Temporary Mechanical Circulatory Support after Cardiac Surgery

Postcardiotomy shock in the cardiac surgical patient is a highly morbid condition characterized by profound myocardial impairment and decreased systemic perfusion inadequate to meet end-organ metabolic demand. Postcardiotomy shock is associated with significant morbidity and mortality. Poor outcomes motivate the increased use of mechanical circulatory support (MCS) to restore perfusion in an effort to prevent multiorgan injury and improve patient survival. Despite growing acceptance and adoption of MCS for postcardiotomy shock, criteria for initiation, clinical management, and future areas of clinical investigation remain a topic of ongoing debate. This article seeks to (1) define critical cardiac dysfunction in the patient after cardiotomy, (2) provide an overview of commonly used MCS devices, and (3) summarize the relevant clinical experience for various MCS devices available in the literature, with additional recognition for the role of MCS as a part of a modified approach to the cardiac arrest algorithm in the cardiac surgical patient.

Factors associated with acute limb ischemia in cardiogenic shock and downstream clinical outcomes: Insights from the Cardiogenic Shock Working Group

BACKGROUND

There are limited data depicting the prevalence and ramifications of acute limb ischemia (ALI) among cardiogenic shock (CS) patients.

METHODS

We employed data from the Cardiogenic Shock Working Group (CSWG), a consortium including 33 sites. We constructed a multi-variable logistic regression to examine the association between clinical factors and ALI, we generated another logistic regression model to ascertain the association of ALI with mortality.

RESULTS

There were 7,070 patients with CS and 399 (5.6%) developed ALI. Patients with ALI were more likely to be female (40.4% vs 29.4%) and have peripheral arterial disease (13.8% vs 8.3%). Stratified by maximum society for cardiovascular angiography & intervention (SCAI) shock stage, the rates of ALI were stage B 0.0%, stage C 1.8%, stage D 4.1%, and stage E 10.3%. Factors associated with higher risk for ALI included: peripheral vascular disease OR 2.24 (95% CI: 1.53-3.23; p < 0.01) and ≥2 mechanical circulatory support (MCS) devices OR 1.66 (95% CI: 1.24-2.21, p < 0.01). ALI was highest for venous-arterial extracorporeal membrane oxygenation (VA-ECMO) patients (11.6%) or VA-ECMO+ intra-aortic balloon pump (IABP)/Impella CP (16.6%) yet use of distal perfusion catheters was less than 50%. Mortality was 38.0% for CS patients without ALI but 57.4% for CS patients with ALI. ALI was significantly associated with mortality, adjusted OR 1.40 (95% CI 1.01-1.95, p < 0.01).

CONCLUSIONS

The rate of ALI was 6% among CS patients. Factors most associated with ALI include peripheral vascular disease and multiple MCS devices. The downstream ramifications of ALI were dire with a considerably higher risk of mortality.

Volume-outcome relationships for extracorporeal membrane oxygenation in acute myocardial infarction

Acute myocardial infarction (MI) is one of the major scenarios of extracorporeal membrane oxygenation (ECMO) use. The utilization of mechanical circulatory support systems including ECMO varies widely at the hospital level, while whether ECMO volume per hospital is associated with outcomes in acute MI is unclear. Using a Japanese nationwide administrative database, a total of 26,913 patients with acute MI undergoing percutaneous coronary intervention from 154 hospitals were included. The relations among PCI volume for acute MI, observed and predicted in-hospital mortality, and observed and predicted rates of ECMO use were evaluated at the hospital level. Of 26,913 patients, 423 (1.6%) were treated with ECMO, and 1561 (5.8%) died during the hospitalization. Median ECMO use per hospital per year was 0.5. An observed rate of ECMO use was linearly correlated with the predicted probability of ECMO use and was not associated with the observed/predicted in-hospital mortality ratio. The observed/predicted mortality ratio was lowest in hospitals with the observed/predicted ECMO use ratio of around one. In conclusion, ECMO was infrequently used in a setting of acute MI at each hospital annually. An observed rate of ECMO use was not associated with observed/predicted in-hospital mortality ratio, while the observed/predicted in-hospital mortality ratio was lowest when ECMO was used as predicted, suggesting that standardized ECMO use may be an institutional quality indicator in acute MI.

Appropriateness of Fluid Therapy in Cardiogenic Shock Management: A Systematic Review of Current Evidence

Fluid therapy plays a pivotal role in maintaining tissue perfusion during the management of cardiogenic shock. Nevertheless, its application in this context is contentious, necessitating a balance between achieving adequate volume and avoiding fluid overload. This systematic review aimed to assess the outcomes of fluid therapy in cardiogenic shock. This review encompasses 11 studies involving 406 participants. Although some studies reported hemodynamic improvements following fluid administration, others presented contrasting findings. Studies that did not highlight the benefits of fluid therapy typically involved patients with unique comorbidities requiring specific etiology-based medical treatments. The most prevalent cause of cardiogenic shock, acute coronary syndrome, exhibited varying responses to fluid therapy based on the infarct location. In conclusion, fluid therapy plays a crucial role in cardiogenic shock management but necessitates integration into an appropriate treatment strategy, accounting for individual circumstances, comorbidities, and etiology. Further research is imperative to amass additional evidence regarding this issue.

SCAI Staging Application for Acute Myocardial Infarction-Related Cardiogenic Shock at a Single-Center Russian Registry

AIM

To access the features of the course of myocardial infarction (MI) in patients with different stages of MI complicated by cardiogenic shock (MI CS) according to the SCAI scale.

METHODS

We retrospectively described the portrait of CS MI (n = 117) at different stages of SCAI from the hospital MI registry (n = 1253).

RESULTS

Hospital mortality increased from stage to stage (p ≤ 0.001). Significant differences in biochemical parameters were found both for indicators characterizing intensive care measures, such as the presence of mechanical lung ventilation or an intra-aortic balloon pump, and for indicators of organ hypoperfusion such as lactate level, pHv (7.39 (7.36; 7.44) at stage A-B; 7.14 (7.06; 7.18) at stage E), creatinine, and glomerular filtration rate. Parameters related to MI characteristics, such as instrumental and laboratory data, anamnesis of ischemia, and performed treatment, did not differ between groups. Polynomial logistic regression showed that lactate level, mechanical ventilation, and monocyte count upon admission (1.15 (0.96; 1.23) at stage A-B; 0.78 (0.49; 0.94) at stage E, p = 0.005) correlated with CS severity.

CONCLUSION

The characteristics of MI at different stages of SCAI do not have differences and do not determine the severity of shock. We revealed a high discriminatory potential of the pH level in predicting refractory shock. The value of monocytes at admission may be a promising predictor of the severity of MI CS. The question of the causes of heterogeneity of MI CS, taking into account the homogeneity of MI characteristics, remains open and promising.

Age and associated outcomes among patients receiving venoarterial extracorporeal membrane oxygenation-analysis of the Extracorporeal Life Support Organization registry

PURPOSE

Venoarterial extracorporeal membrane oxygenation (V-A ECMO) can be used to support severely ill patients with cardiogenic shock. While age is commonly used in patient selection, little is known regarding its association with outcomes in this population. We sought to evaluate the association between increasing age and outcomes following V-A ECMO.

METHODS

We used individual-level patient data from 440 centers in the international Extracorporeal Life Support Organization registry. We included all adult patients receiving V-A ECMO from 2017 to 2019. The primary outcome was hospital mortality. Secondary outcomes included a composite of complications following initiation of V-A ECMO. We conducted Bayesian analyses of the relationship between increasing age and outcomes of interest.

RESULTS

We included 15,172 patients receiving V-A ECMO. Of these, 8172 (53.9%) died in hospital. For the analysis conducted using weakly informed priors, and as compared to the reference category of age 18-29, the age bracket of 30-39 (odds ratio [OR] 0.94, 95% credible interval [CrI] 0.79-1.10) was not associated with hospital mortality, but age brackets 40-49 (odds ratio [OR] 1.26, 95% CrI: 1.08-1.47), 50-59 (OR 1.78, 95% CrI: 1.55-2.06), 60-69 (OR 2.24, 95% CrI: 1.94-2.59), 70-79 (OR 2.90, 95% CrI: 2.49-3.39) and ≥ 80 (OR 4.02, 95% CrI: 3.13-5.20) were independently associated with increasing hospital mortality. Similar results were found in the analysis conducted with an informative prior, as well as between increasing age and post-ECMO complications.

CONCLUSIONS

Among patients receiving V-A ECMO for cardiogenic shock, increasing age is strongly associated with increasing odds of death and complications, and this association emerges as early as 40 years of age.

Trends in Mechanical Circulatory Support Use and Outcomes of Patients With Cardiogenic Shock in Japan, 2010 to 2020 (from a Nationwide Inpatient Database Study)

Little is known about the impact of the downgrade of guideline recommendations for intra-aortic balloon pump (IABP) use and the approval of the Impella in Japan, where IABPs have been predominantly used. This study aimed to describe the annual trends in the mechanical circulatory support (MCS) use and outcomes in patients with cardiogenic shock (CS) requiring MCS. Using the Japanese Diagnosis Procedure Combination database from July 2010 to March 2021, we identified inpatients with CS requiring MCS. The patients were stratified into 3 groups: (1) IABP alone, (2) Impella alone, and (3) extracorporeal membrane oxygenation (ECMO), regardless of IABP or Impella use. The patient characteristics and outcomes were reported by the fiscal year. Of the 160,559 eligible patients, 117,599 (73.2%) used IABP alone, 1,465 (0.9%) Impella alone, and 41,495 (25.8%) ECMO. The prevalence of the use of an IABP alone significantly decreased from 80.5% in 2010 to 65.3% in 2020 (p for trend <0.001), whereas the prevalence of the use of an Impella alone significantly increased from 0.0% to 5.0% and ECMO from 19.5% to 29.6% (p for trend <0.001 for both). In-hospital mortality significantly increased from 29.3% in 2010 to 32.6% in 2020 in the overall patients with CS requiring MCS but significantly decreased in those requiring ECMO from 73.7% to 64.1% (p for trend <0.001 for both). In conclusion, there were significant annual changes in the patterns of MCS use and clinical outcomes in patients with CS requiring MCS.

Escalation strategies, management, and outcomes of acute myocardial infarction-cardiogenic shock patients receiving percutaneous left ventricular support

BACKGROUND

There are limited national-level data on the contemporary practices of mechanical circulatory support (MCS) use in acute myocardial infarction-cardiogenic shock (AMI-CS).

METHODS

We utilized the Healthcare Cost and Utilization Project-National/Nationwide Inpatient Sample data (2005-2017) to identify adult admissions (>18 years) with AMI-CS. MCS devices were classified as intra-aortic balloon pump (IABP), percutaneous left ventricular assist devices (pLVAD), or extracorporeal membrane oxygenation (ECMO). We evaluated trends in the initial device used (IABP alone, pLVAD alone or ≥2 MCS devices), device escalation, bridging to durable LVAD/heart transplantation, and predictors of in-hospital mortality and device escalation.

RESULTS

Among 327,283 AMI-CS admissions, 131,435 (40.2%) had an MCS device placed with available information on timing of placement. IABP, pLVAD, and ≥2 MCS devices were used as initial device in 120,928 (92.0%), 8202 (6.2%), and 2305 (1.7%) admissions, respectively. Most admissions were maintained on the initial MCS device with 1%-1.5% being escalated (IABP to pLVAD/ECMO, pLVAD to ECMO). Urban, medium, and large-sized hospitals and acute multiorgan failure were significant independent predictors of MCS escalation. In admissions receiving MCS, escalation of MCS device was associated with higher in-hospital mortality (adjusted odds ratio: 1.56, 95% confidence interval:  1.38-1.75; p < 0.001). Admissions receiving durable LVAD/heart transplantation increased over time in those initiated on pLVAD and ≥2 MCS devices, resulting in lower in-hospital mortality.

CONCLUSIONS

In this 13-year study, escalation of MCS in AMI-CS was associated with higher in-hospital mortality suggestive of higher acuity of illness. The increase in number of durable LVAD/heart transplantations alludes to the role of MCS as successful bridge strategies.

Advances in the Management of Cardiogenic Shock

OBJECTIVES

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

DATA SOURCES

We reviewed salient medical literature regarding CS.

STUDY SELECTION

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

DATA EXTRACTION

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

DATA SYNTHESIS

Professional society recommendations were integrated with evaluated studies.

CONCLUSIONS

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

Comparative Effectiveness of Percutaneous Microaxial Left Ventricular Assist Device vs Intra-Aortic Balloon Pump or No Mechanical Circulatory Support in Patients With Cardiogenic Shock

Importance

Recent studies have produced inconsistent findings regarding the outcomes of the percutaneous microaxial left ventricular assist device (LVAD) during acute myocardial infarction with cardiogenic shock (AMICS).

Objective

To compare the percutaneous microaxial LVAD vs alternative treatments among patients presenting with AMICS using observational analyses of administrative data.

Design, Setting, and Participants

This comparative effectiveness research study used Medicare fee-for-service claims of patients admitted with AMICS undergoing percutaneous coronary intervention from October 1, 2015, through December 31, 2019. Treatment strategies were compared using (1) inverse probability of treatment weighting to estimate the effect of different baseline treatments in the overall population; (2) instrumental variable analysis to determine the effectiveness of the percutaneous microaxial LVAD among patients whose treatment was influenced by cross-sectional institutional practice patterns; (3) an instrumented difference-in-differences analysis to determine the effectiveness of treatment among patients whose treatment was influenced by longitudinal changes in institutional practice patterns; and (4) a grace period approach to determine the effectiveness of initiating the percutaneous microaxial LVAD within 2 days of percutaneous coronary intervention. Analysis took place between March 2021 and December 2022.

Interventions

Percutaneous microaxial LVAD vs alternative treatments (including medical therapy and intra-aortic balloon pump).

Main Outcomes and Measures

Thirty-day all-cause mortality and readmissions.

Results

Of 23 478 patients, 14 264 (60.8%) were male and the mean (SD) age was 73.9 (9.8) years. In the inverse probability of treatment weighting analysis and grace period approaches, treatment with percutaneous microaxial LVAD was associated with a higher risk-adjusted 30-day mortality (risk difference, 14.9%; 95% CI, 12.9%-17.0%). However, patients receiving the percutaneous microaxial LVAD had a higher frequency of factors associated with severe illness, suggesting possible confounding by measures of illness severity not available in the data. In the instrumental variable analysis, 30-day mortality was also higher with percutaneous microaxial LVAD, but patient and hospital characteristics differed across levels of the instrumental variable, suggesting possible confounding by unmeasured variables (risk difference, 13.5%; 95% CI, 3.9%-23.2%). In the instrumented difference-in-differences analysis, the association between the percutaneous microaxial LVAD and mortality was imprecise, and differences in trends in characteristics between hospitals with different percutaneous microaxial LVAD use suggested potential assumption violations.

Conclusions

In observational analyses comparing the percutaneous microaxial LVAD to alternative treatments among patients with AMICS, the percutaneous microaxial LVAD was associated with worse outcomes in some analyses, while in other analyses, the association was too imprecise to draw meaningful conclusions. However, the distribution of patient and institutional characteristics between treatment groups or groups defined by institutional differences in treatment use, including changes in use over time, combined with clinical knowledge of illness severity factors not captured in the data, suggested violations of key assumptions that are needed for valid causal inference with different observational analyses. Randomized clinical trials of mechanical support devices will allow valid comparisons across candidate treatment strategies and help resolve ongoing controversies.

Bridging with surgically placed microaxial left ventricular assist devices: a high-volume centre experience

OBJECTIVES

The Impella 5.0 and 5.5 have largely superseded non-ambulatory temporary mechanical support devices; yet, clinical outcomes are predominantly limited to small series: this study presents the experience of a high-volume centre.

METHODS

An institutional clinical registry was used to identify all patients with cardiogenic shock who underwent Impella 5.0 or 5.5 implantation from January 2014 to March 2022. The primary outcome was survival to device explantation.

RESULTS

The study cohort comprised 221 patients, including 146 (66.1%) Impella 5.0 and 75 (33.9%) Impella 5.5 patients. The primary aetiology was non-ischaemic cardiomyopathy (50.7%, n = 112), ischaemic cardiomyopathy (23.1%, n = 51) and acute myocardial infarction (26.2%, n = 58). Patients were prospectively classified according to strategy as bridge to transplant (47.5%, n = 105), bridge to durable device (13.6%, n = 30) or bridge to recovery (38.9%, n = 86). Patients were predominantly Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2 (95.0%, n = 210). The median bridging duration was 14 (range 0-137) days. Device exchange, Ischaemic stroke and ipsilateral arm ischaemia occurred in 8.1% (n = 18), 2.7% (n = 6) and 1.8% (n = 4) of patients, respectively. Compared to the 75 most recent Impella 5.0 patients, Impella 5.5 patients (n = 75) had lower rates of device exchange (4.0%, n = 3 vs 13.3%, n = 10, P = 0.04). Overall, 70.1% (n = 155) of patients survived to Impella explantation.

CONCLUSIONS

The Impella 5.0 and 5.5 provide safe and effective temporary mechanical support in appropriately selected patients with cardiogenic shock. The newer device generation may have a lower requirement for device exchange as compared to its predecessor.

Mechanical Circulatory Support Devices in Acute Myocardial Infarction-Cardiogenic Shock: Current Studies and Future Directions

Cardiogenic shock (CS) caused by acute myocardial infarction (AMI) accounts for most deaths in the population with AMI and continues to be associated with high short-term mortality. Several temporary mechanical circulatory support (MCS) devices have been developed to treat CS and studied in randomized controlled trials (RCTs) of patients with AMI-CS. Unfortunately, none of these RCTs has demonstrated an improvement in survival with temporary MCS in AMI-CS. Potential reasons for these negative results in RCTs are numerous and reflect the challenges of enrolling critically ill patients with CS. Researchers have used observational study designs to provide insights about outcomes associated with the use of temporary MCS in AMI-CS. These observational studies have yielded conflicting results, in some cases contrary to the results of RCTs. Several limitations pertinent to both RCTs and observational analyses, mostly relating to selection bias and failure to consider unmeasured confounding variables and population heterogeneity, preclude drawing strong inferences regarding the effects of temporary MCS on survival in populations with AMI-CS. Understanding these limitations is essential to correctly interpreting the literature regarding temporary MCS to treat AMI-CS and is necessary to inform the design of future studies that will potentially provide stronger evidence. Optimally matching temporary MCS devices to the needs of individual patients with AMI-CS will presumably be more successful than indiscriminate application in unselected patients. In this review, we discuss the existing literature on temporary MCS to treat AMI-CS and describe the specific challenges that must be overcome to develop an improved evidence base for guiding clinical practice.

Management of Cardiogenic Shock Unrelated to Acute Myocardial Infarction

Cardiogenic shock is an extreme manifestation of acute decompensated heart failure. Cardiogenic shock is often caused by-and has traditionally been studied in the setting of-acute myocardial infarction (AMI CS); however, there is increasing incidence and recognition of cardiogenic shock not associated with acute myocardial infarction (non-AMI CS) as a distinct entity. Despite decades of study and technologic advancements, cardiogenic shock mortality remains as high as 50%, regardless of etiology. New approaches to shock phenotyping and classification have emerged, with a focus on appropriately matching patient physiology to a growing list of available interventions. Further study is needed to determine whether these efforts will lead to more nuanced use of mechanical circulatory support and improved patient outcomes, especially in non-AMI CS. In the meantime, models of care incorporating multidisciplinary decision making, such as shock teams, may improve patient selection and 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.

Sex Differences in Management and Outcomes Among Patients With High-Risk Pulmonary Embolism: A Nationwide Analysis

OBJECTIVE

To examine the sex differences in management and outcomes among patients with high-risk acute pulmonary embolism (PE).

PATIENTS AND METHODS

The Nationwide Readmissions Database was used to identify hospitalizations with high-risk PE from January 1, 2016, to December 31, 2018. Differences in use of advanced therapies, in-hospital mortality, and bleeding events were compared between men and women.

RESULTS

A total of 125,901 weighted hospitalizations with high-risk PE were identified during the study period; 46.3% were women (n=58,253). Women were older and had a higher prevalence of several comorbidities and risk factors of PE such as morbid obesity, diabetes mellitus, chronic pulmonary disease, heart failure, and metastatic cancer. Systemic thrombolysis and catheter-directed interventions were more commonly used among women; however, mechanical circulatory support was less frequently used. In-hospital mortality was higher among women in the unadjusted analysis (30.7% vs 27.8%, P<.001) and after propensity score matching (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.08 to 1.25; P<.001), whereas the rates of intracranial hemorrhage and non-intracranial hemorrhage were not different. On multivariate regression analysis, female sex (OR, 1.18; 95% CI, 1.15 to 1.21; P<.001) was independently associated with increased odds of in-hospital mortality.

CONCLUSION

In this contemporary observational cohort of patients admitted with high-risk PE, women had higher rates of in-hospital mortality despite receiving advanced therapies more frequently, whereas the rate of major bleeding events was not different from men. Efforts are needed to minimize the excess mortality observed among women.

Sixteen-year national trends in use & outcomes of VA-ECMO in cardiogenic shock

There is a lack of data on contemporary trends in the use and outcomes of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) for cardiogenic shock (CS) at a national level. Patients with CS admitted during January 1st, 2002-December 31, 2018, were identified from the United States National Inpatient Sample. Among all patients admitted with CS, those who received VA-ECMO were identified. We report the trends in use and outcomes in terms of mortality, exit strategies and complications among all patients who received VA ECMO for CS. Among a total of approximately 1.6 million patients admitted with CS during the period from January 1st, 2002 to December 31, 2018; 25, 621(1.5 %) received VA-ECMO. There has been a 23-fold increase in the use of VA-ECMO over the study period, from 0.1 % in 2002 to 3 % in 2018, with a simultaneous decreasing trend of in hospital mortality from 77 % in 2002 to 50 % in 2018. Only approximately 15 % of VA-ECMO patients are discharged home with most survivors discharged to a skilled nursing facility or short-term rehabilitation. Moreover, only a minor proportion of patients on VA ECMO are bridged to heart replacement therapy with durable LVAD (6 %) or cardiac transplantation (2.5 %). In conclusion, the use of VA-ECMO in CS has increased 23-fold from January 2002 to December 2018 with a concomitant decrease in mortality from 77 % in 2002 to 50 % in 2018, only a minority of patients on VA-ECMO for CS are bridged to durable LVAD or cardiac transplantation.

Outcomes Associated With Peripheral Artery Disease in Myocardial Infarction With Cardiogenic Shock

BACKGROUND

Mortality rates for patients presenting with acute myocardial infarction (AMI) and cardiogenic shock (CS) remain high despite advances in revascularization strategies and mechanical circulatory support (MCS) devices.

OBJECTIVES

This study sought to elucidate the association between comorbid lower extremity peripheral artery disease (PAD) and outcomes in CS and AMI.

METHODS

PAD status was defined in Medicare beneficiaries hospitalized with CS and AMI from October 1, 2015 to June 30, 2018. Primary outcomes ascertained through December 31, 2018 included in- and out-of-hospital mortality. Secondary outcomes included bleeding, amputation, stroke, and lower extremity revascularization. Multivariable regression models with adjustment for confounders were used to estimate risk. Subgroup analyses included patients treated with MCS and those who underwent coronary revascularization.

RESULTS

Among 71,690 patients, 5.9% (N = 4,259) had PAD. Mean age was 77.8 ± 7.9 years, 58.7% were male, and 84.3% were White. Cumulative in-hospital mortality was 47.2%, with greater risk among those with PAD (56.3% vs 46.6% without PAD; adjusted OR: 1.50; 95% CI: 1.40-1.59). PAD patients also had greater risk of in-hospital amputation (1.6% vs 0.2%; adjusted OR: 7.0; 95% CI: 5.26-9.37) and out-of-hospital mortality (67.9% vs 40.7%; adjusted HR: 1.78; 95% CI: 1.67-1.90). MCS was less frequently utilized in PAD patients (21.5% vs 38.6% without PAD; P < 0.001) and was associated with higher mortality, need for lower extremity revascularization, and amputation risk. Findings were consistent in patients who underwent coronary revascularization.

CONCLUSIONS

Among patients presenting with AMI and CS, PAD was associated with worse limb outcomes and survival. In addition to lower MCS utilization rates, those with PAD who received MCS had increased mortality, lower extremity revascularization, and amputation rates.

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.

Hospital market concentration and the use of mechanical circulatory support devices in acute myocardial infarction complicated by cardiogenic shock

Background

As health care markets in the United States have become increasingly consolidated, the role of market concentration on physician treatment behavior remains unclear. In cardiology, specifically, there has been evolving treatment of acute myocardial infarction complicated by cardiogenic shock (AMI-CS) with increasing use of mechanical circulatory support (MCS). However, there remains wide variation in it use. The role of market concentration in the utilization of MCS in AMI-CS is unknown. We examined the use of MCS in AMI-CS and its effect on outcomes between competitive and concentrated markets.

Methods and results

We used the National Inpatient Sample to query patients admitted with AMI-CS between 2003 and 2009. The primary study outcome was the use of mechanical circulatory support. The primary study exposure was market concentration, measured using the Herfindahl-Hirschman Index, which was used to classify markets as unconcentrated (competitive), moderately concentrated, and highly concentrated. Baseline characteristics, procedures, and outcomes were compared for patients in differently concentrated markets. Multivariable logistic regression was used to examine the association between HHI and use of MCS.

Results

There were 32,406 hospitalizations for patients admitted with AMI-CS. Patients in unconcentrated markets were more likely to receive MCS than in highly concentrated markets (unconcentrated 46.8% [5087/10,873], moderately concentrated 44.9% [2933/6526], and high concentrated 44.5% [6676/15,007], p < 0.01). Multivariable regression showed that patients in more concentrated markets had decreased use of MCS in patients in later years of the study period (2009, OR 0.64, 95% CI 0.44–0.94, p = 0.02), with no effect in earlier years. There was no significant difference in in-hospital mortality.

Conclusion

Multivariable analysis did not show an association with market concentration and use of MCS in AMI-CS. However, subgroup analysis did show that competitive hospital markets were associated with more frequent use of MCS in AMI-CS as frequency of utilization increased over time. Further studies are needed to evaluate the effect of hospital market consolidation on the use of MCS and outcomes in AMI-CS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07458-1.

Resources for cardiovascular healthcare associated with 30-day mortality in acute myocardial infarction with cardiogenic shock

Aims

Although primary percutaneous coronary intervention (PCI) and mechanical circulatory support (MCS), such as extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pumping (IABP), have been widely used for acute myocardial infarction (AMI) patients with cardiogenic shock (AMICS), their in-hospital mortality remains high. This study aimed to investigate the association of cardiovascular healthcare resources with 30-day mortality in AMICS.

Methods and results

This was an observational study using a Japanese nationwide administrative data (JROAD-DPC) of 260 543 AMI patients between April 2012 and March 2018. Of these, 45 836 AMICS patients were divided into three categories based on MCS use: with MCS (ECMO with/without IABP), IABP only, or without MCS. Certified hospital density and number of board-certified cardiologists were used as a metric of cardiovascular healthcare resources. We estimated the association of MCS use, cardiovascular healthcare resources, and 30-day mortality. The 30-day mortality was 71.2% for the MCS, 23.9% for IABP only, and 37.8% for the group without MCS. The propensity score-matched and inverse probability-weighted Cox frailty models showed that primary PCI was associated with a low risk for mortality. Higher hospital density and larger number of cardiologists in the responsible hospitals were associated with a lower risk for mortality.

Conclusion

Although the 30-day mortality remained extremely high in AMICS, indication of primary PCI and improvement in providing cardiovascular healthcare resources associated with the short-term prognosis of AMICS.

Temporal trends in patient characteristics, presumed causes, and outcomes following cardiogenic shock between 2005 and 2017: a Danish registry-based cohort study

AIMS

Most cardiogenic shock (CS) studies focus on acute coronary syndrome (ACS). Contemporary data on temporal trends in patient characteristics, presumed causes, treatments, and outcomes of ACS- and in particular non-ACS-related CS patients are sparse.

METHODS AND RESULTS

Using nationwide medical registries, we identified patients with first-time CS between 2005 and 2017. Cochrane-Armitage trend tests were used to examine temporal changes in presumed causes of CS, treatments, and outcomes. Among 14 363 CS patients, characteristics remained largely stable over time. As presumed causes of CS, ACS (37.1% in 2005 to 21.4% in 2017), heart failure (16.3% in 2005 to 12.0% in 2017), and arrhythmias (13.0% in 2005 to 10.9% in 2017) decreased significantly over time; cardiac arrest increased significantly (11.3% in 2005 to 24.5% in 2017); and changes in valvular heart disease were insignificant (11.5% in 2005 and 11.6% in 2017). Temporary left ventricular assist device, non-invasive ventilation, and extracorporeal membrane oxygenation use increased significantly over time; intra-aortic balloon pump and mechanical ventilation use decreased significantly. Over time, 30-day and 1-year mortality were relatively stable. Significant decreases in 30-day and 1-year mortality for patients presenting with ACS and arrhythmias and a significant increase in 1-year mortality in patients presenting with heart failure were seen.

CONCLUSION

Between 2005 and 2017, we observed significant temporal decreases in ACS, heart failure, and arrhythmias as presumed causes of first-time CS, whereas cardiac arrest significantly increased. Although overall 30-day and 1-year mortality were stable, significant decreases in mortality for ACS and arrhythmias as presumed causes of CS were seen.

Mechanical circulatory support in acute myocardial infarction and cardiogenic shock: Challenges and importance of randomized control trials

BACKGROUND

Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) is associated with significant morbidity and mortality.

METHODS

We provide an overview of previously conducted studies on the use of mechanical circulatory support (MCS) devices in the treatment of AMI-CS and difficulties which may be encountered in conducting such trials in the United States.

RESULTS

Well powered randomized control trials are difficult to conduct in a critically ill patient population due to physician preferences, perceived lack of equipoise and challenges obtaining informed consent.

CONCLUSIONS

With growth in utilization of MCS devices in patients with AMI-CS, efforts to perform well-powered, randomized control trials must be undertaken.

Extracorporeal Life Support for Cardiac Arrest and Cardiogenic Shock

The rising incidence and recognition of cardiogenic shock has led to an increase in the use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). As clinical experience with this therapy has increased, there has also been a rapid growth in the body of observational and randomized data describing the clinical and logistical considerations required to institute a VA-ECMO program with successful clinical outcomes. The aim of this review is to summarize this contemporary data in the context of four key themes that pertain to VA-ECMO programs: the principles of patient selection; basic hemodynamic and technical principles underlying VA-ECMO; contraindications to VA-ECMO therapy; and common complications and intensive care considerations that are encountered in the setting of VA-ECMO therapy.

A Pragmatic Approach to Weaning Temporary Mechanical Circulatory Support: A State-of-the-Art Review

Temporary mechanical circulatory support (TMCS) provides short-term support to patients with or at risk of refractory cardiogenic shock. Although indications, contraindications, and complications of TMCS may guide device selection, optimal strategies for device weaning and explant remain poorly defined. Under the revised adult heart allocation policy implemented by the United Nations for Organ Sharing in October 2018, rejustification of heart transplant listing status includes demonstrating TMCS dependency with attempted device wean trials. However, standardized device-specific weaning and explant protocols have not been proposed or evaluated. This review highlights when to use percutaneous TMCS in cardiogenic shock, with a focus on weaning and explant considerations. Terminology for important concepts that guide device escalation, de-escalation, and explantation have been defined. Clinical, hemodynamic, metabolic, and imaging features have been defined, which can guide a tailored approach to TMCS weaning and explant based on the approach used at the Cleveland Clinic. A narrative review of published studies that have reported TMCS weaning protocols and survey results of member centers from CS-MCS working group centers is also provided. Future research is needed to better understand optimal timing and implementation of standardized protocols to achieve successful TMCS weaning and explant.

Mortality Predictors in Elderly Patients With Cardiogenic Shock on Venoarterial Extracorporeal Life Support. Analysis From the Extracorporeal Life Support Organization Registry

OBJECTIVES

Because significantly higher mortality is observed in elderly patients undergoing venoarterial extracorporeal membrane oxygenation for refractory cardiogenic shock, decision-making in this setting is challenging. We aimed to elucidate predictors of unfavorable outcomes in these elderly (≥ 70 yr) patients.

DESIGN

Analysis of international worldwide extracorporeal life support organization registry.

SETTING

Refractory cardiogenic shock due to various etiologies (cardiac arrest excluded).

PATIENTS

Elderly patients (≥ 70 yr).

INTERVENTIONS

Venoarterial extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

Three age groups (70-74, 75-79, ≥80 yr) were in-depth analyzed. Uni- and multivariable analysis were performed. From January 1997 to December 2018, 2,644 patients greater than or equal to 70 years (1,395 [52.8%] 70-74 yr old, 858 [32.5%] 75-79 yr, and 391 [14.8%] ≥ 80 yr old) were submitted to venoarterial extracorporeal membrane oxygenation for refractory cardiogenic shock with marked increase in the most recent years. Peripheral access was applied in majority of patients. Median extracorporeal membrane oxygenation support duration was 3.5 days (interquartile range: 1.6-6.1 d), (3.9 d [3.7-4.6 d] in patients ≥ 80 yr) (p < 0.001). Weaning from extracorporeal membrane oxygenation was possible in 1,236 patients (46.7%). Overall in-hospital mortality was estimated at 68.3% with highest crude mortality rates observed in 75-79 years old subgroup (70.1%). Complications were mostly cardiovascular and bleeding, without apparent differences between subgroups. Airway pressures, 24-hour pH after extracorporeal membrane oxygenation start, extracorporeal membrane oxygenation duration, and renal replacement therapy were predictive of higher mortality. In-hospital mortality was lower in heart transplantation recipients, posttranscatheter aortic valve replacement, and pulmonary embolism; conversely, higher mortality followed extracorporeal membrane oxygenation institution after coronary artery bypass + valve and in decompensated chronic heart failure, and nearly 100% mortality followed in extracorporeal membrane oxygenation for sepsis.

CONCLUSIONS

This study confirmed the remarkable increase of venoarterial extracorporeal membrane oxygenation use in elderly affected by refractory cardiogenic shock. Despite in-hospital mortality remains high, venoarterial extracorporeal membrane oxygenation should still be considered in such setting even in elderly patients, since increasing age itself was not linked to increased mortality, whereas several predictors may guide indication and management.

Influence of intra-aortic balloon pump on mortality as a function of cardiogenic shock severity

BACKGROUND

Randomized studies of intra-aortic balloon pump (IABP) in cardiogenic shock (CS) have focused exclusively on patients with acute coronary syndromes (ACS) without stratification according to shock severity. We examined the association between IABP and mortality in CS patients across the Society for Cardiovascular Angiography and Intervention (SCAI) shock stages.

METHODS

We included cardiac intensive care unit patients admitted from 2007 to 2015 with CS from any etiology. In-hospital mortality associated with IABP was examined in each SCAI shock stage. Multivariable logistic regression was performed using inverse probability of treatment weighting (IPTW) to determine the association between IABP and in-hospital mortality.

RESULTS

We included 934 patients, with a mean age of 68 ± 14 years; 60% had ACS. The distribution of SCAI shock stages was: B, 41%; C, 13%; D, 38%; E, 8%. In-hospital mortality was lower in the 39% of patients who received IABP (27% vs. 43%, adjusted OR with IABP after IPTW 0.53, 95% CI 0.40-0.72, p < .0001). IABP use was associated with lower crude in-hospital mortality in each SCAI shock stage (all p < .05, except p = .08 in SCAI shock stage E). We did not observe any significant heterogeneity in the association between IABP use and in-hospital mortality as a function of SCAI shock stage.

CONCLUSIONS

IABP use was associated with substantially lower in-hospital mortality in patients with CS, without differences in this effect across the SCAI shock stages. Future studies should account for the severity and etiology of shock when evaluating the efficacy of IABP for CS.

Ten-year trends, predictors and outcomes of mechanical circulatory support in percutaneous coronary intervention for acute myocardial infarction with cardiogenic shock

AIMS

There are limited data on the trends and outcomes of mechanical circulatory support (MCS)-assisted early percutaneous coronary intervention (PCI) in acute myocardial infarction with cardiogenic shock (AMI-CS). In this study, we sought to assess the use, temporal trends, and outcomes of percutaneous MCS-assisted early PCI in AMI-CS.

METHODS AND RESULTS

Using the National Inpatient Sample database from 2005-2014, a retrospective cohort of AMI-CS admissions receiving early PCI (hospital day zero) was identified. MCS use was defined as intra-aortic balloon pump (IABP), percutaneous left ventricular assist device (pLVAD) and extracorporeal membrane oxygenation (ECMO) support. Outcomes of interest included in-hospital mortality, resource utilisation, trends and predictors of MCS-assisted PCI. Of the 110,452 admissions, MCS assistance was used in 55%. IABP, pLVAD and ECMO were used in 94.8%, 4.2% and 1%, respectively. During 2009-2014, there was a decrease in MCS-assisted PCI due to a decrease in IABP, despite an increase in pLVAD and ECMO. Younger age, male sex, lower comorbidity, and cardiac arrest independently predicted MCS use. MCS-assisted PCI was predictive of higher in-hospital mortality (31% vs 26%, adjusted odds ratio 1.23 [1.19-1.27]; p<0.001) and greater resource utilisation. IABP-assisted PCI had lower in-hospital mortality and lesser resource utilisation compared to pLVAD/ECMO.

CONCLUSIONS

MCS-assisted PCI identified a sicker AMI-CS cohort. There was a decrease in IABP and an increase in pLVAD/ECMO.

Use of Mechanical Circulatory Support Devices Among Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock

IMPORTANCE

Mechanical circulatory support (MCS) devices, including intravascular microaxial left ventricular assist devices (LVADs) and intra-aortic balloon pumps (IABPs), are used in patients who undergo percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) complicated by cardiogenic shock despite limited evidence of their clinical benefit.

OBJECTIVE

To examine trends in the use of MCS devices among patients who underwent PCI for AMI with cardiogenic shock, hospital-level use variation, and factors associated with use.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used the CathPCI and Chest Pain-MI Registries of the American College of Cardiology National Cardiovascular Data Registry. Patients who underwent PCI for AMI complicated by cardiogenic shock between October 1, 2015, and December 31, 2017, were identified from both registries. Data were analyzed from October 2018 to August 2020.

EXPOSURES

Therapies to provide hemodynamic support were categorized as intravascular microaxial LVAD, IABP, TandemHeart, extracorporeal membrane oxygenation, LVAD, other devices, combined IABP and intravascular microaxial LVAD, combined IABP and other device (defined as TandemHeart, extracorporeal membrane oxygenation, LVAD, or another MCS device), or medical therapy only.

MAIN OUTCOMES AND MEASURES

Use of MCS devices overall and specific MCS devices, including intravascular microaxial LVAD, at both patient and hospital levels and variables associated with use.

RESULTS

Among the 28 304 patients included in the study, the mean (SD) age was 65.4 (12.6) years and 18 968 were men (67.0%). The overall MCS device use was constant from the fourth quarter of 2015 to the fourth quarter of 2017, although use of intravascular microaxial LVADs significantly increased (from 4.1% to 9.8%; P < .001), whereas use of IABPs significantly decreased (from 34.8% to 30.0%; P < .001). A significant hospital-level variation in MCS device use was found. The median (interquartile range [IQR]) proportion of patients who received MCS devices was 42% (30%-54%), and the median proportion of patients who received intravascular microaxial LVADs was 1% (0%-10%). In multivariable analyses, cardiac arrest at first medical contact or during hospitalization (odds ratio [OR], 1.82; 95% CI, 1.58-2.09) and severe left main and/or proximal left anterior descending coronary artery stenosis (OR, 1.36; 95% CI, 1.20-1.54) were patient characteristics that were associated with higher odds of receiving intravascular microaxial LVADs only compared with IABPs only.

CONCLUSIONS AND RELEVANCE

This study found that, among patients who underwent PCI for AMI complicated by cardiogenic shock, overall use of MCS devices was constant, and a 2.5-fold increase in intravascular microaxial LVAD use was found along with a corresponding decrease in IABP use and a significant hospital-level variation in MCS device use. These trends were observed despite limited clinical trial evidence of improved outcomes associated with device use.

Novel Porcine Model of Coronary Dissection Reveals the Impact of Impella on Dissected Coronary Arterial Hemodynamics

Background: Coronary artery dissection (CAD) sometimes accompanies unstable hemodynamics and requires mechanical cardiac support. Meanwhile, mechanical cardiac support may influence coronary hemodynamics in CAD. No study has examined the impact of Impella left ventricular (LV) support on CAD. Materials and Methods: CAD was induced in eight Yorkshire pigs by injuring the left anterior descending artery (LAD) using a 0.018-in. stiff guidewire and/or deep engagement of a blunt-cut coronary guiding catheter. After the creation of CAD, hemodynamic parameters, coronary pressure, and flow as well as coronary angiograms were acquired before and after maximum LV support using the Impella CP. Result: CADs with a large flap were successfully created by deep engagement of a blunt-tip guiding catheter with forceful contrast injection. One animal (#8) exhibited thrombolysis in myocardial infarction (TIMI)-1 flow, while the others (animals #1-#7) showed TIMI-2/3 flow. In TIMI-2/3 animals, maximal Impella support increased mean coronary pressure (108.4 ± 22.5 to 124.7 ± 28.0 mmHg, P < 0.001) with unchanged mean coronary flow velocity (63.50 ± 28.66 to 48.32 ± 13.30 cm/s, P = 0.17) of the LAD distal to the dissection. The LV end-diastolic pressure (20.6 ± 6.6 vs. 12.0 ± 3.4 mmHg, P = 0.032), LV end-diastolic volume (127 ± 32 vs. 97 ± 26 ml, P = 0.015), stroke volume (68 ± 16 vs. 48 ± 14 ml, P = 0.003), stroke work (5,744 ± 1,866 vs. 4,424 ± 1,650 mmHg·ml, P = 0.003), and heart rate (71.4 ± 6.6 vs. 64.9 ± 9.3/min, P = 0.014) were all significantly reduced by Impella support, indicating effective unloading of the LV. In the TIMI-1 animal (animal #8), maximal Impella support resulted in further delay in angiographic coronary flow and reduced distal coronary pressure (22.9-17.1 mmHg), together with increased false-lumen pressure. Conclusion: Impella support effectively unloaded the LV and maintained the hemodynamics in a novel porcine model of CAD. Coronary pressure distal to the dissection was increased in TIMI-2/3 animals after Impella support but decreased in the animal with initial TIMI-1 flow.

Invasive Hemodynamic Assessment and Classification of In-Hospital Mortality Risk Among Patients With Cardiogenic Shock

Background:

Risk stratifying patients with cardiogenic shock (CS) is a major unmet need. The recently proposed Society for Cardiovascular Angiography and Interventions (SCAI) stages as an approach to identify patients at risk for in-hospital mortality remains under investigation. We studied the utility of the SCAI stages and further explored the impact of hemodynamic congestion on clinical outcomes.

Methods:

The CS Working Group registry includes patients with CS from 8 medical centers enrolled between 2016 and 2019. Patients were classified by the maximum SCAI stage (B–E) reached during their hospital stay according to drug and device utilization. In-hospital mortality was evaluated for association with SCAI stages and hemodynamic congestion.

Results:

Of the 1414 patients with CS, the majority were due to decompensated heart failure (50%) or myocardial infarction (MI; 35%). In-hospital mortality was 31% for the total cohort, but higher among patients with MI (41% versus 26%, MI versus heart failure, P <0.0001). Risk for in-hospital mortality was associated with increasing SCAI stage (odds ratio [95% CI], 3.25 [2.63–4.02]) in both MI and heart failure cohorts. Hemodynamic data was available in 1116 (79%) patients. Elevated biventricular filling pressures were common among patients with CS, and right atrial pressure was associated with increased mortality and higher SCAI Stage.

Conclusions:

Our findings support an association between the proposed SCAI staging system and in-hospital mortality among patient with heart failure and MI. We further identify that venous congestion is common and identifies patients with CS at high risk for in-hospital mortality. These findings provide may inform future management protocols and clinical studies.

Temporary circulatory support for cardiogenic shock

Cardiogenic shock can occur due to acute ischaemic or non-ischaemic cardiac events, or from progression of long-standing underlying heart disease. When addressing the cause of underlying disease, the management of cardiogenic shock consists of vasopressors and inotropes; however, these agents can increase myocardial oxygen consumption, impair tissue perfusion, and are frequently ineffective. An alternative approach is to temporarily augment cardiac output using mechanical devices. The use of these devices-known as temporary circulatory support systems-has increased substantially in recent years, despite being expensive, resource intensive, associated with major complications, and lacking high-quality evidence to support their use. This Review summarises the physiological basis underlying the use of temporary circulatory support for cardiogenic shock, reviews the evidence informing indications and contraindications, addresses ethical considerations, and highlights the need for further research.

Short-Term Efficacy and Safety of Different Mechanical Hemodynamic Support Devices for Cardiogenic Shock or High-Risk Pci: a Network Meta-Analysis of Thirty-Seven Trials

BACKGROUND

With more advanced mechanical hemodynamic support for patients with cardiogenic shock (CS) or high-risk percutaneous coronary intervention (HS-PCI), the morality rate is now significantly lower than before. While previous studies showed that intra-aortic balloon pumping (IABP) did not reduce the risk of mortality in patients with CS compared to conservative treatment, the efficacy in other mechanical circulatory support (MCS) trials was inconsistent.

OBJECTIVE

We conducted this network meta-analysis to assess the short-term efficacy and safety of different intervention measures for patients with CS or who underwent HS-PCI.

METHODS

Four online databases were searched. From the initial 1,550 articles, we screened 38 studies (an extra 14 studies from references) into this analysis, including a total of 11,270 patients from five interventions (pharmacotherapy, IABP, pMCS, ECMO alone, and ECMO+IABP).

RESULT

The short-term efficacy was determined by 30-day or in-hospital mortality. ECMO+IABP significantly reduced mortality compared with pMCS and ECMO alone (OR = 1.85, 95% CrI [1.03-3.26]; OR = 1.89, 95% CrI [1.19-3.01], respectively). ECMO+IABP did not show reduced mortality when compared with pharmacotherapy and IABP (OR = 1.73, 95% CrI [0.97-3.82]; OR = 1.67, 95% CrI [0.98-2.89], respectively). The rank probability, however, supported that ECMO+IABP might be a more suitable intervention in improving mortality for patients with CS or who underwent HS-PCI. Regarding bleeding, compared with other invasive intervention measures, IABP showed a trend of reduced bleeding (with pMCS OR = 3.86, 95% CrI [1.53-10.66]; with ECMO alone OR = 3.74, 95% CrI [1.13-13.78]; with ECMO+IABP OR = 4.80, 95% CrI [1.61-18.53]). No difference was found in stroke, myocardial infarction, limb ischemia, and hemolysis among the invasive therapies evaluated.

CONCLUSION

Following this analysis, ECMO+IABP might be a more suitable intervention measure in improving short-term mortality for patients with CS and who underwent HS-PCI. However, the result was limited by the lack of sufficient direct comparisons and evidence from randomized controlled trials. Moreover, bleeding and other device-related complications should be considered in clinical applications.

Prognostic Impact of Active Mechanical Circulatory Support in Cardiogenic Shock Complicating Acute Myocardial Infarction, Results from the Culprit-Shock Trial

OBJECTIVES

To analyze the use and prognostic impact of active mechanical circulatory support (MCS) devices in a large prospective contemporary cohort of patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI).

BACKGROUND

Although increasingly used in clinical practice, data on the efficacy and safety of active MCS devices in patients with CS complicating AMI are limited.

METHODS

This is a predefined subanalysis of the CULPRIT-SHOCK randomized trial and prospective registry. Patients with CS, AMI and multivessel coronary artery disease were categorized in two groups: (1) use of at least one active MCS device vs. (2) no active MCS or use of intra-aortic balloon pump (IABP) only. The primary endpoint was a composite of all-cause death or renal replacement therapy at 30 days.

RESULTS

Two hundred of 1055 (19%) patients received at least one active MCS device (n = 112 Impella^®; n = 95 extracorporeal membrane oxygenation (ECMO); n = 6 other devices). The primary endpoint occurred significantly more often in patients treated with active MCS devices compared with those without active MCS devices (142 of 197, 72% vs. 374 of 827, 45%; p < 0.001). All-cause mortality and bleeding rates were significantly higher in the active MCS group (all p < 0.001). After multivariable adjustment, the use of active MCS was significantly associated with the primary endpoint (odds ratio (OR) 4.0, 95% confidence interval (CI) 2.7-5.9; p < 0.001).

CONCLUSIONS

In the CULPRIT-SHOCK trial, active MCS devices were used in approximately one fifth of patients. Patients treated with active MCS devices showed worse outcome at 30 days and 1 year.

Comparison of Hemodynamic Support by Impella vs. Peripheral Extra-Corporeal Membrane Oxygenation: A Porcine Model of Acute Myocardial Infarction

Objectives: Several mechanical circulatory assist devices are used to treat critically ill patients requiring hemodynamic support during post-myocardial infarction or cardiogenic shock. However, little guidance is available to choose an appropriate device to match a particular patient's needs. An increased understanding of hemodynamic effects of the pump systems and their impact on myocardial pre-/afterload might help to better understand their behavior in different clinical settings. Methods: This was an open-labeled, randomized acute animal experiment. A model of acute univentricular myocardial injury by temporary balloon occlusion was used. The experiment was carried out in 10 juveniles female Piétrain pigs. The animals were randomized to mechanical hemodynamic support either by peripheral veno-arterial (VA-)ECMO or Impella CP. Results: While both devices were able to provide flows above 3 L/min and maintain sufficient end-organ perfusion, support by Impella resulted in a significantly more pronounced immediate effect on myocardial unloading: At the onset of device support, the remaining native cardiac output was reduced by 23.5 ± 15.3% ECMO vs. 66.2 ± 36.2% (Impella, p = 0.021). Native stroke volume was significantly decreased by Impella support compared to ECMO, indicating less mechanical work being conducted by the Impella-supported hearts despite similar total assisted cardiac output. Conclusions: Peripheral VA-ECMO and the transaortic Impella pump resulted in contrasting hemodynamic fingerprints. Both devices provided sufficient hemodynamic support and reduce left ventricular end-diastolic pressure in the acute setting. Treatment with the Impella device resulted in a more effective volume unloading of the left ventricle. A significant reduction in myocardial oxygen consumption equivalent was achieved by both devices: The Impella device resulted in a left-shift of the pressure-volume loop and a decreased pressure-volume-area (PVA), while VA-ECMO increased PVA but decreased heart rate. These data highlight the importance of specifically targeting heart rate in the management of AMI patients on hemodynamic support.

Contemporary trends in use of mechanical circulatory support in patients with acute MI and cardiogenic shock

Objectives

To describe the contemporary trends in the use of mechanical circulatory support (MCS) in patients with acute myocardial infarction and cardiogenic shock (AMICS). To evaluate survival benefit with early application of intra-aortic balloon pump (IABP) or Impella CP.

Methods

A cohort study of all consecutive patients with AMICS undergoing percutaneous coronary intervention (PCI) <24 hours of symptom onset (early PCI) in southeastern Denmark from 2010 to 2017. A matched case–control study comparing 30-day mortality between patients receiving early-IABP or early-Impella CP and their respective control group. Controls were matched on age, left ventricular ejection fraction, arterial lactate, estimated glomerular filtration rate and cardiac arrest before PCI. Early-IABP/Impella CP was defined as applied before PCI if shock developed pre-PCI, or immediately after PCI if shock developed during PCI.

Results

903 patients with AMICS undergoing early PCI were identified. Use of MCS decreased from 50% in 2010 to 25% in 2017, p for trend of <0.001. The IABP was abandoned in 2012 and replaced mostly by Impella CP. Patients receiving MCS in 2013–2017 had more compromised haemodynamics compared with patients receiving MCS in 2010–2012. 40 patients received early IABP, and 40 patients received early Impella CP. Only the group receiving early Impella CP was associated with lower 30-day mortality compared with their matched control group (30-day mortality 40% vs 77.5%, plog-rank of<0.001).

Conclusion

Use of MCS decreased by 50% from 2010 to 2017. Patients receiving MCS had more compromised haemodynamics in recent years. Early application of Impella CP was associated with reduced 30-day mortality compared with a matched control group.

Hospital Variation in the Utilization of Short-Term Nondurable Mechanical Circulatory Support in Myocardial Infarction Complicated by Cardiogenic Shock

BACKGROUND

Limited knowledge exists on inter-hospital variation in the utilization of short-term, nondurable mechanical circulatory support (MCS) for myocardial infarction (MI) complicated by cardiogenic shock (CS).

METHODS AND RESULTS

Hospitalizations for MI with CS in 2014 in a nationally representative all-payer database were included. The proportion of hospitalizations for MI with CS using MCS (MCS ratio) and in-hospital mortality were evaluated. Hospital characteristics and outcomes were compared across quartiles of MCS usage. Of 1813 hospitals evaluated, 1440 (79.4%) performed ≥10 percutaneous coronary interventions annually. Of these, 1064 (73.9%) had at least one code for MCS. Forty-one percent of hospitals did not use MCS. The median (interquartile range) proportion of MCS use among admissions for MI with CS was 33.3% (0.0%-50.0%). High MCS utilizing hospitals were larger ( P<0.001). Eighty-five percent (2808/3301) of MCS use was intra-aortic balloon pump. There was significant variation in receipt of MCS at different hospitals (median odds ratio of receiving MCS at 2 random hospitals: 1.58; 95% CI, 1.45-1.70). Adjusted in-hospital mortality was not different across quartiles of MCS use (Q4 versus Q1; odds ratio, 0.95; 95% CI, 0.77-1.16; P=0.58).

CONCLUSIONS

Wide variation exists in hospital use of MCS for MI with CS, unexplained by patient characteristics. The predominant form of MCS use is intra-aortic balloon pump. Risk-adjusted mortality rates were not different between higher and lower MCS-utilizing hospitals.

Extracorporeal Membrane Oxygenation Use in Cardiogenic Shock: Impact of Age on In-Hospital Mortality, Length of Stay, and Costs

OBJECTIVES

Increasing age is a well-recognized risk factor for in-hospital mortality in patients receiving extracorporeal membrane oxygenation for cardiogenic shock, but the shape of this relationship is unknown. In addition, the impact of age on hospital length of stay, patterns of patient disposition, and costs has been incompletely characterized.

DESIGN

Retrospective analysis of the National Inpatient Sample.

SETTING

U.S. nonfederal hospitals, years 2004-2016.

PATIENTS

Adults with cardiogenic shock treated with extracorporeal membrane oxygenation (3,094; weighted national estimate: 15,415).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean age of extracorporeal membrane oxygenation recipients was 54.8 ± 15.4 years (range, 18-90 yr). Crude in-hospital mortality was 57.7%. Median time-to-death was 8 days (interquartile range, 3-17 d). A linear relationship between age and in-hospital mortality was observed with a 14% increase in the adjusted odds of in-hospital mortality for every 10-year increase in age (adjusted odds ratio, 1.14; 95% CI, 1.08-1.21; p < 0.0001). Thirty-four percent of patients were discharged alive at a median time of 30 days (interquartile range, 19-48 d). The median length of stay and total hospitalization costs were 14 days (interquartile range, [5-29 d]) and $134,573 ($71,782-$239,439), respectively, both of which differed significantly by age group (length of stay range from 17 d [18-49 yr] to 9 d [80-90 yr]; p < 0.0001 and cost range $147,548 [18-49 yr] to $105,350 [80-90 yr]; p < 0.0001).

CONCLUSIONS

Age is linearly associated with increasing in-hospital mortality in individuals receiving extracorporeal membrane oxygenation for cardiogenic shock without evidence of a threshold effect. Median time-to-death is approximately 1 week. One third of patients are discharged from the hospital alive, but the median time-to-discharge is 1 month. Median length of stay ranges from 9 to 17 days depending on age. Hospitalization costs exceed $100,000 in all age groups.

Extracorporeal Membrane Oxygenation Use in Acute Myocardial Infarction in the United States, 2000 to 2014

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used in acute myocardial infarction (AMI); however, there are limited large-scale national data.

METHODS

Using the National Inpatient Sample database from 2000 to 2014, a retrospective cohort of AMI utilizing ECMO was identified. Use of percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous left ventricular assist device (LVAD) was also identified in this population. Outcomes of interest included temporal trends in utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD), in-hospital mortality, and resource utilization.

RESULTS

In ≈9 million AMI admissions, ECMO was used in 2962 (<0.01%) and implanted a median of 1 day after admission. ECMO was used in 0.5% and 0.3% AMI admissions complicated by cardiogenic shock and cardiac arrest, respectively. ECMO was used more commonly in admissions that were younger, nonwhite, and with less comorbidity. ECMO use was 11× higher in 2014 as compared with 2000 (odds ratio, 11.37 [95% CI, 7.20-17.97]). Same-day percutaneous coronary intervention was performed in 23.1%; intra-aortic balloon pump/percutaneous LVAD was used in 57.9%, of which 30.3% were placed concomitantly. In-hospital mortality with ECMO was 59.2% overall but decreased from 100% (2000) to 45.1% (2014). Durable LVAD and cardiac transplantation were performed in 11.7% as an exit strategy. Of the hospital survivors, 40.8% were discharged to skilled nursing facilities. Older age, male sex, nonwhite race, and lower socioeconomic status were independently associated with higher in-hospital mortality with ECMO use.

CONCLUSIONS

In AMI admissions, a steady increase was noted in the utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD). In-hospital mortality remained high in AMI admissions treated with ECMO.

Association between Public Reporting of Outcomes and the Use of Mechanical Circulatory Support in Patients with Cardiogenic Shock

Risk-averse behavior has been reported among physicians and facilities treating cardiogenic shock in states with public reporting. Our objective was to evaluate if public reporting leads to a lower use of mechanical circulatory support in cardiogenic shock. We conducted a retrospective study with the use of the National Inpatient Sample from 2005 to 2011. Hospitalizations of patients ≥18 years old with a diagnosis of cardiogenic shock were included. A regional comparison was performed to identify differences between reporting and nonreporting states. The main outcome of interest was the use of mechanical circulatory support. A total of 13043 hospitalizations for cardiogenic shock were identified of which 9664 occurred in reporting and 3379 in nonreporting states (age 69.9 ± 0.4 years, 56.8% men). Use of mechanical circulatory support was 32.8% in this high-risk population. Odds of receiving mechanical circulatory support were lower (OR 0.50; 95% CI 0.43-0.57; p < 0.01) and in-hospital mortality higher (OR 1.19; 95% CI 1.06-1.34; p < 0.01) in reporting states. Use of mechanical circulatory support was also lower in the subgroup of patients with acute myocardial infarction and cardiogenic shock in reporting states (OR 0.61; 95% CI 0.51-0.72; p < 0.01). In conclusion, patients with cardiogenic shock in reporting states are less likely to receive mechanical circulatory support than patients in nonreporting states.

The Evolving Landscape of Impella Use in the United States Among Patients Undergoing Percutaneous Coronary Intervention With Mechanical Circulatory Support

BACKGROUND

Impella was approved for mechanical circulatory support (MCS) in 2008, but large-scale, real-world data on its use are lacking. Our objective was to describe trends and variations in Impella use, clinical outcomes, and costs across US hospitals in patients undergoing percutaneous coronary intervention (PCI) treated with MCS (Impella or intra-aortic balloon pump).

METHODS

From the Premier Healthcare Database, we analyzed 48 306 patients undergoing PCI with MCS at 432 hospitals between January 2004 and December 2016. Association analyses were performed at 3 levels: time period, hospital, and patient. Hierarchical models with propensity adjustment were used for association analyses. We examined trends and variations in the proportion of Impella use, and associated clinical outcomes (in-hospital mortality, bleeding requiring transfusion, acute kidney injury, stroke, length of stay, and hospital costs).

RESULTS

Among patients undergoing PCI treated with MCS, 4782 (9.9%) received Impella; its use increased over time, reaching 31.9% of MCS in 2016. There was wide variation in Impella use across hospitals (>5-fold variation). Specifically, among patients receiving Impella, there was a wide variation in outcomes of bleeding (>2.5-fold variation), and death, acute kidney injury, and stroke (all ≈1.5-fold variation). Adverse outcomes and costs were higher in the Impella era (years 2008-2016) versus the pre-Impella era (years 2004-2007). Hospitals with higher Impella use had higher rates of adverse outcomes and costs. After adjustment for the propensity score, and accounting for clustering of patients by hospitals, Impella use was associated with death: odds ratio, 1.24 (95% CI, 1.13-1.36); bleeding: odds ratio, 1.10 (95% CI, 1.00-1.21); and stroke: odds ratio, 1.34 (95% CI, 1.18-1.53), although a similar, nonsignificant result was observed for acute kidney injury: odds ratio, 1.08 (95% CI, 1.00-1.17).

CONCLUSIONS

Impella use is rapidly increasing among patients undergoing PCI treated with MCS, with marked variability in its use and associated outcomes. Although unmeasured confounding cannot be ruled out, when analyzed by time periods, or at the hospital level or the patient level, Impella use was associated with higher rates of adverse events and costs. More data are needed to define the appropriate role of MCS in patients undergoing PCI.

Clinical Practice Patterns in Temporary Mechanical Circulatory Support for Shock in the Critical Care Cardiology Trials Network (CCCTN) Registry

BACKGROUND

Temporary mechanical circulatory support (MCS) devices provide hemodynamic assistance for shock refractory to pharmacological treatment. Most registries have focused on single devices or specific etiologies of shock, limiting data regarding overall practice patterns with temporary MCS in cardiac intensive care units.

METHODS

The CCCTN (Critical Care Cardiology Trials Network) is a multicenter network of tertiary CICUs in North America. Between September 2017 and September 2018, each center (n=16) contributed a 2-month snapshot of consecutive medical CICU admissions.

RESULTS

Of the 270 admissions using temporary MCS, 33% had acute myocardial infarction-related cardiogenic shock (CS), 31% had CS not related to acute myocardial infarction, 11% had mixed shock, and 22% had an indication other than shock. Among all 585 admissions with CS or mixed shock, 34% used temporary MCS during the CICU stay with substantial variation between centers (range: 17%-50%). The most common temporary MCS devices were intraaortic balloon pumps (72%), Impella (17%), and veno-arterial extracorporeal membrane oxygenation (11%), although intraaortic balloon pump use also varied between centers (range: 40%-100%). Patients managed with intraaortic balloon pump versus other forms of MCS (advanced MCS) had lower Sequential Organ Failure Assessment scores and less severe metabolic derangements. Illness severity was similar at high- versus low-MCS utilizing centers and at centers with more advanced MCS use.

CONCLUSIONS

There is wide variation in the use of temporary MCS among patients with shock in tertiary CICUs. While hospital-level variation in temporary MCS device selection is not explained by differences in illness severity, patient-level variation appears to be related, at least in part, to illness severity.