Left Ventricular Unloading During Veno-Arterial ECMO: A Simulation Study

Ambulatory simultaneous venoarterial extracorporeal membrane oxygenation and temporary percutaneous left ventricular assist device bridge to heart transplantation

Left ventricular (LV) unloading has been shown to improve survival for patients requiring veno-arterial extracorporeal membrane oxygenation (VA ECMO) support for cardiogenic shock. A mortality benefit has been shown for ECMO and concomitant placement of a transcatheter unloading LV pump such as an Impella device (colloquially referred to as ECPELLA or ECMELLA) for patients resuscitated with VA ECMO after a short period of cardiac arrest. Despite the described benefit of LV unloading with VA ECMO for cardiopulmonary resuscitation, it remains unclear as to what criteria should be used and what other diagnostic and therapeutic adjuncts may be useful. We describe here the successful utilization of concomitant VA ECMO and Impella in a 43 year old male with acute heart failure and cardiac arrest. Distinguishing itself from the currently reported methods, our methodology incorporates transesophageal echocardiography (TEE) in the emergency department for rapid decision-making in addition to an automatic chest compression device, the Lund University Cardiac Assist System (LUCAS) device (Stryker, Portage, MI) as a bridge to LV unloading in a hybrid operating suite.

Unloading of the Left Ventricle During Venoarterial Extracorporeal Membrane Oxygenation Therapy in Cardiogenic Shock

Our goal was to compare the haemodynamic effects of different mechanical left ventricular (LV) unloading strategies and clinical outcomes in patients with refractory cardiogenic shock supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO). A total of 448 patients supported with VA-ECMO for refractory cardiogenic shock between 1 March 2015 and 31 January 2020 were included and analysed in a single-centre, retrospective case-control study. Fifty-three patients (11.8%) on VA-ECMO required LV unloading. Percutaneous balloon atrial septostomy (PBAS), intra-aortic balloon pump (IABP) and transapical LV vent (TALVV) strategies were compared with regards to the composite rate of death, procedure-related complications and neurological complications. The secondary outcomes were reduced pulmonary capillary wedge pressure, pulmonary artery pressure, central venous pressure, left atrial diameter and resolution of pulmonary oedema on a chest X-ray within 48 h. No death related to the LV unloading procedure was detected. Reduction in pulmonary capillary wedge pressure was highest with the TALVV technique (17.2 ± 2.1 mmHg; P < 0.001) and was higher in the PBAS than in the IABP group; the difference was significant (9.6 ± 2.5 and 3.9 ± 1.3, respectively; P = 0.001). Reduction in central venous pressure with TALVV was highest with the other procedures (7.4 ± 1.1 mmHg; P < 0.001). However, procedure-related complications were significantly higher with TALVV compared to the PBAS and IABP groups (50% vs 17.6% and 10%, respectively; P = 0.015). We observed no significant differences in mortality or neurological complications between the groups. Our results suggest that TALVV was the most effective method for LV unloading compared with PBAS and IABP for VA-ECMO support but was associated with complications. Efficient LV unloading may not improve survival.

An emerging therapeutic modality, ECPELLA, which combines a transvalvular microaxial left ventricular (LV) assist device, Impella, and venoarterial membrane oxygenation (VA‐ECMO), has been applied for patients with refractory cardiogenic shock. During ECPELLA support, VA‐ECMO increases the LV load, whereas the Impella reduces the LV load. Studies reported that coronary perfusion is influenced by LV unloading conditions, and the effective degree of LV unloading to increase the coronary perfusion on ECPELLA support remains to be determined. Here, we reported a cardiogenic shock case whose coronary arterial flow was assessed by transesophageal echocardiography during ECPELLA support. The left anterior descending coronary artery (LAD) peak blood flow velocity and the velocity time integral (VTI) were not significantly increased when blood was ejected from the LV (partial LV unloading). When the LV blood ejection was completely bypassed by Impella confirmed by non‐pulsatile aortic pressure with significantly reduced LV pressure with no aortic valve opening (LV uncoupling: no blood ejection from the LV), both peak velocity and VTI of the LAD were markedly increased and the blood flow became continuous throughout the cardiac cycle. Our case suggests that the coronary arterial flow in the injured myocardium is sensitive to degrees of LV unloading on ECPELLA support.

Cannula and Pump Positions Are Associated With Left Ventricular Unloading and Clinical Outcome in Patients With HeartWare Left Ventricular Assist Device

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is widely used to treat medically refractory cardiogenic shock and cardiac arrest, and its usage has increased exponentially over time. Although VA-ECMO has many advantages over other mechanical circulatory supports, it has the unavoidable disadvantage of increasing retrograde arterial flow in the afterload, which causes left ventricular (LV) overload and can lead to undesirable consequences during VA-ECMO treatment. Weak or no antegrade flow without sufficient opening of the aortic valve increases the LV end-diastolic pressure, and that can cause refractory pulmonary edema, blood stagnation, thrombosis, and refractory ventricular arrhythmia. This hemodynamic change is also related to an increase in myocardial energy consumption and poor recovery, making LV unloading an essential management issue during VA-ECMO treatment. The principal factors in effective LV unloading are its timing, indications, and modalities. In this article, we review why LV unloading is required, when it is indicated, and how it can be achieved.

Venoarterial extracorporeal membrane oxygenation (VA ECMO) is an established method of short-term mechanical support for patients in cardiogenic shock, but can create left ventricular (LV) distension. This paper analyzes the physiologic basis of this phenomenon and treatment methods. This is a retrospective review of the existing literature on VA ECMO and LV distension. We undertook a PubMed review of all peer-reviewed papers focusing on VA ECMO, LV distension, and LV venting. We reviewed these papers and synthesized our findings. We also will discuss the various methods of LV venting and venting strategies we use at Columbia. LV distension is becoming an increasingly appreciated aspect of caring for patients on VA ECMO support. The literature demonstrates that the consequences of failing to anticipate, recognize, and treat LV distension are grave, and will worsen an already distended and hypocontractile LV. Myocardial recovery will be hindered, and LV thrombus formation more likely. Early recognition and aggressive management of LV distension is paramount in helping care for this critically ill patient population.

Left ventricular (LV) unloading is a crucial intervention to decrease the harmful consequences of extracorporeal membrane oxygenation (ECMO) on hemodynamic status in cardiogenic shock (CS) patients. However, a lingering question preoccupies experts: Should we intervene early or wait until clinical deterioration caused by increasing afterload is detected? A systematic review and meta-analysis synthesizing studies, which were retrieved by systematically searching PubMed, Web of Science, SCOPUS, and Cochrane through December 2023. We used R V. 4.3 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD) with a 95% confidence interval (CI). CRD42024501643. Eight studies with 2.117 patients were included. Early/prophylactic LV unloading was associated with a lower incidence of all-cause mortality [RR: 0.87 with 95% CI (0.79, 0.95), p < 0.01]. However, there was no significant difference between the two groups regarding cardiac mortality [RR: 1.01 with 95% CI (0.68, 1.48), p = 0.98], non-cardiac mortality [RR: 0.86 with 95% CI (0.46, 1.62), p = 0.64], and in-hospital mortality [RR: 0.95 with 95% CI (0.86, 1.05), p = 0.30]. There was no significant difference between the two groups regarding ECMO weaning, myocardial recovery, ECMO duration, and length of hospitalization. Early/prophylactic LV unloading during ECMO for CS patients was associated with a decreased incidence of all-cause mortality and sepsis or infection, with no effect on ECMO weaning, myocardial recovery, ECMO duration, and hospital length of stay.

Pulmonary artery (PA) cannulation during peripheral venoarterial extracorporeal membrane oxygenation (ECMO) has been shown to be effective either for indirect left ventricular (LV) unloading or to allow right ventricular (RV) bypass with associated gas-exchange support in case of acute RV with respiratory failure. This case series reports the results of such peculiar ECMO configurations with PA cannulation in different clinical conditions. All consecutive patients receiving PA cannulation (direct or percutaneous) from January 2015 to September 2018 in 3 institutions were retrospectively reviewed. Isolated LV unloading or RV support, as well as dynamic support including initial drainage followed by perfusion through the PA cannula, was used as part of the ECMO configuration according to the type of patient and the patient's haemodynamic/functional needs. Fifteen patients (8 men, age range 45-73 years, EuroSCORE log range 14.45-91.60%) affected by acute LV, RV or biventricular failure of various aetiologies, were supported by this ECMO mode. Percutaneous PA cannulation was performed in 10 patients and direct PA cannulation, in 5 cases. Dynamic ECMO management (initially draining and then perfusing through the PA cannula) was carried out in 6 patients. Mean ECMO duration was 9.1 days (range 6-17 days). One patient exhibited pericardial fluid during the implant of a PA cannula (no lesion found when the chest was opened), and weaning from temporary circulatory support was achieved in 14 patients (1 who received a transplant). Three patients (20%) died in-hospital, and 12 patients were successfully discharged without major complications. Effective indirect LV unloading in peripheral venoarterial ECMO as well as isolated RV support can be achieved by PA cannulation. Such an ECMO configuration may allow the counteraction of common venoarterial ECMO shortcomings or allow dynamic/adjustable management of ECMO according to specific ventricular dysfunction and haemodynamic needs. Percutaneous PA cannulation was shown to be safe and feasible without major complications. Additional investigation is needed to confirm the safety and efficacy of such an ECMO configuration and management in a larger patient population.

BackgroundCardiogenic shock complicating acute myocardial infarction (CSAMI) is a severe complication associated with unacceptably high mortality rates. Since early revascularisation was introduced more than 20 years ago, no subsequent innovation...

Profoundly impaired left ventricular (LV) function in patients undergoing femoral veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) can result in intra-cardiac stasis and thrombus formation. There have been several attempts to improve LV unloading in patients with peripheral VA-ECMO, either by improving contractility or by venting the LV. Data from all patients who underwent femoral VA-ECMO between 2007 and 2015 due to cardiogenic decompensation were retrospectively analysed regarding intra-cardiac thrombus formation. In total, 11 of 281 patients (3.91%) with femoral VA-ECMO developed an intra- or extra-cardiac thrombus despite adequate anticoagulation therapy. None of the patients survived this serious complication. Management strategies for patients with femoral VA-ECMO support and severely impaired LV function must be reassessed to avoid insufficient LV unloading at an early stage of ECMO therapy. Early LV decompression should be considered in patients with insufficient unloading of the LV to prevent intra-cardiac thrombus formation.

Left ventricular (LV) unloading during veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is essential for managing refractory low cardiac output after complex cardiac surgery. However, direct LV venting is associated with an increased risk of intracardiac thrombosis, particularly when anticoagulation is delayed. A 69-year-old woman with hypertrophic cardiomyopathy and severe left ventricular outflow tract obstruction presented with exertional dyspnea. Echocardiography showed severe mitral regurgitation with marked annular calcification, moderate aortic regurgitation, and systolic anterior motion of the mitral valve. She underwent complex cardiac surgery including septal myectomy, aortic and mitral valve replacement with bioprostheses, and tricuspid annuloplasty. Intraoperative rupture at the anterior mitral commissure required re-clamping, patch repair, and reimplantation of the prostheses. Prolonged cardiopulmonary bypass led to postoperative circulatory failure, necessitating VA-ECMO via the right axillary artery and femoral vein, with left ventricular venting through the right superior pulmonary vein. On postoperative day 4, ECMO was successfully weaned after recovery of contractility; however, the patient developed acute pulmonary edema and cardiogenic shock within hours, prompting urgent ECMO reinstitution. Transesophageal echocardiography on day 9 revealed thrombotic obstruction of the mitral bioprosthesis, confirmed intraoperatively. Both prosthetic valves and the left ventricle were covered with extensive white and red thrombi, which were completely removed. Cardiac function recovered after reoperation, and ECMO was successfully discontinued. Despite subsequent bilateral cerebral infarctions, the patient survived and was gradually weaned from mechanical ventilation at 1-month follow-up. Thrombotic complications in patients supported with VA-ECMO after valve replacement result from multiple interacting factors, including surgical trauma, prosthetic material, altered flow dynamics, and delayed anticoagulation. This case highlights the diagnostic challenges of assessing prosthetic valve function during VA-ECMO and underscores the need for individualized decisions regarding LV unloading strategies and anticoagulation management. Careful ECMO weaning and close echocardiographic surveillance may help reduce the risk of catastrophic valve-related complications.

Background Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a critical form of mechanical circulatory support (MCS) for patients with refractory cardiogenic shock (CS). The combination therapy of VA-ECMO and Impella, known as ECPELLA, provides both systemic circulatory support and left ventricular (LV) unloading. However, whether the LV unloading effect of ECPELLA further reduces myocardial damage and mortality in Society for Cardiovascular Angiography and Interventions (SCAI) Stage E patients remains unclear. Objective To evaluate whether ECPELLA reduces myocardial damage and improves short-term survival in refractory CS patients with ST-elevation myocardial infarction (STEMI) requiring VA-ECMO before reperfusion. Methods Between January 2012 and January 2025, we retrospectively screened 239 acute coronary syndrome patients who required advanced mechanical circulatory support (MCS).Patients with non-STEMI, those who did not receive VA-ECMO during percutaneous coronary intervention (PCI) (n=81), and those with mechanical complications, such as left ventricular free wall rupture (n=8) or ventricular septal perforation (n=1), were excluded. Additionally, patients who had absent vital signs after MCS implantation and were deemed for withdrawal of care (n=7) were also excluded from the study. Ultimately, 77 consecutive STEMI patients who received VA-ECMO before reperfusion were included. Patients were divided into two groups: ECPELLA (n=48) and ECMO with IABP (n=28). Serum CK-MB levels and 30-day all-cause mortality were assessed. Results There were no significant differences between the groups in age, sex, coronary risk factors, left main trunk (LMT) lesion, or the rate of extracorporeal cardiopulmonary resuscitation (E-CPR). However, renal impairment (eGFR &amp;lt;60 mL/min/1.73 m²) was significantly more prevalent in the ECMO with IABP group. Additionally, the IABP-SHOCK II score, a prognostic score for CS, was significantly higher in the ECMO with IABP group than in the ECPELLA group (3 [3–4] vs. 4 [3–6]; p=0.015). The ECPELLA group had significantly higher MCS support flow per unit of body surface area during PCI and the first three days, received a significantly lower catecholamine dose, and demonstrated better lactate clearance. ECPELLA also resulted in significantly lower peak CK-MB levels (330 [115–562] IU/L vs. 500 IU/L; p=0.026). Kaplan-Meier analysis demonstrated a significantly higher 30-day survival rate in the ECPELLA group (p=0.003 by log-rank test). Multivariable Cox proportional hazard analysis, adjusting for age, E-CPR, LMT lesion, renal impairment, IABP-SHOCK II score, and ECPELLA, identified ECPELLA as the only independent factor associated with 30-day all-cause mortality (hazard ratio: 0.52, 95% confidence interval: 0.27–0.98; p=0.044). Conclusion ECPELLA treatment provides greater circulatory support and lower CK-MB levels, which may be associated with improved short-term survival compared to ECMO with IABP support.Figure1 Figure2

Acute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias