Physiology-Guided Resuscitation: Monitoring and Augmenting Perfusion during Cardiopulmonary Arrest.

Given the high morbidity and mortality associated with cardiopulmonary arrest, there have been multiple trials aimed at better monitoring and augmenting coronary, cerebral, and systemic perfusion. This article aims to elucidate these interventions, first by detailing the physiology of cardiopulmonary resuscitation and the available tools for managing cardiopulmonary arrest, followed by an in-depth examination of the newest advances in the monitoring and delivery of advanced cardiac life support.

McConnell's sign predicts normotensive shock in patients with acute pulmonary embolism.

BACKGROUND: Patients with intermediate-risk pulmonary embolism (PE) and normotensive shock may have worse outcomes. However, diagnosis of normotensive shock requires invasive hemodynamics. Our objective was to assess the predictive value of McConnell's sign in identifying normotensive shock in patients with intermediate-risk PE. METHODS: Patients with intermediate-risk PE who underwent percutaneous mechanical thrombectomy between August 2020 and April 2023 at a large academic public hospital were included in the study. Normotensive shock was defined as systolic blood pressure ≥ 90 mmHg without vasopressor support with pre-procedural invasive measures of cardiac index ≤2.2 L/min/m2 and clinical evidence of hypoperfusion (i.e. elevated lactate, oliguria). The primary outcome was the association between McConnell's sign and normotensive shock. RESULTS: Those with McConnell's sign (29/40, 72.5 %) had higher heart rate (114 vs 99 beats/min, p = 0.008), higher rates of elevated lactate (86 % vs 55 %, p = 0.038), lower cardiac index (1.9 vs 3.1 L/min/m2, p = 0.003), and higher rates of normotensive shock (76 % vs 27 %, p = 0.005). McConnell's sign had a sensitivity of 88 % and specificity of 53 % for identifying intermediate-risk PE patients with normotensive shock. Patients with McConnell's sign had an increased odds (odds ratio 8.38, confidence interval: 1.73-40.53, p = 0.008; area under the curve 0.70, 95 % confidence interval: 0.56-0.85) of normotensive shock. CONCLUSION: This is the first study to suggest that McConnell's sign may identify those in the intermediate-risk group who are at risk for normotensive shock. Larger cohorts are needed to validate our findings.

Comparing Management Strategies in Patients With Clot-in-Transit.

BACKGROUND: Clot-in-transit is associated with high mortality, but optimal management strategies remain uncertain. The aim of this study was to compare the outcomes of different treatment strategies in patients with clot-in-transit. METHODS: This is a retrospective study of patients with documented clot-in-transit in the right heart on echocardiography across 2 institutions between January 2020 and October 2023. The primary outcome was a composite of in-hospital mortality, resuscitated cardiac arrest, or hemodynamic decompensation. RESULTS: Among 35 patients included in the study, 10 patients (28.6%) received anticoagulation alone and 2 patients (5.7%) received systemic thrombolysis, while 23 patients (65.7%) underwent catheter-based therapy (CBT; 22 mechanical thrombectomy and 1 catheter-directed thrombolysis). Over a median follow-up of 30 days, 9 patients (25.7%) experienced the primary composite outcome. Compared with anticoagulation alone, patients who received CBT or systemic thrombolysis had significantly lower rates of the primary composite outcome (12% versus 60%; log-rank P<0.001; hazard ratio, 0.13 [95% CI, 0.03-0.54]; P=0.005) including a lower rate of death (8% versus 50%; hazard ratio, 0.10 [95% CI, 0.02-0.55]; P=0.008), resuscitated cardiac arrest (4% versus 30%; hazard ratio, 0.12 [95% CI, 0.01-1.15]; P=0.067), or hemodynamic deterioration (4% versus 30%; hazard ratio, 0.12 [95% CI, 0.01-1.15]; P=0.067). CONCLUSIONS: In this study of CBT in patients with clot-in-transit, CBT or systemic thrombolysis was associated with a significantly lower rate of adverse clinical outcomes, including a lower rate of death compared with anticoagulation alone driven by the CBT group. CBT has the potential to improve outcomes. Further large-scale studies are needed to test these associations.

Percutaneous mechanical thrombectomy in acute pulmonary embolism: Outcomes from a safety-net hospital.

BACKGROUND: Our study aims to present clinical outcomes of mechanical thrombectomy (MT) in a safety-net hospital. METHODS: This is a retrospective study of intermediate or high-risk pulmonary embolism (PE) patients who underwent MT between October 2020 and May 2023. The primary outcome was 30-day mortality. RESULTS: Among 61 patients (mean age 57.6 years, 47% women, 57% Black) analyzed, 12 (19.7%) were classified as high-risk PE, and 49 (80.3%) were intermediate-risk PE. Of these patients, 62.3% had Medicaid or were uninsured, 50.8% lived in a high poverty zip code. The prevalence of normotensive shock in intermediate-risk PE patients was 62%. Immediate hemodynamic improvements included 7.4 mmHg mean drop in mean pulmonary artery pressure (-21.7%, p < 0.001) and 93% had normalization of their cardiac index postprocedure. Thirty-day mortality for the entire cohort was 5% (3 patients) and 0% when restricted to the intermediate-risk group. All 3 patients who died at 30 days presented with cardiac arrest. There were no differences in short-term mortality based on race, insurance type, citizenship status, or socioeconomic status. All-cause mortality at most recent follow up was 13.1% (mean follow up time of 13.4 ± 8.5 months). CONCLUSION: We extend the findings from prior studies that MT demonstrates a favorable safety profile with immediate improvement in hemodynamics and a low 30-day mortality in patients with acute PE, holding true even with relatively higher risk and more vulnerable population within a safety-net hospital.

Low left ventricular outflow tract velocity time integral predicts normotensive shock in patients with acute pulmonary embolism.

In this study, we found that a low LVOT VTI (<15 cm), a simple bedside point-of-care measurement, predicts normotensive shock in patients with acute intermediate-risk PE.

Need for a Cardiogenic Shock Team Collaborative-Promoting a Team-Based Model of Care to Improve Outcomes and Identify Best Practices.

Cardiogenic shock continues to carry a high mortality rate despite contemporary care, with no breakthrough therapies shown to improve survival over the past few decades. It is a time-sensitive condition that commonly results in cardiovascular complications and multisystem organ failure, necessitating multidisciplinary expertise. Managing patients with cardiogenic shock remains challenging even in well-resourced settings, and an important subgroup of patients may require cardiac replacement therapy. As a result, the idea of leveraging the collective cognitive and procedural proficiencies of multiple providers in a collaborative, team-based approach to care (the "shock team") has been advocated by professional societies and implemented at select high-volume clinical centers. A slowly maturing evidence base has suggested that cardiogenic shock teams may improve patient outcomes. Although several registries exist that are beginning to inform care, particularly around therapeutic strategies of pharmacologic and mechanical circulatory support, none of these are currently focused on the shock team approach, multispecialty partnership, education, or process improvement. We propose the creation of a Cardiogenic Shock Team Collaborative-akin to the successful Pulmonary Embolism Response Team Consortium-with a goal to promote sharing of care protocols, education of stakeholders, and discovery of how process and performance may influence patient outcomes, quality, resource consumption, and costs of care.

Relationship Between the Mixed Venous-to-Arterial Carbon Dioxide Gradient and Cardiac Index in Acute Pulmonary Embolism.

BACKGROUND: Among patients with acute pulmonary embolism (PE) undergoing mechanical thrombectomy, the cardiac index (CI) is frequently reduced even among those without clinically apparent shock. The purpose of this study was to describe the mixed venous-to-arterial carbon dioxide gradient (CO2 gap), a surrogate of perfusion adequacy, among patients with acute PE undergoing mechanical thrombectomy. METHODS: This was a single-center retrospective study of consecutive patients with PE undergoing mechanical thrombectomy and simultaneous pulmonary artery catheterization over a 3-year period. RESULTS: Of 107 patients, 97 had simultaneous mixed venous and arterial blood gas measurements available. The CO2 gap was elevated (>6 mmHg) in 51% of the cohort and in 49% of patients with intermediate-risk PE. A reduced CI (≤2.2 L/min/m2) was associated with an increased odds (OR = 7.9; 95% CI 3.49-18.1, p < 0.001) for an elevated CO2 gap. There was an inverse relationship between CI and CO2 gap. For every 1 L/min/m2 decrease in the CI, the CO2 gap increased by 1.3 mmHg (p = 0.001). Among patients with an elevated baseline CO2 gap >6 mmHg, thrombectomy improved CO2 gap, CI, and mixed venous oxygen saturation. When the CO2 gap was dichotomized above and below 6, there was no difference in in-hospital mortality (9% vs. 0%; p = 0.10, HR: 1.24; 95% CI: 0.97-1.60; P = 0.085). CONCLUSIONS: Among patients with acute PE undergoing mechanical thrombectomy, the CO2 gap is abnormal in nearly 50% of patients and inversely related to CI. Further studies should examine the relationship between markers of perfusion and outcomes in this population to refine risk stratification.

Catheter-based therapy for intermediate or high-risk pulmonary embolism is associated with lower in-hospital mortality in patients with cancer: Insights from the National Inpatient Sample.

BACKGROUND: Pulmonary embolism (PE) is a common complication among patients with cancer and is a significant contributor to morbidity and mortality. Catheter-based therapies (CBT), including catheter-directed thrombolysis (CDT) and mechanical thrombectomy, have been developed and are used in patients with intermediate or high-risk PE. However, there is a paucity of data on outcomes in patients with cancer as most clinical studies exclude this group of patients. AIMS: To characterize outcomes of patients with cancer admitted with intermediate or high-risk PE treated with CBT compared with no CBT. METHODS: Patients with an admission diagnosis of intermediate or high-risk PE and a history of cancer from October 2015 to December 2018 were identified using the National Inpatient Sample. Outcomes of interest were in-hospital death or cardiac arrest (CA) and major bleeding. Inverse probability treatment weighting (IPTW) was utilized to compare outcomes between patients treated with and without CBT. Variables that remained unbalanced after IPTW were adjusted using multivariable logistic regression. RESULTS: A total of 2084 unweighted admissions (10,420 weighted) for intermediate or high-risk PE and cancer were included, of which 136 (6.5%) were treated with CBT. After IPTW, CBT was associated with lower death or CA (aOR 0.54, 95% CI 0.46-0.64) but higher major bleeding (aOR 1.41, 95% CI 1.21-1.65). After stratifying by PE risk type, patients treated with CBT had lower risk of death or CA in both intermediate (aOR 0.52, 95% CI 0.36-0.75) and high-risk PE (aOR 0.48, 95% CI 0.33-0.53). However, patients with CBT were associated with increased risk of major bleeding in intermediate-risk PE (aOR 2.12, 95% CI 1.67-2.69) but not in those with high-risk PE (aOR 0.84, 95% CI 0.66-1.07). CONCLUSIONS: Among patients with cancer hospitalized with intermediate or high-risk PE, treatment with CBT was associated with lower risk of in-hospital death or CA but higher risk of bleeding. Prospective studies and inclusion of patients with cancer in randomized trials are warranted to confirm our findings.

Anti-factor Xa as the preferred assay to monitor heparin for the treatment of pulmonary embolism.

INTRODUCTION: The mainstay of acute pulmonary embolism (PE) treatment is anticoagulation. Timely anticoagulation correlates with decreased PE-associated mortality, but the ability to achieve a therapeutic activated partial thromboplastin time (aPTT) with unfractionated heparin (UFH) remains limited. Although some institutions have switched to a more accurate and reproducible test to assess for heparin's effectiveness, the anti-factor Xa (antiXa) assay, data correlating a timely therapeutic antiXa to PE-associated clinical outcomes remains scarce. We evaluated time to a therapeutic antiXa using intravenous heparin after PE response team (PERT) activation and assessed clinical outcomes including bleeding and recurrent thromboembolic events. METHODS: This was a retrospective cohort study at NYU Langone Health. All adult patients ≥18 years with a confirmed PE started on IV UFH with >2 antiXa levels were included. Patients were excluded if they received thrombolysis or alternative anticoagulation. The primary endpoint was the time to a therapeutic antiXa level of 0.3-0.7 units/mL. Secondary outcomes included recurrent thromboembolism, bleeding and PE-associated mortality within 3 months. RESULTS: A total of 330 patients with a PERT consult were identified with 192 patients included. The majority of PEs were classified as sub massive (64.6%) with 87% of patients receiving a bolus of 80 units/kg of UFH prior to starting an infusion at 18 units/kg/hour. The median time to the first therapeutic antiXa was 9.13 hours with 93% of the cohort sustaining therapeutic anticoagulation at 48 hours. Recurrent thromboembolism, bleeding and mortality occurred in 1%, 5% and 6.2%, respectively. Upon univariate analysis, a first antiXa <0.3 units/ml was associated with an increased risk of mortality [27.78% (5/18) vs 8.05% (14/174), p = 0.021]. CONCLUSION: We observed a low incidence of recurrent thromboembolism or PE-associated mortality utilizing an antiXa titrated UFH protocol. The use of an antiXa based heparin assay to guide heparin dosing and monitoring allows for timely and sustained therapeutic anticoagulation for treatment of PE.

The physiology of cardiac tamponade and implications for patient management.

Exceeding the limit of pericardial stretch, intrapericardial collections exert compression on the right heart and decrease preload. Compensatory mechanisms ensue to maintain hemodynamics in the face of a depressed stroke volume but are outstripped as disease progresses. When constrained within a pressurized pericardial space, the right and left ventricles exhibit differential filling mediated by changes in intrathoracic pressure. Invasive hemodynamics and echocardiographic findings inform on the physiologic effects. In this review, we describe tamponade physiology and implications for supportive care and effusion drainage.

Medical and Mechanical Circulatory Support of the Failing Right Ventricle.

PURPOSE OF REVIEW: To describe medical therapies and mechanical circulatory support devices used in the treatment of acute right ventricular failure. RECENT FINDINGS: Experts have proposed several algorithms providing a stepwise approach to medical optimization of acute right ventricular failure including tailored volume administration, ideal vasopressor selection to support coronary perfusion, inotropes to restore contractility, and pulmonary vasodilators to improve afterload. Studies have investigated various percutaneous and surgically implanted right ventricular assist devices in several clinical settings. The initial management of acute right ventricular failure is often guided by invasive hemodynamic data tracking parameters of circulatory function with the use of pharmacologic therapies. Percutaneous microaxial and centrifugal extracorporeal pumps bypass the failing RV and support circulatory function in severe cases of right ventricular failure.

The Latest in Resuscitation Research: Highlights From the 2022 American Heart Association's Resuscitation Science Symposium.

BACKGROUND: Every year the American Heart Association's Resuscitation Science Symposium (ReSS) brings together a community of international resuscitation science researchers focused on advancing cardiac arrest care. METHODS AND RESULTS: The American Heart Association's ReSS was held in Chicago, Illinois from November 4th to 6th, 2022. This annual narrative review summarizes ReSS programming, including awards, special sessions and scientific content organized by theme and plenary session. CONCLUSIONS: By exploring both the science of resuscitation and important related topics including survivorship, disparities, and community-focused programs, this meeting provided important resuscitation updates.

To PLEX or Not to PLEX for Amiodarone-Induced Thyrotoxicosis.

Amiodarone-induced thyrotoxicosis (AIT) carries significant cardiovascular morbidity. There are two types of AIT with treatment including antithyroid medications and corticosteroids and treatment of ventricular arrhythmias. Therapeutic plasma exchange (TPE) also known as "PLEX" may help remove thyroid hormones and amiodarone. We report a case of PLEX in an attempt to treat cardiogenic shock secondary to AIT. This case highlights the robust rapidly deleterious demise of AIT, specifically in patients with decompensated heart failure. The decision to PLEX or not to PLEX for AIT should be individualized, prior to definitive therapy.

Indigo® Aspiration System for thrombectomy in pulmonary embolism.

Anticoagulation is mainstay therapy for patients with acute pulmonary embolism while systemic thrombolysis is reserved for those with hemodynamic instability. Over the last decade, percutaneous interventional options have entered the landscape aimed to achieve rapid pharmacomechanical pulmonary artery recanalization. The Penumbra Indigo® Aspiration System (Penumbra Inc., CA, USA) is a US FDA-approved large-bore aspiration thrombectomy device for the treatment of pulmonary embolism. Recent data has demonstrated improved radiographic end points with low rates of major adverse events in cases of intermediate-risk pulmonary embolism. In this review article, we outline device technology, applications, evidence and future directions.

A pulmonary embolism, or a blood clot in the blood vessels of the lungs, can cause symptoms of chest pain and difficulty breathing. While blood thinners have been the main treatment for pulmonary embolism, procedures aimed to rapidly remove clots have become available as treatment options. In this article we review these procedural options for pulmonary embolism with a focus on the Indigo^® Aspiration System by Penumbra Inc. This device has shown that it works and is very safe compared with other similar devices. In the future, more studies need to be performed to compare how well this device works compared with blood thinners alone, and whether it can lower the chances of long-term symptoms of these clots such as chronic shortness of breath and heart failure.