Extracorporeal life support in the multidisciplinary management of cardiogenic shock complicating acute myocardial infarction

Construction and validation of a personalized risk prediction model for in-hospital mortality in patients with acute myocardial infarction undergoing percutaneous coronary intervention

BACKGROUND

Although emergency Percutaneous Coronary Intervention (PCI) has been shown to reduce mortality in patients with Acute Myocardial Infarction (AMI), the risk of in-hospital death remains high. In this study, the authors aimed to identify risk factors associated with in-hospital mortality in AMI patients who underwent PCI, develop a nomogram prediction model, and evaluate its effectiveness.

METHODS

The authors retrospectively analyzed data from 1260 patients who underwent emergency PCI at Dongyang People's Hospital between June 1, 2013, and December 31, 2021. Patients were divided into two groups based on in-hospital mortality: the death group (n = 61) and the survival group (n = 1199). Clinical data between the two groups were compared. The Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to select non-zero coefficients of predictive factors. Multivariable logistic regression analysis was then performed to identify independent risk factors for in-hospital mortality in AMI patients after emergency PCI. A nomogram model for predicting the risk of in-hospital mortality in AMI patients after PCI was constructed, and its predictive performance was evaluated using the c-index. Internal validation was performed using the bootstrap method with 1000 resamples. The Hosmer-Lemeshow test was used to assess the goodness of fit, and a calibration curve was plotted to evaluate the model's calibration.

RESULTS

LASSO regression identified d-dimer, B-type natriuretic peptide, white blood cell count, heart rate, aspartate aminotransferase, systolic blood pressure, and the presence of postoperative respiratory failure as important predictive factors for in-hospital mortality in AMI patients after PCI. Multivariable logistic regression analysis showed that d-dimer, B-type natriuretic peptide, white blood cell count, systolic blood pressure, and the presence of postoperative respiratory failure were independent factors for in-hospital mortality. A nomogram model for predicting the risk of in-hospital mortality in AMI patients after PCI was constructed using these independent predictive factors. The Hosmer-Lemeshow test yielded a Chi-Square value of 9.43 (p = 0.331), indicating a good fit for the model, and the calibration curve closely approximated the ideal model. The c-index for internal validation was 0.700 (0.560‒0.834), further confirming the predictive performance of the model. Clinical decision analysis demonstrated that the nomogram model had good clinical utility, with an area under the ROC curve of 0.944 (95 % CI 0.903‒0.963), indicating excellent discriminative ability.

CONCLUSION

This study identified B-type natriuretic peptide, white blood cell count, systolic blood pressure, d-dimer, and the presence of respiratory failure as independent factors for in-hospital mortality in AMI patients undergoing emergency PCI. The nomogram model based on these factors showed high predictive accuracy and feasibility.

Impella Versus VA-ECMO for Patients with Cardiogenic Shock: Comprehensive Systematic Literature Review and Meta-Analyses

Impella and VA-ECMO are two possible therapeutic courses for the treatment of patients with cardiogenic shock (CS). The study aims to perform a systematic literature review and meta-analyses of a comprehensive set of clinical and socio-economic outcomes observed when using Impella or VA-ECMO with patients under CS. A systematic literature review was performed in Medline, and Web of Science databases on 21 February 2022. Nonoverlapping studies with adult patients supported for CS with Impella or VA-ECMO were searched. Study designs including RCTs, observational studies, and economic evaluations were considered. Data on patient characteristics, type of support, and outcomes were extracted. Additionally, meta-analyses were performed on the most relevant and recurring outcomes, and results shown using forest plots. A total of 102 studies were included, 57% on Impella, 43% on VA-ECMO. The most common outcomes investigated were mortality/survival, duration of support, and bleeding. Ischemic stroke was lower in patients treated with Impella compared to the VA-ECMO population, with statistically significant difference. Socio-economic outcomes including quality of life or resource use were not reported in any study. The study highlighted areas where further data collection is needed to clarify the value of complex, new technologies in the treatment of CS that will enable comparative assessments focusing both on the health impact on patient outcomes and on the financial burden for government budgets. Future studies need to fill the gap to comply with recent regulatory updates at the European and national levels.

Prognosticating Mortality of Primary Cardiogenic Shock Requiring Extracorporeal Life Support: The RESCUE Score

We aimed to identify prognostic laboratory markers during extracorporeal life support (ECLS) in patients with primary refractory cardiogenic shock (RCS) and to create a preliminary specific mortality score. All 208 consecutive subjects admitted for primary RCS and treated with ECLS between January-2009 and December-2018 were retrospectively analyzed. Multivariate regression analysis on laboratory markers during the first nine days of ECLS was used to develop a "Refractory End-stage Shock CUred with Ecls" (RESCUE) score. Serum creatinine (OR = 3.72, 95%CI: 2.01-6.88), direct bilirubin (OR = 1.40, 95%CI: 1.05-1.8), and platelet count (OR = 0.62, 95%CI: 0.42-0.94) were independent predictors of in-hospital mortality and were included in the score. The mean AUC was 0.763 (95%CI: 0.698-0.828) in the development cohort and 0.729 (95%CI: 0.664-0.794) in the bootstrap internal validation cohort. The RESCUE score represents a novel promising instrument to predict early mortality during the first critical days of ECLS and to help in properly guiding the therapeutic decision-making process.

Rise in Percutaneous Vascular Procedures and Extracorporeal Membrane Oxygenation Is Associated With Increase in Emergent Vascular Operations

Background: The workload of vascular surgeons is widely affected by the procedural activity of other departments within the same medical center. The purpose of this study was to evaluate the trend in emergent vascular surgery procedures over a 5 year period in a tertiary referral hospital and categorize these procedures based on the nature of the operative procedure required. Methods: A single center, retrospective review of all emergent surgical operations performed at our tertiary referral hospital between the years 2017-2021. Data collected included types of emergent vascular surgery performed, in addition to procedures performed by the departments of interventional cardiology (IC), interventional radiology (IR), neurointerventional radiology (NIR) and extracorporeal membrane oxygenation (ECMO) at our institution. Results: During the study period were performed a total of 1783 operative procedures (mean 356 ± 26/year). Of those, 485 (27%) were emergent cases. We observed a gradual increase in emergent operative procedures performed from 2017 to 2021 (22% to 34% of all cases, increase of 56%, P<.01). A striking increase was seen with vascular repairs performed for iatrogenic vascular injuries secondary to arterial access complications (47% to 65% of all iatrogenic vascular injuries, increase of 38%). The increase correlated with an increase in activity seen in the departments of IC, IR/NIR and ECMO (15%, 31% and 300%, respectively). Conclusions: An increasing number of emergent surgical procedures performed by our vascular surgery department correlates with the increasing number of endovascular procedures performed by non- vascular services. As these procedures are expected to increase, together with the number of stroke units and ECMO units being created, medical centers must be aware that these may result in a significant increase in the workload of the vascular surgery department in order to deal with complications associated with these procedures.

Cardiogenic Shock Management and Research: Past, Present, and Future Outlook

Although great strides have been made in the pathophysiological understanding, diagnosis and management of cardiogenic shock (CS), morbidity and mortality in patients presenting with the condition remain high. Acute MI is the commonest cause of CS; consequently, most existing literature concerns MI-associated CS. However, there are many more phenotypes of patients with acute heart failure. Medical treatment and mechanical circulatory support are well-established therapeutic options, but evidence for many current treatment regimens is limited. The issue is further complicated by the fact that implementing adequately powered, randomized controlled trials are challenging for many reasons. In this review, the authors discuss the history, landmark trials, current topics of medical therapy and mechanical circulatory support regimens, and future perspectives of CS management.

Overview of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support for the Management of Cardiogenic Shock

Cardiogenic shock accounts for ~100,000 annual hospital admissions in the United States. Despite improvements in medical management strategies, in-hospital mortality remains unacceptably high. Multiple mechanical circulatory support devices have been developed with the aim to provide hemodynamic support and to improve outcomes in this population. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the most advanced temporary life support system that is unique in that it provides immediate and complete hemodynamic support as well as concomitant gas exchange. In this review, we discuss the fundamental concepts and hemodynamic aspects of VA-ECMO support in patients with cardiogenic shock of various etiologies. In addition, we review the common indications, contraindications and complications associated with VA-ECMO use.

Temporary mechanical circulatory support devices: updates from recent studies

PURPOSE OF REVIEW

Over the past several years, the role of short-term mechanical circulatory support (MCS) devices has become the dominant focus in efforts to improve outcomes in patients with cardiogenic shock (CS). Alongside these efforts, temporary MCS devices have been increasingly used to support patients prior to cardiac surgery, during high-risk percutaneous coronary intervention, awaiting cardiac transplantation, and in the setting of refractory cardiac arrest. The present review aims to provide an update on the recent literature evaluating the evolving role of temporary MCS devices, and to provide insights into the current challenges and future directions of MCS research.

RECENT FINDINGS

Recent observational data have demonstrated potential roles for intra-aortic balloon pump preoperatively in high-risk patients awaiting coronary artery bypass grafting, and advanced heart failure patients awaiting transplantation. Impella continues to demonstrate promising results as part of an early MCS strategy in CS, as a temporary bridge to transplantation, and as a mechanism for left ventricular unloading in patients on venoarterial extracorporeal membrane oxygenation (ECMO). Finally, the first randomized trial of ECMO facilitated resuscitation in the United States demonstrated improved survival in patients with refractory out of hospital cardiac arrest.

SUMMARY

Though randomized data remains limited, observational data continue to support the role of temporary MCS devices in a variety of clinical settings.

Associations between Body Mass Index and Clinical Outcomes in Acute Myocardial Infarction Supported with Extracorporeal Membrane Oxygenation

Background

Previous studies have reported a "body mass index (BMI) paradox" with acute myocardial infarction (AMI), whereby overweight patients are associated with lower mortality. The aim of this study was to evaluate the impact of BMI on survival of patients with AMI supported with extracorporeal membrane oxygenation (ECMO).

Methods

Between May 2009 and July 2018, 60 patients with AMI who underwent ECMO were enrolled from a single center. Receiver operating characteristic curve analysis was used to determine a cutoff for BMI. Patients were divided into two groups: normal weight (18.5 ≤ BMI < 23 kg/m², n = 27) and overweight (BMI ≥ 23 kg/m², n = 33). The composite outcome was all-cause mortality at 30 days.

Results

The overweight group was significantly younger than the normal weight group, and there was a statistically significant difference between the two groups in electrocardiography before ECMO. Ventricular tachycardia or fibrillation occurred in 11 (33.3%) overweight patients, and asystole or pulseless electrical activity occurred in 10 (37%) normal weight patients. More of the normal weight group had successful percutaneous coronary interventions than the overweight group. The overweight group was significantly associated with lower mortality [hazard ratio (HR): 0.491; 95% confidence interval (CI) = 0.267-0.903] at 30 days, which persisted after multivariate adjustments (HR: 0.442; 95% CI = 0.210-0.928). To determine predictive factors for mortality, multivariate logistic analysis revealed that overweight [odds ratio (OR) 0.102; 95% CI (0.018-0.564); p = 0.009] and ECMO under cardiopulmonary resuscitation [OR 19.009; 95% CI (2.139-168.956); p = 0.008] were significantly associated with all-cause mortality at 30 days.

Conclusions

Overweight was associated with lower mortality in AMI patients supported with ECMO.