Cardiac safety research consortium "shock II" think tank report: Advancing practical approaches to generating evidence for the treatment of cardiogenic shock

Research Priorities in Critical Care Cardiology: JACC Expert Panel

Over the last several decades, the cardiac intensive care unit (CICU) has seen a substantial evolution in the patient population, comorbidities, and diagnoses. However, the generation of high-quality evidence to manage these complex and critically ill patients has been slow. Given the scarcity of clinical trials focused on critical care cardiology (CCC), CICU clinicians are often left to extrapolate from studies that either exclude or poorly represent the patient population admitted to CICUs. The lack of high-quality evidence and limited guidance from society guidelines has led to significant variation in practice patterns for many of the most common CICU diagnoses. Several barriers, both common to critical care research and unique to CCC, have impeded progress. In this multinational perspective, we describe key areas of priority for CCC research, current challenges for investigation in the CICU, and essential elements of a path forward for the field.

Trends in Cardiogenic Shock-Related Mortality in Patients With Acute Myocardial Infarction in the United States, 1999 to 2019

Data on mortality trends in patients with acute myocardial infarction (AMI) with cardiogenic shock (CS) are scant. This study aimed to assess the trends in CS-AMI-related mortality in United States (US) subjects over the latest 21 years. Mortality data of US subjects with AMI listed as the underlying cause of death and CS as contributing cause were obtained from the Centers for Disease Control and Prevention WONDER (Wide-Ranging Online Data for Epidemiologic Research) dataset from January 1999 to December 2019. CS-AMI-related age-adjusted mortality rates (AAMRs) per 100,000 US population were stratified by gender, race and ethnicity, geographic areas, and urbanicity. Nationwide annual trends were assessed as annual percent change (APC) and average APC with relative 95% confidence intervals (CIs). Between 1999 and 2019, CS-AMI was listed as the underlying cause of death in 209,642 patients, (AAMR of 3.01 per 100,000 people [95% CI 2.99 to 3.02]). AAMR from CS-AMI remained stable from 1999 to 2007 (APC -0.2%, [95% CI -2.0 to 0.5], p = 0.22) and then significantly increased (APC 3.1% [95% CI 2.6 to 3.6], p <0.0001), especially in male patients. Starting in 2009, the AAMR increase was more pronounced in those <65 years, Black Americans, and residents of rural areas. The higher AAMRs were clustered in the South (average APC 4.5%, [95% CI 4.4 to 4.6]) of the country. In conclusion, CS-AMI-related mortality in US patients increased from 2009 to 2019. Targeted health policy measures are needed to address the rising burden of CS-AMI in US subjects.

Improving Survival in Cardiogenic Shock-A Propensity Score-Matched Analysis of the Impact of an Institutional Allocation Protocol to Short-Term Mechanical Circulatory Support

Temporary mechanical circulatory support (tMCS) is a life-saving treatment option for patients in cardiogenic shock (CS), but many aspects such as patient selection, initiation threshold and optimal modality selection remain unclear. This study describes a standard operating procedure (SOP) for tMCS allocation for CS patients and presents outcome data before and after implementation. Data from 421 patients treated for CS with tMCS between 2018 and 2021 were analyzed. In 2019, we implemented a new SOP for allocating CS patients to tMCS modalities. The association between the time of SOP implementation and the 30-day and 1-year survival as well as hospital discharge was evaluated. Of the 421 patients included, 189 were treated before (pre-SOP group) and 232 after implementation of the new SOP (SOP group). Causes of CS included acute myocardial infarction (n = 80, 19.0%), acute-on-chronic heart failure in patients with dilated or chronic ischemic heart failure (n = 139, 33.0%), valvular cardiomyopathy (n = 14, 3.3%) and myocarditis (n = 5, 1.2%); 102 patients suffered from postcardiotomy CS (24.2%). The SOP group was further divided into an SOP-adherent (SOP-A) and a non-SOP-adherent group (SOP-NA). The hospital discharge rate was higher in the SOP group (41.7% vs. 29.7%), and treating patients according to the SOP was associated with an improved 30-day survival (56.9% vs. 38.9%, OR 2.21, 95% CI 1.01-4.80, p = 0.044). Patient allocation according to the presented SOP significantly improved 30-day survival.

Position Statement on Vascular Access Safety for Percutaneous Devices in AMI Complicated by Cardiogenic Shock

In the United States, the frequency of using percutaneous mechanical circulatory support devices for acute myocardial infarction complicated by cardiogenic shock is increasing. These devices require large-bore vascular access to provide left, right, or biventricular cardiac support, frequently under urgent/emergent circumstances. Significant technical and logistical variability exists in device insertion, care, and removal in the cardiac catheterization laboratory and in the cardiac intensive care unit. This variability in practice may contribute to adverse outcomes observed in centers that receive patients with cardiogenic shock, who are at higher risk for circulatory insufficiency, venous stasis, bleeding, and arterial hypoperfusion. In this position statement, we aim to: 1) describe the public health impact of bleeding and vascular complications in cardiogenic shock; 2) highlight knowledge gaps for vascular safety and provide a roadmap for a regulatory perspective necessary for advancing the field; 3) propose a minimum core set of process elements, or "vascular safety bundle"; and 4) develop a possible study design for a pragmatic trial platform to evaluate which structured approach to vascular access drives most benefit and prevents vascular and bleeding complications in practice.

Hemodynamic-based Assessment and Management of Cardiogenic Shock

Cardiogenic shock (CS) remains a deadly disease entity challenging patients, caregivers, and communities across the globe. CS can rapidly lead to the development of hypoperfusion and end-organ dysfunction, transforming a predictable hemodynamic event into a potential high-resource, intense, hemometabolic clinical catastrophe. Based on the scalable heterogeneity from a cellular level to healthcare systems in the hemodynamic-based management of patients experiencing CS, we present considerations towards systematic hemodynamic-based transitions in which distinct clinical entities share the common path of early identification and rapid transitions through an adaptive longitudinal situational awareness model of care that influences specific management considerations. Future studies are needed to best understand optimal management of drugs and devices along with engagement of health systems of care for patients with CS.

Contemporary Management of Cardiogenic Shock: A RAND Appropriateness Panel Approach

BACKGROUND

Current practice in cardiogenic shock is guided by expert opinion in guidelines and scientific statements from professional societies with limited high quality randomized trial data to inform optimal patient management. An international panel conducted a modified Delphi process with the intent of identifying aspects of cardiogenic shock care where there was uncertainty regarding optimal patient management.

METHODS

An 18-person multidisciplinary panel comprising international experts was convened. A modified RAND/University of California Los Angeles appropriateness methodology was used. A survey comprising 70 statements was completed. Participants anonymously rated the appropriateness of each statement on a scale of 1 to 9: 1 to 3 inappropriate, 4 to 6 uncertain, and 7 to 9 appropriate. A summary of the results was discussed as a group, and the survey was iterated and completed again before final analysis.

RESULTS

There was broad alignment with current international guidelines and consensus statements. Overall, 44 statements were rated as appropriate, 19 as uncertain, and 7 as inappropriate. There was no disagreement with a disagreement index <1 for all statements. Routine fluid administration was deemed to be inappropriate. Areas of uncertainty focused panel on pre-PCI interventions, the use of right heart catheterization to guide management, routine use of left ventricular unloading strategies, and markers of futility when considering escalation to mechanical circulatory support.

CONCLUSIONS

While there was broad alignment with current guidance, an expert panel found several aspects of care where there was clinical equipoise, further highlighting the need for randomized controlled trials to better guide patient management and decision making in cardiogenic shock.

Cardiogenic Shock After Acute Myocardial Infarction: A Review

IMPORTANCE

Cardiogenic shock affects between 40 000 and 50 000 people in the US per year and is the leading cause of in-hospital mortality following acute myocardial infarction.

OBSERVATIONS

Thirty-day mortality for patients with cardiogenic shock due to myocardial infarction is approximately 40%, and 1-year mortality approaches 50%. Immediate revascularization of the infarct-related coronary artery remains the only treatment for cardiogenic shock associated with acute myocardial infarction supported by randomized clinical trials. The Percutaneous Coronary Intervention Strategies with Acute Myocardial Infarction and Cardiogenic Shock (CULPRIT-SHOCK) clinical trial demonstrated a reduction in the primary outcome of 30-day death or kidney replacement therapy; 158 of 344 patients (45.9%) in the culprit lesion revascularization-only group compared with 189 of 341 patients (55.4%) in the multivessel percutaneous coronary intervention group (relative risk, 0.83 [95% CI, 0.71-0.96]; P = .01). Despite a lack of randomized trials demonstrating benefit, percutaneous mechanical circulatory support devices are frequently used to manage cardiogenic shock following acute myocardial infarction.

CONCLUSIONS AND RELEVANCE

Cardiogenic shock occurs in up to 10% of patients immediately following acute myocardial infarction and is associated with mortality rates of nearly 40% at 30 days and 50% at 1 year. Current evidence and clinical practice guidelines support immediate revascularization of the infarct-related coronary artery as the primary therapy for cardiogenic shock following acute myocardial infarction.

Venoarterial Extracorporeal Membrane Oxygenation for Acute Massive Pulmonary Embolism: a Meta-Analysis and Call to Action

Venoarterial extracorporeal membrane oxygenation (ECMO) has been used to treat acute massive pulmonary embolism (PE) patients. However, the incremental benefit of ECMO to standard therapy remains unclear. Our meta-analysis objective is to compare in-hospital mortality in patients treated for acute massive PE with and without ECMO. The National Library of Medicine MEDLINE (USA), Web of Science, and PubMed databases from inception through October 2020 were searched. Screening identified 1002 published articles. Eleven eligible studies were identified, and 791 patients with acute massive PE were included, of whom 270 received ECMO and 521 did not. In-hospital mortality was not significantly different between patients treated with vs. without ECMO (OR = 1.24 [95% CI, 0.63–2.44], p = 0.54). However, these findings were limited by significant study heterogeneity. Additional research will be needed to clarify the role of ECMO in massive PE treatment.

Variability in reporting of key outcome predictors in acute myocardial infarction cardiogenic shock trials

BACKGROUND

Among acute myocardial infarction patients with cardiogenic shock (AMICS), a number of key variables predict mortality, including cardiac arrest (CA) and shock classification as proposed by Society for Cardiovascular Angiography and Intervention (SCAI). Given this prognostic importance, we examined the frequency of reporting of high risk variables in published randomized controlled trials (RCTs) of AMICS patients.

METHODS

We identified 15 RCTs enrolling 2,500 AMICS patients and then reviewed rates of CA, baseline neurologic status, right heart catheterization data, lactate levels, inotrope and vasopressor requirement, hypothermia, mechanical ventilation, left ventricular ejection fraction (LVEF), mechanical circulatory support, and specific cause of death based on the primary manuscript and Data in S1.

RESULTS

A total of 2,500 AMICS patients have been enrolled in 15 clinical trials over 21 years with only four trials enrolling >80 patients. The reporting frequency and range for key prognostic factors was: neurologic status (0% reported), hypothermia (28% reported, prevalence 33-75%), specific cause of death (33% reported), cardiac index and wedge pressure (47% reported, range 1.6-2.3 L min^-1 m^-2 and 15-24 mmHg), lactate (60% reported, range 4-7.7 mmol/L), LVEF (73% reported, range 25-45%), CA (80% reported, prevalence 0-92%), MCS (80% reported, prevalence 13-100%), and mechanical ventilation (93% reported, prevalence 35-100%). This variability was reflected in the 30-day mortality which ranged from 20-73%.

CONCLUSIONS

In a comprehensive review of seminal RCTs in AMICS, important predictors of outcome were frequently not reported. Future efforts to standardize CS trial data collection and reporting may allow for better assessment of novel therapies for AMICS.