Predictors of Mortality in Patients Treated with Veno-Arterial ECMO for Cardiogenic Shock Complicating Acute Myocardial Infarction: a Systematic Review and Meta-Analysis

Scrutinizing the Role of Venoarterial Extracorporeal Membrane Oxygenation: Has Clinical Practice Outpaced the Evidence?

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for temporary mechanical circulatory support in various clinical scenarios has been increasing consistently, despite the lack of sufficient evidence regarding its benefit and safety from adequately powered randomized controlled trials. Although the ARREST trial (Advanced Reperfusion Strategies for Patients with Out-of-Hospital Cardiac Arrest and Refractory Ventricular Fibrillation) and a secondary analysis of the PRAGUE OHCA trial (Prague Out-of-Hospital Cardiac Arrest) provided some evidence in favor of VA-ECMO in the setting of out-of-hospital cardiac arrest, the INCEPTION trial (Early Initiation of Extracorporeal Life Support in Refractory Out-of-Hospital Cardiac Arrest) has not found a relevant improvement of short-term mortality with extracorporeal cardiopulmonary resuscitation. In addition, the results of the recently published ECLS-SHOCK trial (Extracorporeal Life Support in Cardiogenic Shock) and ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) discourage the routine use of VA-ECMO in patients with infarct-related cardiogenic shock. Ongoing clinical trials (ANCHOR [Assessment of ECMO in Acute Myocardial Infarction Cardiogenic Shock, NCT04184635], REVERSE [Impella CP With VA ECMO for Cardiogenic Shock, NCT03431467], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO, NCT05577195], PIONEER [Hemodynamic Support With ECMO and IABP in Elective Complex High-risk PCI, NCT04045873]) may clarify the usefulness of VA-ECMO in specific patient subpopulations and the efficacy of combined mechanical circulatory support strategies. Pending further data to refine patient selection and management recommendations for VA-ECMO, it remains uncertain whether the present usage of this device improves outcomes.

ECMO in Myocardial Infarction-Associated Cardiogenic Shock: Blood Biomarkers as Predictors of Mortality

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (va-ECMO) can provide circulatory and respiratory support in patients with cardiogenic shock. The main aim of this work was to investigate the association of blood biomarkers with mortality in patients with myocardial infarction needing va-ECMO support.

METHODS

We retrospectively analyzed electronic medical charts from patients receiving va-ECMO support in the period from 2008 to 2021 at the Medical University Innsbruck, Department of Anesthesiology and Intensive Care Medicine.

RESULTS

Of 188 patients, 57% (108/188) survived to discharge, with hemorrhage (46%) and thrombosis (27%) as the most frequent adverse events. Procalcitonin levels were markedly higher in non-survivors compared with survivors during the observation period. The multivariable model identified higher blood levels of procalcitonin (HR 1.01, p = 0.002) as a laboratory parameter associated with a higher risk of mortality.

CONCLUSIONS

In our study population of patients with myocardial infarction-associated cardiogenic shock, deceased patients had increased levels of inflammatory blood biomarkers throughout the whole study period. Increased procalcitonin levels have been associated with a higher risk of mortality. Future studies are needed to show the role of procalcitonin in patients receiving ECMO support.

Cardiogenic shock severity and mortality in patients receiving venoarterial extracorporeal membrane oxygenator support

AIMS

Shock severity predicts mortality in patients with cardiogenic shock (CS). We evaluated the association between pre-cannulation Society for Cardiovascular Angiography and Intervention (SCAI) shock classification and mortality among patients receiving venoarterial (VA) extracorporeal membrane oxygenation (ECMO) support for CS.

METHODS AND RESULTS

We included Extracorporeal Life Support Organization (ELSO) Registry patients from 2010 to 2020 who received VA ECMO for CS. SCAI shock stage was assigned based on hemodynamic support requirements prior to ECMO initiation. In-hospital mortality was analyzed using multivariable logistic regression. We included 12 106 unique VA ECMO patient runs with a median age of 57.9 (interquartile range: 46.8, 66.1) years and 31.8% were females; 3472 (28.7%) were post-cardiotomy. The distribution of SCAI shock stages at ECMO initiation was: B, 821 (6.8%); C, 7518 (62.1%); D, 2973 (24.6%); and E, 794 (6.6%). During the index hospitalization, 6681 (55.2%) patients died. In-hospital mortality increased incrementally with SCAI shock stage (adjusted OR: 1.24 per SCAI shock stage, 95% CI: 1.17-1.32, P < 0.001): B, 47.5%; C, 52.8%; D, 60.8%; E, 65.1%. A higher SCAI shock stage was associated with increased in-hospital mortality in key subgroups, although the SCAI shock classification was only predictive of mortality in non-surgical (medical) CS and not in post-cardiotomy CS.

CONCLUSION

The severity of shock prior to cannulation is a strong predictor of in-hospital mortality in patients receiving VA ECMO for CS. Using the pre-cannulation SCAI shock classification as a risk stratification tool can help clinicians refine prognostication for ECMO recipients and guide future investigations to improve outcomes.

ECMO in Cardiogenic Shock: Time Course of Blood Biomarkers and Associated Mortality

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (va-ECMO) is a temporary life support for severe cardiogenic shock, gaining time for organ recovery, permanent assistance, or transplantation. In this work, we aimed to investigate the trends of blood biomarkers over the period of ECMO support and their role in patient outcome.

METHODS

This retrospective study comprised patients receiving va-ECMO support over the period of 14 years at a tertiary university center.

RESULTS

Of 435 patients, 62% (268/435) survived to discharge, and the most frequent adverse event was hemorrhage (46%), followed by thrombosis (25%). Deceased patients had increased blood levels of C-reactive protein, procalcitonin, and white blood cells during the whole observation period, with higher peaks compared with survivors. The multivariable model identified hemorrhage (HR 1.73, p = 0.005) and higher levels of procalcitonin (HR 1.01, p = 0.001) as independent risk factors for death.

CONCLUSIONS

In our population of critically ill patients receiving va-ECMO support, deceased patients had increased inflammatory biomarkers during the whole observation period. Patients having higher values of procalcitonin and experiencing bleeding events showed an increased risk for mortality. Further studies focusing on inflammation in ECMO patients, clarifying its role in patient outcome and potential therapeutic interventions, are warranted.

ECMO Support in Refractory Cardiogenic Shock: Risk Factors for Mortality

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (va-ECMO) is a specialized temporary support for patients with refractory cardiogenic shock. The true value of this potentially lifesaving modality is still a subject of debate. Therefore, we aimed to investigate the overall in-hospital mortality and identify potential risk factors for mortality.

METHODS

We retrospectively analyzed the data of 453 patients supported with va-ECMO over a period of 14 years who were admitted to intensive care units of a tertiary university center in Austria.

RESULTS

We observed in-hospital mortality of 40% for patients with refractory cardiogenic shock. Hemorrhage, ECMO initiation on weekends, higher SAPS III score, and sepsis were identified as significant risk factors for mortality. Hemorrhage was the most common adverse event (46%), with major bleeding events dominating in deceased patients. Thromboembolic events occurred in 25% of patients, followed by sepsis (18%).

CONCLUSIONS

Although the rates of complications are substantial, a well-selected proportion of patients with refractory cardiogenic shock can be rescued from probable death. The reported risk factors could be used to increase the awareness of clinicians towards the development of new therapeutic concepts that may reduce their incidence.

Mechanical circulatory support in refractory cardiogenic shock: retrospective register study

Cardiogenic shock (CS) is one of the main causes of death in patients with acute myocardial infarction (AMI). Mortality from CS remains high, despite the introduction of myocardial revascularization and the use of modern medication. The use of mechanical circulatory support (MCS) is promising, it could reduce mortality in patients with AMI and CS. Aim. To define effectiveness and safety of MCS in patients with AMI and CS. Materials and methods. Our study includes 47 patients with AMI and refractory CS, who were treated at the University Clinic of Cardiology of the Yevdokimov Moscow State University of Medicine and Dentistry from 2019 to 2022. Mortality and various complications were analyzed in patients with refractory CS, patients who received and did not receive mechanical circulatory support (intra-aortic balloon pump IABP, extracorporeal membrane oxygenation ECMO). Results. Mortality among patients with refractory CS was significantly lower in the subgroup of patients who received mechanical circulatory support devices (59% vs 93%; p=0.02). Moreover, reliability is achieved mainly due to patients in whom were VA-ECMO implanted (p=0.02), not IABP (p=0.16). Conclusion. VA-ECMO associated with reduced mortality and should be considered in patients with AMI and refractory CS. Further research is needed to select the optimal method of mechanical circulatory support in patients with CS.

Risk factors associated with in-hospital mortality for patients with ECLS due to post cardiotomy cardiogenic shock after isolated coronary surgery

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) or extracorporeal life support (ECLS) in patients after cardiac surgery and post cardiotomy cardiogenic shock (PCS) is known to be associated with high mortality. Especially in patients after coronary artery bypass grafting (CABG) and PCS, ECLS is frequently established. Aim of this analysis was to evaluate factors associated with in-hospital mortality in patients treated with ECLS due to PCS after CABG.

METHODS

Between August 2006 and January 2017, 92 consecutive patients with V-A ECLS due to PCS after isolated CABG were identified and included in this retrospective analysis. Patients were divided into survivors (S) and non-survivors (NS) and analysed in regard of risk factors of in-hospital mortality.

RESULTS

In-hospital mortality added up to 61 patients (66 %). Non-survivors were significantly older (60±12 (S) vs. 67±10 (NS); p=0.013). Bilateral internal mammary artery graft was significantly more frequently used in S (23% (S) vs. 2% (NS); p=0.001). After 24 hours of ECLS support, median lactate levels were significantly higher in NS (1.9(1.3;3.5) mmol/L (S) vs. 3.5(2.1;6.3) mmol/L (NS); p=0.001). NS suffered more often acute kidney injury requiring dialysis (42% (S) vs. 74% (NS); p=0.002).

CONCLUSION

Mortality in patients with refractory PCS after CABG and consecutive ECLS support remains high. Failing end-organ recovery under ECLS despite optimized concomitant medical therapy is an indicator of adverse outcomes in this specific patient cohort. Moreover, total-arterial revascularization might be beneficial for cardiac recovery in patients suffering PCS after CABG and following ECLS.

Describing and Classifying Shock: Recent Insights

Cardiogenic shock continues to present a daunting challenge to clinicians, despite an increasing array of percutaneous mechanical circulatory support devices. Mortality for cardiogenic shock has not changed meaningfully in more than 20 years. There have been many attempts to generate risk scores or frameworks to evaluate cardiogenic shock and optimize the use of resources and assist with prognostication. These include the Intra-Aortic Balloon Pump in Cardiogenic Shock (IABP-SHOCK) II risk score, the CardShock score and the new CLIP biomarker score. This article reviews the Society for Cardiac Angiography and Interventions (SCAI) classification of cardiogenic shock and subsequent validation studies. The SCAI classification is simple for clinicians to use as it is based on readily available information and can be adapted depending on the data set that can be accessed. The authors consider the future of the field. Underlying all these efforts is the hope that a better understanding and classification of shock will lead to meaningful improvements in mortality rates.