Modes of Death in Patients with Cardiogenic Shock in the Cardiac Intensive Care Unit: A Report from the Critical Care Cardiology Trials Network.

BACKGROUND: There are limited data on how patients with cardiogenic shock (CS) die. METHODS: The Critical Care Cardiology Trials Network is a research network of cardiac intensive care units coordinated by the Thrombolysis In Myocardial Infarction (TIMI) Study Group (Boston, MA). Using standardized definitions, site investigators classified direct modes of in-hospital death for CS admissions (October 2021 to September 2022). Mutually exclusive categories included 4 modes of cardiovascular death and 4 modes of noncardiovascular death. Subgroups defined by CS type, preceding cardiac arrest (CA), use of temporary mechanical circulatory support (tMCS), and transition to comfort measures were evaluated. RESULTS: Among 1068 CS cases, 337 (31.6%) died during the index hospitalization. Overall, the mode of death was cardiovascular in 82.2%. Persistent CS was the dominant specific mode of death (66.5%), followed by arrhythmia (12.8%), anoxic brain injury (6.2%), and respiratory failure (4.5%). Patients with preceding CA were more likely to die from anoxic brain injury (17.1% vs 0.9%; P < .001) or arrhythmia (21.6% vs 8.4%; P < .001). Patients managed with tMCS were more likely to die from persistent shock (P < .01), both cardiogenic (73.5% vs 62.0%) and noncardiogenic (6.1% vs 2.9%). CONCLUSIONS: Most deaths in CS are related to direct cardiovascular causes, particularly persistent CS. However, there is important heterogeneity across subgroups defined by preceding CA and the use of tMCS.

Epidemiology of Acute Heart Failure in Critically Ill Patients With COVID-19: An Analysis From the Critical Care Cardiology Trials Network.

BACKGROUND: Acute heart failure (HF) is an important complication of coronavirus disease 2019 (COVID-19) and has been hypothesized to relate to inflammatory activation. METHODS: We evaluated consecutive intensive care unit (ICU) admissions for COVID-19 across 6 centers in the Critical Care Cardiology Trials Network, identifying patients with vs without acute HF. Acute HF was subclassified as de novo vs acute-on-chronic, based on the absence or presence of prior HF. Clinical features, biomarker profiles and outcomes were compared. RESULTS: Of 901 admissions to an ICU due to COVID-19, 80 (8.9%) had acute HF, including 18 (2.0%) with classic cardiogenic shock (CS) and 37 (4.1%) with vasodilatory CS. The majority (n = 45) were de novo HF presentations. Compared to patients without acute HF, those with acute HF had higher cardiac troponin and natriuretic peptide levels and similar inflammatory biomarkers; patients with de novo HF had the highest cardiac troponin levels. Notably, among patients critically ill with COVID-19, illness severity (median Sequential Organ Failure Assessment, 8 [IQR, 5-10] vs 6 [4-9]; P = 0.025) and mortality rates (43.8% vs 32.4%; P = 0.040) were modestly higher in patients with vs those without acute HF. CONCLUSIONS: Among patients critically ill with COVID-19, acute HF is distinguished more by biomarkers of myocardial injury and hemodynamic stress than by biomarkers of inflammation.

The Range of Cardiogenic Shock Survival by Clinical Stage: Data From the Critical Care Cardiology Trials Network Registry.

OBJECTIVES: Cardiogenic shock presents with variable severity. Categorizing cardiogenic shock into clinical stages may improve risk stratification and patient selection for therapies. We sought to determine whether a structured implementation of the 2019 Society for Cardiovascular Angiography and Interventions clinical cardiogenic shock staging criteria that is ascertainable in clinical registries discriminates mortality in a contemporary population with or at-risk for cardiogenic shock. DESIGN: We developed a pragmatic application of the Society for Cardiovascular Angiography and Interventions cardiogenic shock staging criteria-A (at-risk), B (beginning), C (classic cardiogenic shock), D (deteriorating), or E (extremis)-and examined outcomes by stage. SETTING: The Critical Care Cardiology Trials Network is an investigator-initiated multicenter research collaboration coordinated by the TIMI Study Group (Boston, MA). Consecutive admissions with or at-risk for cardiogenic shock during two annual 2-month collection periods (2017-2019) were analyzed. PATIENTS: Patients with or at-risk for cardiogenic shock. MEASUREMENTS AND MAIN RESULTS: Of 8,240 CICU admissions reviewed, 1,991 (24%) had or were at-risk for cardiogenic shock. Distributions across the five stages were as follows: A: 33%; B: 7%; C: 16%; D: 23%; and E: 21%. Overall in-hospital mortality among patients with established cardiogenic shock was 39%; however, mortality varied from only 15.8% to 32.1% to 62.5% across stages C, D, and E (Cochran-Armitage ptrend < 0.0001). The Society for Cardiovascular Angiography and Interventions stages improved mortality prediction beyond the Sequential Organ Failure Assessment and Intra-Aortic Balloon Pumpin Cardiogenic Shock II scores. CONCLUSIONS: Although overall mortality in cardiogenic shock remains high, it varies considerably based on clinical stage, identifying stage C as relatively lower risk. We demonstrate a pragmatic adaptation of the Society for Cardiovascular Angiography and Interventions cardiogenic shock stages that effectively stratifies mortality risk and could be leveraged for future clinical research.

De Novo vs Acute-on-Chronic Presentations of Heart Failure-Related Cardiogenic Shock: Insights from the Critical Care Cardiology Trials Network Registry.

BACKGROUND: Heart failure-related cardiogenic shock (HF-CS) accounts for an increasing proportion of cases of CS in contemporary cardiac intensive care units. Whether the chronicity of HF identifies distinct clinical profiles of HF-CS is unknown. METHODS AND RESULTS: We evaluated admissions to cardiac intensive care units for HF-CS in 28 centers using data from the Critical Care Cardiology Trials Network registry (2017-2020). HF-CS was defined as CS due to ventricular failure in the absence of acute myocardial infarction and was classified as de novo vs acute-on-chronic based on the absence or presence of a prior diagnosis of HF, respectively. Clinical features, resource use, and outcomes were compared among groups. Of 1405 admissions with HF-CS, 370 had de novo HF-CS (26.3%), and 1035 had acute-on-chronic HF-CS (73.7%). Patients with de novo HF-CS had a lower prevalence of hypertension, diabetes, coronary artery disease, atrial fibrillation, and chronic kidney disease (all P < 0.01). Median Sequential Organ Failure Assessment (SOFA) scores were higher in those with de novo HF-CS (8; 25th-75th: 5-11) vs acute-on-chronic HF-CS (6; 25th-75th: 4-9, P < 0.01), as was the proportion of Society of Cardiovascular Angiography and Intervention (SCAI) shock stage E (46.1% vs 26.1%, P < 0.01). After adjustment for clinical covariates and preceding cardiac arrest, the risk of in-hospital mortality was higher in patients with de novo HF-CS than in those with acute-on-chronic HF-CS (adjusted hazard ratio 1.36, 95% confidence interval 1.05-1.75, P = 0.02). CONCLUSIONS: Despite having fewer comorbidities, patients with de novo HF-CS had more severe shock presentations and worse in-hospital outcomes. Whether HF disease chronicity is associated with time-dependent compensatory adaptations, unique pathobiological features and responses to treatment in patients presenting with HF-CS warrants further investigation.

Early Serial Assessment of Aggregate Vasoactive Support and Mortality in Cardiogenic Shock: Insights From the Critical Care Cardiology Trials Network Registry.

BACKGROUND: Associations of early changes in vasoactive support with cardiogenic shock (CS) mortality remain incompletely defined. METHODS: The Critical Care Cardiology Trials Network is a multicenter registry of cardiac intensive care units. Patients admitted with CS (2018-2023) had vasoactive dosing assessed at 4 and 24 hours from cardiac intensive care unit admission and quantified by the vasoactive-inotropic score (VIS). Prognostic associations of VIS at both time points, as well as change in VIS from 4 to 24 hours, were examined. Interaction testing was performed based on mechanical circulatory support status. RESULTS: Among 3665 patients, 82% had a change in VIS <10, with 7% and 11% having a ≥10-point increase and decrease from 4 to 24 hours, respectively. The 4 and 24-hour VIS were each associated with cardiac intensive care unit mortality (13%-45% and 11%-73% for VIS <10 to ≥40, respectively; Ptrend <0.0001 for each). Stratifying by the 4-hour VIS, changes in VIS from 4 to 24 hours had a graded association with mortality, ranging from a 2- to >4-fold difference in mortality comparing those with a ≥10-point increase to ≥10-point decrease in VIS (Ptrend <0.0001). The change in VIS alone provided good discrimination of cardiac intensive care unit mortality (C-statistic, 0.72 [95% CI, 0.70-0.75]) and improved discrimination of the 24-hour Sequential Organ Failure Assessment score (0.72 [95% CI, 0.69-0.74] to 0.76 [95% CI, 0.74-0.78]) and the clinician-assessed Society for Cardiovascular Angiography and Interventions shock stage (0.72 [95% CI, 0.70-0.74] to 0.77 [95% CI, 0.75-0.79]). Although present in both groups, the mortality risk associated with VIS was attenuated in patients managed with versus without mechanical circulatory support (odds ratio per 10-point higher 24-hour VIS, 1.36 [95% CI, 1.23-1.49] versus 1.84 [95% CI, 1.69-2.01]; Pinteraction <0.0001). CONCLUSIONS: Early changes in the magnitude of vasoactive support in CS are associated with a gradient of risk for mortality. These data suggest that early VIS trajectory may improve CS prognostication, with the potential to be leveraged for clinical decision-making and research applications in CS.

Presentation and Outcomes of Patients With Preoperative Critical Illness Undergoing Cardiac Surgery.

BACKGROUND: Little is known about the prevalence and post-surgical outcomes associated with cardiac intensive care unit (CICU) therapeutics among CICU patients referred for cardiac surgery. OBJECTIVES: The purpose of this study was to investigate the clinical characteristics and outcomes of CICU patients referred for cardiac surgery from the intensive care unit. METHODS: We analyzed characteristics and outcomes of CICU admissions referred from the CICU for cardiac surgery during 2017 to 2020 across 29 centers. The primary outcome was in-hospital mortality. RESULTS: Among 10,321 CICU admissions, 887 (8.6%) underwent cardiac surgery, including 406 (46%) coronary artery bypass graftings, 201 (23%) transplants or ventricular assist devices, 171 (19%) valve surgeries, and 109 (12%) other procedures. Common indications for CICU admission included shock (33.5%) and respiratory insufficiency (24.9%). Preoperative CICU therapies included vasoactive therapy in 52.2%, mechanical circulatory support in 35.9%, renal replacement in 8.2%, mechanical ventilation in 35.7%, and 17.5% with high-flow nasal cannula or noninvasive positive pressure ventilation. In-hospital mortality was 11.7% among all CICU admissions and 9.1% among patients treated with cardiac surgery. After multivariable adjustment, pre-op mechanical circulatory support and renal replacement therapy were associated with mortality, while respiratory support and vasoactive therapy were not. CONCLUSIONS: Nearly 1 in 12 contemporary CICU patients receive cardiac surgery. Despite high preoperative disease severity, CICU admissions undergoing cardiac surgery had a comparable mortality rate to CICU patients overall; highlighting the ability of clinicians to select higher acuity patients with a reasonable perioperative risk.

Clinician and Algorithmic Application of the 2019 and 2022 Society of Cardiovascular Angiography and Intervention Shock Stages in the Critical Care Cardiology Trials Network Registry.

BACKGROUND: Algorithmic application of the 2019 Society of Cardiovascular Angiography and Intervention (SCAI) shock stages effectively stratifies mortality risk for patients with cardiogenic shock. However, clinician assessment of SCAI staging may differ. Moreover, the implications of the 2022 SCAI criteria update remain incompletely defined. METHODS: The Critical Care Cardiology Trials Network is a multicenter registry of cardiac intensive care units (CICUs). Between 2019 and 2021, participating centers (n=32) contributed at least a 2-month snapshot of consecutive medical CICU admissions. In-hospital mortality was assessed across 3 separate staging methods: clinician assessment, Critical Care Cardiology Trials Network algorithmic application of the 2019 SCAI criteria, and a revision of the Critical Care Cardiology Trials Network application using the 2022 SCAI criteria. RESULTS: Of 9612 admissions, 1340 (13.9%) presented with cardiogenic shock with in-hospital mortality of 35.2%. Both clinician and algorithm-based staging using the 2019 SCAI criteria identified a stepwise gradient of mortality risk (stage C-E: 19.0% to 83.7% and 14.6% to 52.2%, respectively; Ptrend<0.001 for each). Clinician assignment of SCAI stages identified higher risk patients compared with algorithm-based assignment (stage D: 49.9% versus 29.3%; stage E: 83.7% versus 52.2%). Algorithmic application of the 2022 SCAI criteria, with incorporation of the vasoactive-inotropic score, more closely approximated clinician staging (mortality for stage C-E: 21.9% to 70.5%; Ptrend<0.001). CONCLUSIONS: Both clinician and algorithm-based application of the 2019 SCAI stages identify a stepwise gradient of mortality risk, although clinician-staging may better allocate higher risk patients into advanced SCAI stages. Updated algorithmic staging using the 2022 SCAI criteria and vasoactive-inotropic score further refines risk stratification.

Prognostic significance of haemodynamic parameters in patients with cardiogenic shock.

AIMS: Invasive haemodynamic assessment with a pulmonary artery catheter is often used to guide the management of patients with cardiogenic shock (CS) and may provide important prognostic information. We aimed to assess prognostic associations and relationships to end-organ dysfunction of presenting haemodynamic parameters in CS. METHODS AND RESULTS: The Critical Care Cardiology Trials Network is an investigator-initiated multicenter registry of cardiac intensive care units (CICUs) in North America coordinated by the TIMI Study Group. Patients with CS (2018-2022) who underwent invasive haemodynamic assessment within 24 h of CICU admission were included. Associations of haemodynamic parameters with in-hospital mortality were assessed using logistic regression, and associations with presenting serum lactate were assessed using least squares means regression. Sensitivity analyses were performed excluding patients on temporary mechanical circulatory support and adjusted for vasoactive-inotropic score. Among the 3603 admissions with CS, 1473 had haemodynamic data collected within 24 h of CICU admission. The median cardiac index was 1.9 (25th-75th percentile, 1.6-2.4) L/min/m2 and mean arterial pressure (MAP) was 74 (66-86) mmHg. Parameters associated with mortality included low MAP, low systolic blood pressure, low systemic vascular resistance, elevated right atrial pressure (RAP), elevated RAP/pulmonary capillary wedge pressure ratio, and low pulmonary artery pulsatility index. These associations were generally consistent when controlling for the intensity of background pharmacologic and mechanical haemodynamic support. These parameters were also associated with higher presenting serum lactate. CONCLUSION: In a contemporary CS population, presenting haemodynamic parameters reflecting decreased systemic arterial tone and right ventricular dysfunction are associated with adverse outcomes and systemic hypoperfusion.

Pulmonary Artery Catheter Use and Mortality in the Cardiac Intensive Care Unit.

BACKGROUND: The appropriate use of pulmonary artery catheters (PACs) in critically ill cardiac patients remains debated. OBJECTIVES: The authors aimed to characterize the current use of PACs in cardiac intensive care units (CICUs) with attention to patient-level and institutional factors influencing their application and explore the association with in-hospital mortality. METHODS: The Critical Care Cardiology Trials Network is a multicenter network of CICUs in North America. Between 2017 and 2021, participating centers contributed annual 2-month snapshots of consecutive CICU admissions. Admission diagnoses, clinical and demographic data, use of PACs, and in-hospital mortality were captured. RESULTS: Among 13,618 admissions at 34 sites, 3,827 were diagnosed with shock, with 2,583 of cardiogenic etiology. The use of mechanical circulatory support and heart failure were the patient-level factors most strongly associated with a greater likelihood of the use of a PAC (OR: 5.99 [95% CI: 5.15-6.98]; P < 0.001 and OR: 3.33 [95% CI: 2.91-3.81]; P < 0.001, respectively). The proportion of shock admissions with a PAC varied significantly by study center ranging from 8% to 73%. In analyses adjusted for factors associated with their placement, PAC use was associated with lower mortality in all shock patients admitted to a CICU (OR: 0.79 [95% CI: 0.66-0.96]; P = 0.017). CONCLUSIONS: There is wide variation in the use of PACs that is not fully explained by patient level-factors and appears driven in part by institutional tendency. PAC use was associated with higher survival in cardiac patients with shock presenting to CICUs. Randomized trials are needed to guide the appropriate use of PACs in cardiac critical care.

Patients With Acute Coronary Syndromes Admitted to Contemporary Cardiac Intensive Care Units: Insights From the CCCTN Registry.

BACKGROUND: With the improvement in outcomes for acute coronary syndrome (ACS), the practice of routine admission to cardiac intensive care units (CICUs) is evolving. We aimed to describe the epidemiology of patients with ACS admitted to contemporary CICUs. METHODS: Using the CCCTN (Critical Care Cardiology Trials Network) Registry for consecutive medical CICU admissions across 26 advanced CICUs in North America between 2017 and 2020, we identified patients with a primary diagnosis of ACS at CICU admission and compared patient characteristics, resource utilization, and outcomes to patients admitted with a non-ACS diagnosis and across sub-populations of patients with ACS, including by indication for CICU admission. RESULTS: Of 10 118 CICU admissions, 29.4% (n=2978) were for a primary diagnosis of ACS, with significant interhospital variability (range, 13.4%-56.6%). Compared with patients admitted with a diagnosis other than ACS, patients with ACS had fewer comorbidities, lower acute severity of illness with less utilization of advanced CICU therapies (41.3% versus 66.1%, P<0.0001), and lower CICU mortality (5.4% versus 9.9%, P<0.0001). Monitoring alone, without another CICU indication at the time of admission, was the most frequent admission indication in patients with ACS (53.8%); less common indications in patients with ACS included respiratory insufficiency, shock, or the need for vasoactive therapy. Of patients with ACS admitted for monitoring alone, 94.8% did not subsequently require advanced intensive care unit therapies and had a low CICU length of stay (1.5 days [0.9-2.4] versus 2.6 [1.4-5.1], P<0.0001) and CICU mortality (0.6% versus 11.0%, P<0.0001), compared with patients with ACS with an admission indication beyond monitoring. CONCLUSIONS: In a registry of tertiary care CICUs, ACS represent ≈1/3 of all admissions with significant variability across hospitals. More than half of the ACS admissions to the CICU were for routine monitoring alone, with a low rate of complications and mortality. This observation highlights an opportunity for prospective studies to refine triage strategies for lower risk patients with ACS.

End-of-life care in the cardiac intensive care unit: a contemporary view from the Critical Care Cardiology Trials Network (CCCTN) Registry.

AIMS: Increases in life expectancy, comorbidities, and survival with complex cardiovascular conditions have changed the clinical profile of the patients in cardiac intensive care units (CICUs). In this environment, palliative care (PC) services are increasingly important. However, scarce information is available about the delivery of PC in CICUs. METHODS AND RESULTS: The Critical Care Cardiology Trials Network (CCCTN) Registry is a network of tertiary care CICUs in North America. Between 2017 and 2020, up to 26 centres contributed an annual 2-month snapshot of all consecutive medical CICU admissions. We captured code status at admission and the decision for comfort measures only (CMO) before all deaths in the CICU. Of 13 422 patients, 10% died in the CICU and 2.6% were discharged to palliative hospice. Of patients who died in the CICU, 68% were CMO at death. In the CMO group, only 13% were do not resuscitate/do not intubate at admission. The median time from CICU admission to CMO decision was 3.4 days (25th-75th percentiles: 1.2-7.7) and ≥7 days in 27%. Time from CMO decision to death was <24 h in 88%, with a median of 3.8 h (25th-75th 1.0-10.3). Before a CMO decision, 78% received mechanical ventilation and 26% mechanical circulatory support. A PC provider team participated in the care of 41% of patients who died. CONCLUSIONS: In a contemporary CICU registry, comfort measures preceded death in two-thirds of cases, frequently without PC involvement. The high utilization of advanced intensive care unit therapies and lengthy times to a CMO decision highlight a potential opportunity for early engagement of PC teams in CICU.

A pragmatic lab-based tool for risk assessment in cardiac critical care: data from the Critical Care Cardiology Trials Network (CCCTN) Registry.

AIMS: Contemporary cardiac intensive care unit (CICU) outcomes remain highly heterogeneous. As such, a risk-stratification tool using readily available lab data at time of CICU admission may help inform clinical decision-making. METHODS AND RESULTS: The primary derivation cohort included 4352 consecutive CICU admissions across 25 tertiary care CICUs included in the Critical Care Cardiology Trials Network (CCCTN) Registry. Candidate lab indicators were assessed using multivariable logistic regression. An integer risk score incorporating the top independent lab indicators associated with in-hospital mortality was developed. External validation was performed in a separate CICU cohort of 9716 patients from the Mayo Clinic (Rochester, MN, USA). On multivariable analysis, lower pH [odds ratio (OR) 1.96, 95% confidence interval (CI) 1.72-2.24], higher lactate (OR 1.40, 95% CI 1.22-1.62), lower estimated glomerular filtration rate (OR 1.26, 95% CI 1.10-1.45), and lower platelets (OR 1.18, 95% CI 1.05-1.32) were the top four independent lab indicators associated with higher in-hospital mortality. Incorporated into the CCCTN Lab-Based Risk Score, these four lab indicators identified a 20-fold gradient in mortality risk with very good discrimination (C-index 0.82, 95% CI 0.80-0.84) in the derivation cohort. Validation of the risk score in a separate cohort of 3888 patients from the Registry demonstrated good performance (C-index of 0.82; 95% CI 0.80-0.84). Performance remained consistent in the external validation cohort (C-index 0.79, 95% CI 0.77-0.80). Calibration was very good in both validation cohorts (r = 0.99). CONCLUSION: A simple integer risk score utilizing readily available lab indicators at time of CICU admission may accurately stratify in-hospital mortality risk.

Critical Care Cardiology Trials Network (CCCTN): a cohort profile.

AIMS: The aims of the Critical Care Cardiology Trials Network (CCCTN) are to develop a registry to investigate the epidemiology of cardiac critical illness and to establish a multicentre research network to conduct randomised clinical trials (RCTs) in patients with cardiac critical illness. METHODS AND RESULTS: The CCCTN was founded in 2017 with 16 centres and has grown to a research network of over 40 academic and clinical centres in the United States and Canada. Each centre enters data for consecutive cardiac intensive care unit (CICU) admissions for at least 2 months of each calendar year. More than 20 000 unique CICU admissions are now included in the CCCTN Registry. To date, scientific observations from the CCCTN Registry include description of variations in care, the epidemiology and outcomes of all CICU patients, as well as subsets of patients with specific disease states, such as shock, heart failure, renal dysfunction, and respiratory failure. The CCCTN has also characterised utilization patterns, including use of mechanical circulatory support in response to changes in the heart transplantation allocation system, and the use and impact of multidisciplinary shock teams. Over years of multicentre collaboration, the CCCTN has established a robust research network to facilitate multicentre registry-based randomised trials in patients with cardiac critical illness. CONCLUSION: The CCCTN is a large, prospective registry dedicated to describing processes-of-care and expanding clinical knowledge in cardiac critical illness. The CCCTN will serve as an investigational platform from which to conduct randomised controlled trials in this important patient population.

Use of Temporary Mechanical Circulatory Support for Management of Cardiogenic Shock Before and After the United Network for Organ Sharing Donor Heart Allocation System Changes.

Importance: The new United Network for Organ Sharing (UNOS) donor heart allocation system gives priority to patients supported with nondischargeable mechanical circulatory support (MCS) devices while awaiting heart transplant. Whether there has been a change in temporary MCS use in cardiac intensive care units (CICUs) since the implementation of this policy is unknown. Objectives: To examine whether the UNOS donor heart allocation system revision in October 2018 was associated with changes in temporary MCS use in CICUs and whether temporary MCS use differed between US transplant centers and US nontransplant centers and Canadian centers. Design, Setting, and Participants: In this cohort study, 14 centers from the Critical Care Cardiology Trials Network (CCCTN), a multicenter network of tertiary CICUs in North America, contributed 2-month snapshots of consecutive medical CICU admissions between September 1, 2017, and September 1, 2018 (prerevision period), and October 1, 2018, and September 1, 2019 (postrevision period). CICUs were classified as US transplant centers (n = 7) or other CICUs (US nontransplant centers or Canadian centers; n = 7). Exposure: Revision to the UNOS donor heart allocation system. Main Outcomes and Measures: Treatment with temporary MCS (intra-aortic balloon pump, microaxial intracardiac ventricular assist device, percutaneous centrifugal ventricular assist device, venoarterial extracorporeal membrane oxygenation, or surgically implanted, nondischargeable MCS device) during hospital admission. Results: A total of 384 admissions for acute, decompensated, heart failure-related cardiogenic shock (ADHF-CS) were included, among which 248 (64.6%) were to US transplant centers; 126 admissions (51%) were in the prerevision period and 122 (49%) were in the postrevision period. The mean (SD) patient age was 61.2 (14.6) years; 246 patients (64.1%) were male. The proportion of admissions with ADHF-CS managed with temporary MCS at US transplant centers significantly increased from 25.4% (32 of 126 admissions) before to 42.6% (52 of 122 admissions) after the UNOS allocation system changes (P = .004). In other CICUs, the proportion did not significantly change (24.5% [13 of 53 admissions] to 24.1% [20 of 83 admissions]; P = .95). After multivariable adjustment, patients admitted to US transplant centers in the postrevision period were more likely to receive temporary MCS compared with those admitted in the prerevision period (adjusted odds ratio, 2.19; 95% CI, 1.13-4.24; P = .02). Conclusions and Relevance: In the year after implementation of the new UNOS donor heart allocation system, temporary MCS use in patients admitted with ADHF-CS increased in US transplant centers but not in other CICUs. Whether this shift in practice will affect outcomes of patients with ADHF-CS or organ distribution should be evaluated.

Advanced Respiratory Support in the Contemporary Cardiac ICU.

The medical complexity and critical care needs of patients admitted to cardiac ICUs are increasing, and prospective studies examining the underlying cardiac and noncardiac diagnoses, the management strategies, and the prognosis of cardiac ICU patients with respiratory failure are needed. DESIGN: Prospective cohort study. SETTING: The Critical Care Cardiology Trials Network is a research collaborative of cardiac ICUs across the United States and Canada. PATIENTS: We included all medical cardiac ICU admissions at 25 cardiac ICUs during two consecutive months annually at each center from 2017 to 2019. MEASUREMENTS: We evaluated the use of advanced respiratory therapies including invasive mechanical ventilation, noninvasive ventilation, and high-flow nasal cannula versus no advanced respiratory support across admission diagnoses and the association with in-hospital mortality. MAIN RESULTS: Of 8,240 cardiac ICU admissions, 1,935 (23.5%) were treated with invasive mechanical ventilation, 573 (7.0%) with noninvasive ventilation, and 281 (3.4%) with high-flow nasal cannula. Admitting diagnoses among those with advanced respiratory support were diverse including general medical problems in patients with heart disease as well as primary cardiac problems. In-hospital mortality was higher in patients who received invasive mechanical ventilation (38.1%; adjusted odds ratio, 2.53; 2.02-3.16) and noninvasive ventilation or high-flow nasal cannula (8.8%; adjusted odds ratio, 2.25; 1.73-2.93) compared with patients without advanced respiratory support (4.6%). Reintubation rate was 7.6%. The most common variables associated with respiratory insufficiency included heart failure, infection, chronic obstructive pulmonary disease, and pulmonary vascular disease. CONCLUSIONS: One-third of cardiac ICU admissions receive respiratory support with associated increased mortality. These data provide benchmarks for quality improvement ventures in the cardiac ICU, inform cardiac critical care training and staffing patterns, and serve as foundation for future studies aimed at improving outcomes.

Clinical Practice Patterns in Temporary Mechanical Circulatory Support for Shock in the Critical Care Cardiology Trials Network (CCCTN) Registry.

BACKGROUND: Temporary mechanical circulatory support (MCS) devices provide hemodynamic assistance for shock refractory to pharmacological treatment. Most registries have focused on single devices or specific etiologies of shock, limiting data regarding overall practice patterns with temporary MCS in cardiac intensive care units. METHODS: The CCCTN (Critical Care Cardiology Trials Network) is a multicenter network of tertiary CICUs in North America. Between September 2017 and September 2018, each center (n=16) contributed a 2-month snapshot of consecutive medical CICU admissions. RESULTS: Of the 270 admissions using temporary MCS, 33% had acute myocardial infarction-related cardiogenic shock (CS), 31% had CS not related to acute myocardial infarction, 11% had mixed shock, and 22% had an indication other than shock. Among all 585 admissions with CS or mixed shock, 34% used temporary MCS during the CICU stay with substantial variation between centers (range: 17%-50%). The most common temporary MCS devices were intraaortic balloon pumps (72%), Impella (17%), and veno-arterial extracorporeal membrane oxygenation (11%), although intraaortic balloon pump use also varied between centers (range: 40%-100%). Patients managed with intraaortic balloon pump versus other forms of MCS (advanced MCS) had lower Sequential Organ Failure Assessment scores and less severe metabolic derangements. Illness severity was similar at high- versus low-MCS utilizing centers and at centers with more advanced MCS use. CONCLUSIONS: There is wide variation in the use of temporary MCS among patients with shock in tertiary CICUs. While hospital-level variation in temporary MCS device selection is not explained by differences in illness severity, patient-level variation appears to be related, at least in part, to illness severity.

Epidemiology of Shock in Contemporary Cardiac Intensive Care Units.

Background Clinical investigations of shock in cardiac intensive care units (CICUs) have primarily focused on acute myocardial infarction (AMI) complicated by cardiogenic shock (AMICS). Few studies have evaluated the full spectrum of shock in contemporary CICUs. Methods and Results The Critical Care Cardiology Trials Network is a multicenter network of advanced CICUs in North America. Anytime between September 2017 and September 2018, each center (n=16) contributed a 2-month snap-shot of all consecutive medical admissions to the CICU. Data were submitted to the central coordinating center (TIMI Study Group, Boston, MA). Shock was defined as sustained systolic blood pressure <90 mm Hg with end-organ dysfunction ascribed to the hypotension. Shock type was classified by site investigators as cardiogenic, distributive, hypovolemic, or mixed. Among 3049 CICU admissions, 677 (22%) met clinical criteria for shock. Shock type was varied, with 66% assessed as cardiogenic shock (CS), 7% as distributive, 3% as hypovolemic, 20% as mixed, and 4% as unknown. Among patients with CS (n=450), 30% had AMICS, 18% had ischemic cardiomyopathy without AMI, 28% had nonischemic cardiomyopathy, and 17% had a cardiac cause other than primary myocardial dysfunction. Patients with mixed shock had cardiovascular comorbidities similar to patients with CS. The median CICU stay was 4.0 days (interquartile range [IQR], 2.5-8.1 days) for AMICS, 4.3 days (IQR, 2.1-8.5 days) for CS not related to AMI, and 5.8 days (IQR, 2.9-10.0 days) for mixed shock versus 1.9 days (IQR, 1.0-3.6) for patients without shock ( P<0.01 for each). Median Sequential Organ Failure Assessment scores were higher in patients with mixed shock (10; IQR, 6-13) versus AMICS (8; IQR, 5-11) or CS without AMI (7; IQR, 5-11; each P<0.01). In-hospital mortality rates were 36% (95% CI, 28%-45%), 31% (95% CI, 26%-36%), and 39% (95% CI, 31%-48%) in AMICS, CS without AMI, and mixed shock, respectively. Conclusions The epidemiology of shock in contemporary advanced CICUs is varied, and AMICS now represents less than one-third of all CS. Despite advanced therapies, mortality in CS and mixed shock remains high. Investigation of management strategies and new therapies to treat shock in the CICU should take this epidemiology into account.

Demographics, Care Patterns, and Outcomes of Patients Admitted to Cardiac Intensive Care Units: The Critical Care Cardiology Trials Network Prospective North American Multicenter Registry of Cardiac Critical Illness.

Importance: Single-center and claims-based studies have described substantial changes in the landscape of care in the cardiac intensive care unit (CICU). Professional societies have recommended research to guide evidence-based CICU redesigns. Objective: To characterize patients admitted to contemporary, advanced CICUs. Design, Setting, and Participants: This study established the Critical Care Cardiology Trials Network (CCCTN), an investigator-initiated multicenter network of 16 advanced, tertiary CICUs in the United States and Canada. For 2 months in each CICU, data for consecutive admissions were submitted to the central data coordinating center (TIMI Study Group). The data were collected and analyzed between September 2017 and 2018. Main Outcomes and Measures: Demographics, diagnoses, management, and outcomes. Results: Of 3049 participants, 1132 (37.1%) were women, 797 (31.4%) were individuals of color, and the median age was 65 years (25th and 75th percentiles, 55-75 years). Between September 2017 and September 2018, 3310 admissions were included, among which 2557 (77.3%) were for primary cardiac problems, 337 (10.2%) for postprocedural care, 253 (7.7%) for mixed general and cardiac problems, and 163 (4.9%) for overflow from general medical ICUs. When restricted to the initial 2 months of medical CICU admissions for each site, the primary analysis population included 3049 admissions with a high burden of noncardiovascular comorbidities. The top 2 CICU admission diagnoses were acute coronary syndrome (969 [31.8%]) and heart failure (567 [18.6%]); however, the proportion of acute coronary syndrome was highly variable across centers (15%-57%). The primary indications for CICU care included respiratory insufficiency (814 [26.7%]), shock (643 [21.1%]), unstable arrhythmia (521 [17.1%]), and cardiac arrest (265 [8.7%]). Advanced CICU therapies or monitoring were required for 1776 patients (58.2%), including intravenous vasoactive medications (1105 [36.2%]), invasive hemodynamic monitoring (938 [30.8%]), and mechanical ventilation (652 [21.4%]). The overall CICU mortality rate was 8.3% (95% CI, 7.3%-9.3%). The CICU indications that were associated with the highest mortality rates were cardiac arrest (101 [38.1%]), cardiogenic shock (140 [30.6%]), and the need for renal replacement therapy (51 [34.5%]). Notably, patients admitted solely for postprocedural observation or frequent monitoring had a mortality rate of 0.2% to 0.4%. Conclusions and Relevance: In a contemporary network of tertiary care CICUs, respiratory failure and shock predominated indications for admission and carried a poor prognosis. While patterns of practice varied considerably between centers, a substantial, low-risk population was identified. Multicenter collaborative networks, such as the CCCTN, could be used to help redesign cardiac critical care and to test new therapeutic strategies.