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

Clinical Characteristics, Management, and Outcomes in Cardiogenic Shock: Insights From a High-Volume Italian Cardiac Intensive Care Unit

ABSTRACT

Cardiogenic shock (CS) is a life-threatening condition. The aim of this study is to evaluate the clinical characteristics, management, and complication rate of patients with CS admitted to a high-volume hospital in Italy. We retrospectively reviewed the clinical, echocardiographic, and laboratory data, therapeutic management, and outcomes of patients with CS admitted to the Policlinico Gemelli (Rome) between January 1, 2020, and January 1, 2023. We included 96 patients [median age 71 years, interquartile range 60-79; 65 (68%) males], of whom 49 patients (51%) presented CS secondary to acute myocardial infarction and 60 (63%) with a de novo presentation of CS. Dobutamine was the most frequently used inotrope and noradrenaline the most frequently used vasopressor (adopted in 56% and 82% of cases, respectively). Forty-five (47%) patients died during the hospitalization. Nonsurvivors were older and had a higher inflammatory burden at admission, elevated lactate levels, a greater increase in lactate levels, higher left ventricular filling pressures, and worse right ventricular function. C-reactive protein levels [odds ratio (OR) 1.03, 95% confidence interval (CI) (1.00-1.04), P = 0.027], lactate levels at admission (OR 3.49, 95% CI, 1.59-7.63, P = 0.02), and increase in lactate levels (OR 2.8, 95% CI, 1.37-5.75, P = 0.005) were independent predictors of in-hospital all-cause death. Our data contribute to the assessment of the regional variations in the management and outcomes of patients with CS. We observed a high mortality and complication rate. Lactate acidosis and C-reactive protein measured at admission may help in identifying patients at higher risk of adverse in-hospital outcomes.

Cardiogenic shock trajectories: is the Society for Cardiovascular Angiography and Interventions definition the right one?

PURPOSE OF REVIEW

We review the current Society for Cardiovascular Angiography and Interventions (SCAI) cardiogenic shock classification system and consider alternatives or iterations that may enhance our current descriptions of cardiogenic shock trajectory.

RECENT FINDINGS

Several studies have identified the potential prognostic value of serial SCAI stage re-assessment, usually within the first 24 h of shock onset, to predict deterioration and clinical outcomes across shock causes. In parallel, numerous registry-based analyses support the utility of a more precise assessment of the macrocirculation and microcirculation, leveraging invasive haemodynamics, imaging and additional laboratory and clinical markers. The emergence of machine learning and artificial intelligence capabilities offers the opportunity to integrate multimodal data into high fidelity, real-time metrics to more precisely define trajectory and inform our therapeutic decision making.

SUMMARY

Whilst the SCAI staging system remains a pivotal tool in cardiogenic shock assessment, communication and reassessment, it is vital that the sophistication with which we measure and assess shock trajectory evolves in parallel our understanding of the complexity and variability of clinical course and clinical outcomes.

Continuum of Preshock to Classic Cardiogenic Shock in the Critical Care Cardiology Trials Network Registry

BACKGROUND

The prognostic implications of phenotypes along the preshock to cardiogenic shock (CS) continuum remain uncertain.

OBJECTIVES

This study sought to better characterize pre- or early shock and normotensive CS phenotypes and examine outcomes compared to those with conventional CS.

METHODS

The CCCTN (Critical Care Cardiology Trials Network) is a registry of contemporary cardiac intensive care units. Consecutive admissions (N = 28,703 across 47 sites) meeting specific criteria based on hemodynamic variables, perfusion parameters, and investigator-reported CS were classified into 1 of 4 groups or none: isolated low cardiac output (CO), heart failure with isolated hypotension, normotensive CS, or SCAI (Society of Cardiovascular Angiography and Intervention) stage C CS. Outcomes of interest were in-hospital mortality and incidence of subsequent hypoperfusion among pre- and early shock states.

RESULTS

A total of 2,498 admissions were assigned to the 4 groups with the following distribution: 4.8% isolated low CO, 4.4% isolated hypotension, 12.1% normotensive CS, and 78.7% SCAI stage C CS. Overall in-hospital mortality was 21.3% (95% CI: 19.7%-23.0%), with a gradient across phenotypes (isolated low CO 3.6% [95% CI: 1.0%-9.0%]; isolated hypotension 11.0% [95% CI: 6.9%-16.6%]; normotensive CS 17.0% [95% CI 13.0%-21.8%]; SCAI stage C CS 24.0% [95% CI: 22.1%-26.0%]; global P < 0.001). Among those with an isolated low CO and isolated hypotension on admission, 47 (42.3%) and 56 (30.9%) subsequently developed hypoperfusion.

CONCLUSIONS

In a large contemporary registry of cardiac critical illness, there exists a gradient of mortality for phenotypes along the preshock to CS continuum with risk for subsequent worsening of preshock states. These data may inform refinement of CS definitions and severity staging.

Machine Learning Identifies Higher Survival Profile In Extracorporeal Cardiopulmonary Resuscitation

OBJECTIVES

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to improve neurologically favorable survival in patients with refractory out-of-hospital cardiac arrest (OHCA) caused by shockable rhythms. Further refinement of patient selection is needed to focus this resource-intensive therapy on those patients likely to benefit. This study sought to create a selection model using machine learning (ML) tools for refractory cardiac arrest patients undergoing ECPR.

DESIGN

Retrospective cohort study.

SETTING

Cardiac ICU in a Quaternary Care Center.

PATIENTS

Adults 18-75 years old with refractory OHCA caused by a shockable rhythm.

METHODS

Three hundred seventy-six consecutive patients with refractory OHCA and a shockable presenting rhythm were analyzed, of which 301 underwent ECPR and cannulation for venoarterial extracorporeal membrane oxygenation. Clinical variables that were widely available at the time of cannulation were analyzed and ranked on their ability to predict neurologically favorable survival.

INTERVENTIONS

ML was used to train supervised models and predict favorable neurologic outcomes of ECPR. The best-performing models were internally validated using a holdout test set.

MEASUREMENTS AND MAIN RESULTS

Neurologically favorable survival occurred in 119 of 301 patients (40%) receiving ECPR. Rhythm at the time of cannulation, intermittent or sustained return of spontaneous circulation, arrest to extracorporeal membrane oxygenation perfusion time, and lactic acid levels were the most predictive of the 11 variables analyzed. All variables were integrated into a training model that yielded an in-sample area under the receiver-operating characteristic curve (AUC) of 0.89 and a misclassification rate of 0.19. Out-of-sample validation of the model yielded an AUC of 0.80 and a misclassification rate of 0.23, demonstrating acceptable prediction ability.

CONCLUSIONS

ML can develop a tiered risk model to guide ECPR patient selection with tailored arrest profiles.

Extra-cardiac management of cardiogenic shock in the intensive care unit

Cardiogenic shock (CS) is a heterogeneous clinical syndrome characterized by low cardiac output leading to end-organ hypoperfusion. Organ dysoxia ranging from transient organ injury to irreversible organ failure and death occurs across all CS etiologies but differing by incidence and type. Herein, we review the recognition and management of respiratory, renal and hepatic failure complicating CS. We also discuss unmet needs in the CS care pathway and future research priorities for generating evidence-based best practices for the management of extra-cardiac sequelae. The complexity of CS admitted to the contemporary cardiac intensive care unit demands a workforce skilled to care for these extra-cardiac critical illness complications with an appreciation for how cardio-systemic interactions influence critical illness outcomes in afflicted patients.

Prognostic performance of the SCAI shock classification at admission and during ICU treatment: A retrospective, observational cohort study

BACKGROUND

Cardiogenic shock (CS) is characterized by high mortality and requires accurate prognostic tools to predict outcomes and guide treatment. The Society for Cardiovascular Angiography and Interventions (SCAI) shock classification indicates shock severity and can be used for outcome prediction.

OBJECTIVE

Here, we compare the prognostic performance of SCAI shock classification determined on admission and during intensive care unit (ICU) stay.

METHODS

We included all patients with CS or conditions associated with developing CS based on ICD codes. SCAI shock stages were determined on admission and during the first 5 days of ICU stay. Receiver operating curves were used to compare the prognostic performance of SCAI stages on admission, SCAI stages during ICU stay and CS evolution (absent, resolved, persistent and new onset) for in-hospital mortality.

RESULTS

Between 01/2018 and 06/2022, 1303 patients were identified and 862 patients were included. On admission, 50.6 % patients had SCAI shock stage A, 3.9 % SCAI shock stage B, 17.7 % SCAI shock stage C, 7.0 % SCAI shock stage D and 20.8 % SCAI shock stage E. Shock stage distribution changed dynamically during ICU stay. Compared to SCAI stage on admission (AUC 0.80; 95 % CI 0.77-0.83), highest achieved SCAI stage during ICU (AUC 0.86, 95 % CI 0.83-0.89, p < 0.0001) and shock evolution (AUC 0.87, 95 % CI 0.85-0.90, p < 0.0001) yielded better prognostic performance.

CONCLUSIONS

SCAI shock stages changed dynamically during ICU stay, and prognostic performance can be improved by considering highest achieved SCAI shock stage as well as the evolution of CS compared to SCAI shock stage on admission.

The Management of Cardiogenic Shock From Diagnosis to Devices: A Narrative Review

Cardiogenic shock (CS) is a heterogenous syndrome broadly characterized by inadequate cardiac output leading to tissue hypoperfusion and multisystem organ dysfunction that carries an ongoing high mortality burden. The management of CS has advanced rapidly, especially with the incorporation of temporary mechanical circulatory support (tMCS) devices. A thorough understanding of how to approach a patient with CS and to select appropriate monitoring and treatment paradigms is essential in modern ICUs. Timely characterization of CS severity and hemodynamics is necessary to optimize outcomes, and this may be performed best by multidisciplinary shock-focused teams. In this article, we provide a review of CS aimed to inform both the cardiology-trained and non-cardiology-trained intensivist provider. We briefly describe the causes, pathophysiologic features, diagnosis, and severity staging of CS, focusing on gathering key information that is necessary for making management decisions. We go on to provide a more detailed review of CS management principles and practical applications, with a focus on tMCS. Medical management focuses on appropriate medication therapy to optimize perfusion-by enhancing contractility and minimizing afterload-and to facilitate decongestion. For more severe CS, or for patients with decompensating hemodynamic status despite medical therapy, initiation of the appropriate tMCS increasingly is common. We discuss the most common devices currently used for patients with CS-phenotyping patients as having left ventricular failure, right ventricular failure, or biventricular failure-and highlight key available data and particular points of consideration that inform tMCS device selection. Finally, we highlight core components of sedation and respiratory failure management for patients with CS.

Non-invasive assessment of left ventricular contractility by myocardial work index in veno-arterial membrane oxygenation patients: rationale and design of the MIX-ECMO multicentre observational study

Introduction and aims

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an increasingly utilized therapeutic choice in patients with cardiogenic shock, however, high complication rate often counteracts with its beneficial cardiopulmonary effects. The assessment of left ventricular (LV) function in key in the management of this population, however, the most commonly used measures of LV performance are substantially load-dependent. Non-invasive myocardial work is a novel LV functional measure which may overcome this limitation and estimate LV function independent of the significantly altered loading conditions of VA-ECMO therapy. The Usefulness of Myocardial Work IndeX in ExtraCorporeal Membrane Oxygenation Patients (MIX-ECMO) study aims to examine the prognostic role of non-invasive myocardial work in VA-ECMO-supported patients.

Methods

The MIX-ECMO is a multicentric, prospective, observational study. We aim to enroll 110 patients 48-72 h after the initiation of VA-ECMO support. The patients will undergo a detailed echocardiographic examination and a central echocardiography core laboratory will quantify conventional LV functional measures and non-invasive myocardial work parameters. The primary endpoint will be failure to wean at 30 days as a composite of cardiovascular mortality, need for long-term mechanical circulatory support or heart transplantation at 30 days, and besides that other secondary objectives will also be investigated. Detailed clinical data will also be collected to compare LV functional measures to parameters with established prognostic role and also to the Survival After Veno-arterial-ECMO (SAVE) score.

Conclusions

The MIX-ECMO study will be the first to determine if non-invasive myocardial work has added prognostic value in patients receiving VA-ECMO support.

Shock Severity Classification and Mortality in Adults With Cardiac, Medical, Surgical, and Neurological Critical Illness

OBJECTIVE

To evaluate whether the Society for Cardiovascular Angiography and Interventions (SCAI) Shock Classification could perform risk stratification in a mixed cohort of intensive care unit (ICU) patients, similar to its validation in patients with acute cardiac disease.

METHODS

We included 21,461 adult Mayo Clinic ICU patient admissions from December 1, 2014, to February 28, 2018, including cardiac ICU (16.7%), medical ICU (37.4%), neurosciences ICU (27.7%), and surgical ICU (18.2%). The SCAI Shock Classification (a 5-stage classification from no shock [A] to refractory shock [E]) was assigned in each 4-hour period during the first 24 hours of ICU admission.

RESULTS

The median age was 65 years, and 43.2% were female. In-hospital mortality occurred in 1611 (7.5%) patients, with a stepwise increase in in-hospital mortality in each higher maximum SCAI Shock stage overall: A, 4.0%; B, 4.6%; C, 7.0%; D, 13.9%; and E, 40.2%. The SCAI Shock Classification provided incremental mortality risk stratification in each ICU, with the best performance in the cardiac ICU and the worse performance in the neurosciences ICU. The SCAI Shock Classification was associated with higher adjusted in-hospital mortality (adjusted odds ratio, 1.32 per each stage; 95% CI, 1.24 to 1.41; P<.001); this association was not observed in the neurosciences ICU when considered separately.

CONCLUSION

The SCAI Shock Classification provided incremental mortality risk stratification beyond established prognostic markers across the spectrum of medical and surgical critical illness, proving utility outside its original intent.

Prognostic performance of the IABP-SHOCK II Risk Score among cardiogenic shock subtypes in the critical care cardiology trials network registry

BACKGROUND

Risk stratification has potential to guide triage and decision-making in cardiogenic shock (CS). We assessed the prognostic performance of the IABP-SHOCK II score, derived in Europe for acute myocardial infarct-related CS (AMI-CS), in a contemporary North American cohort, including different CS phenotypes.

METHODS

The critical care cardiology trials network (CCCTN) coordinated by the TIMI study group is a multicenter network of cardiac intensive care units (CICU). Participating centers annually contribute ≥2 months of consecutive medical CICU admissions. The IABP-SHOCK II risk score includes age > 73 years, prior stroke, admission glucose > 191 mg/dl, creatinine > 1.5 mg/dl, lactate > 5 mmol/l, and post-PCI TIMI flow grade < 3. We assessed the risk score across various CS etiologies.

RESULTS

Of 17,852 medical CICU admissions 5,340 patients across 35 sites were admitted with CS. In patients with AMI-CS (n = 912), the IABP-SHOCK II score predicted a >3-fold gradient in in-hospital mortality (low risk = 26.5%, intermediate risk = 52.2%, high risk = 77.5%, P < .0001; c-statistic = 0.67; Hosmer-Lemeshow P = .79). The score showed a similar gradient of in-hospital mortality in patients with non-AMI-related CS (n = 2,517, P < .0001) and mixed shock (n = 923, P < .001), as well as in left ventricular (<0.0001), right ventricular (P = .0163) or biventricular (<0.0001) CS. The correlation between the IABP-SHOCK II score and SOFA was moderate (r2 = 0.17) and the IABP-SHOCK II score revealed a significant risk gradient within each SCAI stage.

CONCLUSIONS

In an unselected international multicenter registry of patients admitted with CS, the IABP- SHOCK II score only moderately predicted in-hospital mortality in a broad population of CS regardless of etiology or irrespective of right, left, or bi-ventricular involvement.

Treatment of Acute Myocardial Infarction and Cardiogenic Shock: Outcomes of the RECOVER III Postapproval Study by Society of Cardiovascular Angiography and Interventions Shock Stage

BACKGROUND

The Society for Cardiovascular Angiography and Interventions proposed a staging system (A-E) to predict prognosis in cardiogenic shock. Herein, we report clinical outcomes of the RECOVER III study for the first time, according to Society for Cardiovascular Angiography and Interventions shock classification.

METHODS AND RESULTS

The RECOVER III study is an observational, prospective, multicenter, single-arm, postapproval study of patients with acute myocardial infarction with cardiogenic shock undergoing percutaneous coronary intervention with Impella support. Patients enrolled in the RECOVER III study were assigned a baseline Society for Cardiovascular Angiography and Interventions shock stage. Staging was then repeated within 24 hours after initiation of Impella. Kaplan-Meier survival curve analyses were conducted to assess survival across Society for Cardiovascular Angiography and Interventions shock stages at both time points. At baseline assessment, 16.5%, 11.4%, and 72.2% were classified as stage C, D, and E, respectively. At ≤24-hour assessment, 26.4%, 33.2%, and 40.0% were classified as stage C, D, and E, respectively. Thirty-day survival among patients with stage C, D, and E shock at baseline was 59.7%, 56.5%, and 42.9%, respectively (P=0.003). Survival among patients with stage C, D, and E shock at ≤24 hours was 65.7%, 52.1%, and 29.5%, respectively (P<0.001). After multivariable analysis of impact of shock stage classifications at baseline and ≤24 hours, only stage E classification at ≤24 hours was a significant predictor of mortality (odds ratio, 4.8; P<0.001).

CONCLUSIONS

In a real-world cohort of patients with acute myocardial infarction with cardiogenic shock undergoing percutaneous coronary intervention with Impella support, only stage E classification at ≤24 hours was significantly predictive of mortality, suggesting that response to therapy may be more important than clinical severity of shock at presentation.

PROGNOSTIC PERFORMANCE OF SERIAL DETERMINATION OF THE SOCIETY FOR CARDIOVASCULAR ANGIOGRAPHY AND INTERVENTIONS SHOCK CLASSIFICATION IN ADULTS WITH CRITICAL ILLNESS

ABSTRACT

Purpose: The aim of the study is to evaluate whether serial assessment of shock severity can improve prognostication in intensive care unit (ICU) patients. Materials and Methods: This is a retrospective cohort of 21,461 ICU patient admissions from 2014 to 2018. We assigned the Society for Cardiovascular Angiography and Interventions (SCAI) Shock Stage in each 4-h block during the first 24 h of ICU admission; shock was defined as SCAI Shock stage C, D, or E. In-hospital mortality was evaluated using logistic regression. Results: The admission SCAI Shock stages were as follows: A, 39.0%; B, 27.0%; C, 28.9%; D, 2.6%; and E, 2.5%. The SCAI Shock stage subsequently increased in 30.6%, and late-onset shock developed in 30.4%. In-hospital mortality was higher in patients who had shock on admission (11.9%) or late-onset shock (7.3%) versus no shock (4.3%). Persistence of shock predicted higher mortality (adjusted OR = 1.09; 95% CI = 1.06-1.13, for each ICU block with shock). The mean SCAI Shock stage had higher discrimination for in-hospital mortality than the admission or maximum SCAI Shock stage. Dynamic modeling of the SCAI Shock classification improved discrimination for in-hospital mortality (C-statistic = 0.64-0.71). Conclusions: Serial application of the SCAI Shock classification provides improved mortality risk stratification compared with a single assessment on admission, facilitating dynamic prognostication.

Revisiting nitrates use in pre-shock state of contemporary cardiogenic shock classification

Patients at each shock stage may behave and present differently with a spectrum of shock severity and adverse outcomes. Shock severity, shock aetiology, and several factors should be integrated in management decision-making. Although the contemporary shock stages classification provided a standardized shock severity assessment, individual agents or management strategy has not yet been studied in the context of each shock stage. The pre-shock state may comprise a wide range of presentations. Nitrate therapy has potential benefit in myocardial infarction and acute heart failure. Herein, this review aims to discuss the potential use of nitrate therapy in the context of the pre-shock state or stage B of the contemporary shock classification given its various presentations.

Impact of a Cardiogenic Shock Program on Mortality in a Non-Transplant Hospital

INTRODUCTION

Cardiogenic shock is associated with high in-hospital morbidity and mortality. Improvements in this care process could lead to better outcomes.

METHODS

This retrospective study of patients with cardiogenic shock compared two periods: no specific program to address cardiogenic shock and implementation of a cardiogenic shock program. This program included the establishment of a multidisciplinary team (shock team), early alert to the transplant hospital, initiation of a ventricular assist extracorporeal membrane oxygenation (ECMO) program, and extension of continuous care by acute cardiovascular care specialists. The primary objective was to analyse whether there were differences between in-hospital mortality and mortality during follow-up. Predictors of in-hospital mortality were examined as a secondary objective.

RESULTS

A total of 139 patients were enrolled: 69 of them in the previous period and 70 in the cardiogenic shock program period. There was a significant reduction in in-hospital mortality (55.1% vs 37.1%; p=0.03) and mortality during follow-up (62.7% vs 44.6%; p=0.03) in the second period. Diabetes mellitus, ejection fraction, out-of-hospital cardiac arrest, and implementation of the cardiogenic shock program were independent predictors of in-hospital mortality.

CONCLUSIONS

The implementation of a comprehensive cardiogenic shock program in a non-transplanting hospital improved in-hospital and follow-up mortality of patients in cardiogenic shock.

Serial Assessment of Shock Severity in Cardiac Intensive Care Unit Patients

BACKGROUND

One-time assessment of the Society for Cardiovascular Angiography and Interventions (SCAI) shock classification robustly predicts mortality in the cardiac intensive care unit (CICU). We sought to determine whether serial SCAI shock classification could improve risk stratification.

METHODS AND RESULTS

Unique admissions to a single academic level 1 CICU from 2015 to 2018 were included in this retrospective cohort study. Electronic health record data were used to assign the SCAI shock stage during 4-hour blocks of the first 24 hours of CICU admission. Shock was defined as hypoperfusion (SCAI shock stage C, D, or E). In-hospital death was evaluated using logistic regression. Among 2918 unique CICU patients, 1537 (52.7%) met criteria for shock during ≥1 block, and 266 (9.1%) died in the hospital. The SCAI shock stage on admission was: A, 37.6%; B, 31.5%; C, 25.9%; D, 1.8%; and E, 3.3%. Patients who met SCAI criteria for shock on admission (first 4 hours) and those with worsening SCAI shock stage after admission were at higher risk for in-hospital death. Each higher admission (adjusted odds ratio, 1.36 [95% CI, 1.18-1.56]; area under the receiver operating characteristic curve, 0.70), maximum (adjusted odds ratio, 1.59 [95% CI, 1.37-1.85]; area under the receiver operating characteristic curve, 0.73) and mean (adjusted odds ratio, 2.42 [95% CI, 1.99-2.95]; area under the receiver operating characteristic curve, 0.78) SCAI shock stage was incrementally associated with a higher in-hospital mortality rate. Discrimination was highest for the mean SCAI shock stage (P<0.05). Each additional 4-hour block meeting SCAI criteria for shock predicted a higher mortality rate (adjusted odds ratio, 1.15 [95% CI, 1.07-1.24]).

CONCLUSIONS

Dynamic assessment of shock using serial SCAI shock classification assignment can improve mortality risk stratification in CICU patients by quantifying the magnitude and duration of shock.

Extending the 'host response' paradigm from sepsis to cardiogenic shock: evidence, limitations and opportunities

Recent clinical and research efforts in cardiogenic shock (CS) have largely focussed on the restoration of the low cardiac output state that is the conditio sine qua non of the clinical syndrome. This approach has failed to translate into improved outcomes, and mortality has remained static at 30-50%. There is an unmet need to better delineate the pathobiology of CS to understand the observed heterogeneity of presentation and treatment effect and to identify novel therapeutic targets. Despite data in other critical illness syndromes, specifically sepsis, the role of dysregulated inflammation and immunity is hitherto poorly described in CS. High-dimensional molecular profiling, particularly through leukocyte transcriptomics, may afford opportunity to better characterise subgroups of patients with shared mechanisms of immune dysregulation. In this state-of-the-art review, we outline the rationale for considering molecular subtypes of CS. We describe how high-dimensional molecular technologies can be used to identify these subtypes, and whether they share biological features with sepsis and other critical illness states. Finally, we propose how the identification of molecular subtypes of patients may enrich future clinical trial design and identification of novel therapies for CS.

Systematic Assessment of Shock Severity in Postoperative Cardiac Surgery Patients

BACKGROUND

The Society for Cardiovascular Angiography and Interventions (SCAI) shock classification has been shown to provide robust mortality risk stratification in a variety of cardiovascular patients.

OBJECTIVES

This study sought to evaluate the SCAI shock classification in postoperative cardiac surgery intensive care unit (CSICU) patients.

METHODS

This study retrospectively analyzed 26,792 postoperative CSICU admissions at a heart center between 2012 and 2022. Patients were classified into SCAI shock stages A to E using electronic health record data. Moreover, the impact of late deterioration (LD) as an additional risk modifier was investigated.

RESULTS

The proportions of patients in SCAI shock stages A to E were 24.4%, 18.8%, 8.4%, 35.5%, and 12.9%, and crude hospital mortality rates were 0.4%, 0.6%, 3.3%, 4.9%, and 30.2%, respectively. Similarly, the prevalence of postoperative complications and organ dysfunction increased across SCAI shock stages. After multivariable adjustment, each higher SCAI shock stage was associated with increased hospital mortality (adjusted OR: 1.26-16.59) compared with SCAI shock stage A, as was LD (adjusted OR: 8.2). The SCAI shock classification demonstrated a strong diagnostic performance for hospital mortality (area under the receiver operating characteristic: 0.84), which noticeably increased when LD was incorporated into the model (area under the receiver operating characteristic: 0.90).

CONCLUSIONS

The SCAI shock classification effectively risk-stratifies postoperative CSICU patients for mortality, postoperative complications, and organ dysfunction. Its application could, therefore, be extended to the field of cardiac surgery as a triage tool in postoperative care and as a selection criterion in research.

Standardized Definitions for Cardiogenic Shock Research and Mechanical Circulatory Support Devices: Scientific Expert Panel From the Shock Academic Research Consortium (SHARC)

The Shock Academic Research Consortium is a multi-stakeholder group, including representatives from the US Food and Drug Administration and other government agencies, industry, and payers, convened to develop pragmatic consensus definitions useful for the evaluation of clinical trials enrolling patients with cardiogenic shock, including trials evaluating mechanical circulatory support devices. Several in-person and virtual meetings were convened between 2020 and 2022 to discuss the need for developing the standardized definitions required for evaluation of mechanical circulatory support devices in clinical trials for cardiogenic shock patients. The expert panel identified key concepts and topics by performing literature reviews, including previous clinical trials, while recognizing current challenges and the need to advance evidence-based practice and statistical analysis to support future clinical trials. For each category, a lead (primary) author was assigned to perform a literature search and draft a proposed definition, which was presented to the subgroup. These definitions were further modified after feedback from the expert panel meetings until a consensus was reached. This manuscript summarizes the expert panel recommendations focused on outcome definitions, including efficacy and safety.

Distribution and 24-hour transition of SCAI shock stages and their association with 30-day mortality in acute myocardial infarction

The Society for Cardiovascular Angiography and Interventions (SCAI) shock classification has been shown to predict mortality in acute myocardial infarction (AMI). However, data on the transition of SCAI stages and their association with mortality after AMI are limited. All patients with AMI admitted to Vietnam National Heart Institute between August 2022 and February 2023 were classified into SCAI stages A, B, and C/D/E at admission and were reevaluated in 24 hours. We used Kaplan-Meier estimate and multivariable Cox regression analysis to assess the association between SCAI stages transition and 30-day mortality. We included 139 patients (median age 69 years, 29.5% female). On admission, 50.4%, 20.1%, and 29.5% of patients were classified as SCAI stage A, B, and C/D/E, respectively. The proportion of patients whose SCAI stage improved, remained stable, or worsened after 24 hours was 14.4%, 66.2%, and 19.4%, respectively. The 30-day mortality in patients with initial SCAI stages A, B, and C/D/E on admission was 2.9%, 21.4%, and 61.0%, respectively (P < .001). The 30-day mortality was 2.4% for patients with baseline SCAI stage A/B who remained unchanged or improved, 30.0% for patients with baseline SCAI stage C/D/E who remained unchanged or improved, and 92.6% for patients with SCAI stage B/C/D/E who worsened at 24 hours after admission (log-rank P < .001). In patients with AMI, evaluating the SCAI stage shock stage on admission and reevaluating after 24 hours added more information about 30-day mortality.

Long-Term Outcomes of Cardiogenic Shock Complicating Myocardial Infarction

BACKGROUND

Cardiogenic shock secondary to acute myocardial infarction (AMI-CS) is associated with substantial short-term mortality; however, there are limited data on long-term outcomes and trends.

OBJECTIVES

This study sought to examine long-term outcomes of AMI-CS patients.

METHODS

This was a population-based, retrospective cohort study in Ontario, Canada of critically ill adult patients with AMI-CS who were admitted to hospitals between April 1, 2009 and March 31, 2019. Outcome data were captured using linked health administrative databases.

RESULTS

A total of 9,789 consecutive patients with AMI-CS from 135 centers were included. The mean age was 70.5 ± 12.3 years, and 67.7% were male. The incidence of AMI-CS was 8.2 per 100,000 person-years, and it increased over the study period. Critical care interventions were common, with 5,422 (55.4%) undergoing invasive mechanical ventilation, 1,425 (14.6%) undergoing renal replacement therapy, and 1,484 (15.2%) receiving mechanical circulatory support. A total of 2,961 patients (30.2%) died in the hospital, and 4,004 (40.9%) died by 1 year. Mortality at 5 years was 58.9%. Small improvements in short- and long-term mortality were seen over the study period. Among survivors to discharge, 2,870 (42.0%) required increased support in care from their preadmission baseline, 3,244 (47.5%) were readmitted to the hospital within 1 year, and 1,047 (15.3%) died within 1 year. The mean number of days at home in the year following discharge was 307.9 ± 109.6.

CONCLUSIONS

Short- and long-term mortality among patients with AMI-CS is high, with minimal improvement over time. AMI-CS survivors experience significant morbidity, with high risks of readmission and death. Future studies should evaluate interventions to minimize postdischarge morbidity and mortality among AMI-CS survivors.

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.

Mortality and Heart Failure Hospitalization Among Young Adults With and Without Cardiogenic Shock After Acute Myocardial Infarction

OBJECTIVES

To investigate risk factors and outcomes of cardiogenic shock complicating acute myocardial infarction (AMI-CS) in young patients with AMI.

BACKGROUND

AMI-CS is associated with high morbidity and mortality rates. Data regarding AMI-CS in younger individuals are limited.

METHODS AND RESULTS

Consecutive patients with type 1 AMI aged 18-50 years admitted to 2 large tertiary-care academic centers were included, and they were adjudicated as having cardiogenic shock (CS) by physician review of electronic medical records using the Society for Cardiovascular Angiography and Interventions CS classification system. Outcomes included all-cause mortality (ACM), cardiovascular mortality (CVM) and 1-year hospitalization for heart failure (HHF). In addition to using the full population, matching was also used to define a comparator group in the non-CS cohort. Among 2097 patients (mean age 44 ± 5.1 years, 74% white, 19% female), AMI-CS was present in 148 (7%). Independent risk factors of AMI-CS included ST-segment elevation myocardial infarction, left main disease, out-of-hospital cardiac arrest, female sex, peripheral vascular disease, and diabetes. Over median follow-up of 11.2 years, young patients with AMI-CS had a significantly higher risk of ACM (adjusted HR 2.84, 95% CI 1.68-4.81; P < 0.001), CVM (adjusted HR 4.01, 95% CI 2.17-7.71; P < 0.001), and 1-year HHF (adjusted HR 5.99, 95% CI 2.04-17.61; P = 0.001) compared with matched non-AMI-CS patients. Over the course of the study, there was an increase in the incidence of AMI-CS among young patients with MI as well as rising mortality rates for patients with both AMI-CS and non-AMI-CS.

CONCLUSIONS

Of young patients with AMI, 7% developed AMI-CS, which was associated with a significantly elevated risk of mortality and HHF.

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.

Advances in the Staging and Phenotyping of Cardiogenic Shock: Part 1 of 2

Cardiogenic shock (CS) is a heterogeneous syndrome reflecting a broad spectrum of shock severity, diverse etiologies, variable cardiac function, different hemodynamic trajectories, and concomitant organ dysfunction. These factors influence the clinical presentation, management, response to therapy, and outcomes of CS patients, necessitating a tailored approach to care. To better understand the variability inherent to CS populations, recent algorithms for staging the severity of CS have been described and validated. This paper is part 1 of a 2-part state-of-the-art review. In this first article, we consider the context for clinical staging and stratification in CS with a focus on established severity staging systems for CS and their use for risk stratification and clinical care. We describe the use of staging for predicting outcomes in populations with or at risk for CS, including risk modifiers that provide more nuanced risk stratification, and highlight how these approaches may allow individualized care.

Machine Learning Approaches for Phenotyping in Cardiogenic Shock and Critical Illness: Part 2 of 2

Progress in improving cardiogenic shock (CS) outcomes may have been limited by failure to embrace the heterogeneity of pathophysiologic processes driving the underlying syndrome. To better understand the variability inherent to CS populations, recent algorithms for describing underlying CS disease subphenotypes have been described and validated. These strategies hope to identify specific patient subgroups with more favorable responses to standard therapies, as well as those who require novel treatment approaches. This paper is part 2 of a 2-part state-of-the-art review. In this second article, we present machine learning-based statistical approaches to identifying subphenotypes and discuss their strengths and limitations, as well as evidence from other critical illness syndromes and emerging applications in CS. We then discuss how staging and stratification may be considered in CS clinical trials and finally consider future directions for this emerging area of research.

Optimal Perfusion Targets in Cardiogenic Shock

Cardiology shock is a syndrome of low cardiac output resulting in end-organ dysfunction. Few interventions have demonstrated meaningful clinical benefit, and cardiogenic shock continues to carry significant morbidity with mortality rates that have plateaued at upwards of 40% over the past decade. Clinicians must rely on clinical, biochemical, and hemodynamic parameters to guide resuscitation. Several features, including physical examination, renal function, serum lactate metabolism, venous oxygen saturation, and hemodynamic markers of right ventricular function, may be useful both as prognostic markers and to guide therapy. This article aims to review these targets, their utility in the care of patients with cardiology shock, and their association with outcomes.

Shock Severity Assessment in Cardiac Intensive Care Unit Patients With Sepsis and Mixed Septic-Cardiogenic Shock

We sought to validate the Society for Cardiovascular Angiography and Interventions (SCAI) cardiogenic shock classification for mortality risk stratification in patients with sepsis and concomitant cardiovascular disease or mixed septic-cardiogenic shock. We conducted a single-center retropective cohort study of cardiac intensive care unit patients with an admission diagnosis of sepsis. We used clinical, vital sign, and laboratory data during the first 24 hours after admission to assign SCAI shock stage. We included 605 patients with a median age of 69.4 years (interquartile range, 57.9 to 79.8 years), 222 of whom (36.7%) were female. Acute coronary syndrome or heart failure was present in 480 patients (79.3%), and cardiogenic shock or cardiac arrest was present in 271 patients (44.8%). The median day 1 Sequential Organ Failure Assessment (SOFA) cardiovascular subscore was 1.5 (interquartile range, 1 to 4), and the admission SCAI shock stage distribution was stage B, 40.7% (246); stage C, 19.3% (117); stage D, 32.9% (199); and stage E, 7.1% (43). In-hospital mortality occurred in 177 of the 605 patients (29.3%) and increased incrementally with higher SCAI shock stage. After multivariable adjustment, admission SCAI shock stage was associated with in-hospital mortality (adjusted odds ratio per stage, 1.46; 95% CI, 1.14 to 1.88; P=.003). Admission SCAI shock stage had higher discrimination for in-hospital mortality than the day 1 SOFA cardiovascular subscore (area under the receiver operating characteristic curve, 0.68 vs 0.64; P=.04 by the DeLong test). Admission SCAI shock stage was associated with 1-year mortality (adjusted hazard ratio per stage, 1.19; 95% CI, 1.03 to 1.37; P=.02). The SCAI shock classification provides improved mortality risk stratification over the day 1 SOFA cardiovascular subscore in cardiac intensive care unit patients with sepsis and concomitant cardiovascular disease or mixed septic-cardiogenic shock.

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.

Epidemiology and causes of cardiogenic shock

PURPOSE OF REVIEW

Cardiogenic shock is a complex clinical syndrome of end-organ hypoperfusion due to impaired cardiac performance. Although cardiogenic shock has traditionally been viewed as a monolithic disorder predominantly caused by severe left ventricular dysfunction complicating acute myocardial infarction (AMI), there is increasing recognition of the diverse causes of cardiogenic shock and wide spectrum of clinical severity. The purpose of this review is to describe the contemporary epidemiology of cardiogenic shock, including trends in clinical outcomes and recent efforts to refine risk assessment.

RECENT FINDINGS

The incidence of cardiogenic shock among patients with AMI has remained remarkably stable at 3-10%; however, the proportion of cardiogenic shock cases related to AMI has decreased over time to ∼30%, while the proportion of cardiogenic shock cases due to acute decompensated heart failure has steadily increased. Estimated in-hospital mortality from cardiogenic shock in contemporary registries is approximately 30-40%, suggesting modest improvement in cardiogenic shock outcomes over the last decade. There is a wide spectrum of clinical severity among patients presenting with cardiogenic shock, which is described by the Society for Cardiovascular Angiography and Interventions clinical staging criteria.

SUMMARY

Improved clinical characterization and risk assessment of patients with cardiogenic shock may facilitate more effective clinical investigations of this morbid clinical syndrome.