Biventricular unloading in patients with refractory cardiogenic shock

Biventricular Compared to Left Ventricular Impella and Norepinephrine Support in a Porcine Model of Severe Cardiogenic Shock

Contemporary management of cardiogenic shock (CS) with vasopressors is associated with increased cardiac workload and despite the use of unloading devices such as the Impella pump, concomitant vasopressors are often necessary. Therefore, we compared if cardiac workload could be reduced and end-organ perfusion preserved with biventricular support (Bipella) compared to ImpellaCP and norepinephrine in pigs with left ventricular (LV) CS caused by left main coronary microembolization. Cardiac workload was calculated from heart rate × ventricular pressure-volume area obtained from conductance catheters placed in the LV and right ventricle (RV), whereas organ perfusion was measured from venous oxygen saturation in the pulmonary artery (SvO 2 ) and the kidney- and the cerebral vein. A cross-over design was used to access the difference after 30 minutes of ImpellaCP and norepinephrine 0.1 µg/kg/min versus Bipella for 60 minutes. Bipella treatment reduced LV workload ( p = 0.0078) without significant difference in RV workload from ImpellaCP and norepinephrine, however a decrease in SvO 2 (49[44-58] vs . 66[63-73]%, p = 0.01) and cerebral venous oxygen saturations (62[48-66] vs . 71[63-77]%, p = 0.016) was observed during Bipella compared to ImpellaCP and norepinephrine. We conclude that Bipella reduced LV workload but did not preserve end-organ perfusion compared to ImpellaCP and norepinephrine in short-term LV CS.

Optimizing anticoagulation for patients receiving Impella support

Anticoagulation of patients treated with the Impella percutaneous mechanical circulatory support (MCS) devices is complex and lacks consistency across centers, potentially increasing the risk of complications. In order to optimize safety and efficacy, an expert committee synthesized all available evidence evaluating anticoagulation for patients receiving Impella support in order to provide consensus recommendations for the management of anticoagulation with these devices. The evidence synthesis led to the creation of 42 recommendations to improve anticoagulation management related to the use of the Impella devices. Recommendations address purge solution management, intravenous anticoagulation, monitoring, evaluation and management of heparin-induced thrombocytopenia (HIT), and management during combination MCS support. The use of a heparinized, dextrose-containing purge solution is critical for optimal device function, and a bicarbonate-based purge solution may be an alternative in certain situations. Likewise, intravenous (ie, systemic) anticoagulation with heparin is often necessary, although evidence supporting the optimal assay and target range for monitoring the level of anticoagulation is generally lacking. Patients treated with an Impella MCS device may develop HIT, which is more difficult to evaluate and treat in this setting. Lastly, the use of Impella with extracorporeal membrane oxygenation or for biventricular support creates additional anticoagulation challenges.

Modalities of Left Ventricle Decompression during VA-ECMO Therapy

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used to sustain circulatory and respiratory support in patients with severe cardiogenic shock or refractory cardiac arrest. Although VA-ECMO allows adequate perfusion of end-organs, it may have detrimental effects on myocardial recovery. Hemodynamic consequences on the left ventricle, such as the increase of afterload, end-diastolic pressure and volume, can lead to left ventricular (LV) distention, increase of myocardial oxygen consumption and delayed LV function recovery. LV distention occurs in almost 50% of patients supported with VA-ECMO and is associated with an increase in morbidity and mortality. Thus, recognizing, preventing and treating LV distention is key in the management of these patients. In this review, we aim to discuss the pathophysiology of LV distention and to describe the strategies to unload the LV in patients supported with VA-ECMO.

Biventricular Unloading with Impella and Venoarterial Extracorporeal Membrane Oxygenation in Severe Refractory Cardiogenic Shock: Implications from the Combined Use of the Devices and Prognostic Risk Factors of Survival

Since mechanical circulatory support (MCS) devices have become integral component in the therapy of refractory cardiogenic shock (RCS), we identified 67 patients in biventricular support with Impella and venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO) for RCS between February 2013 and December 2019 and evaluated the risk factors of mortality in this setting. Mean age was 61.07 ± 10.7 and 54 (80.6%) patients were male. Main cause of RCS was acute myocardial infarction (AMI) (74.6%), while 44 (65.7%) were resuscitated prior to admission. The mean Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment Score (SOFA) score on admission was 73.54 ± 16.03 and 12.25 ± 2.71, respectively, corresponding to an expected mortality of higher than 80%. Vasopressor doses and lactate levels were significantly decreased within 72 h on biventricular support (p < 0.05 for both). Overall, 17 (25.4%) patients were discharged to cardiac rehabilitation and 5 patients (7.5%) were bridged successfully to ventricular assist device implantation, leading to a total of 32.8% survival on hospital discharge. The 6-month survival was 31.3%. Lactate > 6 mmol/L, vasoactive score > 100 and pH < 7.26 on initiation of biventricular support, as well as Charlson comorbity index > 3 and prior resuscitation were independent predictors of survival. In conclusion, biventricular support with Impella and VA-ECMO in patients with RCS is feasible and efficient leading to a better survival than predicted through traditional risk scores, mainly via significant hemodynamic improvement and reduction in lactate levels.

Early Escalation of Mechanical Circulatory Support Stabilizes and Potentially Rescues Patients in Refractory Cardiogenic Shock

Background:

Limited progress has been made in the management of cardiogenic shock (CS). Morbidity and mortality of refractory CS remain high. The effects of mechanical circulatory support (MCS) are promising, although many aspects are elusive. We evaluated efficacy and safety of early combined MCS (Impella microaxial pump + venoarterial extracorporeal membrane oxygenation [VA-ECMO]) in refractory CS and aimed to determine factors for decision-making in combined MCS.

Methods and Results:

We analyzed 69 consecutive patients with refractory CS from our registry requiring combined MCS. In 12 cases, therapy was actively withdrawn according to patient’s will. Patients were severely sick (Survival After Venoarterial ECMO score mean±SD, –8.9±4.4) predicting 30% in-hospital survival; ventilation 94%, dialysis 56%. Impella pumps and VA-ECMO were combined early (duration of combined MCS: median 94 hours; interquartile range, 49–150 hours). Early MCS escalation stabilized patients rapidly, reducing number and doses of catecholamines ( P <0.05 versus baseline) while hemodynamics improved. Reflecting an improved microcirculation, lactate levels normalized within 24 hours ( P <0.05 versus baseline). Despite refractory CS and disease severity, survival was favorable (on MCS 61%, 30 days 49%, 6 months 40%). In multivariate Cox-regression, duration of shock-to-first device (hours, hazard ratio, 1.05 [95% CI, 1.01–1.08]; P =0.007) and lactate levels after 12 hours of MCS (hazard ratio, 1.28 [95% CI, 1.09–1.51]; P =0.002) independently predicted survival. Additional right ventricular failure predisposed to futility (hazard ratio, 8.48 [95% CI, 1.85–38.91]; P =0.006).

Conclusions:

The early and consequent combination of MCS by Impella microaxial pumps and VA-ECMO enables stabilization and may rescue high-risk patients with refractory CS at low overall risk. Independent predictors of survival may guide prognostication, decision-making, and allocation of medical resources.

Optimal Strategy and Timing of Left Ventricular Venting During Veno-Arterial Extracorporeal Life Support for Adults in Cardiogenic Shock

Background:

Veno-arterial extracorporeal life support (VA-ECLS) is widely used to treat refractory cardiogenic shock. However, increased left ventricular (LV) afterload in VA-ECLS can worsen pulmonary congestion and compromise myocardial recovery. Our objectives were to explore the efficacy, safety, and optimal timing of adjunctive LV venting strategies.

Methods:

A systematic search was performed on Medline, EMBASE, PubMed, CDSR, CCRCT, CINAHL, ClinicalTrials.Gov, and WHO ICTRP from inception until January 2019 for all relevant studies, including LV venting. Data were analyzed for mortality and weaning from VA-ECLS on the basis of timing of LV venting, along with adverse complications.

Results:

A total of 7995 patients were included from 62 observational studies, wherein 3458 patients had LV venting during VA-ECLS. LV venting significantly improved weaning from VA-ECLS (odds ratio, 0.62 [95% CI, 0.47–0.83]; P =0.001) and reduced short-term (30 day; risk ratio [RR], 0.86 [95% CI, 0.77–0.96]; P =0.008) but not in-hospital (RR, 0.92 [95% CI, 0.83–1.01] P =0.09) or long-term (6 months; RR, 0.96 [95% CI, 0.90–1.03]; P =0.27) mortality. Early (<12 hours; RR, 0.86 [95% CI, 0.75–0.99]; P =0.03) but not late (≥12 hours; RR, 0.99 [95% CI, 0.71–1.38]; P =0.93) LV venting significantly reduced short-term mortality. Patients with LV venting spent more time on VA-ECLS (3.6 versus 2.8 days, P <0.001), and mechanical ventilation (7.1 versus 4.6 days, P =0.013). With the exception of hemolysis (RR, 2.18 [95% CI, 1.58–3.01]; P <0.00001), overall adverse events did not differ.

Conclusions:

LV venting, especially if done early (<12 hours), appears to be associated with an increased success of weaning and reduced short-term mortality. Future studies are required to delineate the importance of any or early LV venting adjuncts on mortality and morbidity outcomes.

Clinical Pearls of Venoarterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Extracorporeal membrane oxygenation (ECMO) is a technique that uses a pump to drain blood from a body, circulate blood through a membrane lung, and return the oxygenated blood back into the body. Venoarterial (VA) ECMO is a simplified version of the heart-lung machine that assists native pulmonary and/or cardiac function. VA ECMO is composed of a drainage cannula in the venous system and a return cannula in the arterial system. Because VA ECMO can increase tissue perfusion by increasing the arterial blood flow, it is used to treat medically refractory cardiogenic shock or cardiac arrest. VA ECMO has a distinct physiology that is referred to as differential flows. It can cause several complications such as left ventricular distension with pulmonary edema, distal limb ischemia, bleeding, and thromboembolism. Physicians who are using this technology should be knowledgeable on the prevention and management of these complications. We review the basic physiology of VA ECMO, the mechanism of complications, and the simple management of VA ECMO.

Impella Placement Guided by Echocardiography Can Be Used as a Strategy to Unload the Left Ventricle During Peripheral Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVE

At the authors' institution, before 2015, patients cannulated for peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) did not undergo left ventricular (LV) decompression with the use of an LV vent. After 2015, the authors' institution began using the Impella device to vent the left ventricle in patients on VA-ECMO. The authors hypothesized that survival outcomes would improve in patients on VA-ECMO with the use of an Impella for LV venting.

DESIGN

Retrospective, chart based review study.

SETTING

Single center, university-based hospital.

PARTICIPANTS

All adult patients at the authors' institution who required VA-ECMO between January 2015 and May 2017.

INTERVENTION

An Impella (Abiomed, Danvers, MA) device was placed percutaneously in patients cannulated for VA-ECMO as a mechanism to provide LV venting and decompression, therefore unloading the heart.

MEASUREMENTS AND MAIN RESULTS

Manual chart review was conducted, and a survival analysis was performed. It was observed that patients on VA-ECMO in whom an Impella was implanted had improved survival and an improvement in LV function as demonstrated by echocardiography compared with patients maintained on VA-ECMO alone.

CONCLUSIONS

Patients on VA-ECMO plus Impella implantation demonstrated improved survival compared with patients treated with VA-ECMO alone. Key echocardiographic characteristics such as improved LV function after Impella placement and LV cavity size reduction during therapy may help predict those patients who may benefit most from this cannulation strategy.

Mechanical circulatory support in patients with cardiogenic shock in intensive care units: A position paper of the "Unité de Soins Intensifs de Cardiologie" group of the French Society of Cardiology, endorsed by the "Groupe Athérome et Cardiologie Interventionnelle" of the French Society of Cardiology

Cardiogenic shock (CS) is a major challenge in contemporary cardiology. Despite a better understanding of the pathophysiology of CS, its management has only improved slightly. The prevalence of CS has remained stable over the past decade, but its outcome has seen few improvements, with the 1-month mortality rate still in the range of 40-60%. Inotropes and vasopressors are the first-line therapies for CS, but they are associated with significant hazards, and have well-known deleterious effects. Furthermore, a significant number of patients develop refractory CS with haemodynamic instability, causing critical organ hypoperfusion and/or pulmonary congestion, despite increasing doses of catecholamines. A major change has resulted from the recent advent and availability of potent mechanical circulatory support (MCS) devices. These devices, which ensure sustained blood flow, provide a great and long-awaited opportunity to improve the prognosis of CS. Several efficient MCS devices are now available, including left ventricle-to-aorta circulatory support devices and full pulmonary and circulatory support with venoarterial extracorporeal membrane oxygenation. However, evidence to support their indications, the timing of implantation and the selection of patients and devices is scarce. Because these devices are gaining momentum and are becoming readily available, the "Unité de Soins Intensifs de Cardiologie" group of the French Society of Cardiology aims to propose practical algorithms for the use of these devices, to help intensive care unit and cardiac care unit physicians in this complex area, where evidence is limited.

Cardiogenic shock complicating peripartum cardiomyopathy: Importance of early left ventricular unloading and bromocriptine therapy

INTRODUCTION

Acute peripartum cardiomyopathy complicated by cardiogenic shock is a rare but life-threatening disease. A prolactin fragment is considered causal for the pathogenesis of peripartum cardiomyopathy. This analysis sought to investigate the role of early percutaneous mechanical circulatory support with micro-axial flow-pumps and/or veno-arterial extracorporeal membrane oxygenation in combination with the prolactin inhibitor bromocriptine in refractory cardiogenic shock complicating peripartum cardiomyopathy.

METHODS AND RESULTS

In this single-centre analysis, five peripartum cardiomyopathy patients with refractory cardiogenic shock received mechanical circulatory support with either Impella CP microaxial pump only (n=2) or in combination with veno-arterial extracorporeal membrane oxygenation (n=3) in the setting of biventricular failure. All patients were mechanically ventilated. In all cases mechanical circulatory support was combined with bromocriptine therapy and early administration of levosimendan. All patients survived the acute phase of refractory cardiogenic shock. Mechanical circulatory support using a micro-axial pump allowed to significantly reduce catecholamine dosage. Remarkably, early left ventricular support with micro-axial flow-pumps resulted in myocardial recovery whereas delayed Impella (mechanical circulatory support) implantation was associated with poor left ventricular recovery.

CONCLUSION

Mechanical circulatory support in patients with refractory cardiogenic shock complicating peripartum cardiomyopathy was associated with a 30-day survival of 100% and a favourable outcome. Notably, early left ventricular unloading combined with bromocriptine therapy was associated with left ventricular recovery. Therefore, an immediate transfer to a tertiary hospital experienced in mechanical circulatory support in combination with bromocriptine treatment seems indispensable for successful treatment of peripartum cardiomyopathy complicated by cardiogenic shock.

Place de l’assistance circulatoire dans le choc cardiogénique en France en 2018 : revue de la littérature et perspectives

Le choc cardiogénique reste de nos jours une entité mal définie, assez fréquente en pratique clinique (60 000–70 000 cas/an en Europe), dont le pronostic est sombre, avec une mortalité souvent supérieure à 40 % à 30 jours. À travers cette revue de la littérature, nous essaierons de définir cette entité et ses étiologies, avant de parler de son incidence et de son pronostic. L’approche physiopathologique du choc cardiogénique nous permettra par la suite d’approcher sa prise en charge thérapeutique classique (gestion de la volémie, amines inotropes et vasoconstrictives, ventilation) et les limites de cette dernière. Ainsi, nous aborderons les assistances circulatoires et cardiocirculatoires disponibles en France, afin de les envisager au sein d’une stratégie globale de prise en charge du patient en choc cardiogénique. Nous discuterons plus spécifiquement leurs indications ainsi que l’importance du moment d’implantation afin d’optimiser leur efficacité. Enfin, nous évoquerons les assistances actuellement en développement, mais également les nouvelles stratégies thérapeutiques qui pourraient arriver dans les prochaines années.

ECMO in cardiac arrest and cardiogenic shock

Cardiogenic shock is an acute emergency, which is classically managed by medical support with inotropes or vasopressors and frequently requires invasive ventilation. However, both catecholamines and ventilation are associated with a worse prognosis, and many patients deteriorate despite all efforts. Mechanical circulatory support is increasingly considered to allow for recovery or to bridge until making a decision or definite treatment. Of all devices, extracorporeal membrane oxygenation (ECMO) is the most widely used. Here we review features and strategical considerations for the use of ECMO in cardiogenic shock and cardiac arrest.