Lactate Clearance Is Associated With Improved Survival in Cardiogenic Shock: A Systematic Review and Meta-Analysis of Prognostic Factor Studies

Hemodynamic management of cardiogenic shock in the intensive care unit

Hemodynamic derangements are defining features of cardiogenic shock. Randomized clinical trials have examined the efficacy of various therapeutic interventions, from percutaneous coronary intervention to inotropes and mechanical circulatory support (MCS). However, hemodynamic management in cardiogenic shock has not been well-studied. This State-of-the-Art review will provide a framework for hemodynamic management in cardiogenic shock, including a description of the 4 therapeutic phases from initial 'Rescue' to 'Optimization', 'Stabilization' and 'de-Escalation or Exit therapy' (R-O-S-E), phenotyping and phenotype-guided tailoring of pharmacological and MCS support, to achieve hemodynamic and therapeutic goals. Finally, the premises that form the basis for clinical management and the hypotheses for randomized controlled trials will be discussed, with a view to the future direction of cardiogenic shock.

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.

Lactate as a Predictor of 30-Day Mortality in Cardiogenic Shock

Background/Objectives: This study sought to evaluate the efficacy of various lactate measurements within the first 24 h post-intensive care unit (ICU) admission for predicting 30-day mortality in cardiogenic shock patients. It compared initial lactate levels, 24 h levels, peak levels, and 24 h clearance, alongside the Simplified Acute Physiology Score 3 (SAPS3) score, to enhance early treatment decision-making. Methods: A retrospective analysis of 64 patients assessed the prognostic performance of lactate levels and SAPS3 scores using logistic regression and AUROC calculations. Results: Of the baseline parameters, only the SAPS3 score predicted survival independently. The lactate level after 24 h (LL) was the most accurate predictor of mortality, outperforming initial levels, peak levels, and 24 h-clearance, and showing a significant AUROC. LL greater than 3.1 mmol/L accurately predicted mortality with high specificity and moderate sensitivity. Conclusions: Among lactate measurements for predicting 30-day mortality in cardiogenic shock, the 24 h lactate level was the most effective one, suggesting its superiority for early prognostication over initial or peak levels and lactate clearance.

Contemporary approach to cardiogenic shock care: a state-of-the-art review

Cardiogenic shock (CS) is a time-sensitive and hemodynamically complex syndrome with a broad spectrum of etiologies and clinical presentations. Despite contemporary therapies, CS continues to maintain high morbidity and mortality ranging from 35 to 50%. More recently, burgeoning observational research in this field aimed at enhancing the early recognition and characterization of the shock state through standardized team-based protocols, comprehensive hemodynamic profiling, and tailored and selective utilization of temporary mechanical circulatory support devices has been associated with improved outcomes. In this narrative review, we discuss the pathophysiology of CS, novel phenotypes, evolving definitions and staging systems, currently available pharmacologic and device-based therapies, standardized, team-based management protocols, and regionalized systems-of-care aimed at improving shock outcomes. We also explore opportunities for fertile investigation through randomized and non-randomized studies to address the prevailing knowledge gaps that will be critical to improving long-term outcomes.

The Magnitude of Change in Serum Phosphate Concentration Is Associated with Mortality in Patients with Severe Trauma

PURPOSE

Previous studies have suggested that serum phosphate concentration is a prognostic factor in critically ill patients. However, the association between changes in serum phosphate levels and prognosis of patients with trauma remains unclear.

MATERIALS AND METHODS

This study included patients with severe trauma who were treated at the emergency department. Delta phosphate (Δ phosphate) was defined as the difference between serum phosphate concentrations measured at baseline and after 24 hours from the initial measurement. Patients were divided into five groups according to their Δ phosphate levels: group I (Δ phosphate <-2 mg/dL), group II (Δ phosphate -2 to -0.5 mg/dL), group III (Δ phosphate -0.5 to 0.5 mg/dL), group IV (Δ phosphate 0.5 to 2 mg/dL), and group V (Δ phosphate ≥2 mg/dL).

RESULTS

Overall, 1905 patients with severe trauma were included in the analysis. The 30-day mortality was the lowest in group III and tended to increase in groups with a larger Δ phosphate in both the positive and negative directions (group I: 13.7%, group II: 6.8%, group III: 4.6%, group IV: 6.6%, and group V: 26.8%). In multivariable analysis with group III as the reference group, the odds ratios (ORs) of mortality were statistically significant in group IV [OR, 1.92; 95% confidence interval (CI), 1.05-3.56] and group V (OR, 5.28; 95% CI, 2.47-11.24).

CONCLUSION

An increase in serum phosphate concentrations 24 hours after the initial measurement could be considered as an independent prognostic factor in patients with severe trauma.

Heart failure related cardiogenic shock: An ISHLT consensus conference content summary

In recent years, there have been significant advancements in the understanding, risk-stratification, and treatment of cardiogenic shock (CS). Despite improved pharmacologic and device-based therapies for CS, short-term mortality remains as high as 50%. Most recent efforts in research have focused on CS related to acute myocardial infarction, even though heart failure related CS (HF-CS) accounts for >50% of CS cases. There is a paucity of high-quality evidence to support standardized clinical practices in approach to HF-CS. In addition, there is an unmet need to identify disease-specific diagnostic and risk-stratification strategies upon admission, which might ultimately guide the choice of therapies, and thereby improve outcomes and optimize resource allocation. The heterogeneity in defining CS, patient phenotypes, treatment goals and therapies has resulted in difficulty comparing published reports and standardized treatment algorithms. An International Society for Heart and Lung Transplantation (ISHLT) consensus conference was organized to better define, diagnose, and manage HF-CS. There were 54 participants (advanced heart failure and interventional cardiologists, cardiothoracic surgeons, critical care cardiologists, intensivists, pharmacists, and allied health professionals), with vast clinical and published experience in CS, representing 42 centers worldwide. State-of-the-art HF-CS presentations occurred with subsequent breakout sessions planned in an attempt to reach consensus on various issues, including but not limited to models of CS care delivery, patient presentations in HF-CS, and strategies in HF-CS management. This consensus report summarizes the contemporary literature review on HF-CS presented in the first half of the conference (part 1), while the accompanying document (part 2) covers the breakout sessions where the previously agreed upon clinical issues were discussed with an aim to get to a consensus.

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.

Application of Cardiogenic Shock Working Group-defined Society for Cardiovascular Angiography and Interventions (CSWG-SCAI) Staging of Cardiogenic Shock to the Medical Information Mart for Intensive Care IV (MIMIC-IV) database

BACKGROUND

The optimal parameters for defining stages of cardiogenic shock (CS) are not yet known. The Cardiogenic Shock Working Group-defined Society for Cardiovascular Angiography and Interventions (CSWG-SCAI) staging of CS was developed to provide simple and specific parameters for risk-stratifying patients.

OBJECTIVES

The purpose of this study was to test whether the Cardiogenic Shock Working Group-defined Society for Cardiovascular Angiography and Interventions (CSWG-SCAI) staging is associated with in-hospital mortality, using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database.

METHODS

We utilized the open-access MIMIC-IV database, which includes >300,000 patients admitted between 2008 and 2019. We extracted the clinical profile of patients admitted with CS and stratified them into different SCAI stages at admission based on the CSWG criteria. We then tested the association between in-hospital mortality and parameters of hypotension, hypoperfusion, and overall CSWG-SCAI stage.

RESULTS

Of the 2463 patients, CS was predominantly caused by heart failure (HF; 54.7 %) or myocardial infarction (MI; 26.3 %). Mortality was 37.5 % for the total cohort, 32.7 % for patients with HF, and 40 % for patients with MI (p < 0.001). Mortality was higher among patients with mean arterial pressure < 65 mmHg, lactate >2 mmol/L, ALT >200 IU/L, pH ≤ 7.2, and more than one drug/device support at baseline. Increasing CSWG-SCAI stages at baseline and maximum CSWG-SCAI stage achieved were significantly associated with in-hospital mortality (p < 0.05).

CONCLUSIONS

The CSWG-SCAI stages are significantly associated with in-hospital mortality and may be used to identify hospitalized patients at risk of worsening cardiogenic shock severity.

CONDENSED ABSTRACT

We analyzed data from 2463 patients with cardiogenic shock using the MIMIC-IV database to investigate the relationship between the Cardiogenic Shock Working Group-defined Society for Cardiovascular Angiography and Interventions (CSWG-SCAI) staging and in-hospital mortality. The main causes of cardiogenic shock were heart failure (54.7 %) and myocardial infarction (26.3 %). The overall mortality rate was 37.5 %, with a higher rate among patients with myocardial infarction (40 %) compared to those with heart failure (32.7 %). Mean arterial pressure < 65 mmHg, lactate >2 mmol/L, ALT >200 IU/L, and pH ≤ 7.2 were significantly associated with mortality. Increasing CSWG-SCAI stages at baseline and maximum achieved stages were strongly associated with higher mortality (p < 0.05). Therefore, the CSWG-SCAI staging system can be used to risk-stratify patients with cardiogenic shock.

Efficacy of Milrinone and Dobutamine in Cardiogenic Shock: An Updated Systematic Review and Meta-Analysis

OBJECTIVES

Inotropic support is commonly used in patients with cardiogenic shock (CS). High-quality data guiding the use of dobutamine or milrinone among this patient population is limited. We compared the efficacy and safety of these two inotropes among patients with low cardiac output states (LCOS) or CS.

DATA SOURCES

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched up to February 1, 2023, using key terms and index headings related to LCOS or CS and inotropes.

DATA EXTRACTION

Two independent reviewers included studies that compared dobutamine to milrinone on all-cause in-hospital mortality, length of ICU stay, length of hospital stay, and significant arrhythmias in hospitalized patients.

DATA SYNTHESIS

A total of eleven studies with 21,084 patients were included in the meta-analysis. Only two randomized controlled trials were identified. The primary outcome, all-cause mortality, favored milrinone in observational studies only (odds ratio [OR] 1.19 (95% CI, 1.02-1.39; p = 0.02). In-hospital length of stay (LOS) was reduced with dobutamine in observational studies only (mean difference -1.85 d; 95% CI -3.62 to -0.09; p = 0.04). There was no difference in the prevalence of significant arrhythmias or in ICU LOS.

CONCLUSIONS

Only limited data exists supporting the use of one inotropic agent over another exists. Dobutamine may be associated with a shorter hospital LOS; however, there is also a potential for increased all-cause mortality. Larger randomized studies sufficiently powered to detect a difference in these outcomes are required to confirm these findings.

Derivation and validation of a blood biomarker score for 2-day mortality prediction from prehospital care: a multicenter, cohort, EMS-based study

Identifying potentially life-threatening diseases is a key challenge for emergency medical services. This study aims at examining the role of different prehospital biomarkers from point-of-care testing to derive and validate a score to detect 2-day in-hospital mortality. We conducted a prospective, observational, prehospital, ongoing, and derivation-validation study in three Spanish provinces, in adults evacuated by ambulance and admitted to the emergency department. A total of 23 ambulance-based biomarkers were collected from each patient. A biomarker score based on logistic regression was fitted to predict 2-day mortality from an optimum subset of variables from prehospital blood analysis, obtained through an automated feature selection stage. 2806 cases were analyzed, with a median age of 68 (interquartile range 51-81), 42.3% of women, and a 2-day mortality rate of 5.5% (154 non-survivors). The blood biomarker score was constituted by the partial pressure of carbon dioxide, lactate, and creatinine. The score fitted with logistic regression using these biomarkers reached a high performance to predict 2-day mortality, with an AUC of 0.933 (95% CI 0.841-0.973). The following risk levels for 2-day mortality were identified from the score: low risk (score < 1), where only 8.2% of non-survivors were assigned to; medium risk (1 ≤ score < 4); and high risk (score ≥ 4), where the 2-day mortality rate was 57.6%. The novel blood biomarker score provides an excellent association with 2-day in-hospital mortality, as well as real-time feedback on the metabolic-respiratory patient status. Thus, this score can help in the decision-making process at critical moments in life-threatening situations.

State of Shock: Contemporary Vasopressor and Inotrope Use in Cardiogenic Shock

Cardiogenic shock is characterized by tissue hypoxia caused by circulatory failure arising from inadequate cardiac output. In addition to treating the pathologic process causing impaired cardiac function, prompt hemodynamic support is essential to reduce the risk of developing multiorgan dysfunction and to preserve cellular metabolism. Pharmacologic therapy with the use of vasopressors and inotropes is a key component of this treatment strategy, improving perfusion by increasing cardiac output, altering systemic vascular resistance, or both, while allowing time and hemodynamic stability to treat the underlying disease process implicated in the development of cardiogenic shock. Despite the use of mechanical circulatory support recently garnering significant interest, pharmacologic hemodynamic support remains a cornerstone of cardiogenic shock management, with over 90% of patients receiving at least 1 vasoactive agent. This review aims to describe the pharmacology and hemodynamic effects of current pharmacotherapies and provide a practical approach to their use, while highlighting important future research directions.

The role of temporary mechanical circulatory support in de novo heart failure syndromes with cardiogenic shock: A contemporary review

Cardiogenic shock (CS) is a complex clinical syndrome with a high mortality rate. It can occur to due to multiple etiologies of cardiovascular disease and is phenotypically heterogeneous. Acute myocardial infarction-related CS (AMI-CS) has historically been the most prevalent cause, and thus, research and guidance have focused primarily on this. Recent data suggest that the burden of non-ischemic CS is increasing in the population of patents requiring intensive care admission. There is, however, a paucity of data and guidelines to inform the management of these patients who fall into two broad groups: those with existing heart failure and CS and those with no known history of heart failure who present with "de novo" CS. The use of temporary mechanical circulatory support (MCS) has expanded across all etiologies, despite its high cost, resource intensity, complication rates, and lack of high-quality outcome data. Herein, we discuss the currently available evidence on the role of MCS in the management of patients with de novo CS to include fulminant myocarditis, right ventricular (RV) failure, Takotsubo syndrome, post-partum cardiomyopathy, and CS due to valve lesions and other cardiomyopathies.

Association of lactate detection with in-hospital mortality in critically ill patients with acute myocardial infarction: a retrospective cohort study

OBJECTIVES

To assess the associations of lactate level or lactate clearance at different time points with in-hospital mortality in critically ill patients with acute myocardial infarction (AMI).

DESIGN

A cohort study.

SETTING

The Medical Information Mart for Intensive Care III database.

PARTICIPANT

490 AMI patients.

INTERVENTION

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

In-hospital mortality of patients.

RESULTS

In total, 120 (24.49%) patients died at the end of follow-up. After adjusting for confounders, increased risk of in-hospital mortality in patients with AMI was observed in those with high lactate level (24 hours) (HR=1.156, 95%CI: 1.002 to 1.333). Increased lactate clearance (24 hours) was correlated with a decreased risk of in-hospital mortality in patients with AMI (HR=0.995, 95% CI: 0.994 to 0.997). The area under the curves (AUCs) of lactate level (24 hours) and lactate clearance (24 hours) were 0.689 (95% CI: 0.655 to 0.723) and 0.672 (95% CI: 0.637 to 0.706), respectively. The AUC of lactate level (24 hours) and lactate clearance (24 hours) was higher than lactate level (baseline).

CONCLUSIONS

Increased lactate level (24 hours) was associated with an elevated risk of in-hospital mortality in patients with AMI and increased lactate clearance (24 hours) was correlated with a decreased risk of in-hospital mortality in patients with AMI despite the age and genders.

One-year outcomes in cardiogenic shock triggered by ventricular arrhythmia: An analysis of the FRENSHOCK multicenter prospective registry

Background

Cardiogenic shock (CS) is a life-threatening condition carrying poor prognosis, potentially triggered by ventricular arrhythmia (VA). Whether the occurrence of VA as trigger of CS worsens the prognosis compared to non-VA triggers  remains  unclear.  The  aim  of  this  study  was  to  evaluate  1-year  outcomes [mortality, heart transplantation, ventricular assist devices (VAD)] between VA-triggered and non-VA-triggered CS.

Methods

FRENSHOCK is a prospective multicenter registry including 772 CS patients from 49 centers. One to three triggers can be identified in the registry (ischemic, mechanical complications, ventricular/supraventricular arrhythmia, bradycardia, iatrogenesis, infection, non-compliance). Baseline characteristics, management and 1-year outcomes were analyzed according to the VA-trigger in the CS population.

Results

Within 769 CS patients included, 94 were VA-triggered (12.2%) and were compared to others. At 1 year, although there was no mortality difference [42.6 vs. 45.3%, HR 0.94 (0.67-1.30), p = 0.7], VA-triggered CS resulted in more heart transplantations and VAD (17 vs. 9%, p = 0.02). Into VA-triggered CS group, though there was no 1-year mortality difference between ischemic and non-ischemic cardiomyopathies [42.5 vs. 42.6%, HR 0.97 (0.52-1.81), p = 0.92], non-ischemic cardiomyopathy led to more heart transplantations and VAD (25.9 vs. 5%, p = 0.02).

Conclusion

VA-triggered CS did not show higher mortality compared to other triggers but resulted in more heart transplantation and VAD at 1 year, especially in non-ischemic cardiomyopathy, suggesting the need for earlier evaluation by advanced heart failure specialized team for a possible indication of mechanical circulatory support or heart transplantation.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT02703038.

Phenotyping and Hemodynamic Assessment in Cardiogenic Shock: From Physiology to Clinical Application

There is growing interest in invasive hemodynamic assessment in cardiogenic shock, primarily due to the widespread adoption of mechanical circulatory support (MCS). Invasive hemodynamic assessment is central to two aspects of cardiogenic shock management: (1) the phenotyping of cardiogenic shock, and (2) the assessment of response to therapy. Phenotyping of cardiogenic shock serves to guide timely therapeutic intervention, and the assessment of hemodynamic response to therapy directs the escalation or de-escalation of therapy, including MCS. This review aims to discuss these two aspects of hemodynamic assessment in cardiogenic shock. Firstly, the physiologic underpinnings of a phenotyping schema, and the implication of the cardiogenic shock phenotype on the MCS strategy in cardiogenic shock will be discussed. Secondly, the concept of cardiac power output and 'effective' oxygen delivery will be discussed in relation to hemodynamic response to therapy in cardiogenic shock.

Escalating and De-escalating Temporary Mechanical Circulatory Support in Cardiogenic Shock: A Scientific Statement From the American Heart Association

The use of temporary mechanical circulatory support in cardiogenic shock has increased dramatically despite a lack of randomized controlled trials or evidence guiding clinical decision-making. Recommendations from professional societies on temporary mechanical circulatory support escalation and de-escalation are limited. This scientific statement provides pragmatic suggestions on temporary mechanical circulatory support device selection, escalation, and weaning strategies in patients with common cardiogenic shock causes such as acute decompensated heart failure and acute myocardial infarction. The goal of this scientific statement is to serve as a resource for clinicians making temporary mechanical circulatory support management decisions and to propose standardized approaches for their use until more robust randomized clinical data are available.

Epidemiology and management of right ventricular-predominant heart failure and shock in the cardiac intensive care unit

Cardiogenic shock from left ventricular failure is a common presentation in the intensive care unit. In contrast, right ventricular (RV)-predominant heart failure (HF) causing shock is less well recognized. We review the epidemiology and mechanisms of RV-predominant HF and discuss pharmacologic and device-based approaches for the management of this challenging clinical problem.

Criteria for Defining Stages of Cardiogenic Shock Severity

BACKGROUND

Risk-stratifying patients with cardiogenic shock (CS) is a major unmet need. The recently proposed Society for Cardiovascular Angiography and Interventions (SCAI) staging system for CS severity lacks uniform criteria defining each stage.

OBJECTIVES

The purpose of this study was to test parameters that define SCAI stages and explore their utility as predictors of in-hospital mortality in CS.

METHODS

The CS Working Group registry includes patients from 17 hospitals enrolled between 2016 and 2021 and was used to define clinical profiles for CS. We selected parameters of hypotension and hypoperfusion and treatment intensity, confirmed their association with mortality, then defined formal criteria for each stage and tested the association between both baseline and maximum Stage and mortality.

RESULTS

Of 3,455 patients, CS was caused by heart failure (52%) or myocardial infarction (32%). Mortality was 35% for the total cohort and higher among patients with myocardial infarction, out-of-hospital cardiac arrest, and treatment with increasing numbers of drugs and devices. Systolic blood pressure, lactate level, alanine transaminase level, and systemic pH were significantly associated with mortality and used to define each stage. Using these criteria, baseline and maximum stages were significantly associated with mortality (n = 1,890). Lower baseline stage was associated with a higher incidence of stage escalation and a shorter duration of time to reach maximum stage.

CONCLUSIONS

We report a novel approach to define SCAI stages and identify a significant association between baseline and maximum stage and mortality. This approach may improve clinical application of the staging system and provides new insight into the trajectory of hospitalized CS patients. (Cardiogenic Shock Working Group Registry [CSWG]; NCT04682483).

Outcomes in cardiogenic shock: the role of surrogate endpoints

PURPOSE OF REVIEW

Early revascularization, invasive hemodynamic profiling, and initiation of temporary mechanical circulatory support (MCS) have all become routine components of cardiogenic shock (CS) management. Despite this evolution in clinical practice, patient selection and timing of treatment initiation remain a significant barrier to achieving sustained improvement in CS outcomes. Recent efforts to standardize CS management, through the development of treatment algorithms, have relied heavily on surrogate endpoints to drive therapeutic decisions. The present review aims to provide an overview of the basis of evidence for those surrogate endpoints commonly employed in clinical trials and CS management algorithms.

RECENT FINDINGS

Recent publications from both observational and randomized cohorts have demonstrated the utility of surrogate endpoints in risk stratifying patients with CS. In particular, invasive hemodynamics using pulmonary artery catheters to guide initiation and weaning of MCS, biochemical markers that portend imminent end-organ failure, and clinical risk scores that combine multiple hemodynamic and laboratory parameters have demonstrated an ability to prognosticate outcomes in patients with CS.

SUMMARY

Although further validation is necessary, multiple clinical, hemodynamic, and biochemical markers have demonstrated utility as surrogate endpoints in CS, and will undoubtedly assist physicians in clinical decision-making.

Laboratory Predictors of Prognosis in Cardiogenic Shock Complicating Acute Myocardial Infarction

Cardiogenic shock is a state of reduced cardiac output leading to hypotension, pulmonary congestion, and hypoperfusion of tissues and vital organs. Despite the advances in intensive care over the last years, the morbidity and mortality of patients remain high. The available studies of patients with cardiogenic shock suggest a connection between clinical variables, the level of biomarkers, the results of imaging investigations, strategies of management and the outcome of this group of patients. The management of patients with cardiogenic shock initially complicating acute myocardial infarction is challenging, and the number of studies in this area is growing fast. The purpose of this review is to summarize the currently available evidence on cardiogenic shock initially complicating acute myocardial infarction with particular attention to predictors of prognosis, focusing on laboratory variables (established and new), and to discuss the practical implementation. Currently available scoring systems developed during the past few decades predict the clinical outcome of this group of patients using some of the established biomarkers among other variables. With the new laboratory biomarkers that have shown their predictive value in cardiogenic shock outcomes, a new design of scoring systems would be of interest. Identifying high-risk patients offers the opportunity for early decision-making.

Cardiac power output index to define hemodynamic response to Impella support in cardiogenic shock

BACKGROUND

Early assessment of response to Impella in cardiogenic shock may guide escalation of mechanical circulatory support. Therapeutic goal and response to Impella have not previously been defined. This study tested the hypothesis that targeting 3-h post- Impella cardiac power output index (CPOi)-"hemodynamic response"-in cardiogenic shock is associated with 12-h lactate clearance.

METHODS

Single-center study of 37 consecutive patients who underwent left-sided Impella support for cardiogenic shock due to either acute myocardial infarction or decompensated heart failure. Patients who achieved 3-h post-Impella CPOi ⩾ 0.30 W/m² were defined as Impella "hemodynamic responder."

RESULTS

Twelve of the thirty-seven patients achieved 3-h post-impella CPOi  ⩾ 0.30 W/m² ("hemodynamic responders"). Post-Impella CPOi correlated with 12-h lactate (r = -0.779, p < 0.001) and lactate clearance (r = 0.747, p < 0.001). "Hemodynamic responders" had lower 12-h lactate level and greater 12-h lactate clearance (52 (44-58) vs 17 (14-26)%, p < 0.001). Higher pre-Impella norepinephrine dose (-0.341, p = 0.003) and baseline lactate (-0.009, p = 0.003) were independently associated with lower 3-h post-Impella CPOi. Eighteen patients died within 30 days (2/12 "hemodynamic responders" compared to 16/25 "non-responders," p < 0.001).

CONCLUSION

Patients who achieved early 3-h post-Impella CPOi of ⩾0.30 W/m² have greater lactate clearance and better short-term survival. Early post-Impella CPOi of 0.30 W/m² may be used as a therapeutic goal and define favorable response to Impella in cardiogenic shock.

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.

Lactate Clearance as a Surrogate for Mortality in Cardiogenic Shock: Insights From the DOREMI Trial

Background

Recent studies have shown improved outcomes in cardiogenic shock through protocols directed toward early identification and initiation of mechanical circulatory support. However, objective therapeutic targets—based on clinical and/or laboratory data—to guide real‐time clinical decision making are lacking. Lactate clearance has been suggested as a potential treatment target because of its independent association with mortality.

Methods and Results

In a post hoc analysis of the DOREMI (Dobutamine Compared to Milrinone in the Treatment of Cardiogenic Shock) trial—a randomized, double‐blind, controlled trial comparing milrinone to dobutamine in the treatment of cardiogenic shock—we used prospectively collected lactate data to evaluate lactate clearance as a surrogate marker for in‐hospital mortality. In total, 82 (57.7%) patients survived to hospital discharge (survivors). In multivariate logistic regression analysis, complete lactate clearance, percentage lactate clearance, and percentage lactate clearance per hour were independently associated with survival beginning as early as 8 hours after enrollment. Complete lactate clearance was the strongest predictor of survival at all time points, with odds ratios ranging between 2.46 (95% CI, 1.09–5.55; P=0.03) at 8 hours to 5.44 (95% CI, 2.14–13.8; P<0.01) at 24 hours.

Conclusions

Complete lactate clearance is a strong and independent predictor of in‐hospital survival in patients with cardiogenic shock. Together with previously published data, these results further support the validity of lactate clearance as an appropriate surrogate for mortality and as a potential therapeutic target in future cardiogenic shock trials.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03207165.