Mechanical circulatory support in cardiogenic shock

Outcomes of Impella 5.0 and 5.5 for cardiogenic shock: A single-center 137 patient experience

BACKGROUND

This study evaluated the outcomes of patients with cardiogenic shock (CS) supported with Impella 5.0 or 5.5 and identified risk factors for in-hospital mortality.

METHODS

Adults with CS who were supported with Impella 5.0 or 5.5 at a single institution were included. Patients were stratified into three groups according to their CS etiology: (1) acute myocardial infarction (AMI), (2) acute decompensated heart failure (ADHF), and (3) postcardiotomy (PC). The primary outcome was survival, and secondary outcomes included adverse events during Impella support and length of stay. Multivariable logistic regression was performed to identify risk factors for in-hospital mortality.

RESULTS

One hundred and thirty-seven patients with CS secondary to AMI (n = 47), ADHF (n = 86), and PC (n = 4) were included. The ADHF group had the highest survival rates at all time points. Acute kidney injury (AKI) was the most common complication during Impella support in all 3 groups. Increased rates of AKI and de novo renal replacement therapy were observed in the PC group, and the AMI group experienced a higher incidence of bleeding requiring transfusion. Multivariable analysis demonstrated diabetes mellitus, elevated pre-insertion serum lactate, and elevated pre-insertion serum creatinine were independent predictors of in-hospital mortality, but the etiology of CS did not impact mortality.

CONCLUSIONS

This study demonstrates that Impella 5.0 and 5.5 provide effective mechanical support for patients with CS with favorable outcomes, with nearly two-thirds of patients alive at 180 days. Diabetes, elevated pre-insertion serum lactate, and elevated pre-insertion serum creatinine are strong risk factors for in-hospital mortality.

ECMO Alone Versus ECPELLA in Patients Affected by Cardiogenic Shock: The Multicenter EVACS Study

The objective was to investigate the outcomes of concomitant venoarterial extracorporeal membrane oxygenation (ECMO) and left ventricular unloading with Impella (ECPELLA) compared with ECMO alone to treat patients affected by cardiogenic shock. Data from patients needing mechanical circulatory support from 4 international centers were analyzed. Of 438 patients included, ECMO alone and ECPELLA were adopted in 319 (72.8%) and 119 (27.2%) patients, respectively. Propensity score matching analysis identified 95 pairs. In the matched cohort, 30-day mortality rates in the ECMO and ECPELLA were 49.5% and 43.2% ( P = 0.467). The incidences of complications did not differ significantly between groups ( P = 0.877, P = 0.629, P = 1.000, respectively). After a median follow-up of 0.18 years (interquartile range 0.02-2.55), the use of ECPELLA was associated with similar mortality compared with ECMO alone (hazard ratio 0.81, 95% confidence interval 0.54-1.20, P = 0.285), with 1-year overall survival rates of 51.3% and 46.6%, for ECPELLA and ECMO alone, respectively. ECMO alone and ECPELLA are both effective strategies in patients needing mechanical circulatory support for cardiogenic shock, showing similar rates of early and mid-term survival.

Predictors of Mortality in Acute Myocardial Infarction Complicated by Cardiogenic Shock despite Intra-Aortic Balloon Pump: Opportunities for Advanced Mechanical Circulatory Support in Asia

Introduction: Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) mortality remains high despite revascularization and the use of the intra-aortic balloon pump (IABP). Advanced mechanical circulatory support (MCS) devices, such as catheter-based ventricular assist devices (cVAD), may impact mortality. We aim to identify predictors of mortality in AMI-CS implanted with IABP and the proportion eligible for advanced MCS in an Asian population. Methods: We retrospectively analyzed a cohort of Society for Cardiovascular Angiography and Intervention (SCAI) stage C and above AMI-CS patients with IABP implanted from 2017-2019. We excluded patients who had IABP implanted for indications other than AMI-CS. Primary outcome was 30-day mortality. Binary logistic regression was used to calculate adjusted odds ratios (aOR) for patient characteristics. Results: Over the 3-year period, 242 patients (mean age 64.1 ± 12.4 years, 88% males) with AMI-CS had IABP implanted. 30-day mortality was 55%. On univariate analysis, cardiac arrest (p < 0.001), inotrope/vasopressor use prior to IABP (p = 0.004) was more common in non-survivors. Non-survivors were less likely to be smokers (p = 0.001), had lower ejection fraction, higher creatinine/ lactate and lower pH (all p < 0.001). On multi-variate analysis, predictors of mortality were cardiac arrest prior to IABP (aOR 4.00, CI 2.28-7.03), inotrope/vasopressor prior to IABP (aOR 2.41, CI 1.18-4.96), lower arterial pH (aOR 0.02, CI 0.00-0.31), higher lactate (aOR 2.42, CI 1.00-1.19), and lower hemoglobin (aOR 0.83, CI 0.71-0.98). Using institutional MCS criteria, 106 patients (44%) would have qualified for advanced MCS. Conclusions: Early mortality in AMI-CS remains high despite IABP. Many patients would have qualified for higher degrees of MCS.

Combined use of intra-aortic balloon pump and impella in cardiogenic shock: A systematic review

BACKGROUND

Use of Intra-Aortic Balloon Pump (IABP) in combination with Impella has been described as an alternative strategy for mechanical circulatory support (MCS) in patients with cardiogenic shock (CS). We provide a systematic review aimed to explore the effectiveness of this paired MCS approach.

METHODS

We conducted a comprehensive systematic search in MEDLINE, Scopus, and Cochrane databases to identify all studies that investigated dual MCS with IABP and Impella.

RESULTS

Our search strategy identified 12 articles, including 1 randomized controlled trial, 1 retrospective study, 1 case series, 7 case report and 2 animal studies. Rationale for this combined MCS strategy stems from an observed reduction in myocardial oxygen demand/supply ratio compared to the use of each device alone, without determining significant variations in left ventricular work. Nonetheless, this combined approach also leads to a 30-40 % decline in Impella flow, increasing the risk of bleeding, Impella displacement, as well as triggering positioning and pressure alarms. Additionally, hemolytic risk data yielded inconclusive results. Importantly, there were no notable disparities in mortality rates when comparing the combined strategy to the use of each device individually.

CONCLUSION

At the current state-of-the-art, there are no conclusive data demonstrating net clinical benefits of combining Impella with IABP. Considering the substantial risks of morbidity associated, we recommend against its use in clinical practice.

Impact of Age, Gender, and Body Mass Index on Short-Term Outcomes of Patients With Cardiogenic Shock on Mechanical Circulatory Support

This single-center, observational study assessed the impact of age, gender, and body mass index (BMI) in patients with cardiogenic shock (CS) on temporary mechanical circulatory support. All adult patients admitted to the Cleveland Clinic main campus Cardiac Intensive Care Unit (CICU) between December 1, 2015, to December 31, 2019, CICU with CS necessitating mechanical circulatory support (MCS) with intra-aortic balloon pump, Impella, or venous arterial-extra corporeal membrane oxygenation were retrospectively analyzed for this study. Baseline characteristics and 30-day outcomes were collected through physician-directed chart review. The impact of age, gender, and BMI on 30-day mortality was assessed using multivariable logistic regression. Kaplan-Meier survival curves were used to analyze the survival difference in specific subsets. A total of 393 patients with CS on temporary MCS were admitted to our CICU during the study period. The median age of our cohort was 63 years (interquartile range 54 to 70 years), median BMI was 28.50 kg/m2 (interquartile range 24.62 to 29.72) and 70% (n = 276) were men. In total, 22 patients >80 years had received MCS compared with 372 patients <80 years. Patients >80 years on MCS had significantly higher 30-day mortality compared with those <80 years (81.8% vs 49.3%, p = 0.006). Upon stratifying patients by BMI, 161 (41%) patients were found to have BMI ≥30 kg/m2 whereas 232 (59%) patients had BMI <30 kg/m2. Comparison of 30-day mortality revealed that patients with BMI ≥30 did significantly worse than patients with BMI <30 (59.6% vs 45.3%, p = 0.007). There was no difference in 30-day mortality between men and women. On multivariable logistic regression, both age and BMI had a positive linear relation with adjusted 30-day mortality whereas gender did not have a major effect. Advanced age and higher BMI are independently associated with worse outcomes in patients with CS on MCS. Utilizing a strict selection criterion for patients in CS is pertinent to derive the maximum benefit from advanced mechanical support.

The diagnosis and treatment of pediatric clinical myocarditis in China: a multicenter retrospective study

This study aims to examine the clinical characteristics and outcomes of clinical myocarditis in pediatric patients in China. This is a multicenter retrospective study. Children diagnosed with clinical myocarditis from 20 hospitals in China and admitted between January 1, 2015, and December 30, 2021, were enrolled. The clinical myocarditis was diagnosed based on the "Diagnostic Recommendation for Myocarditis in Children (Version 2018)". The clinical data were collected from their medical records. A total of 1210 patients were finally enrolled in this study. Among them, 45.6% had a history of respiratory tract infection. An abnormal electrocardiogram was observed in 74.2% of patients. Echocardiography revealed that 32.3% of patients had a left ventricular ejection fraction of less than 50%. Cardiac MRI was performed in 4.9% of children with clinical myocarditis, of which 61% showed localized or diffuse hypersignal on T2-weighted images. Serum levels of cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), and N-terminal B-type natriuretic peptide (NT-proBNP) were higher in patients with fulminant myocarditis than in patients with myocarditis, making them potential risk factors for fulminant myocarditis. Following active treatment, 12.1% of patients were cured, and 79.1% were discharged with improvement.

CONCLUSION

Clinical myocarditis in children often presents with symptoms outside the cardiovascular system. CK-MB, cTnI, and NT-proBNP are important indicators for assessing clinical myocarditis. The electrocardiogram and echocardiogram findings in children with clinical myocarditis exhibit significant variability but lack specificity. Cardiac MRI can be a useful tool for screening clinical myocarditis. Most children with clinical myocarditis have a favorable prognosis.

WHAT IS KNOWN

• Pediatric myocarditis presents complex clinical manifestations and exhibits varying degrees of severity. Children with mild myocarditis generally have a favorable prognosis, while a small number of children with critically ill myocarditis experience sudden onset, hemodynamic disorders, and fatal arrhythmias. Therefore, early diagnosis and timely treatment of myocarditis are imperative.

WHAT IS NEW

• To the best of our knowledge, this multicenter retrospective study is the largest ever reported in China, aiming to reveal the clinical characteristics and outcomes of pediatric clinical myocarditis in China. We provided an extensive analysis of the clinical characteristics, diagnosis, treatment, prognosis, and factors impacting disease severity in pediatric clinical myocarditis in China, which provides insights into the epidemiological characteristics of pediatric clinical myocarditis.

Preserving flow, saving lives: Successful treatment of aortic valve failure in acute myocardial infarction without flow down-regulation using ECMO - a case report and mini review

Direct percutaneous coronary intervention (PPCI) has significantly reduced cardiac mortality in patients with acute myocardial infarction (AMI), but the mortality rate remains high for those who develop cardiogenic shock (CS), reaching 40% to 50%. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) provides robust hemodynamic support and oxygen delivery for AMI patients with refractory CS, ensuring adequate organ perfusion and oxygen supply. However, there is currently no standardized optimal Mean Arterial Pressure (MAP) range during V-A ECMO support. Achieving the proper MAP is crucial for adequate myocardial perfusion, cardiac function recovery, successful weaning off of V-A ECMO, and improving long-term outcomes. In this case study, we successfully treated a 55-year-old man with AMI and refractory cardiogenic shock using V-A ECMO. By adjusting ECMO blood flow and employing hemodynamic strategies, including vasoactive drugs, we optimized the MAP, leading to improved cardiac function and successful weaning off of V-A ECMO. This presents a potential opportunity for MAP optimization under ECMO support in patients with acute myocardial infarction and cardiogenic shock.

Mechanical circulatory support for cardiogenic shock: a network meta-analysis of randomized controlled trials and propensity score-matched studies

PURPOSE

Cardiogenic shock is associated with high mortality. In refractory shock, it is unclear if mechanical circulatory support (MCS) devices improve survival. We conducted a network meta-analysis to determine which MCS devices confers greatest benefit.

METHODS

We searched MEDLINE, Embase, and Scopus databases through 27 August 2023 for relevant randomized controlled trials (RCTs) and propensity score-matched studies (PSMs). We conducted frequentist network meta-analysis, investigating mortality (either 30 days or in-hospital) as the primary outcome. We assessed risk of bias (Cochrane risk of bias 2.0 tool/Newcastle-Ottawa Scale) and as sensitivity analysis reconstructed survival data from published survival curves for a one-stage unadjusted individual patient data (IPD) meta-analysis using a stratified Cox model.

RESULTS

We included 38 studies (48,749 patients), mostly reporting on patients with Society for Cardiovascular Angiography and Intervention shock stages C-E cardiogenic shock. Compared with no MCS, extracorporeal membrane oxygenation with intra-aortic balloon pump (ECMO-IABP; network odds ratio [OR]: 0.54, 95% confidence interval (CI): 0.33-0.86, moderate certainty) was associated with lower mortality. There were no differences in mortality between ECMO, IABP, microaxial ventricular assist device (mVAD), ECMO-mVAD, centrifugal VAD, or mVAD-IABP and no MCS (all very low certainty). Our one-stage IPD survival meta-analysis based on the stratified Cox model found only ECMO-IABP was associated with lower mortality (hazard ratio, HR, 0.55, 95% CI 0.46-0.66).

CONCLUSION

In patients with cardiogenic shock, ECMO-IABP may reduce mortality, while other MCS devices did not reduce mortality. However, this must be interpreted within the context of inter-study heterogeneity and limited certainty of evidence.

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.

Early left atrial venting versus conventional treatment for left ventricular decompression during venoarterial extracorporeal membrane oxygenation support: The EVOLVE-ECMO randomized clinical trial

AIMS

Few studies have reported data on the optimal timing of left ventricular (LV) unloading during venoarterial extracorporeal membrane oxygenation (VA-ECMO) for cardiac arrest or shock. This study evaluated the feasibility of an early LV unloading strategy compared with a conventional strategy in VA-ECMO.

METHODS AND RESULTS

Between December 2018 and August 2022, 60 patients at two institutions were randomized in a 1:1 ratio to receive early (n = 30) or conventional (n = 30) LV unloading strategies. The early LV unloading strategy was defined as LV unloading performed at the time of VA-ECMO insertion. LV unloading was performed using a percutaneous transseptal left atrial cannulation via the femoral vein incorporated into the ECMO venous circuit. The early and conventional LV unloading groups included 29 (96.7%) and 23 (76.7%) patients, respectively (median time from VA-ECMO insertion to LV unloading: 48.4 h, interquartile range 47.8-96.5 h). The groups showed no significant differences in the rate of VA-ECMO weaning as the primary endpoint (70.0% vs. 76.7%; relative risk 0.91; 95% confidence interval 0.67-1.24; p = 0.386) and survival to discharge (53.3% vs. 50.0%, p = 0.796). However, the pulmonary congestion score index at 48 h after LV unloading was significantly improved only in the early LV unloading group (2.0 ± 0.7 vs. 1.7 ± 0.6 at baseline vs. at 48 h; p = 0.008).

CONCLUSIONS

Compared with the conventional approach, early LV unloading did not improve the VA-ECMO weaning rate, despite the rapid improvement in pulmonary congestion. Therefore, the results of this study do not support the application of this strategy after VA-ECMO insertion.

Analysis of 24-hour Death Risk Factors in Circulatory Failure Patients Treated with Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVE

To explore the factors affecting short-term prognosis of circulatory failure patients undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) treatment.

METHODS

A total of 136 patients undergoing VA-ECMO were enrolled in this study and subsequently divided into the death group (n=35) and the survival group (n=101) based on whether death occurred during hospitalisation. Extracorporeal membrane oxygenation (ECMO) running time, length of intensive care unit stay, length of hospital stay, costs, and ECMO complications were then compared between the two groups.

RESULTS

The average age of all patients undergoing ECMO was 47.64±16.78 years (53.2±16.20 years in the death group and 45.713±16.62 years in the survival group) (P=0.022). Patients in the survival group exhibited a clear downward trend in lactic acid value following ECMO treatment compared to those in the death group. Total hospitalisation stay was longer in the survival group (35 days) than in the death group (15.5 days) (P<0.001). In the analysis of ECMO complications, the incidence of neurological complications, renal failure, limb complications, and infection were higher in the death group than in the survival group (P<0.05 for all). Specifically, as a risk factor for patient survival and discharge, the occurrence of infection will lead to increased hospitalisation stays and costs (P<0.05 for both).

CONCLUSION

Complications such as kidney failure and infection are associated with in-hospital death, and ECMO-related complications should be actively prevented to improve the survival rate of VA-ECMO treatment.

Regurgitation during the fully supported condition of the percutaneous left ventricular assist device

Objective.A percutaneous left ventricular assist device (PLVAD) can be used as a bridge to heart transplantation or as a temporary support for end-stage heart failure. Transvalvularly placed PLVADs may result in aortic regurgitation due to unstable pump position during fully supported operation, which may diminish the pumping effect of forward flow and predispose to complications. Therefore, accurate characterization of aortic regurgitation is essential for proper modeling of heart-pump interactions and validation of control strategies.Approach.In the present study, an improved aortic valve model was used to analyze the severity of regurgitation produced by different pump position offsets. The link between pump position offset degree and regurgitation is validated in the fixed speed mode, and the influence of pump speed on regurgitation is verified in the variable speed mode, using the mock circulatory loop (MCL) experimental platform.Main results.The greater the pump offset and the more severe the regurgitation, the more carefully the pump speed needs to be managed. To avoid over-pumping, the recommended pump speed in this study should not exceed 30 000 rpm.Significance.The modeling approach provide in this study not only makes it easier to comprehend the impact of regurgitation events on the entire interactive system during mechanical assistance, but it also aids in providing timely alerts and suitable management measures.

Acute mechanical circulatory support for cardiogenic shock in India

Cardiogenic shock continues to have high morbidity and mortality, despite advances in the field. Temporary mechanical circulatory support (TMCS) devices, if instituted in a timely fashion, can help stabilize critically ill patients with cardiogenic shock from various aetiologies and cardiac arrest, and provide time for organ recovery or till durable support or transplantation can be achieved. Currently, several options for TMCS devices exist. In this review, we discuss indications, contraindications, characteristics of the various available devices, and important issues pertaining to their management.

Anticoagulation practices and complications associated with Impella® support at an advanced cardiac center in the Middle East gulf region

Anticoagulation during Impella® support is a challenge due to its complications and inconsistent practice across the globe. This observational, retrospective chart review included all patients with Impella® support at our advanced cardiac center at a quaternary care hospital in the Middle East gulf region. The study was conducted over six years (2016-2022), a time period during which manufacturer recommendations for purge solution, anticoagulation protocols as well as Impella® place in therapy and utilization were all evolving. We aimed to evaluate the efficacy of different anticoagulation practices and association with complications and outcomes. Forty-one patients underwent Impella® during the study period, including 25 patients with support for more than 12 h, and are the focus of our analysis. Cardiogenic shock (n = 25, 60.9%) was the primary indication for Impella®, followed by facilitating high-risk PCI (n = 15, 36.7%) and left ventricular afterload reduction in patients undergoing veno-arterial extracorporeal membrane oxygenation (n = 1, 2.4%). Our overall Impella® usage evolved over the years from a primary use to facilitate a high-risk PCI to the recent more common use of LV unloading in cardiogenic shock. No patients experienced device malfunction and the incidence of other complications including ischemic stroke and bleeding were comparable to those reported in the literature (12.2% and 24% respectively). The 30-day all-cause mortality of 41 patients was 53.6%. In line with the evolving recommendations and evidence, we observed an underutilization of non-heparin-based purge solutions and inconsistent management of anticoagulation in the setting of both Impella® and VA ECMO which necessitates more education and protocols.

Adjusted mortality of extracorporeal membrane oxygenation for acute myocardial infarction patients in cardiogenic shock

Cardiogenic shock (CS) is a common cause of death following acute myocardial infarction (MI). This study aimed to evaluate the adjusted mortality of venoarterial extracorporeal membrane oxygenation (VA-ECMO) with intra-aortic balloon counterpulsation (IABP) for patients with MI-CS. We included 300 MI patients selected from a multinational registry and categorized into VA-ECMO + IABP (N = 39) and no VA-ECMO (medical management ± IABP) (N = 261) groups. Both groups' 30-day and 1-year mortality were compared using the weighted Kaplan-Meier, propensity score, and inverse probability of treatment weighting methods. Adjusted incidences of 30-day (VA-ECMO + IABP vs No VA-ECMO, 77.7% vs 50.7; P = .083) and 1-year mortality (92.3% vs 84.8%; P = .223) along with propensity-adjusted and inverse probability of treatment weighting models in 30-day (hazard ratio [HR], 1.57; 95% confidence interval [CI], 0.92-2.77; P = .346 and HR, 1.44; 95% CI, 0.42-3.17; P = .452, respectively) and 1-year mortality (HR, 1.56; 95% CI, 0.95-2.56; P = .076 and HR, 1.33; 95% CI, 0.57-3.06; P = .51, respectively) did not differ between the groups. However, better survival benefit 30 days post-ECMO could be supposed (31.6% vs 83.4%; P = .022). Therefore, patients with MI-CS treated with IABP with additional VA-ECMO and those not supported with ECMO have comparable overall 30-day and 1-year mortality risks. However, VA-ECMO-supported survivors might have better long-term clinical outcomes.

Review of Pathophysiology of Cardiogenic Shock and Escalation of Mechanical Circulatory Support Devices

PURPOSE OF REVIEW

Cardiogenic shock (CS) is a complex clinical entity that continues to carry a high risk of mortality. The landscape of CS management has changed with the advent of several temporary mechanical circulatory support (MCS) devices designed to provide hemodynamic support. It remains challenging to understand the role of different temporary MCS devices in patients with CS, as many of these patients are critically ill, requiring complex care with multiple MCS device options. Each temporary MCS device can provide different types and levels of hemodynamic support. It is important to understand the risk/benefit profile of each one of them for appropriate device selection in patients with CS.

RECENT FINDINGS

MCS may be beneficial in CS patients through augmentation of cardiac output with subsequent improvement of systemic perfusion. Selecting the optimal MCS device depends on several variables including the underlying etiology of CS, clinical strategy of MCS use (bridge to recovery, bridge to transplant or durable MCS, or abridge to decision), amount of hemodynamic support needed, associated respiratory failure, and institutional preference. Furthermore, it is even more challenging to determine the appropriate time to escalate from one MCS device to another or combine different MCS devices. In this review, we discuss the current available data published in the literature on the management of CS and propose a standardized approach for escalation of MCS devices in patients with CS. Shock teams can play an important role to help in hemodynamic-guided management and algorithm-based step-by-step approach in early initiation and escalation of temporary MCS devices at different stages of CS. It is important to define the etiology of CS, and stage of shock and recognize univentricular vs biventricular shock for appropriate device selection and escalation of therapy.

Intervention in Cardiogenic Shock

Cardiogenic shock is characterized by hypotension along with signs of hypoperfusion. It has been defined by various societies and clinical trials in different manner. Acute myocardial infarction is the most common cause of cardiogenic shock. Despite early percutaneous coronary intervention, shock secondary to acute coronary syndrome carries mortality rates reaching up to 40–50%. Mechanical circulatory support has been designed to potentially improve outcomes in such patients, but data remains scarce on mortality benefits and long-term outcomes.

Characteristics and Outcomes of Early vs Late Initiation of Mechanical Circulatory Support in Non-Acute Myocardial Infarction related Cardiogenic Shock: An Analysis of the National Inpatient Sample Database

Cardiogenic shock (CS) is significant cause of mortality. The use of mechanical circulatory support (MCS) in patients with non-acute myocardial infarction (Non-AMI) CS is lacking. We inquired data regarding the trends and outcomes early vs late initiation of MCS in non-AMI CS. We investigated National Inpatient Sample database between October 2015-December 2018, identifying hospitalizations with CS, either complicated by AMI or Non-AMI. Patients were divided into 2 cohorts, early initiation of MCS (<48 hours) and late initiation of MCS (>48 hours). The primary analysis included death within first 24 hours. A secondary analysis was adjusted after excluding patients who died in first 24 hours. A total of 85,318 patients with non-AMI-related CS with MCS placement were identified. Among this cohort, 54.6% (n=46,579) underwent early initiation of MCS within 48 hours, and 45.4% (n=38,739) underwent late initiation of MCS after 48 hours. In primary analysis, early MCS initiation was associated with more in-hospital mortality in primary outcome of all-cause hospital mortality (35.72% vs 27.63%, P<0.0001, OR 1.44, 95% CI: 1.40-1.49, P<0.0001), however, adjusted secondary analysis showed a statistically significant decrease in all-cause hospital mortality (23.63% vs 27.63%, P<0.0001, OR 0.80, 95% CI: 0.78-0.83, P<0.0001). In non-AMI-related CS and based on survival to 24 hours after admission, early initiation of MCS had statistically significant decrease in all-cause hospital mortality, with less incidence of vascular and renal complications, and shorter hospital stay. Late initiation of MCS was associated with a higher incidence of advanced therapies, including LVAD and transplant.

Single center experience and early outcomes of Impella 5.5

Background

Acute decompensated heart failure (HF) and cardiogenic shock (CS) frequently are refractory to conservative treatment and require mechanical circulatory support (MCS). We report our early clinical experience and evaluate patient outcomes with the newer generation surgical Impella 5.5.

Methods

Seventy patients that underwent Impella 5.5 implantation between October 2019 and December 2021 at a single center were enrolled in this study. Pre-operative characteristics, peri-operative clinical course information, and post-operative outcomes were retrospectively collected.

Results

Fifty-seven (81%) patients survived to discharge, and 51 (76%) patients survived at the time of the first 30 days post-discharge visit. Thirty-one patients (44%) received Impella support for a bridge to advanced surgical heart failure therapy (transplant or durable left ventricular assist device [LVAD]), 27 (39%) cases were used for a bridge to recovery/decision and 12 (17.1%) cases was used for planned perioperative support for high-risk cardiac surgery procedure.

Conclusion

Our results suggest that Impella 5.5 provides favorable survival in the management of HF and CS, particularly used for a bridge to heart transplant or LVAD. Early extubation and mobilization with high flow circulatory support allowed effective tailoring of MCS approaches from peri-operative support for high-risk cardiac surgery, bridge to recovery, and to advanced surgical heart failure therapy.

Veno-arterial extracorporeal membrane oxygenation with concomitant Impella versus concomitant intra-aortic-balloon-pump for cardiogenic shock

INTRODUCTION

The intra-aortic balloon pump (IABP) and Impella are left ventricular unloading devices with peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) in place and later serve as bridging therapy when VA-ECMO is terminated. We aimed to determine the potential differences in clinical outcomes and rate of complications between the two combinations of mechanical circulatory support.

METHODS

This was a retrospective, single institutional cohort study conducted in the intensive care unit (ICU) of Queen Elizabeth Hospital, Hong Kong. Inclusion criteria included all patients aged ⩾18 years, who had VA-ECMO support, and who had left ventricular unloading by either IABP or Impella between January 1, 2018 and October 31, 2020. Patients <18 years old, with central VA-ECMO, who did not require left ventricular unloading, or who underwent surgical venting procedures were excluded. The primary outcome was ECMO duration. Secondary outcomes included length of stay (LOS) in the ICU, hospital LOS, mortality, and complication rate.

RESULTS

Fifty-two patients with ECMO + IABP and 14 patients with ECMO + Impella were recruited. No statistically significant difference was observed in terms of ECMO duration (2.5 vs 4.6 days, p = 0.147), ICU LOS (7.7 vs 10.8 days, p = 0.367), and hospital LOS (14.8 vs 16.5 days, p = 0.556) between the two groups. No statistically significant difference was observed in the ECMO, ICU, and hospital mortalities between the two groups. Specific complications related to the ECMO and Impella combination were also noted.

CONCLUSIONS

Impella was not shown to offer a statistically significant clinical benefit compared with IABP in conjunction with ECMO. Clinicians should be aware of the specific complications of using Impella.

The Preventive Effect of Distal Perfusion Catheters on Vascular Complications in Patients Undergoing Venous Artery Extracorporeal Membrane Oxygenation

Objective

To investigate the preventive effect of distal perfusion catheters (DPCs) on vascular complications in patients undergoing venous artery extracorporeal membrane oxygenation (VA-ECMO).

Methods

Patients who underwent VA-ECMO through a femoral approach in our hospital were included in this study, and they were divided into two groups according to their use of DPC. Clinical indicators were compared between the two groups, including the ECMO running time, intensive care unit (ICU) time, length of hospital stay, ECMO auxiliary results, the incidence of limb ischemia and vascular complications.

Results

In total, 250 patients were included in this study, including the DPC group (age: 48 [32-62] years old, 58.4% male, n = 125) and the non-DPC group (age: 51 [36-63] years old, 65.6% male, n = 125). The DPC group was less likely to have limb complications than the non-DPC group (6.4% vs 17.6%, P = 0.006), mainly resulting from distal ischemia (4.0% vs 15.2%, P = 0.003) and necrosis (1.6% vs 9.6%, P = 0.006). The ECMO duration had a median of 92.3 (75.7-109) h in the DPC group and 71.2 (59.4-82.8) h in the DPC group, with a difference close to the statistical threshold (P = 0.054). There was no significant difference in ICU time or length of hospital stay between the two groups. The multivariate analysis showed that the DPC implantation was negatively associated with limb complications (odds ratio: 0.265, 95% confidence interval: 0.107-0.657, P = 0.004) after adjustment for confounding factors.

Conclusion

Distal perfusion catheter placement might be associated with a decreased risk of vascular complications and limb ischemia in patients undergoing femoral VA-ECMO cannulation. Further randomised studies are still needed to verify its benefit on clinical outcomes.

Contemporary Management of Concomitant Cardiac Arrest and Cardiogenic Shock Complicating Myocardial Infarction

Cardiogenic shock (CS) and cardiac arrest (CA) are the most life-threatening complications of acute myocardial infarction. Although there is a significant overlap in the pathophysiology with approximately half the patients with CS experiencing a CA and approximately two-thirds of patients with CA developing CS, comprehensive guideline recommendations for management of CA + CS are lacking. This paper summarizes the current evidence on the incidence, pathophysiology, and short- and long-term outcomes of patients with acute myocardial infarction complicated by concomitant CA + CS. We discuss the hemodynamic factors and unique challenges that need to be accounted for while developing treatment strategies for these patients. A summary of expert-based step-by-step recommendations to the approach and treatment of these patients, both in the field before admission and in-hospital management, are presented.

Veno-Arterial Extracorporeal Membrane Oxygenation as a Bridge to Heart Transplant-Change of Paradigm

Despite advances in medical therapy and mechanical circulatory support (MCS), heart transplant (HT) remains the gold standard therapy for end-stage heart failure. Patients in cardiogenic shock require prompt intervention to reverse hypoperfusion and end-organ damage. When medical therapy becomes insufficient, MCS should be considered. Historically, it has been reported that critically ill patients bridged with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) directly to HT have worse outcomes. However, when the heart allocation system gives the highest priority to patients on VA-ECMO support, those patients have a higher incidence of HT and a lower incidence of death or removal from the transplant list. Moreover, patients with a short waiting time on VA-ECMO have a similar hazard of mortality to non-ECMO patients. According to the reported data, bridging with VA-ECMO directly to HT may be a solution in the selection of critically ill patients when the anticipated waiting list time is short. However, when a prolonged waiting time is expected, more durable MCS should be considered. Regardless of the favorable results of the direct bridging to HT with ECMO in selected patients, the superiority of this strategy compared to the bridge-to-bridge strategy (ECMO to durable MCS) has not been established and further studies are mandatory in order to clarify this issue.

IMPELLA VERSUS EXTRACORPOREAL MEMBRANE OXYGENATION IN CARDIOGENIC SHOCK: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT

Background: Cardiogenic shock (CS) carries high mortality. The roles of specific mechanical circulatory support (MCS) systems are unclear. We compared the clinical outcomes of Impella versus extracorporal membrane oxygenation (ECMO) in patients with CS. Methods: This is a systematic review and meta-analysis that was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines. We searched PubMed, Cochrane Central Register, Embase, Web of Science, Google Scholar, and ClinicalTrials.gov (inception through May 10, 2022) for studies comparing the outcomes of Impella versus ECMO in CS. We used random-effects models to calculate risk ratios (RRs) with 95% confidence interval (CIs). End points included in-hospital, 30-day, and 12-month all-cause mortality, successful weaning from MCS, bridge to transplant, all reported bleeding, stroke, and acute kidney injury. Results: A total of 10 studies consisting of 1,827 CS patients treated with MCS were included in the analysis. The risk of in-hospital all-cause mortality was significantly lower with Impella compared with ECMO (RR, 0.80; 95% CI, 0.65-1.00; P = 0.05), whereas there was no statistically significant difference in 30-day (RR, 0.97, 95% CI, 0.82-1.16; P = 0.77) and 12-month mortality (RR, 0.90; 95% CI, 0.74-1.11; P = 0.32). There were no significant differences between the two groups in terms of successful weaning (RR, 0.97; 95% CI, 0.81-1.15; P = 0.70) and bridging to transplant (RR, 0.88; 95% CI, 0.58-1.35; P = 0.56). There was less risk of bleeding and stroke in the Impella group compared with the ECMO group. Conclusions: In patients with CS, the use of Impella is associated with lower rates of in-hospital mortality, bleeding, and stroke than ECMO. Future randomized studies with adequate sample sizes are needed to confirm these findings.

Minimally invasive apical cannulation and cannula design for short-term mechanical circulatory support devices

BACKGROUND

Refractory cardiogenic shock is still a major clinical challenge with high mortality rates, although several devices can be used to conquer this event. These devices have different advantages and disadvantages originating from their insertion or cannulation method, therefore many complications can occur during their use. The aim of our study was to develop and create prototypes of a novel minimal invasively insertable, transapical cannula for surgical ventricular assist devices, which uniquely incorporates the inflow and outflow routes for the blood of the patient in itself, therefore it enables the use for only one cannula for patients in cardiogenic shock.

METHODS

To define the available space for the planned cannula in the left ventricle and ascending aorta, we analyzed computed tomography scans of 24 heart failure patients, who were indicated to left ventricular assist device therapy. Parallel to these measurements, hydrodynamical calculations were performed to determine the sizes of the cannulas, which were necessary to provide effective cardiac output.

RESULTS

After the designing steps, we produced prototypes of double-lumened, tube-in-tube apically insertable devices for three different patient groups, which included a separated venous and an arterial part using 3D modelling and printing technology. All the created cannulas are able to provide 5 l/min circulatory support.

CONCLUSION

As a result of our research we created a sizing method based on the specific analysis of computed tomography pictures of end stage heart failure patients and a cannula concept, which can provide effective antegrade flow for patients in cardiogenic shock. We believe the improved version of our tool could have a significant therapeutic role in the future after further development based on animal and in vivo tests.

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.

Use of Impella device in cardiogenic shock and its clinical outcomes: A systematic review and meta-analysis

Introduction

Cardiogenic shock (CS) is a life-threatening condition and mechanical circulatory support (MCS) might exert a relevant impact on its clinical course. Among MCS devices, Impella is very promising. Yet, its usefulness is still debated. We performed a meta-analysis of all studies evaluating the clinical impact of Impella in CS.

Methods

All studies including patients with CS and treated with Impella were included. The primary endpoint was short-term mortality. Secondary endpoints were vascular access complications and major bleeding. Data synthesis was obtained using random-effects metanalysis.

Results

Thirty-three studies and 5204 patients were included. Short-term mortality was 47%. Meta-regression analysis showed that patients age (p = 0.01), higher support level (p = 0.004) and pre-PCI insertion (p < 0.001) were significant moderators for the primary endpoint. Vascular access complications were registered in 6.4% of cases, whereas age (p = 0.05) and diabetes (p = 0.007) were significant predictors. Major bleeding occurred in 16.4% of patients. Meta-analysis of the subgroup of studies comparing Impella to IABP showed no significant difference in short-term mortality (RR = 1.08, p = 0.45), while rates of vascular access complications (p < 0.001) or major bleeding (p < 0.001) were significantly higher with Impella. Subgroup and metaregression analyses showed that these results were influenced by lower adoption rates of higher degree of MCS support (p = 0.003), and by higher vascular complications rates (p = 0.014).

Conclusions

Our results suggest that the choice of adequate device size, careful patients selection and optimal timing of MCS initiation are key to clinical success with Impella in CS. Large prospective studies are mandatory to confirm these results deriving from retrospective studies.

Associated factors and clinical outcomes in mechanical circulatory support use in patients undergoing high risk on-pump cardiac surgery: Insights from the LEVO-CTS trial

BACKGROUND

We describe variables and outcomes associated with peri-operative mechanical circulatory support (MCS) utilization among patients enrolled in the Levosimendan in patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial.

METHODS

In the LEVO-CTS trial, MCS utilization (defined as intra-aortic balloon pump, extracorporeal membrane oxygenation, or surgical ventricular assist device) within 5 days of surgery was examined. The association between MCS use and outcomes including 90-day mortality, 30-day renal-replacement therapy, and hospital and critical stay length of stay were determined.

RESULTS

Among the 849 patients from 70 centers randomized to levosimendan or placebo, 85 (10.0%) patients were treated with MCS (71 intra-aortic balloon pump, 7 extracorporeal membrane oxygenation, 7 ventricular assist device); with 89.4% started on post-operative day 0. Inter-institutional use ranged from 0% to 100%. Variables independently associated with MCS utilization included combined coronary artery bypass grafting and valve surgery (adjusted odds ratio [OR] 2.73, 95% confidence interval [CI] 1.70-4.37, P < .001), history of lung disease (OR 1.70, 95% CI 1.06-2.70, P = .029), and history of heart failure (OR 2.44, 95% CI 1.10-5.45, P = .027). Adjusted 90-day mortality (22.4% vs 4.1%, hazard ratio 6.11, 95% CI 3.95-9.44, P < .001) was higher, and median critical care length of stay (8.0 vs 4.0 days, P < .001) was longer in patients managed with MCS.

CONCLUSIONS

In a randomized controlled trial of high-risk cardiac surgical patients in North America, we observed patient, and surgical variables associated with MCS utilization. MCS use was associated with a higher risk of post-operative mortality.

Predictive value of the APACHE II score in cardiogenic shock patients treated with a percutaneous left ventricular assist device

Background

The APACHE II score assesses patient prognosis in intensive care units. Different disease entities are predictable by using a specific factor called Diagnostic Category Weight (DCW). We aimed to validate the prognostic value of the APACHE II score in patients treated with a percutaneous left ventricular assist device because of refractory cardiogenic shock (CS).

Methods

From the Dresden Impella Registry, we analyzed 180 patients receiving an Impella CP®. The main outcome was the observed intrahospital mortality (S^(thosp)), which was compared to the predicted mortality estimated by the APACHE II score.

Results

The APACHE II score, which was 33.5 ± 0.6, significantly overestimated intrahospital mortality (S^(thosp) 54.4 ± 3.7% vs. APACHE II 74.6 ± 1.6%; p < 0.001). Nevertheless, the APACHE II score showed an acceptable accuracy to predict intrahospital mortality (ROC AUC 0.70; 95% CI 0.62–0.78). Thus, we adapted the formula for calculation of predicted mortality by adjusting DCW. The total registry cohort was randomly divided into derivation group for calculation of adjusted DCW and validation group for testing. Intrahospital mortality was much more precisely predicted using the adjusted DCW compared to the conventional DCW (difference of predicted and observed mortality: –4.7 ± 2.4% vs. –23.2 ± 2.3%; p < 0.001). The new calculated DCW was −1.183 for the total cohort.

Conclusion

The APACHE II score has an acceptable accuracy for the prediction of intrahospital mortality but overestimates its total amount in CS patients. Adjustment of the DCW can lead to a much more precise prediction of prognosis.

Influence of inflammation and cardiac hypertrophy on mechanical properties of human pericardium

Different devices for mechanical circulatory support (MCS) have been developed for the treatment of refractory cardiogenic shock. However, all of them are associated with direct blood contact, the need for anticoagulation and bleeding complications. To overcome these limitations the pericardial sac got into the focus as a promising implantation site for MCS. For this purpose, further knowledge about the mechanical properties of human pericardium is required. In this prospective, monocentric, experimental pilot study 56 samples of human pericardium were extracted postmortem from 13 critically ill patients. After preparation of test specimens uniaxial tensile tests were performed. The primary end points were load at fracture per sample width and strain at fracture. Acute inflammation was assessed by blood levels of C-reactive protein, white blood count and procalcitonin measured at several times during hospital stay. Inflammatory load was estimated by area under the inflammatory curves. Correlation and regression analysis were used to assess the relationship of primary end points to inflammation, comorbidities and postmortem time to preparation. Human pericardium showed a load at fracture per sample width of 1.95 [1.38–2.94] N/mm (median [inter quartile range]) and a strain at fracture of 89.29 [73.84–135.23] %. Markers of acute inflammation and cardiac hypertrophy did not correlate to load or strain at fracture. However, strain at fracture increased with higher body mass index and an increasing number of postmortem days. In contrast, higher patient age was associated with a lower strain at fracture. Inflammation and cardiac hypertrophy did not influence mechanical properties of human pericardium.

Radiology of Intra-Aortic Balloon Pump Catheters

Radiographs play an important role in ascertaining appropriate placement of the intra-aortic balloon pump catheter. This imaging essay highlights correct and incorrect positioning of these catheters, with emphasis on the variability of radiopaque markers used with different catheter models and on axillary versus femoral catheter placement routes. Keywords: Conventional Radiography, CT, Percutaneous, Cardiac, Vascular, Aorta, Anatomy, Cardiac Assist Devices, Catheters © RSNA, 2022.

Ventricular Unloading Using the ImpellaTM Device in Cardiogenic Shock

Cardiogenic shock (CS) remains a leading cause of hospital death. However, the use of mechanical circulatory support has fundamentally changed CS management over the last decade and is rapidly increasing. In contrast to extracorporeal membrane oxygenation as well as counterpulsation with an intraaortic balloon pump, ventricular unloading by the Impella™ device actively reduces ventricular volume as well as pressure and augments systemic blood flow at the same time. By improving myocardial oxygen supply and enhancing systemic circulation, the Impella device potentially protects myocardium, facilitates ventricular recovery and may interrupt the shock spiral. So far, the evidence supporting the use of Impella™ in CS patients derives mostly from observational studies, and there is a need for adequate randomized trials. However, the Impella™ device appears a promising technology for management of CS patients. But a profound understanding of the device, its physiologic impact and clinical application are all important when evaluating CS patients for percutaneous circulatory support. This review provides a comprehensive overview of the percutaneous assist device Impella™. Moreover, it highlights in depth the rationale for ventricular unloading in CS and describes practical aspects to optimize care for patients requiring hemodynamic support.

A Comprehensive Review of Mechanical Circulatory Support Devices

Treatment strategies to combat cardiogenic shock (CS) have remained stagnant over the past decade. Mortality rates among patients who suffer CS after acute myocardial infarction (AMI) remain high at 50%. Mechanical circulatory support (MCS) devices have evolved as novel treatment strategies to restore systemic perfusion to allow cardiac recovery in the short term, or as durable support devices in refractory heart failure in the long term. Haemodynamic parameters derived from right heart catheterization assist in the selection of an appropriate MCS device and escalation of mechanical support where needed. Evidence favouring the use of one MCS device over another is scant. An intra-aortic balloon pump is the most commonly used short-term MCS device, despite providing only modest haemodynamic support. Impella CP® has been increasingly used for CS in recent times and remains an important focus of research for patients with AMI-CS. Among durable devices, Heartmate® 3 is the most widely used in the USA. Adequately powered randomized controlled trials are needed to compare these MCS devices and to guide the operator for their use in CS. This article provides a brief overview of the types of currently available MCS devices and the indications for their use.

A Risk Stratification Scheme for In-Hospital Cardiogenic Shock in Patients With Acute Myocardial Infarction

Objective

Cardiogenic shock (CS) is the leading cause of death in patients with acute myocardial infarction (AMI) despite advances in care. This study aims to derive and validate a risk score for in-hospital development of CS in patients with AMI.

Methods

In this study, we used the Improving Care for Cardiovascular Disease in China–Acute Coronary Syndrome (CCC–ACS) registry of 76,807 patients for model development and internal validation. These patients came from 158 tertiary hospitals and 82 secondary hospitals between 2014 and 2019, presenting AMI without CS upon admission. The eligible patients with AMI were randomly assigned to derivation (n = 53,790) and internal validation (n = 23,017) cohorts. Another cohort of 2,205 patients with AMI between 2014 and 2016 was used for external validation. Based on the identified predictors for in-hospital CS, a new point-based CS risk scheme, referred to as the CCC–ACS CS score, was developed and validated.

Results

A total of 866 (1.1%) and 39 (1.8%) patients subsequently developed in-hospital CS in the CCC–ACS project and external validation cohort, respectively. The CCC–ACS CS score consists of seven variables, including age, acute heart failure upon admission, systolic blood pressure upon admission, heart rate, initial serum creatine kinase-MB level, estimated glomerular filtration rate, and mechanical complications. The area under the curve for in-hospital development of CS was 0.73, 0.71, and 0.85 in the derivation, internal validation and external validation cohorts, respectively.

Conclusion

This newly developed CCC–ACS CS score can quantify the risk of in-hospital CS for patients with AMI, which may help in clinical decision making.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT02306616.

Withdrawal of Temporary Mechanical Circulatory Support in Patients With Capacity

CONTEXT

Little is known about the real-time decision-making process of patients with capacity to choose withdrawal of temporary mechanical circulatory support (MCS).

OBJECTIVES

To assess how withdrawal of temporary MCS occurs when patients possess the capacity to make this decision themselves.

METHODS

This retrospective case series included adults supported by CentriMag Acute Circulatory Support or Veno-Arterial Extracorporeal Membrane Oxygenation from February 2, 2007 to May 27, 2020 at a tertiary academic medical center who possessed capacity to participate in end-of-life discussions. Authors performed chart review to determine times between "initiation of temporary MCS," "determination of 'bridge to nowhere,'" "patient expressing desire to withdraw," "agreement to withdraw," "withdrawal," and "death," as well as reasons for withdrawal and the role of ethics, psychiatry, and palliative care.

RESULTS

A total of 796 individuals were included. MCS was withdrawn in 178 (22.4%) of cases. Six of these 178 patients (3.4%) possessed the capacity to decide to withdraw MCS. Time between "patient expressing desire to withdraw" and "agreement to withdraw" ranged from 0 to 3 days; time between "agreement to withdraw" and "withdrawal" ranged from 0 to 6 days. Common reasons for withdrawal include perceived decline in quality of life or low probability of recovery. Ethics and psychiatry were consulted in 3 of 6 cases and palliative care in 5 of 6 cases.

CONCLUSION

While it is rare for patients on MCS to request withdrawal, such cases provide insight into reasons for withdrawal and the important roles of multidisciplinary teams in helping patients and families through end-of-life decision-making.

Perioperative Management of Patients Receiving Short-term Mechanical Circulatory Support with the Transvalvular Heart Pump

Use of the transvalvular heart pump to provide short-term circulatory support in the perioperative setting is growing. The considerations for the perioperative management of patients receiving transvalvular heart pump support are reviewed for the anesthesiologist.

[Cardiogenic shock complicating myocardial infarction]

Cardiogenic shock as a complication of myocardial infarction (5-10%) increases the mortality of uncomplicated myocardial infarction from less than 10% to 40%. This is due to the development of multiple organ dysfunction syndrome triggered by the extensive shock-induced impairment of organ perfusion. Therefore, guideline-based treatment should not only be restricted to reopening of the occluded coronary artery and management of complications of the infarction: important for survival are also guideline-driven optimization of organ perfusion by inotropic and vasoactive substances and, with well-defined indications, by temporary mechanical circulatory support but not by intra-aortic counterpulsation. Equally important, however, are shock-specific intensive care measures to prevent or attenuate organ dysfunction, such as lung protective ventilation in cases where ventilation is obligatory.

Impella in Transport: Physiology, Mechanics, Complications, and Transport Considerations

Cardiogenic shock (CS) represents a spectrum of hemodynamic deficits in which the cardiac output is insufficient to provide adequate tissue perfusion. The Impella (Abiomed Inc, Danvers, MA) device, a contemporary percutaneous ventricular support, is most often indicated for classic, deteriorating, and extremis Society for Coronary Angiography and Intervention stages of CS, which describe CS that is not responsive to optimal medical management and conventional treatment measures. Impella devices are an evolving field of mechanical support that is used with increasing frequency. Critical care transport medicine crews are required to transport patient support by the Impella device with increasing frequency. It is important that critical care transport medicine crews are familiar with the Impella device and are able to troubleshoot complications that may arise in the transport environment. This article reviews many aspects of the Impella device critical to the transport of this complex patient population.

Concomitant Respiratory Failure Can Impair Myocardial Oxygenation in Patients with Acute Cardiogenic Shock Supported by VA-ECMO

Venous-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment for acute cardiogenic shock in patients who also have acute lung injury predisposes development of a serious complication called "north-south syndrome" (NSS) which causes cerebral hypoxia. NSS is poorly characterized and hemodynamic studies have focused on cerebral perfusion ignoring the heart. We hypothesized in NSS the heart would be more likely to receive hypoxemic blood than the brain due to the proximity of the coronary arteries to the aortic annulus. To test this, we conducted a computational fluid dynamics simulation of blood flow in a human supported by VA-ECMO. Simulations quantified the fraction of blood at each aortic branching vessel originating from residual native cardiac output versus VA-ECMO. As residual cardiac function was increased, simulations demonstrated myocardial hypoxia would develop prior to cerebral hypoxia. These results illustrate the conditions where NSS will develop and the relative cardiac function that will lead to organ-specific hypoxia. Illustration of the impact of north-south syndrome on organ-specific oxygen delivery. Patients on VA-ECMO have two sources of blood flow, one from the VA-ECMO circuit and one from the residual cardiac function. When there is no residual cardiac function, all organs are perfused with oxygenated blood. As myocardial recovery progresses, blood supply from the two sources will begin to mix resulting in non-homogeneous mixing and differential oxygenation based upon the anatomical site of branching vessels.

Awake Implementation of Extracorporeal Life Support in Refractory Cardiogenic Shock

Background and objectives: Extracorporeal life support (ECLS) is a widely accepted and effective strategy for use in patients presenting with refractory cardiogenic shock. Implantation in awake and non-intubated patients allows for optimized evaluation of further therapy options while avoiding potential side effects associated with the need for sedation and intubation. The aim of the study was the assessment of safety and feasibility of awake ECLS implementation and of outcomes in patients treated with this concept. Materials and Methods: We retrospectively reviewed the concept of awake ECLS implantation in 16 consecutive patients (mean age 58 ± 8 years; male: 88%; ischemic cardiomyopathy: 50%) from 02/2017 to 01/2021. Study endpoints were survival to weaning or bridging to durable support or organ replacement and development of end-organ function and hemodynamic parameters on ECLS. Results: Fourteen patients (88%) were able to be successfully transitioned to definite therapy options. ECLS support stabilized end-organ function, led to a decrease in mean lactate levels (5.3 ± 3.7 mmol/L at baseline to 1.9 ± 1.3 mmol/L 12 h after ECLS start; p = 0.01) and improved hemodynamics (median central venous pressure 20 ± 5 mmHg vs. 10 ± 2 mmHg, p = 0.001) over a median duration of two days (1–8 days IQR). Two patients (13%) died on ECLS support due to multi-organ dysfunction syndrome. Survival to discharge of initially successfully bridged or weaned patients was 64%. Conclusions: Awake ECLS implantation is feasible and safe with the key advantage of omitting or delaying general anesthesia and intubation, with their associated risks in cardiogenic-shock patients, facilitating further decision making.

Hyperglycemia and Thrombocytopenia - Combinatorially Increase the Risk of Mortality in Patients With Acute Myocardial Infarction Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation

Background: Patients with cardiogenic shock due to acute myocardial infarction (AMI) can rapidly undergo veno-arterial extracorporeal membrane oxygenation (VA-ECMO) therapy to recover cardiac output and decrease mortality. However, the clinical indicators predictive of mortality in these patients remain unknown.

Methods and Results: We conducted a single-center retrospective cohort study targeting AMI patients undergoing VA-ECMO. All 63 patients undergoing VA-ECMO for AMI at the Japanese Red Cross Kumamoto Hospital between January 1, 2010 and June 30, 2020 were enrolled. An exploratory analysis was conducted using a survival tree model and variables selected in a univariate Cox proportional hazard model. The median survival time from the start of VA-ECMO was 6.3 days, and 77.8% (n=49) of patients died. Survival analysis divided patients into 3 groups based on 2 parameters at the initial medical examination: Group 1, patients with neither hyperglycemia (blood glucose ≥213 mg/dL) nor thrombocytopenia (platelets ≤145,100/μL); Group 2, patients with hyperglycemia; and Group 3, patients with hyperglycemia plus thrombocytopenia. Relative to Group 1, the risk of in-hospital mortality was significantly increased in Group 2 (hazard ratio [HR] 2.25; 95% confidence interval [CI] 1.13–4.46), and that risk further increased in Group 3 (HR 7.60; 95% CI 3.21–17.95).

Conclusions: Hyperglycemia plus thrombocytopenia on initial medical examination combinatorially increase the risk of mortality in patients with cardiogenic shock due to AMI undergoing VA-ECMO.

Impella support for cardiogenic shock and high-risk percutaneous coronary intervention: A single-center experience

INTRODUCTION AND OBJECTIVES

The use of mechanical circulatory support is increasing in cases of cardiogenic shock (CS) and high-risk percutaneous coronary intervention (HR-PCI). The Impella® is a percutaneous ventricular assist device that unloads the left ventricle by ejecting blood to the ascending aorta. We report our center's experience with the use of the Impella® device in these two clinical settings.

METHODS

We performed a single-center retrospective study including all consecutive patients implanted with the Impella® between 2007 and 2019 for CS treatment or prophylactic support of HR-PCI. Data on clinical and safety endpoints were collected and analyzed.

RESULTS

Twenty-two patients were included: 12 were treated for CS and 10 underwent an HR-PCI procedure. In the CS-treated population, the main cause of CS was acute myocardial infarction (five patients); hemolysis was the most frequent device-related complication (63.7%). In-hospital, cumulative 30-day and one-year mortality were 58.3%, 66.6% and 83.3%, respectively. In the HR-PCI group, all patients had multivessel disease (mean baseline SYNTAX I score: 44.1±13.7). In-hospital, 30-day and one-year mortality were 10.0%, 10.0% and 20.0%, respectively. There were no device- or procedure-related deaths in either group.

CONCLUSION

The short- and long-term results of Impella®-supported HR-PCI were comparable to those in the literature. In the CS group, in-hospital and short-term outcomes were poor, with high mortality and non-negligible complication rates.

To Balloon or Not to Balloon? The Effects of an Intra-Aortic Balloon-Pump on Coronary Artery Flow during Extracorporeal Circulation Simulating Normal and Low Cardiac Output Syndromes

ECMO is the most frequently used mechanical support for patients suffering from low cardiac output syndrome. Combining IABP with ECMO is believed to increase coronary artery blood flow, decrease high afterload, and restore systemic pulsatile flow conditions. This study evaluates that combined effect on coronary artery flow during various load conditions using an in vitro circuit. In doing so, different clinical scenarios were simulated, such as normal cardiac output and moderate-to-severe heart failure. In the heart failure scenarios, we used peripheral ECMO support to compensate for the lowered cardiac output value and reach a default normal value. The increase in coronary blood flow using the combined IABP-ECMO setup was more noticeable in low heart rate conditions. At baseline, intermediate and severe LV failure levels, adding IABP increased coronary mean flow by 16%, 7.5%, and 3.4% (HR 60 bpm) and by 6%, 4.5%, and 2.5% (HR 100 bpm) respectively. Based on our in vitro study results, combining ECMO and IABP in a heart failure setup further improves coronary blood flow. This effect was more pronounced at a lower heart rate and decreased with heart failure, which might positively impact recovery from cardiac failure.