry) conducted between June 2014 and December 2015 in Japan included OHCA patients aged ≥18 years who were treated with TTM. The primary outcome was one-month survival with neurologically favorable outcomes defined by cerebral performance category 1 or 2. To investigate the effect of TTM by 1 °C change in ordered target temperature of 33-36 °C on each outcome, random effects logistic regression analyses were performed.

RESULTS

The final analysis included 738 patients. The proportion of patients with neurologically favorable outcome was 30.4% (7/23), 31.7% (175/552), 28.9% (11/38), and 30.4% (38/125) in the 33 °C, 34 °C, 35 °C, and 36 °C groups, respectively. In the multivariable logistic regression analysis, no group had a higher proportion of neurologically favorable outcome compared with the 34 °C group (vs. 33 °C group, adjusted odds ratio [AOR] 0.90; 95% confidence interval [CI] 0.25-3.12, vs. 35 °C group, AOR 1.17; 95% CI 0.44-3.13, vs. 36 °C group, AOR 1.26; 95% CI 0.78-2.02).

CONCLUSIONS

In this population, we evaluated the difference in outcomes after adult OHCA patients received TTM by 1 °C change in ordered target temperature of 33-36 °C and demonstrated that there was no statistically significant difference in neurologically favorable outcomes after OHCA irrespective of target temperature.

Targeted Temperature Management; Review of Literature and Guidelines; A Cardiologist's Perspective

BACKGROUND

Out of Hospital Cardiac Arrest (OHCA) remains not an uncommon occurrence in USA and the rest of the world. However, the survival to discharge following an episode of OHCA in adults is still very disappointing at around 10%. Several areas of improvement including education of general public in early Cardio Pulmonary Resuscitation (CPR) by bystander, chest compression first, and improvement of Emergency Medical response time have had a positive effect on the outcomes and survival but still much needs to be done. Recently, new data has emerged with regards to post resuscitation care and mild induced hypothermia (now preferably called; Targeted Temperature Management {TTM}) and several advances have been made.

CONCLUSION

The purpose of this review is to summarize and compare the most recent guidelines and also provide a practical approach to TTM especially with regards to the field of cardiology.

Out-of-hospital cardiac arrest: in-hospital intervention strategies

The prognosis after out-of-hospital cardiac arrest (OHCA) has improved in the past few decades because of advances in interventions used outside and in hospital. About half of patients who have OHCA with initial ventricular tachycardia or ventricular fibrillation and who are admitted to hospital in coma after return of spontaneous circulation will survive to discharge with a reasonable neurological status. In this Series paper we discuss in-hospital management of patients with post-cardiac-arrest syndrome. In most patients, the most important in-hospital interventions other than routine intensive care are continuous active treatment (in non-comatose and comatose patients and including circulatory support in selected patients), cooling of core temperature to 32-36°C by targeted temperature management for at least 24 h, immediate coronary angiography with or without percutaneous coronary intervention, and delay of final prognosis until at least 72 h after OHCA. Prognosis should be based on clinical observations and multimodal testing, with focus on no residual sedation.

Patient Outcomes After Palliative Care Consultation Among Patients Undergoing Therapeutic Hypothermia

OBJECTIVES

To compare the clinical outcomes of patients who did and did not receive palliative care consultation among those who experienced out-of-hospital cardiac arrest and underwent therapeutic hypothermia.

METHODS

We identified patients at a single academic medical center who had undergone therapeutic hypothermia after out-of-hospital cardiac arrest between 2009 and 2013. We performed a retrospective chart review for demographic data, hospital and critical care length of stay, and clinical outcomes of care.

RESULTS

We reviewed the charts of 62 patients, of which 35 (56%) received a palliative care consultation and 27 (44%) did not. Palliative care consultation occurred an average of 8.3 days after admission. Patients receiving palliative care consultation were more likely to have a do-not-resuscitate (DNR) order placed (odds ratio: 2.3, P < .001). The mean length of stay in the hospital was similar for patients seen by palliative care or not (16.7 vs 17.1 days, P = .90). Intensive care length of stay was also similar (11.3 vs 12.6 days, P = .55).

CONCLUSIONS

Palliative care consultation was underutilized and utilized late in this cohort. Palliative consultation was associated with DNR orders but did not affect measures of utilization such as hospital and intensive care length of stay.

Enhanced contractility of intraparenchymal arterioles after global cerebral ischaemia in rat - new insights into the development of delayed cerebral hypoperfusion

AIM

Delayed cerebral hypoperfusion is a secondary complication found in the days after transient global cerebral ischaemia that worsens the ischaemic damage inflicted by the initial transient episode of global cerebral ischaemia. A recent study demonstrated increased cerebral vasoconstriction in the large arteries on the brain surface (pial arteries) after global cerebral ischaemia. However, smaller arterioles inside the brain (parenchymal arterioles) are equally important in the regulation of cerebral blood flow and yet their pathophysiology after global cerebral ischaemia is largely unknown. Therefore, we investigated whether increased contractility occurs in the intraparenchymal arterioles.

METHODS

Global cerebral ischaemia was induced in male Wistar rats by bilateral common carotid occlusion for 15 min combined with hypovolaemia. Regional cerebral blood flow was determined by quantitative autoradiography. Intraparenchymal arterioles were isolated and pressurized, and concentration-response curves to endothelin-1 with and without the endothelin B receptor-selective antagonist BQ788 was generated. Endothelin B receptor expression was investigated by quantitative flow cytometry and immunohistochemistry.

RESULTS

We observed increased endothelin-1-mediated contractility of parenchymal arterioles correlating with reduced cerebral blood flow of the cortex, hippocampus and caudate nucleus 48 h after global cerebral ischaemia. The increased endothelin-1-mediated contractility was abolished by BQ788, and the vascular smooth muscle cell-specific expression of endothelin B receptors was significantly increased after global cerebral ischaemia.

CONCLUSION

Increased endothelin-1-mediated contractility and expression of endothelin B receptors in the intraparenchymal vasculature contributes to the development of delayed cerebral hypoperfusion after global cerebral ischaemia in combination with vascular changes of the pial vasculature.

Adaptation of global hemostasis to therapeutic hypothermia in patients with out-of-hospital cardiac arrest: Thromboelastography study

BACKGROUND

The use of mild therapeutic hypothermia (MTH) in patients after out-of-hospital cardiac arrest (OHCA) who are undergoing primary percutaneous coronary intervention (pPCI) can protect patients from thromboembolic complications. The aim of the study was to evaluate the adaptive mecha- nisms of the coagulation system in MTH-treated comatose OHCA survivors.

METHODS

Twenty one comatose OHCA survivors with acute coronary syndrome undergoing imme- diate pPCI were treated with MTH. Quantitative and qualitative analyses of physical clot properties were performed using thromboelastography (TEG). Two analysis time points were proposed: 1) during MTH with in vitro rewarming conditions (37°C) and 2) after restoration of normothermia (NT) under normal (37°C) and in vitro cooling conditions (32°C).

RESULTS

During MTH compared to NT, reaction time (R) was lengthened, clot kinetic parameter (a) was significantly reduced, but no effect on clot strength (MA) was observed. Finally, the coagulation index (CI) was significantly reduced with clot fibrinolysis attenuated during MTH. The clot lysis time (CLT) was shortened, and clot stability (LY60) was lower compared with those values during NT. In vitro cooling generally influenced clot kinetics and reduced clot stability after treatment.

CONCLUSIONS

Thromboelastography is a useful method for evaluation of coagulation system dysfunc- tion in OHCA survivors undergoing MTH. Coagulation impairment in hypothermia was associated with a reduced rate of clot formation, increased weakness of clot strength, and disturbances of fibrinoly- sis. Blood sample analyses performed at 32°C during MTH, instead of the standard 37°C, seems to enhance the accuracy of the evaluation of coagulation impairment in hypothermia.

A systematic review and meta-synthesis of the qualitative literature exploring the experiences and quality of life of survivors of a cardiac arrest

BACKGROUND

Survival following cardiac arrest and subsequent cardiopulmonary resuscitation (CPR) is increasing worldwide, mainly due to greater awareness of the symptoms of cardiac events and an increased attention to CPR training. Although patient outcomes remain unpredictable and quantitative studies suggest that the overall quality of life (QOL) is acceptable, it is valuable to synthesise qualitative studies exploring these phenomena in depth, providing a deeper knowledge of survivors' experiences and QOL.

AIMS

To critically appraise and synthesise the qualitative literature on survivors' experiences of a cardiac arrest and CPR with the aim of identifying common themes that can inform clinical pathways and thereby improve survivor outcomes and QOL.

METHODS

A systematic review and meta-synthesis of the qualitative literature, using Thomas and Harden's framework, and confined to peer-reviewed papers published from 2000 to 2015, which were identified through database searches of EBSCO, OVID and ProQuest.

RESULTS

The search produced 204 papers, and of these, seven relevant papers were identified for review. Data extraction included setting, participants, research design, data collection, analysis and themes. Five qualitative themes were identified and were the subject of this meta-synthesis: multitude of contrasting feelings; disruption in the continuum of time; new reality and psychological challenges; changed body with new limitations; and confrontation with death.

CONCLUSION

This review provides insights into the experiences of survivors' QOL after CPR. Increased knowledge can improve person-centred care in the immediate and forthcoming care after the event, both in terms of planning for discharge and in the future care of people who survive a cardiac arrest.

Neuroprotective Effects of the Glucagon-Like Peptide-1 Analog Exenatide After Out-of-Hospital Cardiac Arrest

Background:

In-hospital mortality in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA) is ≈50%. In OHCA patients, the leading cause of death is neurological injury secondary to ischemia and reperfusion. Glucagon-like peptide-1 analogs are approved for type 2 diabetes mellitus; preclinical and clinical data have suggested their organ-protective effects in patients with ischemia and reperfusion injury. The aim of this trial was to investigate the neuroprotective effects of the glucagon-like peptide-1 analog exenatide in resuscitated OHCA patients.

Methods:

We randomly assigned 120 consecutive comatose patients resuscitated from OHCA in a double-blind, 2-center trial. They were administered 17.4 μg exenatide (Byetta) or placebo over a 6-hour and 15-minute infusion, in addition to standardized intensive care including targeted temperature management. The coprimary end points were feasibility, defined as initiation of the study drug in >90% patients within 240 minutes of return of spontaneous circulation, and efficacy, defined as the geometric area under the neuron-specific enolase curve from 24 to 72 hours after admission. The main secondary end points included a composite end point of death and poor neurological function, defined as a Cerebral Performance Category score of 3 to 5 assessed at 30 and 180 days.

Results:

The study drug was initiated within 240 minutes of return of spontaneous circulation in 96% patients. The median blood glucose 8 hours after admission in patients receiving exenatide was lower than that in patients receiving placebo (5.8 [5.2–6.7] mmol/L versus 7.3 [6.2–8.7] mmol/L, P <0.0001). However, there were no significant differences in the area under the neuron-specific enolase curve, or a composite end point of death and poor neurological function between groups. Adverse events were rare with no significant difference between groups.

Conclusions:

Acute administration of exenatide to comatose patients in the intensive care unit after OHCA is feasible and safe. Exenatide did not reduce neuron-specific enolase levels and did not significantly improve a composite end point of death and poor neurological function after 180 days.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02442791.

The Role of Targeted Temperature Management in Adult Patients Resuscitated from Nonshockable Cardiac Arrests: An Updated Systematic Review and Meta-Analysis

Routine targeted temperature management is recommended for comatose adult patients with return of spontaneous circulation after cardiac arrest. However, the role of targeted temperature management in patients resuscitated from nonshockable cardiac arrests remains uncertain. We conducted an updated systematic review and meta-analysis to evaluate the effects of targeted temperature management in this population. Medline, EMBASE, and Cochrane databases were systematically reviewed for studies published between January 2005 and March 2016, in which targeted temperature management was compared with standard care or normothermia for adult patients resuscitated from nonshockable cardiac arrests. A total of 25 trials that included 5715 patients were identified from 10985 relevant papers. Pooled data showed that targeted temperature management not only associated with improved short-term survival (RR = 1.42, 95% CI: 1.28-1.57) and neurological function (RR = 1.63, 95% CI: 1.39-1.91) but also associated with improved long-term survival (RR = 1.64, 95% CI: 1.27-2.12) and neurological recovery (RR = 1.42, 95% CI: 1.07-1.90) in observational cohort studies. However, more frequent infectious complications were reported in hypothermia-treated patients (RR = 1.46, 95% CI: 1.26-1.70) and the quality of the evidence ranged from moderate to very low.

GLP-1 analogues for neuroprotection after out-of-hospital cardiac arrest: study protocol for a randomized controlled trial

Background

Attenuating the neurological damage occurring after out-of-hospital cardiac arrest is an ongoing research effort. This dual-centre study investigates the neuroprotective effects of the glucagon-like-peptide-1 analogue Exenatide administered within 4 hours from the return of spontaneous circulation to comatose patients resuscitated from out-of-hospital cardiac arrest.

Methods/design

This pilot study will randomize a total of 120 unconscious patients with sustained return of spontaneous circulation after out-of-hospital cardiac arrest undergoing targeted temperature management in a blinded one-to-one fashion to a 6-hour and 15-minute infusion of either Exenatide or placebo. Patients are eligible for inclusion if resuscitated from cardiac arrest with randomization from 20 minutes to 240 minutes after return of spontaneous circulation. The co-primary endpoint is feasibility, defined as the initiation of treatment within the inclusion window in more than 90 % of participants, and efficacy, defined as the area under the neuron-specific enolase curve from 0 to 72 hours after admission. Secondary endpoints include all-cause mortality at 30 days and Cerebral Performance Category as well as a modified Rankin Score at 180 days. The study has been approved by the Danish National Board of Health and the local Ethics Committee and is monitored by Good Clinical Practice units. The study is currently enrolling.

Discussion

This paper presents the methods and planned statistical analyses used in the GLP-1 trial and aims to minimize bias and data-driven reporting of results.

Trial registration

1) Danish National Board of Health, EudraCT 2013-004311-45. Registered on 25 March 2014.

2) Videnskabsetisk komité C, Region Hovedstaden, No. 45728. Registered on 29 January 2014.

3) Clinicaltrial.gov, NCT02442791. Registered on 25 of January 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1421-2) contains supplementary material, which is available to authorized users.

Recovery, long-term cognitive outcome and quality of life following out-of-hospital cardiac arrest

OBJECTIVE

Among survivors of out-of-hospital cardiac arrest (OHCA), the functional outcomes of those with rapid early or with very delayed recoveries are known. For patients between those extremes early recovery is variable, and the probability of longer-term recovery and the implications for quality of life have not been clearly defined.

METHODS

Twenty-five patients of a consecutive cohort of OHCA survivors with coma duration between 12 h and 7 days and a matched group with acute coronary syndrome underwent cognitive and disability assessments 3 and 12 months after OHCA. Correlations and regression analyses of demographic, clinical arrest variables, and cognitive tests with quality of life outcomes were performed.

RESULTS

The OHCA group had impairments in all cognitive domains. There was little cognitive improvement. The OHCA group reported significantly greater health impact and lower quality of life at twelve months than the controls. Longer duration of coma (4-7 versus ≤ 3 days) and greater cognitive impairment at three months, particularly memory impairment, were both associated with reduced late quality of life.

CONCLUSIONS

These survivors of OHCA had persistent long-term cognitive deficits. Quality of life at one year after OHCA was reduced compared to cardiac controls. Coma duration and memory impairment at three months were harbingers of long term reduced quality of life.

Association between therapeutic hypothermia and long-term quality of life in survivors of cardiac arrest: A systematic review

OBJECTIVES

Therapeutic hypothermia (TH) has increasingly become a part of the current standard of care for treating patients with cardiac arrest (CA). However, little is known regarding the association between TH and long-term quality of life (QoL) in adult survivors of CA. We conducted a systematic review to investigate the association between TH implementation and long-term QoL outcomes in adult survivors of CA following hospital discharge.

METHODS

We systematically searched MEDLINE and Cochrane databases to identify randomized and observational studies from January 2005 to January 2016 investigating the relationship between TH implementation immediately post-CA and long-term QoL in CA survivors post-hospital discharge.

RESULTS

We included 9 studies with a total of 801 patients. Six of these were prospective cohort studies, 2 were substudies of randomized controlled trials, and 1 was a retrospective cohort study. Six studies included patients only with out-of-hospital CA while 3 included patients with both in-hospital and out-of-hospital CA. There was marked between-study heterogeneity with respect to study population, TH implementation, and QoL assessment tool. TH was not associated with long-term QoL in this population.

CONCLUSIONS

In this systematic review, the included studies do not suggest any association between TH implementation in CA with long-term QoL in CA survivors. Further larger scale studies are needed to investigate the sustainability of TH effects long term in this patient population.

Prehospital transportation to therapeutic hypothermia centers and survival from out-of-hospital cardiac arrest

Background

Clinical trials supporting the use of therapeutic hypothermia (TH) in the treatment of out-of-hospital cardiac arrest (OHCA) are based on small patient samples and do not reflect the wide variation in patient selection, cooling methods, and other elements of post-arrest care that are used in everyday practice. This study provides a real world evaluation of the effectiveness of post-arrest care in TH centers during a time of growing TH dissemination in the state of New Jersey (NJ).

Methods

Using a linked database of prehospital, hospital, and mortality records for NJ in 2009-2010, we compared rates of neurologically intact survival at discharge and at 30 days for OHCA patients transported to TH centers (N = 2363) versus other hospitals (N = 2479). We used logistic regression to adjust for patient and hospital covariates. To account for potential endogeneity in prehospital transportation decisions, we used an instrumental variable (IV) based on differential distance to the nearest TH and non-TH hospitals.

Results

Patients taken to TH centers were older, more likely to have a witnessed arrest, more likely to receive defibrillation, and waited a shorter amount of time for initial EMS response. Also, TH hospitals were larger, more likely to be teaching facilities, and operated in a service area with a relatively lower poverty rate compared to hospitals statewide. A Stock-Yogo test confirmed the strength of our IV (F = 2349.91, p < 0.0001). Nevertheless, the data showed no evidence of endogenous transportation to TH centers related to in-hospital survival (Z = -0.08, p = 0.934) or 30-day survival (Z = 0.94, p = 0.349). In logistic regression models, treatment at a TH center was associated with greater odds of 30-day neurologically intact survival (OR = 1.70; 95 % CI: 1.19 – 2.42) but not associated with the odds of neurologically intact survival to hospital discharge (OR = 0.90; 95 % CI: 0.61 – 1.31).

Conclusions

Post-arrest outcomes are more favorable at TH centers but these improved outcomes are not apparent until after hospital discharge. This finding may reflect superior care by TH centers in later stages of post-arrest treatment such as care provided in the intensive care unit, which has greater potential to affect longer term outcomes than initial treatment in the emergency department.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-1199-z) contains supplementary material, which is available to authorized users.

Cognitive function, quality of life and mental health in survivors of our-of-hospital cardiac arrest: a review

There is growing interest in the long-term outcomes of patients surviving out-of-hospital cardiac arrest (OHCA). This paper aims to summarise the available literature on the long-term cognitive, health-related quality of life (QoL) and mental health outcomes of survivors of OHCA. Between 30% and 50% of survivors of OHCA experience cognitive deficits for up to several years post-discharge. Deficits of attention, declarative memory, executive function, visuospatial abilities and verbal fluency are commonly reported. Survivors of OHCA appear to report high rates of mental illness, with up to 61% experiencing anxiety, 45% experiencing depression and 27% experiencing post-traumatic stress. Fatigue appears to be a commonly reported long-term outcome for survivors of OHCA. Investigations of long-term QoL for these patients have produced mixed findings. Carers of survivors of OHCA report high rates of depression, anxiety and post-traumatic stress, with insufficient social and financial support. The heterogeneous range of instruments used to assess cognitive function and QoL prevent any clear conclusions being drawn from the available literature. The potential biases inherent in this patient population and the interaction between QoL, cognitive performance and mental health warrant further investigation, as does the role of post-discharge support services in improving long-term patient outcomes.

Cost-effectiveness analysis of alternative cooling strategies following cardiac arrest

OBJECTIVES

Using survival and neurologic outcome as endpoints , this study explored the incremental cost effectiveness of three mutually exclusive cooling strategies employed after resuscitated out-of-hospital cardiac arrests.

DESIGN

Economic analysis based on retrospective data collection and Markov modeling.

SETTING

Modeling based on patients housed in a tertiary ICU setting.

PATIENTS

Patients >18 years following resuscitation from out-of-hospital cardiac arrest.

INTERVENTIONS

Therapeutic cooling vs. conventional care.

MEASUREMENTS AND MAIN RESULTS

Using societal-based analytic decision modeling with a lifetime study horizon, incremental cost effectiveness ratios (ICERs) for blanket, peritoneal lavage, and V-V ECMO cooling strategies were compared with conventional care. Comprehensive cost data were obtained from available literature, national and local databases; health utility data were abstracted from previous publications and converted to quality-adjusted life years (QALYs)/person and stratified by neurologic outcome state. Future costs were discounted using a standard 3% discount rate. Cooling blankets produced better overall health outcomes at a lower cost than conventional care and V-V ECMO. Peritoneal lavage added an additional 0.67 QALYs at an ICER of $58,329/QALY. Monte-Carlo simulations incorporating uncertainty in all parameters showed that peritoneal lavage was 70% likely to be the preferred, cost-effective therapy if one were willing to pay (WTP) $100,000/QALY.

CONCLUSIONS

This analysis suggests that blankets are the most cost effective cooling strategy for post-ROSC therapeutic hypothermia, with peritoneal lavage as an acceptable alternative at higher WTP thresholds. Though uncertainty about the optimal therapy could be reduced with additional research, these results can inform policy-makers and healthcare providers about cost effectiveness of alternative cooling modalities designed to improve neurologic outcome for this expanding patient population. This may be particularly relevant as societal-based cost effectiveness analyses become more widely incorporated into studies evaluating treatment for frequently encountered diseases.

Prolonged Local Hypothermia Has No Long-Term Adverse Effect on the Spinal Cord

Hypothermia is known to be neuroprotective and is one of the most effective and promising first-line treatments for central nervous system (CNS) trauma. At present, induction of local hypothermia, as opposed to general hypothermia, is more desired because of its ease of application and safety; fewer side effects and an absence of severe complications have been noted. Local hypothermia involves temperature reduction of a small and specific segment of the spinal cord. Our group has previously shown the neuroprotective effect of short-term, acute moderate general hypothermia through improvements in electrophysiological and motor behavioral assessments, as well as histological examination following contusive spinal cord injury (SCI) in rats. We have also shown the benefit of using short-term local hypothermia versus short-term general hypothermia post-acute SCI. The overall neuroprotective benefit of hypothermia can be categorized into three main components: (1) induction modality, general versus local, (2) invasive, semi-invasive or noninvasive, and (3) duration of hypothermia induction. In this study, a series of experiments were designed to investigate the feasibility, long-term safety, as well as eventual complications and side effects of prolonged, semi-invasive, moderate local hypothermia (30°C±0.5°C for 5 and 8 hours) in rats with uninjured spinal cord while maintaining their core temperature at 37°C±0.5°C. The weekly somatosensory evoked potential and motor behavioral (Basso, Beattie and Bresnahan) assessments of rats that underwent 5 and 8 hours of semi-invasive local hypothermia, which revealed no statistically significant changes in electrical conductivity and behavioral outcomes. In addition, 4 weeks after local hypothermia induction, histological examination showed no anatomical damages or morphological changes in their spinal cord structure and parenchyma. We concluded that this method of prolonged local hypothermia is feasible, safe, and has the potential for clinical translation.

Post-discharge outcomes after resuscitation from out-of-hospital cardiac arrest: A ROC PRIMED substudy

IMPORTANCE

Assessment of morbidity is an important component of evaluating interventions for patients with out-of-hospital cardiac arrest (OHCA).

OBJECTIVE

We evaluated among survivors of OHCA cognition, functional status, health-related quality of life and depression as functions of patient and emergency medical services (EMS) factors.

DESIGN

Prospective cohort sub-study of a randomized trial.

SETTING

The parent trial studied two comparisons in persons with non-traumatic OHCA treated by EMS personnel participating in the Resuscitation Outcomes Consortium.

PARTICIPANTS

Consenting survivors to discharge.

MAIN OUTCOME MEASURES

Telephone assessments up to 6 months after discharge included neurologic function (modified Rankin score, MRS), cognitive impairment (Adult Lifestyle and Function Mini Mental Status Examination, ALFI-MMSE), health-related quality of life (Health Utilities Index Mark 3, HUI3) and depression (Telephone Geriatric Depression Scale, T-GDS).

RESULTS

Of 15,794 patients enrolled in the parent trial, 729 (56% of survivors) consented. About 644 respondents (88% of consented) completed ≥ 1 assessment. Likelihood of assessment was associated with baseline characteristics and study site. Most respondents had MRS ≤ 3 (82.7%), no cognitive impairment (82.7% ALFI-MMSE ≥ 17), no severe impairment in health (71.6%, HUI3 ≥ 0.7) and no depression (90.1% T-GDS≤10). Outcomes did not differ by trial intervention or time from hospital discharge.

CONCLUSIONS AND RELEVANCE

The majority of patients in this large cohort who survived cardiac arrest and were interviewed had no, mild or moderate health impairment. Concern about poor quality of life is not a valid reason to abandon efforts to improve an EMS system's response to cardiac arrest.

Cognitive function in survivors of out-of-hospital cardiac arrest after target temperature management at 33°C versus 36°C

BACKGROUND

Target temperature management is recommended as a neuroprotective strategy after out-of-hospital cardiac arrest. Potential effects of different target temperatures on cognitive impairment commonly described in survivors have not been investigated sufficiently. The primary aim of this study was to evaluate whether a target temperature of 33°C compared with 36°C was favorable for cognitive function; the secondary aim was to describe cognitive impairment in cardiac arrest survivors in general.

METHODS AND RESULTS

Study sites included 652 cardiac arrest survivors originally randomized and stratified for site to temperature control at 33°C or 36°C within the Target Temperature Management trial. Survival until 180 days after the arrest was 52% (33°C, n=178/328; 36°C, n=164/324). Survivors were invited to a face-to-face follow-up, and 287 cardiac arrest survivors (33°C, n=148/36°C, n=139) were assessed with tests for memory (Rivermead Behavioural Memory Test), executive functions (Frontal Assessment Battery), and attention/mental speed (Symbol Digit Modalities Test). A control group of 119 matched patients hospitalized for acute ST-segment-elevation myocardial infarction without cardiac arrest performed the same assessments. Half of the cardiac arrest survivors had cognitive impairment, which was mostly mild. Cognitive outcome did not differ (P>0.30) between the 2 temperature groups (33°C/36°C). Compared with control subjects with ST-segment-elevation myocardial infarction, attention/mental speed was more affected among cardiac arrest patients, but results for memory and executive functioning were similar.

CONCLUSIONS

Cognitive function was comparable in survivors of out-of-hospital cardiac arrest when a temperature of 33°C and 36°C was targeted. Cognitive impairment detected in cardiac arrest survivors was also common in matched control subjects with ST-segment-elevation myocardial infarction not having had a cardiac arrest.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01946932.

Functional outcome, cognition and quality of life after out-of-hospital cardiac arrest and therapeutic hypothermia: data from a randomized controlled trial

Background

To study functional neurologic and cognitive outcome and health-related quality of life (HRQoL) in a cohort of patients included in a randomised controlled trial on glucose control following out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation (VF) treated with therapeutic hypothermia.

Methods

Patients alive at 6 months after being discharged from the hospital underwent clinical neurological and extensive neuropsychological examinations. Functional outcome was evaluated with the Cerebral Performance Category scale, the modified Rankin scale and the Barthel Index. Cognitive outcome was evaluated by neuropsychological test battery including two measures of each cognitive function: cognitive speed, execution, memory, verbal skills and visuospatial performance. We also assessed quality of life with a HRQoL 15D questionnaire.

Results

Of 90 OHCA-VF patients included in the original trial, 57 were alive at 6 months. Of these, 52 (91%) were functionally independent and 54 (95%) lived at their previous home. Focal neurological deficits were scarce. Intact cognitive performance was observed in 20 (49%), mild to moderate deficits in 14 (34%) and severe cognitive deficits in 7 (17%) of 41 patients assessed by a neuropsychologist. Cognitive impairments were most frequently detected in executive and memory functions. HRQoL of the CA survivors was comparable to that of age- and gender matched population.

Conclusions

Functional outcome six months after OHCA and therapeutic hypothermia was good in the great majority of the survivors, and half of them were cognitively intact. Of note, the HRQoL of CA survivors did not differ from that of age- and gender matched population.

Sinus bradycardia during hypothermia in comatose survivors of out-of-hospital cardiac arrest - a new early marker of favorable outcome?

BACKGROUND

Bradycardia is a common finding in patients undergoing therapeutic hypothermia (TH) following out-of-hospital cardiac arrest (OHCA), presumably as a normal physiological response to low body temperature. We hypothesized that a normal physiological response with sinus bradycardia (SB) indicates less neurological damage and therefore would be associated with lower mortality.

METHODS

We studied 234 consecutive comatose survivors of OHCA with presumed cardiac etiology and shockable primary rhythm, who underwent a full 24-h TH-protocol (33°C) at a tertiary heart center (years: 2004-2010). Primary endpoint was 180-day mortality; secondary endpoint was favorable neurological outcome (180-day cerebral performance category: 1-2).

RESULTS

SB, defined as sinus rhythm <50 beats per minute during TH, was present in 115 (49%) patients. Baseline characteristics including sex, witnessed arrest, bystander cardiopulmonary resuscitation and time to return of spontaneous circulation were not different between SB- and no-SB patients. However, SB-patients were younger, 57±14 vs. 63±14 years, p<0.001 and less frequently had known heart failure (7% vs. 20%, p<0.01). Patients experiencing SB during the hypothermia phase of TH had a 17% 180-day mortality rate compared to 38% in no-SB patients (p<0.001), corresponding to a 180-day hazard ratio (HRadjusted=0.45 (0.23-0.88, p=0.02)) in the multivariable analysis. Similarly, SB during hypothermia was directly associated with lower odds of unfavorable neurological outcome (ORunadjusted=0.42 (0.23-0.75, p<0.01).

CONCLUSION

Sinus bradycardia during therapeutic hypothermia is independently associated with a lower 180-day mortality rate and may thus be a novel, early marker of favorable outcome in comatose survivors of OHCA.

Higher achieved mean arterial pressure during therapeutic hypothermia is not associated with neurologically intact survival following cardiac arrest

INTRODUCTION

To determine if higher achieved mean arterial blood pressure (MAP) during treatment with therapeutic hypothermia (TH) is associated with neurologically intact survival following cardiac arrest.

METHODS

Retrospective analysis of a prospectively collected cohort of 188 consecutive patients treated with TH in the cardiovascular intensive care unit of an academic tertiary care hospital.

RESULTS

Neurologically intact survival was observed in 73/188 (38.8%) patients at hospital discharge and in 48/162 (29.6%) patients at a median follow up interval of 3 months. Patients in shock at the time of admission had lower baseline MAP at the initiation of TH (81 versus 87mmHg; p=0.002), but had similar achieved MAP during TH (80.3 versus 83.7mmHg; p=0.11). Shock on admission was associated with poor survival (18% versus 52%; p<0.001). Vasopressor use among all patients was common (84.6%) and was not associated with increased mortality. A multivariable analysis including age, initial rhythm, time to return of spontaneous circulation, baseline MAP and achieved MAP did not demonstrate a relationship between MAP achieved during TH and poor neurological outcome at hospital discharge (OR 1.28, 95% CI 0.40-4.06; p=0.87) or at outpatient follow up (OR 1.09, 95% CI 0.32-3.75; p=0.976).

CONCLUSION

We did not observe a relationship between higher achieved MAP during TH and neurologically intact survival. However, shock at the time of admission was clearly associated with poor outcomes in our study population. These data do not support the use of vasopressors to artificially increase MAP in the absence of shock. There is a need for prospective, randomized trials to further define the optimum blood pressure target during treatment with TH.