Activation of the kynurenine pathway predicts mortality and neurological outcome in cardiac arrest patients: A validation study

Introduction: Kynurenine pathway (KP) is emerging as one of the potential components affecting cardiac arrest (CA) outcomes. The aim of this study is to evaluate the effects of KP inhibition through genetic deletion of the rate-limiting enzyme of the KP, indoleamine-2,3-dyoxygenase (IDO) on survival and neurological outcome after CA. Methods and Results: Sixteen adult male wild-type (WT) and IDO-deleted (IDO -/- ) mice were subjected to 8 min untreated CA followed by resuscitation. At baseline heart rate and mean arterial pressure (MAP) did not differ among groups. At the time of return of spontaneous circulation, 30 and 60 min later, MAP was higher in the IDO -/- group compared to the WT one (p=0.0005). IDO -/- mice showed higher survival compared to WT at 7 days after CA (68.5% in IDO -/- vs 37.5% in WT; log rank p=0.036). Neurological function was higher in IDO -/- than in WT mice during the 7 days following CA (p=0.0124). IDO -/- mice also showed an improved locomotor function compared to WT mice (p=0.037). Brain magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI) sequences showed a reduction in fractional anisotropy in the external capsule of the corpus callosum in WT mice compared to IDO -/- mice at 7 days after resuscitation (p=0.015). We then treated additional IDO -/- mice with L-kyn 15 min before CA, to revert the IDO -/- phenotype. Brain MRI with diffusion-weighted imaging (DWI) sequences and histological analysis were performed 24h after CA in WT, IDO -/- , and IDO -/- +L-Kyn mice. Brain MRI revealed restriction of water diffusivity 24h after CA in WT mice. IDO-deletion reduced water diffusion abnormalities while the beneficial effect was reverted in the L-kyn group (p=0.01). Degenerating neurons in the frontal cortex, represented as Fluoro-Jade B positive cells, were more numerous in WT compared to IDO -/- mice; L-kyn halted this IDO deletion-induced reduction in degenerating cells (p=0.05). Conclusion: KP inhibition improves survival and neurological outcome after CA. The neuroprotective effect of IDO-deletion was associated with preservation of brain white matter microintegrity and with reduction of cerebral cytotoxic edema. Reversal of these beneficial effects by L-kyn administration in IDO -/- mice further confirm the KP role in CA outcome.

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Mechanical circulatory support for refractory out-of-hospital cardiac arrest: a Danish nationwide multicenter study

Critical Care ◽

10.1186/s13054-021-03606-5 ◽

2021 ◽

Vol 25 (1) ◽

Author(s):

Sivagowry Rasalingam Mørk ◽

Carsten Stengaard ◽

Louise Linde ◽

Jacob Eifer Møller ◽

Lisette Okkels Jensen ◽

...

Keyword(s):

Logistic Regression ◽

Cardiac Arrest ◽

Survival Rate ◽

Neurological Outcome ◽

Mechanical Circulatory Support ◽

Circulatory Support ◽

Good Neurological Outcome ◽

Factors Associated ◽

National Consensus ◽

Hospital Cardiac Arrest

Abstract Background Mechanical circulatory support (MCS) with either extracorporeal membrane oxygenation or Impella has shown potential as a salvage therapy for patients with refractory out-of-hospital cardiac arrest (OHCA). The objective of this study was to describe the gradual implementation, survival and adherence to the national consensus with respect to use of MCS for OHCA in Denmark, and to identify factors associated with outcome. Methods This retrospective, observational cohort study included patients receiving MCS for OHCA at all tertiary cardiac arrest centers (n = 4) in Denmark between July 2011 and December 2020. Logistic regression and Kaplan–Meier survival analysis were used to determine association with outcome. Outcome was presented as survival to hospital discharge with good neurological outcome, 30-day survival and predictors of 30-day mortality. Results A total of 259 patients were included in the study. Thirty-day survival was 26%. Sixty-five (25%) survived to hospital discharge and a good neurological outcome (Glasgow–Pittsburgh Cerebral Performance Categories 1–2) was observed in 94% of these patients. Strict adherence to the national consensus showed a 30-day survival rate of 30% compared with 22% in patients violating one or more criteria. Adding criteria to the national consensus such as signs of life during cardiopulmonary resuscitation (CPR), pre-hospital low-flow < 100 min, pH > 6.8 and lactate < 15 mmol/L increased the survival rate to 48%, but would exclude 58% of the survivors from the current cohort. Logistic regression identified asystole (RR 1.36, 95% CI 1.18–1.57), pulseless electrical activity (RR 1.20, 95% CI 1.03–1.41), initial pH < 6.8 (RR 1.28, 95% CI 1.12–1.46) and lactate levels > 15 mmol/L (RR 1.16, 95% CI 1.16–1.53) as factors associated with increased risk of 30-day mortality. Patients presenting signs of life during CPR had reduced risk of 30-day mortality (RR 0.63, 95% CI 0.52–0.76). Conclusions A high survival rate with a good neurological outcome was observed in this Danish population of patients treated with MCS for OHCA. Stringent patient selection for MCS may produce higher survival rates but potentially withholds life-saving treatment in a significant proportion of survivors.

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Does Targeted Temperature Management Improve Neurological Outcome in Extracorporeal Cardiopulmonary Resuscitation (ECPR)?

Journal of Intensive Care Medicine ◽

10.1177/08850666211018982 ◽

2021 ◽

pp. 088506662110189

Author(s):

Merry Huang ◽

Aaron Shoskes ◽

Migdady Ibrahim ◽

Moein Amin ◽

Leen Hasan ◽

...

Keyword(s):

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Neurological Outcome ◽

Targeted Temperature Management ◽

Temperature Management ◽

Survival Outcomes ◽

Pool Data ◽

Good Neurological Outcome ◽

Extracorporeal Cardiopulmonary Resuscitation ◽

Over Time

Purpose: Targeted temperature management (TTM) is a standard of care in patients after cardiac arrest for neuroprotection. Currently, the effectiveness and efficacy of TTM after extracorporeal cardiopulmonary resuscitation (ECPR) is unknown. We aimed to compare neurological and survival outcomes between TTM vs non-TTM in patients undergoing ECPR for refractory cardiac arrest. Methods: We searched PubMed and 5 other databases for randomized controlled trials and observational studies reporting neurological outcomes or survival in adult patients undergoing ECPR with or without TTM. Good neurological outcome was defined as cerebral performance category <3. Two independent reviewers extracted the data. Random-effects meta-analyses were used to pool data. Results: We included 35 studies (n = 2,643) with the median age of 56 years (interquartile range [IQR]: 52-59). The median time from collapse to ECMO cannulation was 58 minutes (IQR: 49-82) and the median ECMO duration was 3 days (IQR: 2.0-4.1). Of 2,643, 1,329 (50.3%) patients received TTM and 1,314 (49.7%) did not. There was no difference in the frequency of good neurological outcome at any time between TTM (29%, 95% confidence interval [CI]: 23%-36%) vs. without TTM (19%, 95% CI: 9%-31%) in patients with ECPR ( P = 0.09). Similarly, there was no difference in overall survival between patients with TTM (30%, 95% CI: 22%-39%) vs. without TTM (24%, 95% CI: 14%-34%) ( P = 0.31). A cumulative meta-analysis by publication year showed improved neurological and survival outcomes over time. Conclusions: Among ECPR patients, survival and neurological outcome were not different between those with TTM vs. without TTM. Our study suggests that neurological and survival outcome are improving over time as ECPR therapy is more widely used. Our results were limited by the heterogeneity of included studies and further research with granular temperature data is necessary to assess the benefit and risk of TTM in ECPR population.

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Echocardiographic parameters during prolonged targeted temperature Management in out-of-hospital Cardiac Arrest Survivors to predict neurological outcome – a post-hoc analysis of the TTH48 trial

Scandinavian Journal of Trauma Resuscitation and Emergency Medicine ◽

10.1186/s13049-021-00849-7 ◽

2021 ◽

Vol 29 (1) ◽

Author(s):

Thomas Hvid Jensen ◽

Peter Juhl-Olsen ◽

Bent Roni Ranghøj Nielsen ◽

Johan Heiberg ◽

Christophe Henri Valdemar Duez ◽

...

Keyword(s):

Cardiac Arrest ◽

Neurological Outcome ◽

Global Longitudinal Strain ◽

Left Ventricular ◽

Targeted Temperature Management ◽

Temperature Management ◽

Left Ventricular Ejection ◽

Secondary Outcome ◽

Ventricular Ejection Fraction ◽

Hospital Cardiac Arrest

Abstract Background Transthoracic echocardiographic (TTE) indices of myocardial function among survivors of out-of-hospital cardiac arrest (OHCA) have been related to neurological outcome; however, results are inconsistent. We hypothesized that changes in average peak systolic mitral annular velocity (s’) from 24 h (h) to 72 h following start of targeted temperature management (TTM) predict six-month neurological outcome in comatose OHCA survivors. Methods We investigated the association between peak systolic velocity of the mitral plane (s’) and six-month neurological outcome in a population of 99 patients from a randomised controlled trial comparing TTM at 33 ± 1 °C for 24 h (h) (n = 47) vs. 48 h (n = 52) following OHCA (TTH48-trial). TTE was conducted at 24 h, 48 h, and 72 h after reaching target temperature. The primary outcome was 180 days neurological outcome assessed by Cerebral Performance Category score (CPC180) and the primary TTE outcome measure was s’. Secondary outcome measures were left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), e’, E/e’ and tricuspid annular plane systolic excursion (TAPSE). Results Across all three scan time points s’ was not associated with neurological outcome (ORs: 24 h: 1.0 (95%CI: 0.7–1.4, p = 0.98), 48 h: 1.13 (95%CI: 0.9–1.4, p = 0.34), 72 h: 1.04 (95%CI: 0.8–1.4, p = 0.76)). LVEF, GLS, E/e’, and TAPSE recorded on serial TTEs following OHCA were neither associated with nor did they predict CPC180. Estimated median e’ at 48 h following TTM was 5.74 cm/s (95%CI: 5.27–6.22) in patients with good outcome (CPC180 1–2) vs. 4.95 cm/s (95%CI: 4.37–5.54) in patients with poor outcome (CPC180 3–5) (p = 0.04). Conclusions s’ assessed on serial TTEs in comatose survivors of OHCA treated with TTM was not associated with CPC180. Our findings suggest that serial TTEs in the early post-resuscitation phase during TTM do not aid the prognostication of neurological outcome following OHCA. Trial registration NCT02066753. Registered 14 February 2014 – Retrospectively registered,

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