Etiological diagnoses of out-of-hospital cardiac arrest survivors admitted to the intensive care unit: Insights from a French registry

High-sensitivity troponin T for detection of culprit lesions in patients with out-of-hospital cardiac arrest

BACKGROUND

Patients with an out-of-hospital cardiac arrest (OHCA) often undergo coronary angiography, although a culprit lesion is found in only 30%-40% of patients. The aim of this study was to investigate high-sensitivity troponin T (hsTnT) levels in post cardiac arrest patients with and without coronary culprit lesions; factors affecting hsTnT levels after return of spontaneous circulation (ROSC); and the diagnostic ability of hsTnT in identifying patients with culprit lesions. We hypothesized that peak hsTnT levels were higher during the initial 48 h after cardiac arrest in patients with a coronary culprit lesion.

METHODS

This was a retrospective observational study, which included patients admitted to the Intensive Care Unit after an OHCA and who received a coronary angiography. Peak values and dynamic changes in hsTnT were analyzed in relation to the presence of a culprit lesion at coronary angiography.

RESULTS

A total of 238 patients were studied, of whom 140 had a culprit lesion. HsTnT levels during the initial 48 h were higher in patients with culprit lesions, longer time to ROSC and an unwitnessed cardiac arrest. At 6 to 12 h after ROSC, a hsTnT cut-off level of 1690 ng/L had a sensitivity of 64% and specificity of 84% to identify a culprit lesion. In patients without ST-elevations, hsTnT measured between 6 and 12 h after ROSC had a specificity above 90%, with a sensitivity of 46%.

CONCLUSION

HsTnT levels after cardiac arrest are higher in patients with coronary culprit lesions. Presence of a culprit lesion, witnessed status and the duration of CPR are important factors affecting hsTnT levels. Repeated measurement of hsTnT within the first 12 h after admission improved diagnostic accuracy but the value of hsTnT as a predictor of culprit lesions early after OHCA is limited.

Increased survival for resuscitated Utstein-comparator group patients conveyed directly to cardiac arrest centres in a large rural and suburban population in England

AIM

The cohort of patients in which cardiac arrest centres (CAC) in rural and suburban populations confer the greatest survival benefit remains unclear. The aim of this study was to assess whether the transfer of resuscitated Utstein-comparator out-of-hospital cardiac arrest (OHCA) patients direct to a CAC was associated with improved survival to hospital discharge compared to patients conveyed to non-specialist centres.

METHODS

A consecutive sample of adult (≥18 years old) Utstein-comparator patients (witnessed collapse and initial shockable rhythm) were included from the East of England Ambulance Service NHS Trust Utstein resuscitation registry; 2018-2022. Logistic regression was used to compare survival to discharge in patients transported to CACs compared with patients transported to non-specialist centres.

RESULTS

During the study period, resuscitation was attempted in 18,276 OHCA patients. N = 2448 (13.4%) met the Utstein-comparator definition and 1151 patients were included in the final analysis; per protocol. Survival was greater for patients conveyed directly to a CAC (n = 768, 60.7%) compared to non-specialist centres (n = 383, 47.3%); adjusted OR 1.44 (95%CI 1.07-1.94),p = 0.017. Amongst the centres analysed in this study, there was significant inter-hospital variability in survival between CACs (p = 0.017). There was no association between patient volume and survival (p = 0.850).

CONCLUSION

Direct transport to a cardiac arrest centre was associated with a 44% increase in the odds of survival compared to conveyance to a non-specialist centre for resuscitated adult patients presenting with witnessed collapse and initial shockable OHCA rhythm.

Impact of time to revascularization on outcomes in patients after out-of-hospital cardiac arrest with STEMI

BACKGROUND

International guidelines recommend emergency coronary angiography in patients after out-of-hospital cardiac arrest (OHCA) with ST-segment elevation on 12‑lead electrocardiography. However, the association between time to revascularization and outcomes remains unknown. This study aimed to evaluate the association between time to revascularization and outcomes in patients with OHCA due to ST-segment-elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI).

METHODS

This multicenter, retrospective, nationwide observational study included patients aged ≥18 years with OHCA due to STEMI who underwent PCI between 2014 and 2020. The time of the first return of spontaneous circulation (ROSC) was defined as the time of first ROSC during resuscitation, regardless of the pre-hospital or in-hospital setting. The primary outcome was a 1-month favorable neurological outcome, defined as cerebral performance category 1 or 2. Multivariable logistic regression analysis was used to assess the association between the time to revascularization and favorable neurological outcomes.

RESULTS

A total of 547 patients were included in this analysis. The multivariable logistic regression analysis showed that a shorter time from the first ROSC to revascularization was associated with 1-month favorable neurological outcomes (63/86 [73.3%] in the time from the first ROSC to revascularization ≤60 min group versus 98/193 [50.8%] in the >120 min group; adjusted OR, 0.26; 95% CI, 0.11-0.56; P for trend, 0.015).

CONCLUSIONS

Shorter time to revascularization was significantly associated with 1-month favorable neurological outcomes in patients with OHCA due to STEMI who underwent PCI.

Etiology-Based Prognosis of Extracorporeal CPR Recipients After Out-of-Hospital Cardiac Arrest: A Retrospective Multicenter Cohort Study

BACKGROUND

A better understanding of the relative contributions of various factors to patient outcomes is essential for optimal patient selection for extracorporeal CPR (ECPR) therapy for patients with out-of-hospital cardiac arrest (OHCA). However, evidence on the prognostic comparison based on the etiologies of cardiac arrest is limited.

RESEARCH QUESTION

What is the etiology-based prognosis of patients undergoing ECPR for OHCA?

STUDY DESIGN AND METHODS

This retrospective multicenter registry study involved 36 institutions in Japan and included all adult patients with OHCA who underwent ECPR between January 2013 and December 2018. The primary etiology for OHCA was determined retrospectively from all hospital-based data at each institution. We performed a multivariable logistic regression model to determine the association between etiology of cardiac arrest and two outcomes: favorable neurologic outcome and survival at hospital discharge.

RESULTS

We identified 1,781 eligible patients, of whom 1,405 (78.9%) had cardiac arrest because of cardiac causes. Multivariable logistic regression analysis for favorable neurologic outcome showed that accidental hypothermia (adjusted OR, 5.12; 95% CI, 2.98-8.80; P < .001) was associated with a significantly higher rate of favorable neurologic outcome than cardiac causes. Multivariable logistic regression analysis for survival showed that accidental hypothermia (adjusted OR, 5.19; 95% CI, 3.15-8.56; P < .001) had significantly higher rates of survival than cardiac causes. Acute aortic dissection/aneurysm (adjusted OR, 0.07; 95% CI, 0.02-0.28; P < .001) and primary cerebral disorders (adjusted OR, 0.12; 95% CI, 0.03-0.50; P = .004) had significantly lower rates of survival than cardiac causes.

INTERPRETATION

In this retrospective multicenter cohort study, although most patients with OHCA underwent ECPR for cardiac causes, accidental hypothermia was associated with favorable neurologic outcome and survival; in contrast, acute aortic dissection/aneurysm and primary cerebral disorders were associated with nonsurvival compared with cardiac causes.

Idiopathic ventricular fibrillation: is it a case for genetic testing?

Idiopathic ventricular fibrillation (IVF) is a diagnosis of exclusion in sudden cardiac arrest (SCA) survivors. Although there are clear guidelines on the clinical work-up of SCA survivors, less than one in five patients receives a complete work-up. This increases the chances of erroneously labelling these patients as having IVF, while 10-20% of them have an inherited cardiac condition (ICC). Diagnoses of ICC increase over time due to (additional) deep phenotyping or as a result of spontaneous expression of ICC over time. As SCA survivors can also harbor (likely) pathogenic variants in cardiomyopathy-associated genes in the absence of a phenotype, or can have another ICC without a clear cardiac phenotype, the question arises as to whether genetic testing in this group should be routinely performed. Family history (mainly in the case of sudden death) can increase suspicion of an ICC in an SCA victim, but does not add great value when adults underwent a complete cardiological work-up. The diagnosis of ICC has treatment consequences not only for the patient but also for their family. Genetic diagnostic yield does not appear to increase with larger gene panels, but variants of unknown significance (VUS) do. Although VUS can be confusing, careful and critical segregation analysis in the family can be performed when discussed in a multidisciplinary team at a center of expertise with at least a cardiologist as well as a clinical and laboratory geneticist, thereby degrading or promoting VUS. When to introduce genetic testing in SCA survivors remains a matter of debate, but the combination of quick, deep phenotyping with additional genetic testing for the unidentifiable phenotypes, especially in the young, seems preferable.

Intra-aortic balloon pump in patients with extracorporeal cardiopulmonary resuscitation after cardiac arrest caused by acute coronary syndrome

BACKGROUND

This study evaluated the association between intra-aortic balloon pump (IABP) use in patients with out-of-hospital cardiac arrest (OHCA) caused by acute coronary syndrome (ACS) who received extracorporeal cardiopulmonary resuscitation (ECPR) and 30-day outcomes.

METHODS

This study was a secondary analysis of data from the SAVE-J II study, a retrospective, multicenter registry study involving 36 participating institutions in Japan. Patients with cardiac arrest caused by ACS who received ECPR were divided into two groups depending on whether or not they received IABP. The primary outcome was 30-day survival. Subgroup analysis was performed to detect what type of patients were mostly associated with improved outcomes.

RESULTS

Of 2,157 patients registered in the SAVE-J II study, 877 patients were enrolled in this study, 702 patients in the IABP group and 175 patients in the non-IABP group. Multivariable logistic regression analysis did not reveal a significant difference in 30-day survival (OR 1.37, 95% CI 0.91-2.07, p = 0.13). In the subgroup analysis, 30-day survival among patients without percutaneous coronary intervention (PCI) and stenosis of multiple coronary vessels were associated with IABP use.

CONCLUSIONS

IABP use in patients with OHCA with ACS who received ECPR is not associated with 30-day survival. The use of IABP in patients who did not have PCI and have multiple coronary vessel stenoses warrants further study.

Prolonged follow-up after apparently unexplained sudden cardiac arrest: A retrospective study

BACKGROUND

We hypothesized that a prolonged follow-up of survivors of unexplained sudden cardiac arrest (USCA) would subsequently unmask electrical heart disorders in a significant proportion of cases.

PATIENTS AND METHODS

We retrospectively analyzed all out-of-hospital cardiac arrest (OHCA) admitted alive in our cardiac arrest center over 20-years (2002-2022). The diagnosis of USCA was made when no etiology was found after thorough initial hospital investigations. We identified all the new diagnoses established during follow-up, and compared outcomes according to underlying heart diseases.

RESULTS

Out of the 2482 OHCA patients, 68 (2.7%) were initially classified as USCA and 30 (1.2%) with electrical heart disorders. Compared to other cardiac etiologies of OHCA, both USCA and electrical heart disorders patients were younger (mean age 48.5 and 43.5 year-old respectively, versus 62.5 year-old; p < 0.0001), with a higher rate of family history of SCA (17.6 and 23.3% respectively versus 9.2%; p = 0.003). Six patients in each group were lost to follow-up at discharge (6/68, 8.8% in the USCA group, 6/30 20% in the electrical heart disorders group). During a mean follow-up of 8.1 ± 6.3 years, a diagnosis was eventually established in 24.3% of USCA patients (9/35), most of them as electrical heart disorders (55.6%, 5/9). No post-discharge death occurred in both USCA and electrical heart disorders groups, with approximately 10% of appropriate therapy delivered by the implantable cardioverter defibrillator.

CONCLUSION

Our findings emphasized that approximately a quarter of patients who had been initially considered as having apparently USCA after index hospital stay actually reveal heart conditions, especially electrical heart disorders.

Long-term heart function in cardiac-arrest survivors

Purpose

To assess outcomes and predictors of long-term myocardial dysfunction after cardiac arrest (CA) of cardiac origin.

Methods

We retrospectively included consecutive, single-center, prospective-registry patients who survived to hospital discharge for adult out-of-hospital and in-hospital CA of cardiac origin in 2005-2019. The primary objective was to collect the 1-year New York Heart Association Functional Class (NYHA-FC) and major adverse cardiovascular events (MACE).

Results

Of 135 patients, 94 (72%) had their NYHA-FC determined after 1 year, including 75 (75/94, 80%) who were I, 17 (17/94, 18%) II, 2 (2/94, 2%) III, and none IV. The echocardiographic left ventricular ejection fraction was abnormal in 87/130 (67%) patients on day 1, 52/123 (42%) at hospital discharge, and 17/52 (33%) at 6 months. During the median follow-up of 796 [283-1975] days, 38/119 (32%) patients experienced a MACE. These events were predominantly related to acute heart failure (13/38) or ischemic cardiovascular events (16/38), with acute coronary syndrome being the most prevalent among them (8/16). Pre-CA cardiovascular disease was a risk factor for 1-year NYHA-FC > I (P = 0.01), absence of bystander cardiopulmonary resuscitation was significantly associated with NYHA-FC > I at 1 year.

Conclusion

Most patients had no heart-failure symptoms a year after adult out-of hospital or in-hospital CA of cardiac origin, and absence of bystander cardiopulmonary resuscitation was the only treatment component significantly associated with NYHA-FC > I at 1 year. Nearly a third experienced MACE and the most common types of MACE were ischemic cardiovascular events and acute heart failure. Early left ventricular dysfunction recovered within 6 months in half the patients with available values.

Coronary Angiography After Out-of-Hospital Cardiac Arrest Without ST-Segment Elevation: One-Year Outcomes of a Randomized Clinical Trial

Importance

Myocardial infarction is a frequent cause of out-of-hospital cardiac arrest (OHCA). The long-term effect of early coronary angiography on patients with OHCA with possible coronary trigger but no ST-segment elevation remains unclear.

Objective

To compare the clinical outcomes of early unselective angiography with the clinical outcomes of a delayed or selective approach for successfully resuscitated patients with OHCA of presumed cardiac origin without ST-segment elevation at 1-year follow-up.

Design, Setting, and Participants

The TOMAHAWK trial was a multicenter, international (Germany and Denmark), investigator-initiated, open-label, randomized clinical trial enrolling 554 patients between November 23, 2016, to September 20, 2019. Patients with stable return of spontaneous circulation after OHCA of presumed cardiac origin but without ST-segment elevation on the postresuscitation electrocardiogram were eligible for inclusion. A total of 554 patients were randomized to either immediate coronary angiography after hospital admission or an initial intensive care assessment with delayed or selective angiography after a minimum of 24 hours. All 554 patients were included in survival analyses during the follow-up period of 1 year. Secondary clinical outcomes were assessed only for participants alive at 1 year to account for the competing risk of death.

Interventions

Early vs delayed or selective coronary angiography and revascularization if indicated.

Main Outcomes and Measures

Evaluations in this secondary analysis included all-cause mortality after 1 year, as well as severe neurologic deficit, myocardial infarction, and rehospitalization for congestive heart failure in survivors at 1 year.

Results

A total of 281 patients were randomized to the immediate angiography group and 273 to the delayed or selective group, with a median age of 70 years (IQR, 60-78 years). A total of 369 of 530 patients (69.6%) were male, and 268 of 483 patients (55.5%) had a shockable arrest rhythm. At 1 year, all-cause mortality was 60.8% (161 of 265) in the immediate angiography group and 54.3% (144 of 265) in the delayed or selective angiography group without significant difference between the treatment strategies, trending toward an increase in mortality with immediate angiography (hazard ratio, 1.25; 95% CI, 0.99-1.57; P = .05). For patients surviving until 1 year, the rates of severe neurologic deficit, myocardial infarction, and rehospitalization for congestive heart failure were similar between the groups.

Conclusions and Relevance

This study found that a strategy of immediate coronary angiography does not provide clinical benefit compared with a delayed or selective invasive approach for patients 1 year after resuscitated OHCA of presumed coronary cause and without ST-segment elevation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02750462.

Intracoronary imaging in addition to coronary angiography for patients with out-of-hospital cardiac arrest: More information for better care?

About 70% of out-of-hospital cardiac arrests are related to an ischaemic heart disease in Western countries. Percutaneous coronary intervention has been shown to improve the prognosis of survivors when an unstable coronary lesion is identified as the potential cause of the cardiac arrest. Acute complete coronary occlusion is often demonstrated among patients with ST-segment elevation on electrocardiogram after the return of spontaneous circulation. In patients without ST-segment elevation, routine coronary angiography has been shown to be not superior to conservative management. However, an electrocardiogram-based decision to perform immediate coronary angiography could be insufficient to identify unstable coronary lesions, which are frequently associated with intermediate coronary stenosis. Intracoronary imaging can be helpful to detect plaque rupture or erosion and intracoronary thrombus, but could also lead to better stent implantation, and help to reduce the risk of stent thrombosis. In patients with coronary lesions without the instability characteristic, conservative management should be the default strategy, and a search for another cause of the cardiac arrest should be systematic. In the present review, we sought to describe the potential benefit of intracoronary imaging in patients with out-of-hospital cardiac arrest.

Scoping review of echocardiographic parameters associated with diagnosis and prognosis after resuscitated sudden cardiac arrest

AIM

Current international guidelines recommend early echocardiography after resuscitated sudden death despite limited data. Our aim was to analyze published data on early post-resuscitation echocardiography to identify cardiac causes of sudden death and prognostic implications.

METHODS

We reviewed MEDLINE, EMBASE, and CENTRAL databases to December 2021 for echocardiographic studies of adult patients after resuscitation from non-traumatic sudden death. Studies were included if echocardiography was performed <48 hours after resuscitation and reported (1) diagnostic accuracy to detect cardiac etiologies of sudden death or (2) prognostic outcomes. Diagnostic endpoints were associations of regional wall motion abnormalities (RWMA), ventricular function, and structural abnormalities with cardiac etiologies of arrest. Prognostic endpoints were associations of echocardiographic findings with survival to hospital discharge and favorable neurological outcome.

RESULTS

Of 2877 articles screened, 16 (0.6%) studies met inclusion criteria, comprising 2035 patients. Two of six studies formally reported diagnostic accuracy for echocardiography identifying cardiac etiology of arrest; RWMA (in 5 of 6 studies) were associated with presumed cardiac ischemia in 17-89% of cases. Among 12 prognostic studies, there was no association of reduced left ventricular ejection fraction with hospital survival (v10) or favorable neurologic status (n = 5). Echocardiographic high mitral E/e' ratio (n = 1) and right ventricular systolic dysfunction (n = 2) were associated with poor survival.

CONCLUSION

This scoping review highlights the limited data on early echocardiography in providing etiology of arrest and prognostic information after resuscitated sudden death. Further research is needed to refine the clinical application of early echocardiographic findings in post arrest care.

Early Versus Delayed Coronary Angiography After Out-of-Hospital Cardiac Arrest Without ST-Segment Elevation-A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The optimal timing of coronary angiography remains unclear following out-of-hospital cardiac arrest (OHCA) without ST elevation on electrocardiogram. The objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of early angiography versus delayed angiography following OHCA without ST elevation.

DATA SOURCES

The databases MEDLINE, PubMed EMBASE, and CINHAL, as well as unpublished sources from inception to March 9, 2022.

STUDY SELECTION

A systematic search was performed for randomized controlled trials of adult patients after OHCA without ST elevation who were randomized to early as compared to delayed angiography.

DATA EXTRACTION

Reviewers screened and abstracted data independently and in duplicate. The certainty of evidence was assessed for each outcome using the Grading Recommendations Assessment, Development and Evaluation approach. The protocol was preregistered (CRD 42021292228).

DATA SYNTHESIS

Six trials were included (n = 1,590 patients). Early angiography probably has no effect on mortality (relative risk [RR] 1.04; 95% CI 0.94-1.15; moderate certainty) and may have no effect on survival with good neurologic outcome (RR 0.97; 95% CI 0.87-1.07; low certainty) or ICU length of stay (LOS) (mean difference 0.41 days fewer; 95% CI -1.3 to 0.5 d; low certainty). Early angiography has an uncertain effect on adverse events.

CONCLUSIONS

In OHCA patients without ST elevation, early angiography probably has no effect on mortality and may have no effect on survival with good neurologic outcome and ICU LOS. Early angiography has an uncertain effect on adverse events.

Acute Coronary Occlusion in Patients With Non-ST-Segment Elevation Out-of-Hospital Cardiac Arrest

BACKGROUND

According to current guidelines, hemodynamic status should guide the decision between immediate and delayed coronary angiography (CAG) in out-of-hospital cardiac arrest (OHCA) patients without ST-segment elevation. A delayed strategy is advised in hemodynamically stable patients, and an immediate approach is recommended in unstable patients.

OBJECTIVES

This study sought to assess the frequency, predictors, and clinical impact of acute coronary occlusion in hemodynamically stable and unstable OHCA patients without ST-segment elevation.

METHODS

Consecutive unconscious OHCA patients without ST-segment elevation who were undergoing CAG at Bern University Hospital (Bern, Switzerland) between 2011 and 2019 were included. Frequency and predictors of acute coronary artery occlusions and their impact on all-cause and cardiovascular mortality at 1 year were assessed.

RESULTS

Among the 386 patients, 169 (43.8%) were hemodynamically stable. Acute coronary occlusions were found in 19.5% of stable and 24.0% of unstable OHCA patients (P = 0.407), and the presence of these occlusions was predicted by initial chest pain and shockable rhythm, but not by hemodynamic status. Acute coronary occlusion was associated with an increased risk of cardiovascular death (adjusted HR: 2.74; 95% CI: 1.22-6.15) but not of all-cause death (adjusted HR: 0.72; 95% CI: 0.44-1.18). Hemodynamic instability was not predictive of fatal outcomes.

CONCLUSIONS

Acute coronary artery occlusions were found in 1 in 5 OHCA patients without ST-segment elevation. The frequency of these occlusions did not differ between stable and unstable patients, and the occlusions were associated with a higher risk of cardiovascular death. In OHCA patients without ST-segment elevation, chest pain or shockable rhythm rather than hemodynamic status identifies patients with acute coronary occlusion.

Post-Cardiac Arrest: Mechanisms, Management, and Future Perspectives

Cardiac arrest is an important public health issue, with a survival rate of approximately 15 to 22%. A great proportion of these deaths occur after resuscitation due to post-cardiac arrest syndrome, which is characterized by the ischemia-reperfusion injury that affects the role body. Understanding physiopathology is mandatory to discover new treatment strategies and obtain better results. Besides improvements in cardiopulmonary resuscitation maneuvers, the great increase in survival rates observed in recent decades is due to new approaches to post-cardiac arrest care. In this review, we will discuss physiopathology, etiologies, and post-resuscitation care, emphasizing targeted temperature management, early coronary angiography, and rehabilitation.

Effect of calcium in patients with pulseless electrical activity and electrocardiographic characteristics potentially associated with hyperkalemia and ischemia-sub-study of the Calcium for Out-of-hospital Cardiac Arrest (COCA) trial

OBJECTIVE

The Calcium for Out-of-hospital Cardiac Arrest (COCA) trial was recently conducted and published. This pre-planned sub-study evaluated the effect of calcium in patients with pulseless electrical activity (PEA) including subgroup analyses based on electrocardiographic characteristics potentially associated with hyperkalemia and ischemia.

METHODS

Patients aged ≥ 18 years were included if they had a non-traumatic out-of-hospital cardiac arrest and received adrenaline. The trial drug consisted of calcium chloride (5 mmol) or saline placebo given after the first, and again after the second, dose of adrenaline for a maximum of two doses. This sub-study analyzed patients with PEA as their last known rhythm prior to receiving the trial drug. Outcomes were return of spontaneous circulation and survival at 30 days.

RESULTS

104 patients were analyzed. In the calcium group, 9 patients (20 %) achieved return of spontaneous circulation vs 23 patients (39 %) in the placebo group (risk ratio 0.51; 95 %CI 0.26, 1.00). Subgroup analyses based on electrocardiographic characteristics potentially associated with hyperkalemia and ischemia showed similar results. At 30 days, 1 patient (2.2 %) was alive in the calcium group while 8 patients (13.6 %) were alive in the placebo group (risk ratio 0.16; 95 %CI 0.02, 1.26).

CONCLUSION

In adults with out-of-hospital cardiac arrest presenting with PEA, effect estimates suggested harm of calcium administration as compared to placebo but with wide confidence intervals. Results were consistent for patients with electrocardiographic characteristics potentially associated with hyperkalemia and ischemia. The results do not support calcium administration based strictly on electrocardiographic findings seen during out-of-hospital cardiac arrest.

Early coronary angiography in patients after out-of-hospital cardiac arrest without ST-segment elevation: Meta-analysis of randomized controlled trials

OBJECTIVES

To compare early coronary angiography to a delayed or selective approach in out-of-hospital cardiac arrest (OHCA) without ST-segment elevation of possible cardiac cause by means of meta-analysis of available randomized controlled trials (RCTs).

METHODS

We searched MEDLINE and the Cochrane Central Register of Controlled Trials for RCTs comparing early with delayed or selective coronary angiography in OHCA patients of possible cardiac origin without ST-segment elevation. The primary endpoint was all-cause short-term mortality (PROSPERO CRD42021271484).

RESULTS

The search strategy identified three RCTs enrolling a total of 1167 patients. An early invasive approach was not associated with improved short-term mortality (odds ratio 1.19, 95% confidence interval 0.94-1.52; p = 0.15). Further, no significant differences were shown with respect to the risk of severe neurological deficit, the composite of all-cause mortality or severe neurological deficit, need for renal replacement therapy due to acute renal failure, and significant bleeding at short-term follow-up.

CONCLUSION

Early coronary angiography in OHCA without ST-segment elevation is not superior compared to a delayed/selective approach.

Cerebrospinal fluid features in comatose survivors of cardiac arrest: A pilot study

INTRODUCTION

Lumbar puncture is among the investigations used to identify various neurological conditions, including some that can cause cardiac arrest (CA). However, CA per se may alter cerebrospinal fluid (CSF) characteristics. Few studies have investigated CSF findings after CA. In this descriptive work, we assessed the frequency and risk factors of abnormal CSF findings after CA and the contribution of CSF analysis to the etiological diagnosis.

MATERIALS AND METHODS

We retrospectively studied data from prospectively established databases of consecutive patients who were admitted to two French ICUs in 2007-2016 with sustained return of spontaneous circulation (ROSC) after CA and who underwent lumbar puncture as an etiological investigation.

RESULTS

Of 1984 patients with sustained ROSC, 55 (2.7%) underwent lumbar puncture and were included. Lumbar puncture identified a neurological cause of CA in 2/55 (3.6%) patients. Nonspecific CSF abnormalities were noted in 37/53 (69.8%) patients. By multivariate analysis, postresuscitation shock was positively associated with CSF abnormalities (OR, 6.92; 95% confidence interval [95%CI], 1.62-37.26; P = 0.013). A no-flow time above 6 minutes (OR, 0.19; 95%CI, 0.03-1.11; P = 0.076) and a respiratory cause of CA (OR, 2.91; 95%CI, 0.53-23.15; P = 0.24) were not statistically associated with CSF abnormalities. Nonspecific CSF abnormalities were not significantly associated with poor outcomes (Cerebral Performance Category ≥3; P = 0.06).

CONCLUSIONS

Lumbar puncture, although infrequently performed, may contribute to the etiological diagnosis of CA, albeit rarely. Nonspecific CSF abnormalities seem common after CA, notably with postresuscitation shock, and may be related to blood-brain barrier disruption. These findings may help to interpret CSF findings after CA. Further studies are warranted to assess our results.

Coronary angiographic findings for out-of-hospital cardiac arrest survivors presenting with nonshockable rhythms and no ST elevation post resuscitation

BACKGROUND

Recent guidelines suggest that coronary angiography (CAG) should be considered for out-of-hospital cardiac arrest (OHCA) survivors, including those without ST elevation (STE) and without shockable rhythms. However, there is no prospective data to support CAG for survivors with nonshockable rhythms and no STE post resuscitation.

METHODS

This was a re-analysis of the PEARL study (randomized OHCA survivors without STE to early CAG versus not). Patients were subdivided by initial rhythm as nonshockable (Nsh) vs shockable (Sh). The primary outcome was coronary angiographic evidence of acute culprit lesion, with secondary outcomes being survival to hospital discharge and neurological recovery.

RESULTS

The PEARL study included 99 patients with OHCA from a presumed cardiac etiology, 24 with nonshockable and 75 with shockable rhythms. There was no difference in the frequency of CAG between the two groups [71% (Nsh) and 75% (Sh); p = 0.79], presence of CAD [81% (Nsh) and 68% (sh); p = 0.37, or culprit lesions identified in each group [50% (Nsh) and 45% (Sh); p = 0.78. Nonshockable patients had worse discharge survival [33% (Nsh) vs 57% (Sh); p = 0.04] and those survived, had worse neurological recovery [30% (Nsh) vs 54% (Sh); p = 0.02] compared to shockable patients.

CONCLUSIONS

OHCA survivors presenting with nonshockable rhythms and no STE post resuscitation had similar prevalence of culprit coronary lesions to those with shockable rhythms. CAG may be considered in patients with OHCA without STE regardless of initial presenting rhythm. There was no benefit of emergent CAG both in shockable and non-shockable rhythms.

Temporal trends of suicide-related non-traumatic out-of-hospital cardiac arrest characteristics and outcomes with the COVID-19 pandemic

Background

Jurisdictions have reported COVID-19-related increases in the incidence and mortality of non-traumatic out-of-hospital cardiac arrest (OHCA). We hypothesized that changes in suicide incidence during the COVID-19 pandemic may have contributed to these changes. We investigated whether the COVID-19 pandemic was associated with changes in the: (1) incidence of suicide-related OHCA, and (2) characteristics and outcomes of such cases.

Methods

We used the provincial British Columbia Cardiac Arrest Registry, including non-traumatic emergency medical system (EMS)-assessed OHCA, to compare suicide-related OHCA (defined as clear self-harm or a priori communication of intent) one-year prior to, and one year after, the start of the COVID-19 pandemic (March 15, 2020). We calculated differences in incidence (with 95% CI), overall and within subgroups of mechanism (hanging, suffocation, poisoning, or unclear mechanism), and in case characteristics and hospital-discharge favourable neurological outcomes (CPC 1–2).

Results

Of 13,785 EMS-assessed OHCA, we included 274/6430 (4.3%) pre-pandemic and 221/7355 (3.0%) pandemic-period suicide-related cases. The median age was 43 years (IQR 30–57), 157 (32%) were female, and 7 (1.4%) survived with favourable neurological status. Suicide-related OHCA incidence decreased from 5.4 pre-pandemic to 4.3 per 100 000 person-years (-1.1, 95% CI −2.0 to −0.28). Hanging-related OHCA incidence also decreased. Patient characteristics and hospital discharge outcomes between periods were similar.

Conclusion

Suicide-related OHCA incidence decreased with the COVID-19 pandemic and we did not detect changes in patient characteristics or outcomes, suggesting that suicide is not a contributor to increases in COVID-related OHCA incidence or mortality. Overall suicide-related OHCA outcomes in both time periods were poor.

Extracorporeal Membrane Oxygenation in Infarct-Related Cardiogenic Shock

Mortality in infarct-related cardiogenic shock (CS) remains high, reaching 40–50%. In refractory CS, active mechanical circulatory support devices including veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are rapidly evolving. However, supporting evidence of VA-ECMO therapy in infarct-related CS is low. The current review aims to give an overview on the basics of VA-ECMO therapy, current evidence, ongoing trials, patient selection and potential complications.

Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation

BACKGROUND

Myocardial infarction is a frequent cause of out-of-hospital cardiac arrest. However, the benefits of early coronary angiography and revascularization in resuscitated patients without electrocardiographic evidence of ST-segment elevation are unclear.

METHODS

In this multicenter trial, we randomly assigned 554 patients with successfully resuscitated out-of-hospital cardiac arrest of possible coronary origin to undergo either immediate coronary angiography (immediate-angiography group) or initial intensive care assessment with delayed or selective angiography (delayed-angiography group). All the patients had no evidence of ST-segment elevation on postresuscitation electrocardiography. The primary end point was death from any cause at 30 days. Secondary end points included a composite of death from any cause or severe neurologic deficit at 30 days.

RESULTS

A total of 530 of 554 patients (95.7%) were included in the primary analysis. At 30 days, 143 of 265 patients (54.0%) in the immediate-angiography group and 122 of 265 patients (46.0%) in the delayed-angiography group had died (hazard ratio, 1.28; 95% confidence interval [CI], 1.00 to 1.63; P = 0.06). The composite of death or severe neurologic deficit occurred more frequently in the immediate-angiography group (in 164 of 255 patients [64.3%]) than in the delayed-angiography group (in 138 of 248 patients [55.6%]), for a relative risk of 1.16 (95% CI, 1.00 to 1.34). Values for peak troponin release and for the incidence of moderate or severe bleeding, stroke, and renal-replacement therapy were similar in the two groups.

CONCLUSIONS

Among patients with resuscitated out-of-hospital cardiac arrest without ST-segment elevation, a strategy of performing immediate angiography provided no benefit over a delayed or selective strategy with respect to the 30-day risk of death from any cause. (Funded by the German Center for Cardiovascular Research; TOMAHAWK ClinicalTrials.gov number, NCT02750462.).

Aetiology of resuscitated out-of-hospital cardiac arrest treated at hospital

INTRODUCTION

Precipitating aetiology of out-of-hospital cardiac arrest (OHCA), as confirmed by diagnostic testing or autopsy, provides important insights into burden of OHCA and has potential implications for improving OHCA survivorship. This study aimed to describe the aetiology of non-traumatic resuscitated OHCAs treated at hospital within a local health network according to available documentation, and to investigate differences in outcome between aetiologies.

METHODS

Observational retrospective cohort study of consecutive OHCA treated at hospital within a local health network between 2011-2016. Cases without sustained ROSC (≥20 minutes), unverified cardiac arrest, and retrievals to external acute care facilities were excluded. A single aetiology was determined from the hospital medical record and available autopsy results. Survival to hospital discharge was compared between adjudicated aetiologies.

RESULTS

In the 314 included cases, distribution of precipitating aetiology was 53% cardiac, 18% respiratory, 3% neurological, 6% toxicological, 9% other, and 11% unknown. A presumed cardiac pre-hospital diagnosis was assigned in 235 (84%) cases, 20% of which were incorrect after exclusion of unknown cases. Rates of survival to hospital discharge varied significantly across aetiologies: cardiac 64%, respiratory 21%, neurological 0%, toxicological 58%, other 32% (p < 0.001). A two-fold difference in survival was observed between cardiac and non-cardiac aetiologies (64% versus 29%, excluding unknown, p < 0.001).

CONCLUSIONS

Non-cardiac aetiologies represented a substantial burden of resuscitated OHCA treated at hospital within a local health network and were associated with poor outcome. The results confirmed that true aetiology was not evident on initial examination in 1 in 5 cases with a pre-hospital cardiac diagnosis.

Prediction of Brain Death After Out-of-Hospital Cardiac Arrest: Development and Validation of the Brain Death After Cardiac Arrest Score

BACKGROUND

Among patients successfully resuscitated after an out-of-hospital cardiac arrest (OHCA), 10% to 15% evolve toward brain death (BD), thus becoming potential organ donors.

RESEARCH QUESTION

Is it possible to establish a score for early estimation of BD risk after OHCA?

STUDY DESIGN AND METHODS

The BD after cardiac arrest (BDCA) score was developed from data available within 24 hours after OHCA from two OHCA trials: Cyclosporine in Cardiac Arrest Resuscitation and Erythropoietin After OHCA. The BDCA score was then validated in another large prospective multicenter data set. The main outcome was the occurrence of BD. Independent prognostic covariates for BD were identified using a binomial two-stage adaptive least absolute shrinkage and selection operator procedure.

RESULTS

The development cohort included 569 patients alive 24 hours after OHCA, among whom 84 (14.8%) experienced BD. Independent predictors of BD used to build the BDCA score were being female (4 points), nonshockable rhythm (24 points), cardiac cause of OHCA (-6 points), neurological cause of OHCA (45 points), natremia at 24 hours (natremia in millimoles per liter minus 140 points), and vasoactive drug at admission (4 points) and at 24 hours (6 points). The area under the curve (AUC) of the BDCA score was 0.82 (95% CI, 0.77-0.86), and the discrimination value in the validation cohort (n = 487) was consistent (AUC, 0.81; 95% CI, 0.76-0.86). In the validation cohort, BD occurred in 4.0%, 20.4%, and 67.7% of patients with scores of < 20, 20 to 50, and > 50, respectively.

INTERPRETATION

The BDCA score allows early detection of patients with a high probability of experiencing BD, which may help increase organ donation after OHCA.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01595958, and ClinicalTrials.gov; No.: NCT00999583; URL: www.clinicaltrials.gov.

Immediate postcardiac arrest treatment: coronary catherization or not?

PURPOSE OF REVIEW

Early coronary angiogram (CAG) remains a cornerstone in postcardiac arrest management as coronary disease (CAD)-related cardiac arrest is the leading cause of sudden death in adults. The opportunity to treat the cause early on with immediate CAG may improve outcome in cardiac arrest patients with AMI. Identifying the patients who will benefit from such an early invasive strategy is an unanswered question. Recent and ongoing trials may improve the level of evidence on this problematic, especially for some subgroup; however, current guidelines remain founded upon a very heterogeneous level of evidence.

RECENT FINDINGS

The key variable to argue for immediate CAD remains the pattern of the ECG monitored after return of spontaneous of circulation (ROSC). ST-segment elevation (STE) on postresuscitation ECG is the strongest argument to rule for an early CAG strategy. In other situations, identifying the best candidates for early CAG is very challenging. Different approaches including elements, such as circumstances of cardiac arrest and expected outcomes. may also drive the strategy.

SUMMARY

This review aims to provide an overview of these different discussion points. The indication for early CAG should rely on multiple factors and an individual approach.

European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation and organ donation.

European Resuscitation Council and European Society of Intensive Care Medicine Guidelines 2021: Post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation, and organ donation.

Cardiac Magnetic Resonance Imaging for Nonischemic Cardiac Disease in Out-of-Hospital Cardiac Arrest Survivors Treated with Targeted Temperature Management: A Multicenter Retrospective Analysis

(1) Background: Cardiac magnetic resonance (CMR) imaging is an emerging tool for investigating nonischemic cardiomyopathies and cardiac systemic disease. However, data on the cardiac arrest population are limited. This study aimed to evaluate the usefulness of CMR imaging in out-of-hospital cardiac arrest (OHCA) survivors treated with targeted temperature management (TTM). (2) Methods: We conducted the retrospective observational study using a multicenter registry of adult non-traumatic comatose OHCA survivors who underwent TTM between January 2010 and December 2019. Of the 949 patients, 389 with OHCA of non-cardiac cause, 145 with significant lesions in the coronary artery, 151 who died during TTM, 81 without further evaluation due to anticipated poor neurological outcome, and 51 whose etiology is underlying disease were excluded. In 36 of the 132 remaining patients, the etiologies included variant angina, long QT syndrome, and complete atrioventricular block in ancillary studies. Fifty-six patients were diagnosed idiopathic ventricular fibrillation without CMR. (3) Results: CMR imaging was performed in the remaining 40 patients with cardiac arrest of unknown cause. The median time from cardiac arrest to CMR imaging was 10.1 days. The CMR finding was normal in 23 patients, non-diagnostic in 12, and abnormal in 5, which suggested non-ischemic cardiomyopathy but did not support the final diagnosis. (4) Conclusions: CMR imaging may not be useful for identifying unknown causes of cardiac arrest in OHCA survivors treated with targeted temperature management without definitive diagnosis even after coronary angiography, echocardiography, and electrophysiology studies. However, further large-scale studies will be needed to confirm these findings.

A descriptive analysis of cross-sectional imaging findings in patients after non-traumatic sudden cardiac arrest

Introduction

Cross-sectional imaging is frequently obtained after sudden cardiac arrest (SCA) to determine the aetiology. Although imaging studies may reveal acute and/or chronic findings that may impact downstream medical management, lack of standardized guidelines results in significant practice variability. We aimed to perform a descriptive analysis and to report on radiographic findings after SCA.

Methods

This was a retrospective observational descriptive study that included all adult SCA patients who presented to our emergency department (ED) over a 6-year period, achieved sustained return of spontaneous circulation, and subsequently received cross-sectional imaging while in the ED. Each imaging study was reviewed and graded based on a predefined scale, and significant radiographic findings were tabulated.

Results

1573 patients were identified, and 452 patients remained after applying predefined exclusion criteria. A total of 298, 184, and 113 computed tomography (CT) studies were performed of the head, chest, and abdomen, respectively. For head, chest, and abdominal imaging, 13 (4.4%), 23 (12.5%), and 6 (5.3%) studies had radiographic findings that likely contributed to SCA, respectively. Altogether, 42 (7.1%) radiographic studies had findings that likely contributed to SCA. Eighty (13.4%) studies (head [n = 38, 12.8%], chest [n = 26, 14.1%], abdomen [n = 16, 14.2%]) resulted in a change of clinical care (e.g. specialty consultation or procedures).

Conclusion

Given the clinical uncertainty and relative instability during the post-SCA phase, cross-sectional imaging frequently reveals important acute and chronic diagnostic findings.

Post-resuscitation shock: recent advances in pathophysiology and treatment

A post-resuscitation shock occurs in 50–70% of patients who had a cardiac arrest. It is an early and transient complication of the post-resuscitation phase, which frequently leads to multiple-organ failure and high mortality. The pathophysiology of post-resuscitation shock is complex and results from the whole-body ischemia–reperfusion process provoked by the sequence of circulatory arrest, resuscitation manoeuvers and return of spontaneous circulation, combining a myocardial dysfunction and sepsis features, such as vasoplegia, hypovolemia and endothelial dysfunction. Similarly to septic shock, the hemodynamic management of post-resuscitation shock is based on an early and aggressive hemodynamic management, including fluid administration, vasopressors and/or inotropes. Norepinephrine should be considered as the first-line vasopressor in order to avoid arrhythmogenic effects of other catecholamines and dobutamine is the most established inotrope in this situation. Importantly, the optimal mean arterial pressure target during the post-resuscitation shock still remains unknown and may probably vary according to patients. Mechanical circulatory support by extracorporeal membrane oxygenation can be necessary in the most severe patients, when the neurological prognosis is assumed to be favourable. Other symptomatic treatments include protective lung ventilation with a target of normoxia and normocapnia and targeted temperature management by avoiding the lowest temperature targets. Early coronary angiogram and coronary reperfusion must be considered in ST-elevation myocardial infarction (STEMI) patients with preserved neurological prognosis although the timing of coronary angiogram in non-STEMI patients is still a matter of debate. Further clinical research is needed in order to explore new therapeutic opportunities regarding inflammatory, hormonal and vascular dysfunction.

Epidemiology of out-of-Hospital Cardiac Arrests, knowledge of cardiovascular disease and risk factors in a regional setting in India: The Warangal Area out-of-hospital Cardiac Arrest Registry (WACAR)

OBJECTIVE

Out-of-Hospital Cardiac Arrest (OHCA) is a global public health problem. There is inadequate data on OHCA in India. The Warangal Area out-of-hospital Cardiac Arrest Registry (WACAR) was planned to understand OHCA in a regional setting in India.

METHODS

WACAR is a prospective one-year observational cohort study of OHCA in the Warangal area, Telangana, India. The study included 814 subjects of OHCA of presumed cardiac etiology brought to the Mahatma Gandhi Memorial Hospital during January 1, 2018, and December 31, 2018. The data collected included; standard Utstein variables with additional data on clinical characteristics (modified Utstein template).

RESULTS

The majority of OHCA subjects were male with a median age of 60 years, and mostly occurring in residential locations within 1 h of onset of symptoms. Individuals with knowledge of CVD risk factors were more likely to report symptoms before OHCA. Data on resuscitation characteristics were inadequate.

CONCLUSIONS

The WACAR study provides baseline data regarding OHCA in a regional setting in India. The study demonstrated barriers involving data collection, patient knowledge of CVD risk factors and disease, and access to healthcare, which; impacted the data registry.

[Postcardiac arrest treatment guide]

BACKGROUND

Treatment after cardiac arrest has become more complex and interdisciplinary over the last few years. Thus, the clinically active intensive and emergency care physician not only has to carry out the immediate care and acute diagnostics, but also has to prognosticate the neurological outcome.

AIM

The different, most important steps are presented by leading experts in the area, taking into account the interdisciplinarity and the currently valid guidelines.

MATERIALS AND METHODS

Attention was paid to a concise, practice-oriented presentation.

RESULTS AND DISCUSSION

The practical guide contains all important steps from the acute care to the neurological prognosis generation that are relevant for the clinically active intensive care physician.

Immediate unselected coronary angiography versus delayed triage in survivors of out-of-hospital cardiac arrest without ST-segment elevation: Design and rationale of the TOMAHAWK trial

Patients experiencing out-of-hospital cardiac arrest (OHCA) without ST-segment elevation are a heterogenic group with a variety of underlying causes. Up to one-third of patients display a significant coronary lesion compatible with myocardial infarction as OHCA trigger. There are no randomized data on patient selection and timing of invasive coronary angiography after admission. METHODS AND RESULTS: The TOMAHAWK trial randomly assigns 558 patients with return of spontaneous circulation after OHCA with no obvious extracardiac origin of cardiac arrest and no ST-segment elevation/left bundle-branch block on postresuscitation electrocardiogram to either immediate coronary angiography or initial intensive care assessment with delayed/selective angiography in a 1:1 ratio. The primary end point is 30-day all-cause mortality. Secondary analyses will be performed with respect to initial rhythm, electrocardiographic patterns, myocardial infarction as underlying cause, neurological outcome, as well as clinical and laboratory markers. Clinical follow-up will be performed at 6 and 12 months. Safety end points include bleeding and stroke. CONCLUSION: The TOMAHAWK trial will address the unresolved issue of timing and general indication of angiography after OHCA without ST-segment elevation.

Role of genetic heart disease in sentinel sudden cardiac arrest survivors across the age spectrum

BACKGROUND

Sudden cardiac arrest (SCA) may be the sentinel expression of a sudden cardiac death-predisposing genetic heart disease (GHD). Although shown to underlie many unexplained SCAs in the young, the contribution of GHDs to sentinel SCA has never been quantified across the age spectrum. Thus, we sought to determine the contribution of GHDs in single-center referral cohort of non-ischemic SCA survivors.

METHODS AND RESULTS

Retrospective analysis of 3037 patients was used to identify all individuals who experienced a sentinel event of SCA. Following exclusion of patients with ischemic or complex congenital heart disease, cases were classified by clinical diagnoses. Overall, 180 (5.9%) referral patients experienced a sentinel SCA (average age at SCA 28 ± 15 years, 99 females). An etiology was identified in 113/180 patients (62.8%) including channelopathies in 26.7%, arrhythmogenic bileaflet mitral valve prolapse in 10.6%, cardiomyopathies in 9.4%, other etiologies in 6.7%, acquired long QT syndrome in 6.7%, and multiple disorders in 2.8%. The remaining 67/180 (37.2%) cases were classified as idiopathic ventricular fibrillation (IVF). Interestingly, the contribution of GHDs declined precipitously after the first decade of life [90.0% (age 0-9; n = 20), 58.7% (age 10-19; n = 46), 28.1% (age 20-29; n = 32), 23.8% (age 30-39; n = 42), 16.7% (age 40-49; n = 24), and 12.5% (age 50+; n = 16)].

CONCLUSIONS

Within a referral population enriched for GHDs, the ability of a comprehensive cardiac evaluation, including genetic testing, to elucidate a root cause in non-ischemic SCA survivors declined with age. Although rare, GHDs can underlie SCA into adulthood and merit consideration across the age spectrum.

Comparison of presumed cardiac and respiratory causes of out-of-hospital cardiac arrest

AIMS OF THE STUDY

Most interventional and observational studies include cardiac arrest from cardiac origin. However, an increasing proportion of cardiac arrest results from an extra-cardiac origin, mainly respiratory. The aim of our study was to compare the characteristics and outcome of cardiac arrest patients according to the presumed cardiac or respiratory causes.

METHODS

This retrospective multicenter observational study included out-of-hospital cardiac arrest patients from presumed cardiac and respiratory origin treated with therapeutic hypothermia. Demographic data (age, sex, initial rhythm as shockable or non-shockable, durations of no-flow and low-flow), clinical evolution in ICU, lactate and outcome (CPC scale at ICU discharge) were compared between patients according to the presumed cardiac or respiratory origin of the cardiac arrest.

RESULTS

Two hundred and fifty-one cardiac arrest patients were included, 156 from presumed cardiac origin (62%) and 95 from presumed respiratory origin (38%). Patients with presumed cardiac cause presented more frequently a shockable rhythm (68% vs. 5%, p < 0.001), received more defibrillations attempts (2 [1-5] vs. 0 [0-0], <0.001) and needed less adrenaline (3 mg [0-5] vs. 4 mg [2-7], p = 0.01). The arterial lactate concentration on admission was higher in patients with presumed respiratory causes (6.3 mmol/L [4.2-9.8] vs. 3.2 mmol/L [1.6-5.0], p < 0.001). The proportion of patients presenting a favorable outcome was higher in the population with presumed cardiac causes, compared to its respiratory counterpart (42% vs. 19%, p < 0.001).

CONCLUSIONS

Compared to presumed cardiac origin, a worse outcome and a different mode of death are associated with the presumed respiratory origin, resulting from a greater insult preceding cardiac arrest. The presumed cause of cardiac arrest could be integrated in the multimodal prognostication process.