Faculty Bibliography

BACKGROUND:The Shock Academic Research Consortium (SHARC) recently proposed pragmatic consensus definitions to standardize classification of cardiogenic shock (CS) in registries and clinical trials. We aimed to describe contemporary CS epidemiology using the SHARC definitions in a cardiac intensive care unit (CICU) population. METHODS:The Critical Care Cardiology Trials Network (CCCTN) is a multinational research network of advanced CICUs coordinated by the TIMI Study Group (Boston, MA). CS was defined as a cardiac disorder resulting in SBP<90mmHg for ≥30 minutes (or the need for vasopressors, inotropes, or mechanical circulatory support [MCS] to maintain SBP ≥90mmHg) with evidence of hypoperfusion. Primary etiologic categories included acute myocardial infarction-related CS (AMI-CS), heart failure-related CS (HF-CS), and non-myocardial (secondary) CS. Post-cardiotomy CS was not included. HF-CS was further subcategorized as de novo vs. acute-on-chronic HF-CS. Patients with both cardiogenic and non-cardiogenic components of shock were classified separately as mixed CS. RESULTS:Of 8,974 patients meeting shock criteria (2017-2023), 65% had isolated CS and 17% had mixed shock. Among patients with CS (n=5,869), 27% had AMI-CS (65% STEMI), 59% HF-CS (72% acute-on-chronic, 28% de novo), and 14% secondary CS. Patients with AMI-CS and de novo HF-CS were most likely to have had concomitant cardiac arrest (p<0.001). Patients with AMI-CS and mixed CS were most likely to present in more severe shock stages (SCAI D or E; p<0.001). Temporary MCS use was highest in AMI-CS (59%). In-hospital mortality was highest in mixed CS (48%), followed by AMI-CS (41%), similar in de novo HF-CS (31%) and secondary CS (31%), and lowest in acute-on-chronic HF-CS (25%; p<0.001). CONCLUSIONS:SHARC consensus definitions for CS classification can be pragmatically applied in contemporary registries and reveal discrete subpopulations of CS with distinct phenotypes and outcomes that may be relevant to clinical practice and future research.

BACKGROUND/UNASSIGNED:Sodium azide exposures are rare but can be lethal as the substance inhibits complex IV in the electron transport chain, blocking adenosine-triphosphate (ATP) synthesis. Sodium azide is mostly used as a propellant in vehicular airbags but is also used in laboratory, pharmacy, and industrial settings. No known antidote exists and its cardiotoxic effects are poorly described in the literature. CASE SUMMARY/UNASSIGNED:We describe the case of a 31-year-old patient with major depressive disorder presenting with altered mental status after ingestion of an unknown amount of sodium azide. Although initially chest pain free, she developed pleuritic chest pain 48 h after ingestion. This was accompanied by new diffuse ST elevations on the electrocardiogram and serum troponin elevations concerning for myopericarditis. Treatment was pursued with a 14-day course of colchicine resulting in complete symptom resolution within 4 days of treatment initiation. The patient's transthoracic echocardiogram was only notable for a preserved left ventricular ejection fraction (LVEF). DISCUSSION/UNASSIGNED:Cardiac toxicity after sodium azide ingestion usually occurs days after ingestion and has been previously described in the forms of heart failure with reduced ejection fraction complicated by cardiogenic shock. We describe the first case of sodium azide-induced myopericarditis with a preserved LVEF treated with colchicine. Colchicine is an established treatment for pericarditis, but its inhibition of endocytosis, an ATP-dependent cellular function, could be mechanistically relevant to this case.

BACKGROUND:Arterial hyperoxia (hyperoxemia), defined as a high arterial partial pressure of oxygen (PaO2), has been associated with adverse outcomes in critically ill populations, but has not been examined in the cardiac intensive care unit (CICU). We evaluated the association between exposure to hyperoxia on admission with in-hospital mortality in a mixed CICU cohort. METHODS:We included unique Mayo Clinic CICU patients admitted from 2007 to 2018 with admission PaO2 data (defined as the PaO2 value closest to CICU admission) and no hypoxia (PaO2 < 60mmHg). The admission PaO2 was evaluated as a continuous variable and categorized (60-100 mmHg, 101-150 mmHg, 151-200 mmHg, 201-300 mmHg, >300 mmHg). Logistic regression was used to evaluate predictors of in-hospital mortality before and after multivariable adjustment. RESULTS:We included 3,368 patients with a median age of 70.3 years; 70.3% received positive-pressure ventilation. The median PaO2 was 99 mmHg, with a distribution as follows: 60-100 mmHg, 51.9%; 101-150 mmHg, 28.6%; 151-200 mmHg, 10.6%; 201-300 mmHg, 6.4%; >300 mmHg, 2.5%. A J-shaped association between admission PaO2 and in-hospital mortality was observed, with a nadir around 100 mmHg. A higher PaO2 was associated with increased in-hospital mortality (adjusted OR 1.17 per 100 mmHg higher, 95% CI 1.01-1.34, p = 0.03). Patients with PaO2 >300 mmHg had higher in-hospital mortality versus PaO2 60-100 mmHg (adjusted OR 2.37, 95% CI 1.41-3.94, p < 0.001). CONCLUSIONS:Hyperoxia at the time of CICU admission is associated with higher in-hospital mortality, primarily in those with severely elevated PaO2 >300 mmHg.

BACKGROUND/UNASSIGNED:Cardiogenic shock (CS) is the leading cause of death among patients with acute myocardial infarction (AMI) and is managed with temporary mechanical circulatory support (tMCS) in advanced cases. Patients with cancer are at high risk of AMI and CS. However, outcomes of patients with cancer and AMI-CS managed with tMCS have not been rigorously studied. METHODS/UNASSIGNED:Adult patients with AMI-CS managed with tMCS from 2006 to 2018 with and without cancer were identified using the National Inpatient Sample. Propensity score matching (PSM) was performed for variables associated with cancer. Primary outcome was in-hospital death, and secondary outcomes were major bleeding and thrombotic complications. RESULTS/UNASSIGNED:< .001). After PSM, there was no difference in in-hospital death (odds ratio [OR], 1.00; 95% CI, 0.88-1.13) or thrombotic complications (OR, 1.10; 95% CI, 0.91-1.34) between patients with and without cancer. Patients with cancer had a higher risk of major bleeding (OR, 1.29; 95% CI, 1.15-1.46). CONCLUSIONS/UNASSIGNED:Among patients with AMI-CS managed with tMCS, cancer is becoming increasingly frequent and associated with increased risk of major bleeding, although there was no difference in in-hospital death. Further studies are needed to further characterize outcomes, and inclusion of patients with cancer in trials of tMCS is needed.

OBJECTIVES:The aim of this study was to compare the hemodynamic impact and clinical outcomes of saddle vs non-saddle pulmonary embolism (PE). METHODS:This was a retrospective analysis of clinical characteristics and outcomes among patients with saddle and non-saddle PE within a cohort referred for catheter-based thrombectomy (CBT) with invasive hemodynamic assessments. Patients who underwent CBT between August 2020 and January 2024 were included. The primary outcome was the proportion of patients with a low cardiac index (CI < 2.2 L/min/m²). Secondary outcomes included 30-day mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS. RESULTS:A total of 107 patients (84 intermediate risk, 23 high-risk; mean age 58 years, 47.6% female) were included in the study, with 44 patients having saddle PE and 63 having non-saddle PE. There were no significant differences in baseline demographics and clinical characteristics between saddle and non-saddle PE, including rates of high-risk PE (25% vs 16%, P = .24), rates of RV dysfunction, pulmonary artery systolic pressure (55 vs 53 mm Hg, P = .74), mean pulmonary artery pressure (34 mm Hg vs 33 mm Hg), low cardiac index (56% vs 51%, P = .64), rates of normotensive shock (27% vs 20%, P = .44), or Composite Pulmonary Embolism Shock scores (4.5 vs 4.7, P = .25). Additionally, 30-day mortality (6% vs 5%, P = .69), ICU LOS, and hospital LOS were similar between the groups. CONCLUSIONS:Among patients undergoing CBT, there were no significant differences in invasive hemodynamic parameters or clinical outcomes between those with saddle and non-saddle PE.

AIMS/OBJECTIVE:Among patients with acute pulmonary embolism (PE) undergoing mechanical thrombectomy, the cardiac index (CI) is frequently reduced even among those without a clinically apparent shock. The purpose of this study is 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 AND RESULTS/RESULTS:This was a single-centre retrospective study of consecutive patients with PE undergoing mechanical thrombectomy and simultaneous pulmonary artery catheterization over a 3-year period. 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 [odds ratio = 7.9; 95% confidence interval (CI) 3.49-18.1, P < 0.001] for an elevated CO2 gap. There was an inverse relationship between the CI and the 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 the CO2 gap, CI, and mixed venous oxygen saturation. When the CO2 gap was dichotomized above and below 6, there was no difference in the in-hospital mortality rate (9 vs. 0%; P = 0.10; hazard ratio: 1.24; 95% CI 0.97-1.60; P = 0.085). CONCLUSION/CONCLUSIONS:Among patients with acute PE undergoing mechanical thrombectomy, the CO2 gap is abnormal in nearly 50% of patients and inversely related to the CI. Further studies should examine the relationship between markers of perfusion and outcomes in this population to refine risk stratification.

This consensus statement emerges from collaborative efforts among leading figures in critical care cardiology throughout the United States, who met to share their collective expertise on issues faced by those active in or pursuing contemporary critical care cardiology education. The panel applied fundamentals of adult education and curriculum design, reviewed requisite training necessary to provide high-quality care to critically ill patients with cardiac pathology, and devoted attention to a purposeful approach emphasizing diversity, equity, and inclusion in developing this nascent field. The resulting paper offers a comprehensive guide for current trainees, with insights about the present landscape of critical care cardiology while highlighting issues that need to be addressed for continued advancement. By delineating future directions with careful consideration and intentionality, this Expert Panel aims to facilitate the continued growth and maturation of critical care cardiology education and practice.

BACKGROUND AND AIMS/OBJECTIVE:Patients with intermediate-risk pulmonary embolism (PE) commonly present with a significantly reduced cardiac index (CI). However, the identification of this more severe profile requires invasive hemodynamic monitoring. Whether inferior vena cava (IVC) contrast reflux, as a marker of worse right ventricular function, can predict invasive hemodynamics has not been explored. METHODS:This was a single-center retrospective study over a 3-year period of consecutive patients with PE undergoing mechanical thrombectomy and simultaneous pulmonary artery catheterization. CT pulmonary angiograms were reviewed, and contrast reflux was graded as no/minimal reflux (limited to the IVC) or substantial (opacification including hepatic veins) based on an established scale. RESULTS:were 62.6 %, 93.1 %, 94.6 %, and 56.2 %, respectively. These findings remained significant in a multivariable model and were similar when isolating for intermediate-risk patients (n = 72, 85 %). CONCLUSIONS:The degree of contrast reflux is highly specific for a reduced cardiac index in PE even when isolating for intermediate-risk patients. Real-time prediction of a hemodynamic profile may have added value in the risk-stratification of PE.

INTRODUCTION/BACKGROUND:Despite the growing use of temporary mechanical circulatory support (tMCS), little data exists to inform management and weaning of these devices. METHODS:We performed an online survey among cardiac intensive care unit directors in North America to examine current practices in the management of patients treated with intraaortic balloon pump and Impella. RESULTS:We received responses from 84% of surveyed centers (n=37). Our survey focused on three key aspects of daily management: 1. Hemodynamic monitoring; 2. Hemocompatibility; and 3. Weaning and removal. We found substantial variability surrounding all three areas of care. CONCLUSION/CONCLUSIONS:Our findings highlight the need for consensus around practices associated with improved outcomes in patients treated with tMCS.