Cardiogenic shock in ACS. Part 2: role of mechanical circulatory support

Lung ultrasound to evaluate pulmonary changes in patients with cardiogenic shock undergoing extracorporeal membrane oxygenation: a retrospective study

PURPOSE

The aim of the study was to evaluate the value of lung ultrasound (LUS) in patients with cardiogenic shock treated by venoarterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

A retrospective study was conducted in Xuzhou Central Hospital from September 2015 to April 2022. Patients with cardiogenic shock who received VA-ECMO treatment were enrolled in this study. The LUS score was obtained at the different time points of ECMO.

RESULTS

Twenty-two patients were divided into a survival group (n = 16) and a nonsurvival group (n = 6). The intensive care unit (ICU) mortality was 27.3% (6/22). The LUS scores in the nonsurvival group were significantly higher than those in the survival group after 72 h (P < 0.05). There was a significant negative correlation between LUS scores and PaO₂/FiO₂ and LUS scores and pulmonary dynamic compliance(Cdyn) after 72 h of ECMO treatment (P < 0.001). ROC curve analysis showed that the area under the ROC curve (AUC) of T₇₂-LUS was 0.964 (95% CI 0.887 ~ 1.000, P < 0.01).

CONCLUSION

LUS is a promising tool for evaluating pulmonary changes in patients with cardiogenic shock undergoing VA-ECMO.

TRIAL REGISTRATION

The study had been registered in the Chinese Clinical Trial Registry(NO.ChiCTR2200062130 and 24/07/2022).

Right Ventricular Limitation: A Tale of Two Elastances

Right ventricular (RV) dysfunction is a commonly considered cause of low cardiac output in critically ill patients. Its management can be difficult and requires an understanding of how the RV limits cardiac output. We explain that RV stroke output is caught between the passive elastance of the RV walls during diastolic filling and the active elastance produced by the RV in systole. These two elastances limit RV filling and stroke volume and consequently limit left ventricular stroke volume. We emphasize the use of the term "RV limitation" and argue that limitation of RV filling is the primary pathophysiological process by which the RV causes hemodynamic instability. Importantly, RV limitation can be present even when RV function is normal. We use the term "RV dysfunction" to indicate that RV end-systolic elastance is depressed or diastolic elastance is increased. When RV dysfunction is present, RV limitation occurs at lowerpulmonary valve opening pressures and lower stroke volume, but stroke volume and cardiac output still can be maintained until RV filling is limited. We use the term "RV failure" to indicate the condition in which RV output is insufficient for tissue needs. We discuss the physiological underpinnings of these terms and implications for clinical management.

Insufficient left ventricular unloading after extracorporeal membrane oxygenation : A case-series observational study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a method widely used to support circulation in patients with fulminant myocarditis (FM). However, a common complication associated with ECMO is left ventricular (LV) overload.

METHODS

This case series observed the effects of intra-aortic balloon pump (IABP) and beta-blockers for the treatment of LV overload after ECMO. The cases of eight patients with FM who underwent ECMO from September 2009 to July 2016 were reviewed.

RESULTS

Six of the eight patients survived. After ECMO treatment, insufficient LV unloading occurred in six patients. Among these six patients, three experienced electrical storm but spontaneous circulation returned after interventions with beta-blockers and IABP. The survivors demonstrated full recovery of cardiac function.

CONCLUSION

Beta-blockers may prevent the occurrence of electrical storm, and IABP is feasible for the treatment of LV overload after ECMO application.

Long-term clinical results of acute myocardial infarction at the left main trunk requiring percutaneous cardiopulmonary support

The clinical results of patients with acute myocardial infarction (AMI) at the left main trunk (LMT) remain unclear, especially in cases requiring percutaneous cardiopulmonary support (PCPS). Twenty seven cases of AMI at the LMT requiring emergent PCPS were retrospectively investigated. These 27 patients were aged 44-83 years (65.6 ± 8.6 years) and 20 (81.5%) were men. Peak creatine kinase (CK) leakage ranged from 538 to 34,010 IU/l (13,553 ± 7656 IU/l). Eight (29.6%) patients were discharged without mechanical support. Ten (37.0%) patients underwent left ventricular assist device (LVAD) implantation, five of whom with preoperative organ failure could not survive more than 6 months after implantation. The other nine (33.3%) patients died of low output syndrome or brain damage. The overall survival rates were 53.7, 41.3, 33.0, and 28.3% at 3 months, 6 months, 1 year, and 2 years, respectively. Multivariate analysis showed that Killip class 3/4 at hospital arrival was an independent risk factor for hospital mortality (odds ratio 20.4). Patients with more than 5 days of PCPS support period (n = 6), ≥ 4 h to revascularization (n = 6) or maximum CK leakage ≥20,000 IU/dl (n = 3) were not associated with successful PCPS or IABP weaning. The long-term clinical outcomes of patients with LMT disease requiring PCPS is devastating. Rapid cardiopulmonary resuscitation and coronary revascularization and timely insertion of LVAD before the onset of complications might lead to better survival.

Intra-aortic balloon pump protects against hydrostatic pulmonary oedema during peripheral venoarterial-extracorporeal membrane oxygenation

Background:

Increased left ventricular afterload during peripheral venoarterial-extracorporeal membrane oxygenation (VA-ECMO) support frequently causes hydrostatic pulmonary oedema. Because physiological studies demonstrated left ventricular afterload decrease during VA-ECMO assistance combined with the intra-aortic balloon pump (IABP), we progressively changed our standard practice systematically to associate an IABP with VA-ECMO. This study aimed to evaluate IABP efficacy in preventing pulmonary oedema in VA-ECMO-assisted patients.

Methods:

A retrospective single-centre study.

Results:

Among 259 VA-ECMO patients included, 104 received IABP. Weinberg radiological score-assessed pulmonary oedema was significantly lower in IABP+ than IABP– patients at all times after ECMO implantation. This protection against pulmonary oedema persisted when death and switching to central ECMO were used as competing risks (subhazard ratio 0.49, 95% confidence interval (CI) 0.33–0.75; P<0.001). Multivariable analysis retained IABP as being independently associated with a lower risk of radiological pulmonary oedema (odds ratio (OR) 0.4, 95% CI 0.2–0.7; P=0.001) and a trend towards lower mortality (OR 0.54, 95% CI 0.29–1.01; P=0.06). Finally, the time on ECMO free from mechanical ventilation increased in IABP+ patients (2.2±4.3 vs. 0.7±2.0 days; P=0.0003). Less frequent pulmonary oedema and more days off mechanical ventilation were also confirmed in 126 highly comparable IABP+ and IABP– patients, propensity score matched for receiving an IABP.

Conclusions:

Associating an IABP with peripheral VA-ECMO was independently associated with a lower frequency of hydrostatic pulmonary oedema and more days off mechanical ventilation under ECMO.

Combined pulmonary and left ventricular support with veno-pulmonary ECMO and impella 5.0 for cardiogenic shock after coronary surgery

BACKGROUND

Mechanical circulatory support is a common practice nowadays in the management of patients after cardiogenic shock due to myocardial infarction. The single or combined use of one or more devices for mechanical support depends not only on the advantage or disadvantage of these devices but also on the timing of use of these devices before the development of multi organ failure. In our case we used more than one tool for mechanical circulatory support during the prolonged and complicated course of our patient with postcardiotomy cardiogenic shock after coronary artery bypass surgery.

CASE PRESENTATION

We describe the combined use of Impella 5.0 and veno- pulmonary extra corporeal membrane oxygenation (VP-ECMO) for biventricular failure in a 52 years-old man. He presented with cardiogenic shock after inferior wall ST-elevation myocardial infarction. After emergency coronary artery bypass surgery and failure to wean from extracorporeal circulation we employed V-P ECMO and consecutively Impella 5.0 to manage the primarily failing right and secondarily failing left ventricles. He remained hemodynamically stable on both Impella 5.0 and VP-ECMO until Heart Mate II left ventricular assist device implantation on the 14^th postoperative day. Right sided support was weaned on 66^th postoperative day. The patient remained in the intensive care unit for 77 days. During his prolonged stay, he underwent renal replacement therapy and tracheostomy with complete recovery. Six months later, he was successfully heart transplanted and has completed three and half years of unremarkable follow up.

CONCLUSIONS

The combined use of VP ECMO and Impella 5.0 is effective in the management of postcardiotomy biventricular failure as a bridge for further mechanical support or heart transplantation.

Venous Cannula Positioning in Arterial Deoxygenation During Veno-Arterial Extracorporeal Membrane Oxygenation-A Simulation Study and Case Report

Venoarterial extracorporeal membrane oxygenation (VA‐ECMO) is indicated in reversible life‐threatening circulatory failure with or without respiratory failure. Arterial desaturation in the upper body is frequently seen in patients with peripheral arterial cannulation and severe respiratory failure. The importance of venous cannula positioning was explored in a computer simulation model and a clinical case was described. A closed‐loop real‐time simulation model has been developed including vascular segments, the heart with valves and pericardium. ECMO was simulated with a fixed flow pump and a selection of clinically relevant venous cannulation sites. A clinical case with no tidal volumes due to pneumonia and an arterial saturation of below 60% in the right hand despite VA‐ECMO flow of 4 L/min was described. The case was compared with simulation data. Changing the venous cannulation site from the inferior to the superior caval vein increased arterial saturation in the right arm from below 60% to above 80% in the patient and from 64 to 81% in the simulation model without changing ECMO flow. The patient survived, was extubated and showed no signs of hypoxic damage. We conclude that venous drainage from the superior caval vein improves upper body arterial saturation during veno‐arterial ECMO as compared with drainage solely from the inferior caval vein in patients with respiratory failure. The results from the simulation model are in agreement with the clinical scenario.

Refractory cardiogenic shock due to extensive anterior STEMI with covered left ventricular free wall rupture treated with awake VA-ECMO and LVAD as a double bridge to heart transplantation - collaboration of three cardiac centres

AIM

To highlight an optimal collaborative strategy of three different levels of specialized care cardiac centres.

BACKGROUND

Refractory cardiogenic shock is a life-threatening condition. A myocardial recovery is not achieved in many cases despite all efforts and subsequently the heart transplantation remains an ultimate option. Thereby, the use of extracorporeal membrane oxygenation (ECMO) followed by a ventricular assist device in staged bridging provides an attractive approach.

CASE REPORT

We report on an optimal cooperation of PCI (percutaneous coronary intervention) centre with ELSO (extracorporeal life support organization) centre and transplant centre in a patient suffering from refractory cardiogenic shock due to acute myocardial infarction (RCSMI) complicated by left ventricle free wall rupture with pericardial tamponade.

CONCLUSION

The interhospital collaboration can be essential in the context of patients with RCSMI. The use of ECMO enables safe interhospital transport and gains time for further diagnostic and therapeutic steps in such critically ill patients.

[Percutaneous mechanical circulatory support: options and importance]

In cases of low cardiac output and chronic cardiac failure despite conventional therapy, mechanical circulatory support may be the only option to ensure adequate organ perfusion and to save the life of the patient. In recent years, several conceptionally different methods of circulatory support have been developed for percutaneous application in interventional cardiology and intensive care. Indications range from elective use in complex cardiac interventions to long-term support as a bridge to recovery. As intra-aortic balloon pump support can no longer be considered for routine use in ischemic cardiogenic shock, micro-axial pumps for extracorporeal membrane oxygenation and extracorporeal life support systems (ECMO/ECLS) gain attractiveness due to a more convincing impact on the hemodynamics. However, an increasing level of support is paralleled by greater invasiveness and complexity of the systems. Due to a lack of larger comparative trials, the benefits and risks of adverse events must be balanced against those of conventional therapy with inotropes and largely on an individual basis. This review summarizes the options for percutaneous circulatory support with special consideration to applications in the catheter laboratory and intensive care units in internal medicine.

Clinical impact of intra-aortic balloon pump during extracorporeal life support in patients with acute myocardial infarction complicated by cardiogenic shock

Background

There is no available data on clinical outcome in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock who are supported by an intra-aortic balloon pump (IABP) in combination with extracorporeal life support (ECLS).

Methods

We analysed 96 consecutive patients with AMI and complicating cardiogenic shock who were assisted by an ECLS system between January 2004 and December 2011. The primary outcome was in-hospital mortality. The secondary outcomes were the success rate of weaning from ECLS and the lactate clearance for 48 hours (%).

Results

A combination of IABP and ECLS was used in 41 (42.7%) patients. In-hospital mortality occurred for 51 patients (ECLS with IABP versus ECLS alone; 51.2% vs. 54.5%, p = 0.747). The success rate of weaning from ECLS was similar between the two groups (63.4% vs. 58.2%, p = 0.604). Complications such as ischemia of a lower extremity or bleeding at the ECLS insertion site (p = 0.521 and p = 0.667, respectively) did not increase when ECLS was combined with IABP. Among patients who survived for 24 hours after intervention, lactate clearance was not significantly different between patients who received ECLS alone and those who received ECLS with IABP (p = 0.918).

Conclusions

The combined use of ECLS and IABP did not improve in-hospital survival in patients with AMI complicated by cardiogenic shock.

Preventing LVAD implantation by early short-term mechanical support and prolonged inodilator therapy : A case series with acute refractory cardiogenic shock treated with veno-arterial extracorporeal membrane oxygenation and optimised medical strategy

Cardiogenic shock continues to be a life-threatening condition carrying a high mortality and morbidity, where the prognosis remains poor despite intensive modern treatment modalities. In recent years, mainly technical improvements have led to a more widespread use of short- and long-term mechanical circulatory support, such as veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and left ventricular assist devices (LVADs). Currently, LVADs are indispensable as 'bridge' to cardiac recovery, heart transplantation (HTX), and/or as destination therapy Importantly, both LVADs and HTX put a vast burden on financial resources, besides significant short- and long-term risks of morbidity and mortality. These considerations underscore the importance of optimal timing and appropriate patient selection for LVAD therapy, avoiding as much as possible an unfortunate and costly clinical path. In this report, we present a series of three cases with acute refractory cardiogenic shock ('crash and burn', INTERMACS profile 1) successfully treated by ECMO and early optimal medical therapy preventing a certain path towards LVAD and/or HTX, for which they were initially referred. This conservative approach in INTERMACS profile one patients warrants very early introduction of adequate medical heart failure therapy under the umbrella of a combination of short-term mechanical circulatory and inotropic support by phosphodiesterase inhibitors. Therefore, this novel combined medical-mechanical approach could have important clinical implications for this extremely challenging patient category, as it may avoid an unnecessary and costly clinical path towards LVAD and/or heart transplantation.

Cardiogenic Shock and the ICU Patient

Cardiogenic shock is one of the most important complications of acute myocardial infarction (MI) and acute left ventricular failure (LVF). It threatens the life of 5–10% of patients with ST-segment elevation myocardial infarction (STEMI) particularly in the presence of inappropriately low peripheral vascular resistance. Cardiogenic shock results in poor tissue perfusion, end-organ damage and carries a high mortality risk. The goal of therapy is to prevent end-organ dysfunction and severe metabolic derangement by raising mean arterial blood pressure, which is achieved with the use of inotropes and vasopressors, often at the expense of tachycardia, elevated myocardial oxygen consumption and extended myocardial ischaemia. Current therapeutic approaches include early coronary artery revascularisation (which has significantly improved the survival rate), fluid resuscitation, inotropic support and mechanical circulatory support using intra-aortic balloon pumps or ventricular assist devices. In this article, we review the pathophysiology, diagnosis and management of cardiogenic shock.

Mechanical circulatory support for cardiogenic shock

Cardiogenic shock (CS) is a syndrome of progressive depression of myocardial function with systemic hypoperfusion. It occurs due to various aetiologies such as acute myocardial infarction, myocarditis, acute decompensated heart failure and postcardiotomy. Cardiogenic shock carries poor prognosis, and medical therapy alone is not effective. Mechanical circulatory support is required to unload the ventricles, decrease the myocardial demand, prevent further injury, improve the coronary perfusion, stabilise the haemodynamics and maintain the end-organ perfusion before definitive interventions such as coronary reperfusion can take place. Currently, there are several methods of mechanical circulatory support. These include extracorporeal life support, paracorporeal or extracorporeal ventricular-assist devices, percutaneous ventricular assist devices, intra-aortic balloon counterpulsation and total artificial heart. In this review, we discuss the role of each of these circulatory support devices in the management of acute cardiac failure.

[Ischaemic cardiogenic shock. Where do we stand in 2012?]

With a stable frequency (about 5% of acute coronary syndromes) and a mortality of nearly 45%, cardiogenic shock (CS), especially when it occurs in the immediate waning of myocardial infarction, still represents a therapeutic challenge. In this review, will be detailed the actual epidemiologic data of CS, its physiopathology and the different modalities of treatments available to the interventional cardiologist, especially the coronary revascularisation and the percutaneous left ventricular assistance, whether by intra-aortic balloon counterpulsation or by more complex systems.

Cardiogenic shock in ACS. Part 1: prediction, presentation and medical therapy

Ischemic cardiogenic shock is a complex, self-perpetuating pathological process that frequently causes death irrespective of medical therapy. Early definition of coronary anatomy is a pivotal step towards survival. Those destined to develop shock are likely to have three-vessel or left main stem disease with previously impaired left ventricular function. Early reperfusion of the occluded artery can limit infarct size, but ischemia-reperfusion injury or the 'no-reflow' phenomenon can preclude improvement in myocardial contractility. Emergence of shock depends upon the volume of ischemic myocardium, stroke volume, and peripheral vascular resistance. If cytokine release triggers the systemic inflammatory response, systemic vascular resistance falls and inadequate coronary perfusion pressure heralds the downward spiral. Survival depends on early recognition of shock, followed by aggressive targeted treatment of left, right, or biventricular failure. The goal is to prevent end-organ dysfunction and severe metabolic derangement by raising mean arterial pressure, which is achieved with inotropes and vasopressors, often at the expense of tachycardia, elevated myocardial oxygen consumption, and extended ischemia. The value of intra-aortic balloon counter-pulsation is now questioned in patients with advanced shock. When mean arterial pressure is <55 mmHg with serum lactate >11 mmol/l, death is likely and mechanical circulatory support becomes the only chance for survival.