Pathophysiology and Advanced Hemodynamic Assessment of Cardiogenic Shock

Science of left ventricular unloading

The concept of left ventricular unloading has its foundation in heart physiology. In fact, the left ventricular mechanics and energetics represent the cornerstone of this approach. The novel sophisticated therapies for acute heart failure, particularly mechanical circulatory supports, strongly impact on the mechanical functioning and energy consuption of the heart, ultimately affecting left ventricle loading. Notably, extracorporeal circulatory life support which is implemented for life-threatening conditions, may even overload the left heart, requiring additional unloading strategies. As a consequence, the understanding of ventricular overload, and the associated potential unloading strategies, founds its utility in several aspects of day-by-day clinical practice. Emerging clinical and pre-clinical research on left ventricular unloading and its benefits in heart failure and recovery has been conducted, providing meaningful insights for therapeutical interventions. Here, we review the current knowledge on left ventricular unloading, from physiology and molecular biology to its application in heart failure and recovery.

Left Ventricular Unloading in Extracorporeal Membrane Oxygenation: A Clinical Perspective Derived from Basic Cardiovascular Physiology

PURPOSE OF REVIEW

To present an abridged overview of the literature and pathophysiological background of adjunct interventional left ventricular unloading strategies during veno-arterial extracorporeal membrane oxygenation (V-A ECMO). From a clinical perspective, the mechanistic complexity of such combined mechanical circulatory support often requires in-depth physiological reasoning at the bedside, which remains a cornerstone of daily practice for optimal patient-specific V-A ECMO care.

RECENT FINDINGS

Recent conventional clinical trials have not convincingly shown the superiority of V-A ECMO in acute myocardial infarction complicated by cardiogenic shock as compared with medical therapy alone. Though, it has repeatedly been reported that the addition of interventional left ventricular unloading to V-A ECMO may improve clinical outcome. Novel approaches such as registry-based adaptive platform trials and computational physiological modeling are now introduced to inform clinicians by aiming to better account for patient-specific variation and complexity inherent to V-A ECMO and have raised a widespread interest. To provide modern high-quality V-A ECMO care, it remains essential to understand the patient's pathophysiology and the intricate interaction of an individual patient with extracorporeal circulatory support devices. Innovative clinical trial design and computational modeling approaches carry great potential towards advanced clinical decision support in ECMO and related critical care.

Extracorporeal Life Support in Myocardial Infarction: New Highlights

Background and Objectives: Cardiogenic shock (CS) is a potentially severe complication following acute myocardial infarction (AMI). The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in these patients has risen significantly over the past two decades, especially when conventional treatments fail. Our aim is to provide an overview of the role of VA-ECMO in CS complicating AMI, with the most recent literature highlights. Materials and Methods: We have reviewed the current VA-ECMO practices with a particular focus on CS complicating AMI. The largest studies reporting the most significant results, i.e., overall clinical outcomes and management of the weaning process, were identified in the PubMed database from 2019 to 2024. Results: The literature about the use of VA-ECMO in CS complicating AMI primarily has consisted of observational studies until 2019, generating the need for randomized controlled trials. The EURO-SHOCK trial showed a lower 30-day all-cause mortality rate in patients receiving VA-ECMO compared to those receiving standard therapy. The ECMO-CS trial compared immediate VA-ECMO implementation with early conservative therapy, with a similar mortality rate between the two groups. The ECLS-SHOCK trial, the largest randomized controlled trial in this field, found no significant difference in mortality at 30 days between the ECMO group and the control group. Recent studies suggest the potential benefits of combining left ventricular unloading devices with VA-ECMO, but they also highlight the increased complication rate, such as bleeding and vascular issues. The routine use of VA-ECMO in AMI complicated by CS cannot be universally supported due to limited evidence and associated risks. Ongoing trials like the Danger Shock, Anchor, and Recover IV trials aim to provide further insights into the management of AMI complicated by CS. Conclusions: Standardizing the timing and indications for initiating mechanical circulatory support (MCS) is crucial and should guide future trials. Multidisciplinary approaches tailored to individual patient needs are essential to minimize complications from unnecessary MCS device initiation.

Clinical impact of pulmonary artery catheter in patients with cardiogenic shock: A systematic review and meta-analysis

BACKGROUND

The clinical utility of the pulmonary artery catheter (PAC) for the management of cardiogenic shock (CS) remains controversial. We performed a systematic review and meta-analysis exploring the association between PAC use and mortality among patients with CS.

METHODS

Published studies of patients with CS treated with or without PAC hemodynamic guidance were retrieved from MEDLINE and PubMed databases from January 1, 2000, to December 31, 2021. The primary outcome was mortality, which was defined as a combination of in-hospital mortality and 30-day mortality. Secondary outcomes assessed 30-day and in-hospital mortality separately. To assess the quality of nonrandomized studies, the Newcastle-Ottawa Scale (NOS), a well-established scoring system was used. We analyzed outcomes for each study using NOS with a threshold value of >6, indicating high quality. We also performed analyses based on the countries of the studies conducted.

RESULTS

Six studies with a total of 930,530 patients with CS were analyzed. Of these, 85,769 patients were in the PAC-treated group, and 844,761 patients did not receive a PAC. PAC use was associated with a significantly lower risk of mortality (PAC: 4.6 % to 41.5 % vs control: 18.8 % to 51.0 %) (OR 0.63, 95 % CI: 0.41-0.97, I2 = 0.96). Subgroup analyses demonstrated no difference in the risk of mortality between NOS ≥ 6 studies and NOS < 6 studies (p-interaction = 0.57), 30-day and in-hospital mortality (p-interaction = 0.83), or the country of origin of studies (p-interaction = 0.08).

CONCLUSIONS

The use of PAC in patients with CS may be associated with decreased mortality. These data support the need for a randomized controlled trial testing the utility of PAC use in CS.

Extracorporeal Membrane Oxygenation (VA-ECMO) in Management of Cardiogenic Shock

Cardiogenic shock is a critical condition of low cardiac output resulting in insufficient systemic perfusion and end-organ dysfunction. Though significant advances have been achieved in reperfusion therapy and mechanical circulatory support, cardiogenic shock continues to be a life-threatening condition associated with a high rate of complications and excessively high patient mortality, reported to be between 35% and 50%. Extracorporeal membrane oxygenation can provide full cardiopulmonary support, has been increasingly used in the last two decades, and can be used to restore systemic end-organ hypoperfusion. However, a paucity of randomized controlled trials in combination with high complication and mortality rates suggest the need for more research to better define its efficacy, safety, and optimal patient selection. In this review, we provide an updated review on VA-ECMO, with an emphasis on its application in cardiogenic shock, including indications and contraindications, expected hemodynamic and echocardiographic findings, recommendations for weaning, complications, and outcomes. Furthermore, specific emphasis will be devoted to the two published randomized controlled trials recently presented in this setting.

Management of Cardiogenic Shock Unrelated to Acute Myocardial Infarction

Cardiogenic shock is an extreme manifestation of acute decompensated heart failure. Cardiogenic shock is often caused by-and has traditionally been studied in the setting of-acute myocardial infarction (AMI CS); however, there is increasing incidence and recognition of cardiogenic shock not associated with acute myocardial infarction (non-AMI CS) as a distinct entity. Despite decades of study and technologic advancements, cardiogenic shock mortality remains as high as 50%, regardless of etiology. New approaches to shock phenotyping and classification have emerged, with a focus on appropriately matching patient physiology to a growing list of available interventions. Further study is needed to determine whether these efforts will lead to more nuanced use of mechanical circulatory support and improved patient outcomes, especially in non-AMI CS. In the meantime, models of care incorporating multidisciplinary decision making, such as shock teams, may improve patient selection and outcomes.

Inotropic support in cardiogenic shock: who leads the battle, milrinone or dobutamine?

Cardiovascular diseases remain the leading cause of death globally, with acute myocardial infarction being one of the most frequent. One of the complications that can occur after a myocardial infarction is cardiogenic shock. At present, the evidence on the use of inotropic agents for the management of this complication is scarce, and only a few trials have evaluated the efficacy-adverse effects relationship of some agents. Milrinone and Dobutamine are some of the most frequently mentioned drugs that have been studied recently. However, there are still no data that affirm with certainty the supremacy of one over the other. The aim of this review is to synthesize evidence on basic and practical aspects of these agents, allowing us to conclude which might be more useful in current clinical practice, based on the emerging literature.

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Studies suggest that Milrinone has a higher safety and efficacy profile over Dobutamine.

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The evidence on the advantages of using Milrinone vs. Dobutamine is heterogeneous.

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Additional factors need to be considered to reduce the risk of adverse events.

Evolving Presentation of Cardiogenic Shock: A Review of the Medical Literature and Current Practices

Cardiogenic shock (CS) remains a leading cause of morbidity and mortality among patients with cardiovascular disease. In the past, acute myocardial infarction was the leading cause of CS. However, in recent years, other etiologies, such as decompensated chronic heart failure, arrhythmia, valvular disease, and post-cardiotomy, each with distinct hemodynamic profiles, have risen in prevalence. The number of treatment options, particularly with regard to device-mediated therapy has also increased. In this review, we sought to survey the medical literature and provide an update on current practices.

Recombinant human brain natriuretic peptide ameliorates venous return function in congestive heart failure

Aims

Recombinant human brain natriuretic peptide (rh‐BNP) is commonly used as a decongestive therapy. This study aimed to investigate the instant effects of rh‐BNP on cardiac output and venous return function in post‐cardiotomy patients with congestive heart failure (CHF).

Methods and results

Twenty‐four post‐cardiotomy heart failure patients were enrolled and received a standard loading dose of rh‐BNP. Haemodynamic monitoring was performed via a pulmonary artery catheter before and after the administration of rh‐BNP. The cardiac output and venous return functions were estimated by depicting Frank‐Starling and Guyton curves. After rh‐BNP infusion, variables reflecting cardiac congestion and venous return function, such as pulmonary artery wedge pressure, mean systemic filling pressure (Pmsf) and venous return resistance index (VRRI), reduced from 15 ± 3 to 13 ± 3 mmHg, from 32 ± 7 to 28 ± 7 mmHg and from 6.7 ± 2.6 to 5.7 ± 1.8 mmHg min m²/L, respectively. Meanwhile, cardiac index, stroke volume index, and the cardiac output function curve remained unchanged per se. The decline in Pmsf [−13% (−22% to −8%)] and VRRI [−12% (−25% to −5%)] was much greater than that in the systemic vascular resistance index [−7% (−14% to 0%)]. In the subgroup analysis of reduced ejection fraction (<40%) patients, the aforementioned changes were more significant.

Conclusions

rh‐BNP might ameliorate venous return rather than cardiac output function in post‐cardiotomy CHF patients.

Neutrophil-Albumin Ratio as a Predictor of in-Hospital Mortality in Patients with Cardiogenic Shock

Intoduction: Cardiogenic shock (SK) is the most severe phase of the acute heart failure syndrome. One of the most widely studied inflammatory mediators in cardiogenic shock is neutrophils. Albumin has several functions, including in pressure regulation, plays a role as an antioxidant and anti-inflammatory agent. Several studies have shown the association of albumin levels with mortality in patients with cardiogenic shock. Purpose: This study aimed to evaluate the utilization of neutrophil-albumin ratio (NAR) in predicting in-hospital mortality in patients with cardiogenic shock (CS) Patients and methods: This study was an observational study with cross sectional design conducted at the Department of Cardiovascular, Harapan Kita Cardiovascular Hospital. The data were collected from the patient registry (January 2018 to April 2020). The study participants were all patients with cardiogenic shock admitted to our hospital. The endpoint was in-hospital mortality in CS patients. Predictors of hospital mortality were identified using multivariable logistic regression, followed by receiver operator characteristic (ROC) curve analysis and cut-off value for optimal NAR level. Results: A total of 130 patients hospitalized with CS were enrolled in this study, In-hospital mortality was found in 75 (57,7%) patients, among which 102 (78,5%) were male and 101 (77,7%) patients had acute coronary syndrome. There was a significant positive correlation between NAR levels and in-hospital mortality. The multivariate logistic regression showed that NAR was independently associated with increased risk of in-hospital mortality with odd ratio (OR) of 5,81, 95% confidence interval (CI) 2,303 - 14,692, P <0,001. NAR had a prognostic value in predicting in-hospital mortality of CS based on ROC curve analysis (AUC 0,802), with an optimal NAR cut-off value of 25. Conclusion: NAR is independently associated with in-hospital mortality in patients with CS Keywords: Neutropil-albumin ratio, cardiogenic Shock, mortality predictor

Timing and Causes of Death in Acute Myocardial Infarction Complicated by Cardiogenic Shock (from the RETROSHOCK Cohort)

Acute myocardial infarction complicated by cardiogenic shock (AMICS) comprises a heterogeneous population with high mortality. Insight in timing and cause of death may improve understanding of the condition and aid individualization of treatment. This was assessed in a retrospective, multicenter observational cohort study based on 1,716 patients with AMICS treated during the period of 2010 to 2017, of whom 904 died before hospital discharge. Patients with AMICS were identified through national registries and review of individual patients charts. In 904 patients with AMICS who died before hospital discharge (median age 72 years [interquartile range (IQR) 63 to 79], 70% men), 342 (38%) had suffered out-of-hospital cardiac arrest. The most frequent cause of death was primary cardiac (54%), whereas 24% died of neurologic injury, and 20% of multiorgan failure (MOF). Time to death was 13 hours (IQR 5 to 43) for heart failure; 140 hours (IQR 95 to 209) in neurologic injury; and 137 hours (IQR 59 to 321) in MOF, p <0.001. The causes of death in patients presenting with out-of-hospital cardiac arrest (OHCA) were: neurologic injury in 57%, as opposed to 4% in patients not presenting with OHCA, p <0.001. In conclusion, in patients with AMICS, cause of death was mainly primary heart failure followed by neurologic injury and MOF. Median time from first medical contact to death was only 13 hours in patients dying from cardiac causes. The risk of dying of neurologic injury was low in patients without OHCA.

Pulmonary Artery Catheter Monitoring in Patients with Cardiogenic Shock: Time for a Reappraisal?

Cardiogenic shock represents one of the most dramatic scenarios to deal with in intensive cardiology care and is burdened by substantial short-term mortality. An integrated approach, including timely diagnosis and phenotyping, along with a well-established shock team and management protocol, may improve survival. The use of the Swan-Ganz catheter could play a pivotal role in various phases of cardiogenic shock management, encompassing diagnosis and haemodynamic characterisation to treatment selection, titration and weaning. Moreover, it is essential in the evaluation of patients who might be candidates for long-term heart-replacement strategies. This review provides a historical background on the use of the Swan-Ganz catheter in the intensive care unit and an analysis of the available evidence in terms of potential prognostic implications in this setting.

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.

Update on cardiogenic shock: The evolving landscape of a multidisciplinary and collaborative approach

ABSTRACT

The American Heart Association scientific statement on cardiogenic shock and the National Cardiogenic Shock Initiative have provided the impetus to advance knowledge and development of national guidelines for cardiogenic shock. We evaluate the current state of knowledge surrounding cardiogenic shock and limitations to the development of national guidelines.

Intra-Aortic Balloon Pump as a Bridge to Durable Left Ventricular Assist Device

Left ventricular assist devices (LVAD) are increasingly being used as destination therapy in patients with Stage D heart failure. It has been reported that a majority of patients who receive a durable LVAD (dLVAD) present in cardiogenic shock due to decompensated heart failure (ADHF‐CS). As it stands, there is no consensus on the optimal management strategy for patients presenting with ADHF. Bridging with intra‐aortic balloon pumps (IABPs) continues to be a therapeutic option in patients with hemodynamic instability due to cardiogenic shock. The majority of data regarding the use of IABP in cardiogenic shock come from studies in patients presenting with acute myocardial infarction with cardiogenic shock and demonstrates that there is no benefit of routine IABP use in this patient population. However, the role of IABPs as a bridge to dLVAD in ADHF‐CS has yet to be determined. The hemodynamic changes seen in acute myocardial infarction with cardiogenic shock are known to be different and more acutely impaired than those presenting with ADHF‐CS as evidenced by differences in pressure/volume loops. Thus, data should not be extrapolated across these 2 very different disease processes. The aim of this review is to describe results from contemporary studies examining the use of IABPs as a bridge to dLVAD in patients with ADHF‐CS. Retrospective evidence from large registries suggests that the use of IABP as a bridge to dLVAD is feasible and safe when compared with other platforms of temporary mechanical circulatory support. However, there is currently a paucity of high‐quality evidence examining this increasingly important clinical question.

Estimation of Stressed Blood Volume in Patients With Cardiogenic Shock From Acute Myocardial Infarction and Decompensated Heart Failure

BACKGROUND

Sympathetically mediated redistribution of blood from the unstressed venous reservoir to the hemodynamically active stressed compartment is thought to contribute to congestion in cardiogenic shock (CS). We used a novel computational method to estimate stressed blood volume (SBV) in CS and assess its relationship with clinical outcomes.

METHODS AND RESULTS

Hemodynamic parameters including estimated SBV (eSBV) were compared among patients from the Cardiogenic Shock Working Group registry with a complete set of hemodynamic data. eSBV was compared across shock etiologies (acute myocardial infarction and CS (AMI-CS) vs heart failure with CS (HF-CS), Society for Cardiovascular Angiography and Interventions stage, and between survivors and nonsurvivors. Among 528 patients with patients analyzed, the mean eSBV was 2423 mL/70 kg and increased with increasing Society for Cardiovascular Angiography and Interventions stage (B, 2029 mL/70 kg; C, 2305 mL/70 kg; D, 2496 mL/70 kg; E, 2707 mL/70 kg; P < .001). The eSBV was significantly greater among patients with HF-CS who died compared with survivors (2733 vs 2357 mL/70 kg; P < .001), whereas no significant difference was observed between outcome groups in AMI-CS (2501 mL/70 kg vs 2384 mL/70 kg; P = .19).

CONCLUSIONS

eSBV is a novel integrated index of congestion which correlates with shock severity. eSBV was higher in patients with HF-CS who died; no difference was observed in patients with AMI-CS, suggesting that congestion may play a more significant role in the deterioration of patients with HF-CS.