Recent developments in the management of patients resuscitated from cardiac arrest

Cardiac arrest, stony heart, and cardiopulmonary resuscitation: An updated revisit

The post-resuscitation period is recognized as the main predictor of cardiopulmonary resuscitation (CPR) outcomes. The first description of post-resuscitation syndrome and stony heart was published over 50 years ago. Major manifestations may include but are not limited to, persistent precipitating pathology, systemic ischemia/reperfusion response, post-cardiac arrest brain injury, and finally, post-cardiac arrest myocardial dysfunction (PAMD) after successful resuscitation. Why do some patients initially survive successful resuscitation, and others do not? Also, why does the myocardium response vary after resuscitation? These questions have kept scientists busy for several decades since the first successful resuscitation was described. By modifying the conventional modalities of resuscitation together with new promising agents, rescuers will be able to salvage the jeopardized post-resuscitation myocardium and prevent its progression to a dismal, stony heart. Community awareness and staff education are crucial for shortening the resuscitation time and improving short- and long-term outcomes. Awareness of these components before and early after the restoration of circulation will enhance the resuscitation outcomes. This review extensively addresses the underlying pathophysiology, management, and outcomes of post-resuscitation syndrome. The pattern, management, and outcome of PAMD and post-cardiac arrest shock are different based on many factors, including in-hospital cardiac arrest vs out-of-hospital cardiac arrest (OHCA), witnessed vs unwitnessed cardiac arrest, the underlying cause of arrest, the duration, and protocol used for CPR. Although restoring spontaneous circulation is a vital sign, it should not be the end of the game or lone primary outcome; it calls for better understanding and aggressive multi-disciplinary interventions and care. The development of stony heart post-CPR and OHCA remain the main challenges in emergency and critical care medicine.

Methylene blue as an adjuvant during cardiopulmonary resuscitation: an experimental study in rats

INTRODUCTION

Methylene Blue (MB) has been shown to attenuate oxidative, inflammatory, myocardial, and neurological lesions during ischemia-reperfusion and has great potential during cardiac arrest. This study aimed to determine the effects of MB combined with epinephrine during cardiac arrest on myocardial and cerebral lesions.

METHOD

Thirty-eight male Wistar rats were randomly assigned to four groups: the sham group (SH, n = 5), and three groups subjected to cardiac arrest (n = 11/group) and treated with EPI 20 µg.kg-1 (EPI), EPI 20 µg.kg-1 + MB 2 mg.kg-1 (EPI + MB), or saline 0.9% 0.2 ml (CTL). Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes, and anoxia was maintained for 5 minutes. Cardiopulmonary Resuscitation (CPR) consisted of medications, ventilation, chest compressions, and defibrillation. After returning to spontaneous circulation, animals were observed for four hours. Blood gas, troponin, oxidative stress, histology, and TUNEL staining measurements were analyzed. Groups were compared using generalized estimating equations.

RESULTS

No differences in the Returning of Spontaneous Circulation (ROSC) rate were observed among the groups (EPI: 63%, EPI + MB: 45%, CTL: 40%, p = 0.672). The mean arterial pressure immediately after ROSC was higher in the EPI+MB group than in the CTRL group (CTL: 30.5 [5.8], EPI: 63 [25.5], EPI+MB: 123 [31] mmHg, p = 0.007). Serum troponin levels were high in the CTL group (CTL: 130.1 [333.8], EPI: 3.70 [36.0], EPI + MB: 43.7 [116.31] ng/mL, p < 0.05).

CONCLUSION

The coadministration of MB and epinephrine failed to yield enhancements in cardiac or brain lesions in a rodent model of cardiac arrest.

The Effect of Early Application of Synthetic Peptides 19-2.5 and 19-4LF to Improve Survival and Neurological Outcome in a Mouse Model of Cardiac Arrest and Resuscitation

The synthetic antimicrobial peptides (sAMPs) Pep19-2.5 and Pep19-4LF have been shown in vitro and in vivo to reduce the release of pro-inflammatory cytokines, leading to the suppression of inflammation and immunomodulation. We hypothesized that intervention with Pep19-2.5 and Pep19-4LF immediately after cardiac arrest and resuscitation (CA-CPR) might attenuate immediate systemic inflammation, survival, and long-term outcomes in a standardized mouse model of CA-CPR. Long-term outcomes up to 28 days were assessed between a control group (saline) and two peptide intervention groups. Primarily, survival as well as neurological and cognitive parameters were assessed. In addition, systemic inflammatory molecules and specific biomarkers were analyzed in plasma as well as in brain tissue. Treatment with sAMPs did not provide any short- or long-term benefits for either survival or neurological outcomes, and no significant benefit on inflammation in the CA-CPR animal model. While no difference was found in the plasma analysis of early cytokines between the intervention groups four hours after resuscitation, a significant increase in UCH-L1, a biomarker of neuronal damage and blood–brain barrier rupture, was measured in the Pep19-4LF-treated group. The theoretical benefit of both sAMPs tested here for the treatment of post-cardiac arrest syndrome could not be proven.

Managing the first 120 min of cardiogenic shock: from resuscitation to diagnosis

PURPOSE OF REVIEW

Cardiogenic shock continues to carry a high mortality, and recent randomized trials have not identified novel therapies that improve survival. Early optimization of patients with confirmed or suspected cardiogenic shock is crucial, as patients can quickly transition from a hemodynamic shock state to a treatment-resistant hemometabolic shock state, where accumulated metabolic derangements trigger a self-perpetuating cycle of worsening shock.

RECENT FINDINGS

We describe a structured ABCDE approach involving stabilization of the airway, breathing and circulation, followed by damage control and etiologic assessment. Respiratory failure is common and many cardiogenic shock patients require invasive mechanical ventilation. Norepinephrine is titrated to restore mean arterial pressure and dobutamine is titrated to restore cardiac output and organ perfusion. Echocardiography is essential to identify potential causes and characterize the phenotype of cardiogenic shock. Coronary angiography is usually indicated, particularly when acute myocardial ischemia is suspected, followed by culprit-vessel revascularization if indicated. An invasive hemodynamic assessment can clarify whether temporary mechanical circulatory support is necessary.

SUMMARY

Early stabilization of hemodynamics and end-organ function is necessary to achieve best outcomes in cardiogenic shock. Using a structured approach tailored to initial cardiogenic shock resuscitation may help to demonstrate benefit from novel therapies in the future.

Use of Post-Acute Care Services and Readmissions After Acute Myocardial Infarction Complicated by Cardiac Arrest and Cardiogenic Shock

OBJECTIVE

To evaluate post-acute care utilization and readmissions after cardiac arrest (CA) and cardiogenic shock (CS) complicating acute myocardial infarction (AMI).

METHODS

With use of an administrative claims database, AMI patients from January 1, 2010, to May 31, 2018, were stratified into CA+CS, CA only, CS only, and AMI alone. Outcomes included 90-day post-acute care (inpatient rehabilitation or skilled nursing facility) utilization and 1-year emergency department visits and readmissions.

RESULTS

Of 163,071 AMI patients, CA+CS, CA only, and CS only were noted in 3965 (2.4%), 8221 (5.0%), and 6559 (4.0%), respectively. In-hospital mortality was noted in 10,686 (6.6%) patients: CA+CS, 1935 (48.8%); CA only, 2948 (35.9%); CS only, 1578 (24.1%); and AMI alone, 4225 (2.9%) (P<.001). Among survivors, post-acute care services were used in 67,799 (44.5%), with higher use in the CS+CA cohort (1310 [64.6%]; hazard ratio [HR], 1.19; 95% CI, 1.06 to 1.33; P=.003) and CA cohort (2738 [51.9%]; HR, 1.27; 95% CI, 1.20 to 1.35; P<.001) but not in the CS cohort (3048 [61.2%]; HR, 1.03; 95% CI, 0.97 to 1.11; P=.35) compared with the AMI cohort (60,703 [43.3%]). Compared with the AMI cohort (48,990 [35.0%]), patients with CS only (2,085 [41.9%]; HR, 1.16; 95% CI, 1.10 to 1.22; P<.001) but not those with CA+CS (724 [35.7%]; HR, 1.07; 95% CI, 0.98 to 1.17; P=.14) had higher rates of readmissions (P=.03). Readmissions were lower in those with CA (1,590 [30.2%]; HR, 0.94; 95% CI, 0.89 to 0.99). Repeated AMI, coronary artery disease, and heart failure were the most common readmission reasons. There were no differences for emergency department visits.

CONCLUSION

CA is associated with increased post-acute care use, whereas CS is associated with increased readmission risk in AMI survivors.

Trends in Therapy and Outcomes Associated With Respiratory Failure in Patients Admitted to the Cardiac Intensive Care Unit

PURPOSE

To describe the epidemiology, outcomes, and temporal trends of respiratory failure in the cardiac intensive care unit (CICU).

MATERIALS AND METHODS

Retrospective cohort analysis of 2,986 unique Mayo Clinic CICU patients from 2007 to 2018 with respiratory failure. Temporal trends were analyzed, along with hospital and 1-year mortality. Multivariable logistic regression was used to determine adjusted hospital mortality trends.

RESULTS

The prevalence of respiratory failure in the CICU increased from 15% to 38% during the study period (P < 0.001 for trend). Among patients with respiratory failure, the utilization of invasive ventilation decreased and noninvasive ventilation modalities increased over time. Hospital mortality and 1-year mortality were 24% and 54%, respectively, with variation according to the type of respiratory support (highest among patients receiving invasive ventilation alone: 35% and 46%, respectively). Hospital mortality was highest among patients with concomitant cardiac arrest and/or shock (52% for patients with both). Hospital mortality decreased in the overall population from 35% to 25% (P < 0.001 for trend), but was unchanged among patients receiving positive-pressure ventilation.

CONCLUSIONS

The prevalence of respiratory failure in CICU more than doubled during the last decade. The use of noninvasive respiratory support increased, while overall mortality declined over time. Cardiac arrest and shock accounted for the majority of deaths. Further research is needed to optimize the outcomes of high-risk CICU patients with respiratory failure.

Management of ST-Elevation Myocardial Infarction in High-Risk Settings

Despite the widespread adoption of primary percutaneous intervention and modern antithrombotic therapy, ST-segment elevation myocardial infarction (STEMI) remains the leading cause of death in the United States and remains one of the most important causes of morbidity and mortality worldwide. Certain high-risk patients present a challenge for diagnosis and treatment. The widespread adoption of primary percutaneous intervention in addition to modern antithrombotic therapy has resulted in substantial improvement in the short- and long-term prognosis following STEMI. In this review, we aim to provide a brief analysis of the state-of-the-art treatment for patients presenting with STEMI, focusing on cardiogenic shock, current treatment and controversies, cardiac arrest, and diagnosis and treatment of mechanical complications, as well as multivessel and left main-related STEMI.

Comprehensive Cardiac Care After Cardiac Arrest

Cardiac arrest (CA) results in multiorgan ischemia until return of spontaneous circulation and often is followed by a low-flow shock state. Upon restoration of circulation and organ perfusion, resuscitative teams must act quickly to achieve clinical stability while simultaneously addressing the underlying etiology of the initial event. Optimal cardiovascular care demands focused management of the post-cardiac arrest syndrome and associated shock. Acute coronary syndrome should be considered and managed in a timely manner, because early revascularization improves patient outcomes and may suppress refractory arrhythmias. This review outlines the diagnostic and therapeutic considerations that define optimal cardiovascular care after CA.

Utility and Challenges of an Early Invasive Strategy in Patients Resuscitated From Out-of-Hospital Cardiac Arrest

Out-of-hospital cardiac arrest (OHCA) is frequently triggered by acute myocardial ischemia. Coronary angiography is an important component of post-resuscitation care for patients with OHCA without an evident noncardiac cause, to identify underlying coronary artery disease and allow revascularization. Most patients undergoing coronary angiography after OHCA have obstructive coronary artery disease, and nearly one-half of patients have acute coronary occlusion. Early coronary angiography and percutaneous coronary intervention after OHCA have been associated with improved survival in observational studies, but these studies demonstrate selection bias, and randomized trials are lacking. Selection of patients for coronary angiography after OHCA can be challenging, particularly in comatose patients whose outcomes are driven primarily by anoxic brain injury. As for other patients with acute coronary syndromes, patients with ST-segment elevation after OHCA have a high probability of acute coronary occlusion warranting emergent coronary angiography. Patients with cardiogenic shock after OHCA are a high-risk population also requiring emergent coronary angiography. Among patients in stable condition after OHCA without ST-segment elevation, other clinical predictors can be used to identify those needing early coronary angiography to identify obstructive coronary artery disease. Despite the challenges with early neurological prognostication in comatose patients with OHCA, those with multiple objective markers of poor prognosis appear less likely to benefit from revascularization, and early coronary angiography may be reasonably deferred in appropriately selected patients meeting these criteria. The authors propose an algorithm to guide patient selection for coronary angiography after OHCA that combines clinical predictors of acute coronary occlusion and early clinical predictors of severe brain injury.

A service evaluation of transport destination and outcome of patients with post-ROSC STEMI in an English ambulance service

Background

In the UK, there are approximately 60,000 cases of out-of-hospital cardiac arrest (OHCA) each year. There is mounting evidence that post-resuscitation care should include early angiography and primary percutaneous coronary intervention (pPCI) in cases of OHCA where a cardiac cause is suspected. Yorkshire Ambulance Service (YAS) staff can transport patients with a return of spontaneous circulation (ROSC) directly to a pPCI unit if their post-ROSC ECG shows evidence of ST elevation myocardial infarction (STEMI). This service evaluation aimed to determine the factors that affect the transport destination, hospital characteristics and 30-day survival rates of post-ROSC patients with presumed cardiac aetiology.

Methods

All patient care records (PCRs) previously identified for the AIRWAYS-2 trial between January and July 2017 were reviewed. Patients were eligible for inclusion if they were an adult non-traumatic OHCA, achieved ROSC on scene and were treated and transported by (YAS). Descriptive statistics were used to analyse the data.

Results

478 patients met the inclusion criteria. 361/478 (75.6%) patients had a post-ROSC ECG recorded, with 149/361 (41.3%) documented cases of STEMI and 88/149 (59.1%) referred to a pPCI unit by the attending clinicians. 40/88 (45.5%) of referrals made were accepted by the pPCI units. Patients taken directly to pPCI were most likely to survive to 30 days (25/39, 53.8%), compared to patients taken to an emergency department (ED) at a pPCI-capable hospital (34/126, 27.0%), or an ED at a non-pPCI-capable hospital (50/310, 16.1%).

Conclusion

Staff should be encouraged to record a 12-lead ECG on all post-ROSC patients, and make a referral to the regional pPCI-capable centre if there is evidence of a STEMI, or a cardiac cause is likely, since 30-day survival is highest for patients who are taken directly for pPCI. Ambulance services should continue to work with regional pPCI-capable centres to ensure that suitable patients are accepted to maximise potential for survival.

Influence of cardiac arrest and SCAI shock stage on cardiac intensive care unit mortality

BACKGROUND

Patients with concomitant cardiac arrest (CA) and shock are at increased risk of mortality, even when stratified according to shock severity. We sought to determine whether the presence of ventricular fibrillation (VF) modified the relationship between CA and mortality in cardiac intensive care unit (CICU) patients.

METHODS

We retrospectively analyzed unique Mayo Clinic CICU patients admitted between 2007 and 2015. Society for Cardiovascular Angiography and Intervention (SCAI) shock stages A through E were classified at admission. Hospital mortality in each SCAI shock stage was stratified by the presence of CA, VF CA, or non-VF CA.

RESULTS

We included 9,898 patients with a mean age of 68 years (38% females). CA was present in 12%, including 53% with VF CA and 47% with non-VF CA. Hospital mortality was higher in patients with CA compared to patients without CA (34% vs. 6%; adjusted odds ratio [OR] = 3.1, 95% CI [2.4, 4.0], p < .001), and patients with non-VF CA had higher hospital mortality than patients with VF CA (44% vs. 25%; adjusted OR = 2.1, 95% CI [1.4, 3.0], p < .001). After adjustment, patients with any CA or non-VF CA had higher hospital mortality at each SCAI stage, except stage E (all other p < .05), whereas patients with VF CA did not (all p > .1).

CONCLUSIONS

CA rhythm modifies the relationship between CA and mortality in CICU patients, when accounting for coma, shock, and organ failure. Outcome studies examining CA in patients with cardiogenic shock need to account for important differences such as CA rhythm.