Managing the first 120 min of cardiogenic shock: from resuscitation to diagnosis

Hemodynamic monitoring and echocardiographic evaluation in cardiogenic shock

Cardiogenic shock (CS) is characterized by the presence of a state of tissue hypoperfusion secondary to ventricular dysfunction. Hemodynamic monitoring allows us to obtain information about cardiovascular pathophysiology that will help us make the diagnosis and guide therapy in CS situations. The most used monitoring system in CS is the pulmonary artery catheter since it provides key hemodynamic variables in CS, such as cardiac output, pulmonary artery pressure, and pulmonary artery occlusion pressure. On the other hand, echocardiography makes it possible to obtain, at the bedside, anatomical and hemodynamic data that complement the information obtained through continuous monitoring devices. CS monitoring can be considered multimodal and integrative by including hemodynamic, metabolic, and echocardiographic parameters that allow describing the characteristics of CS and guiding therapeutic interventions during hemodynamic resuscitation.

What is cardiogenic shock? New clinical criteria urgently needed

PURPOSE OF REVIEW

Cardiogenic shock is a clinical syndrome with different causes and a complex pathophysiology. Recent evidence from clinical trials evokes the urgent need for redefining clinical diagnostic criteria to be compliant with the definition of cardiogenic shock and current diagnostic methods.

RECENT FINDINGS

Conflicting results from randomized clinical trials investigating mechanical circulatory support in patients with cardiogenic shock have elicited several extremely important questions. At minimum, it is questionable whether survivors of cardiac arrest should be included in trials focused on cardiogenic shock. Moreover, considering the wide availability of ultrasound and hemodynamic monitors capable of arterial pressure analysis, the current clinical diagnostic criteria based on the presence of hypotension and hypoperfusion have become insufficient. As such, new clinical criteria for the diagnosis of cardiogenic shock should include evidence of low cardiac output and appropriate ventricular filling pressure.

SUMMARY

Clinical diagnostic criteria for cardiogenic shock should be revised to better define cardiac pump failure as a primary cause of hemodynamic compromise.

ICU management of cardiogenic shock before mechanical support

PURPOSE OF REVIEW

Treatment of cardiogenic shock remains largely driven by expert consensus due to limited evidence from randomized controlled trials. In this review, we aim to summarize the approach to the management of patients with cardiogenic shock in the ICU prior to mechanical circulatory support (MCS).

RECENT FINDINGS

Main topics covered in this article include diagnosis, monitoring, initial management and key aspects of pharmacological therapy in the ICU for patients with cardiogenic shock.

SUMMARY

Despite efforts to improve therapy, short-term mortality in patients with cardiogenic shock is still reaching 40-50%. Early recognition and treatment of cardiogenic shock are crucial, including early revascularization of the culprit lesion with possible staged revascularization in acute myocardial infarction (AMI)-CS. Optimal volume management and vasoactive drugs titrated to restore arterial pressure and perfusion are the cornerstone of cardiogenic shock therapy. The choice of vasoactive drugs depends on the underlying cause and phenotype of cardiogenic shock. Their use should be limited to the shortest duration and lowest possible dose. According to recent observational evidence, assessment of the complete hemodynamic profile with a pulmonary artery catheter (PAC) was associated with improved outcomes and should be considered early in patients not responding to initial therapy or with unclear shock. A multidisciplinary shock team should be involved early in order to identify potential candidates for temporary and/or durable MCS.

Cardiogenic Shock: Pathogenesis, Classification, and Management

Cardiogenic shock (CS) is a life-threatening circulatory failure syndrome which can progress rapidly to irreversible multiorgan failure through self-perpetuating pathophysiological processes. Recent developments in CS classification have highlighted its etiologic, mechanistic, and hemodynamic heterogeneity. Optimal CS management depends on early recognition, rapid reversal of the underlying cause, and prompt initiation of hemodynamic support.

Advances in the Management of Cardiogenic Shock

OBJECTIVES

To review a contemporary approach to the management of patients with cardiogenic shock (CS).

DATA SOURCES

We reviewed salient medical literature regarding CS.

STUDY SELECTION

We included professional society scientific statements and clinical studies examining outcomes in patients with CS, with a focus on randomized clinical trials.

DATA EXTRACTION

We extracted salient study results and scientific statement recommendations regarding the management of CS.

DATA SYNTHESIS

Professional society recommendations were integrated with evaluated studies.

CONCLUSIONS

CS results in short-term mortality exceeding 30% despite standard therapy. While acute myocardial infarction (AMI) has been the focus of most CS research, heart failure-related CS now predominates at many centers. CS can present with a wide spectrum of shock severity, including patients who are normotensive despite ongoing hypoperfusion. The Society for Cardiovascular Angiography and Intervention Shock Classification categorizes patients with or at risk of CS according to shock severity, which predicts mortality. The CS population includes a heterogeneous mix of phenotypes defined by ventricular function, hemodynamic profile, biomarkers, and other clinical variables. Integrating the shock severity and CS phenotype with nonmodifiable risk factors for mortality can guide clinical decision-making and prognostication. Identifying and treating the cause of CS is crucial for success, including early culprit vessel revascularization for AMI. Vasopressors and inotropes titrated to restore arterial pressure and perfusion are the cornerstone of initial medical therapy for CS. Temporary mechanical circulatory support (MCS) is indicated for appropriately selected patients as a bridge to recovery, decision, durable MCS, or heart transplant. Randomized controlled trials have not demonstrated better survival with the routine use of temporary MCS in patients with CS. Accordingly, a multidisciplinary team-based approach should be used to tailor the type of hemodynamic support to each individual CS patient's needs based on shock severity, phenotype, and exit strategy.

The Role of Echocardiography in Extracorporeal Membrane Oxygenation

PURPOSE OF REVIEW

Extracorporeal membrane oxygenation (ECMO) is increasingly used to temporarily support patients in severe circulatory and/or respiratory failure. Echocardiography is a core component of successful ECMO deployment. Herein, we review the role of echocardiography at different phases on extracorporeal support including candidate identification, cannulation, maintenance, complication vigilance, and decannulation.

RECENT FINDINGS

During cannulation, ultrasound is used to confirm intended vascular access and appropriate inflow cannula positioning. While on ECMO, echocardiographic evaluation of ventricular loading conditions and hemodynamics, cannula positioning, and surveillance for intracardiac or aortic thrombi is needed for complication mitigation. Echocardiography is crucial during all phases of ECMO use. Specific echocardiographic queries depend on the ECMO type, V-V, or V-A, and the specific cannula configuration strategy employed.

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.

Association Between the Acidemia, Lactic Acidosis, and Shock Severity With Outcomes in Patients With Cardiogenic Shock

Background

Lactic acidosis is associated with mortality in patients with cardiogenic shock (CS). Elevated lactate levels and systemic acidemia (low blood pH) have both been proposed as drivers of death. We, therefore, analyzed the association of both high lactate concentrations and low blood pH with 30‐day mortality in patients with CS.

Methods and Results

This was a 2‐center historical cohort study of unselected patients with CS with available data for admission lactate level or blood pH. CS severity was graded using the Society for Cardiovascular Angiography and Intervention (SCAI) shock classification. All‐cause survival at 30 days was analyzed using Kaplan‐Meier curves and Cox proportional‐hazards analysis. There were 1814 patients with CS (mean age, 67.3 years; 68.5% men); 51.8% had myocardial infarction and 53.0% had cardiac arrest. The distribution of SCAI shock stages was B, 10.8%; C, 30.7%; D, 38.1%; and E, 18.7%. In both cohorts, higher lactate or lower pH predicted a higher risk of adjusted 30‐day mortality. Patients with a lactate ≥5 mmol/L or pH <7.2 were at increased risk of adjusted 30‐day mortality; patients with both lactate ≥5 mmol/L and pH <7.2 had the highest risk of adjusted 30‐day mortality. Patients in SCAI shock stages C, D, and E had higher 30‐day mortality in each SCAI shock stage if they had lactate ≥5 mmol/L or pH <7.2, particularly if they met both criteria.

Conclusions

Higher lactate and lower pH predict mortality in patients with cardiogenic shock beyond standard measures of shock severity. Severe lactic acidosis may serve as a risk modifier for the SCAI shock classification. Definitions of refractory or hemometabolic shock should include high lactate levels and low blood pH.