Ventriculo-arterial uncoupling with an impella assisted HVAD: The p-D LVAD.

This paper presents the novel use of a temporary percutaneous ventricular assist device (pVAD) in a 51-year-old man with an implanted durable left ventricular assist device (d-LVAD). The pre-existing left ventricular assist device was unable to successfully unload the left ventricle, and the addition of the temporary pVAD achieved successful unloading as well as a decrease in pulmonary artery pressures without compromising the function of the right ventricle allowing safe UNOS listing for orthotopic heart transplantation.

Comparison of in-hospital outcomes of ST-elevation myocardial infarction patients with cardiogenic shock receiving left ventricular mechanical circulatory support devices based on transfer status.

BACKGROUND: We aimed to compare outcomes in patients who receive on-site left ventricular mechanical support versus those transferred to other facilities for mechanical support in ST-elevation myocardial infarction (STEMI) patients with cardiogenic shock. METHODS: This retrospective study analyzed data from the 2016 to 2020 Nationwide Inpatient Sample (NIS) database. We identified patients with STEMI and cardiogenic shock who received Impella and LVAD placement during their hospital stay. They were divided into two groups: those with in-house (direct) placement and those transferred to higher-level medical centers. The primary goal was to compare mortality rates between these groups. RESULTS: During the study, 15,934 (75.2%) received in-house left ventricular support, while 5255 (24.8%) were transferred. Mean age (63 vs. 64 years) and female percentage (25 vs. 26%) were similar. The average time from admission to receiving LV support was 0.8 days for direct group versus 2.8 days for transfer group (p < 0.001). Transferred patients had a higher rate of prior heart failure (68 vs. 79%, p < 0.001) and peripheral vascular disease (10 vs. 14%, p < 0.001) but a lower rate of hypertension (23 vs. 17%, p = 0.003). There were no significant differences in other comorbidities. Primary outcome mortality did not significantly differ (44.9 vs. 44.2, p = 0.66). After multivariate analysis, transferred patients had higher rates of ECMO usage, acute kidney injury, renal replacement therapy, major bleeding, and ischemic stroke. Length of stay (8 vs. 15 days, p < 0.001) and total charges ($391,472 vs. $581,183, p < 0.001) were significantly higher in the transferred group. CONCLUSION: Among STEMI patients with cardiogenic shock, our study found no significant difference in mortality between patients transferred for and those with on-site LV support. Those transferred patients experienced more complications, longer length of stay, and increased hospital costs.

Mechanical circulatory support versus vasopressors alone in patients with acute myocardial infarction and cardiogenic shock undergoing percutaneous coronary intervention.

BACKGROUND: Previous studies have compared Impella use to intra-aortic balloon pump (IABP) use in patients with acute myocardial infarction and cardiogenic shock (AMI-CS) undergoing percutaneous coronary intervention (PCI). Our objective was to compare clinical outcomes in patients with AMI-CS undergoing PCI who received Impella (percutaneous left ventricular assist device) without vasopressors, IABP without vasopressors, and vasopressors without mechanical circulatory support (MCS). METHODS: We queried the National Inpatient Sample (NIS) using ICD-10 codes (2015-2018) to identify patients with AMI-CS undergoing PCI. We created three propensity-matched cohorts to examine clinical outcomes in patients receiving Impella versus IABP, Impella versus vasopressors without MCS, and IABP versus vasopressors without MCS. RESULTS: Among 17,762 patients, Impella use was associated with significantly higher in-hospital major bleeding (31.4% vs. 13.6%; p < 0.001) and hospital charges (p < 0.001) compared to IABP use, with no benefit in mortality (34.1% vs. 26.9%; p = 0.06). Impella use was associated with significantly higher mortality (42.3% vs. 35.7%; p = 0.02), major bleeding (33.9% vs. 22.7%; p = 0.001), and hospital charges (p < 0.001), when compared to the use of vasopressors without MCS. There were no significant differences in clinical outcomes between IABP use and the use of vasopressor without MCS. CONCLUSIONS: In this analysis of retrospective data of patients with AMI-CS undergoing PCI, Impella use was associated with higher mortality, major bleeding, and in-hospital charges when compared to vasopressor therapy without MCS. When compared to IABP use, Impella was associated with no mortality benefit, along with higher major bleeding events and in-hospital charges. A vasopressor-only strategy suggested no difference in clinical outcomes when compared to IABP. This study uses the NIS for the first time to highlight outcomes in AMI-CS patients undergoing PCI when treated with vasopressor support without MCS, compared to Impella and IABP use.

Biventricular catheterization combined with pressure-volume loop monitoring provides insight into the dynamic effects of left ventricular assist devices ramp on right ventricular function.

Ramp studies are utilized for speed optimization of continuous flow left ventricular assist devices (CF-LVADs). We here report the utility of combined left and right heart catheterization during a ramp study to ensure a comprehensive understanding of the hemodynamic implications on both ventricles. Pressure-volume loop (PV loop) monitoring uncovered compromised systolic and mildly compromised right ventricular function with increasing LVAD speeds, despite improvement in left ventricular unloading. These findings informed patient management and highlight the potential utility of PV loop monitoring as an adjunct to left and right heart catheterization during ramp studies of next-generation LVADs.

In-Hospital Mortality in Patients With Cardiogenic Shock Requiring Veno-Arterial Extracorporeal Membrane Oxygenation With Concomitant Use of Impella vs. Intra-Aortic Balloon Pump　- A Retrospective Cohort Study Using a Japanese Claims-Based Database.

BACKGROUND: Patients with refractory cardiogenic shock (CS) necessitating peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) often require an intra-aortic balloon pump (IABP) or Impella for unloading; however, comparative effectiveness data are currently lacking. METHODS AND RESULTS: Using Diagnosis Procedure Combination data from approximately 1,200 Japanese acute care hospitals (April 2018-March 2022), we identified 940 patients aged ≥18 years with CS necessitating peripheral VA-ECMO along with IABP (ECMO-IABP; n=801) or Impella (ECPella; n=139) within 48 h of admission. Propensity score matching (126 pairs) indicated comparable in-hospital mortality between the ECPella and ECMO-IABP groups (50.8% vs. 50.0%, respectively; P=1.000). However, the ECPella cohort was on mechanical ventilator support for longer (median [interquartile range] 11.5 [5.0-20.8] vs. 9.0 [4.0-16.8] days; P=0.008) and had a longer hospital stay (median [interquartile range] 32.5 [12.0-59.0] vs. 23.0 [6.3-43.0] days; P=0.017) than the ECMO-IABP cohort. In addition, medical costs were higher for the ECPella than ECMO-IABP group (median [interquartile range] 9.09 [7.20-12.20] vs. 5.23 [3.41-7.00] million Japanese yen; P<0.001). CONCLUSIONS: Our nationwide study could not demonstrate compelling evidence to support the superior efficacy of Impella over IABP in reducing in-hospital mortality among patients with CS necessitating VA-ECMO. Further investigations are imperative to determine the clinical situations in which the potential effect of Impella can be maximized.

Scrutinizing mechanical circulatory support in cardiogenic shock: Have we jumped the gun?

Despite increasing therapeutic options and disposable resources, cardiogenic shock (CS) remains a formidable condition with high mortality. Today, veno-arterial extracorporeal membrane oxygenation and microaxial flow devices (Impella, Abiomed, Danvers, USA) are established forms of mechanical circulatory support (MCS) in CS, with increasing application over the years. Despite this trend, incorporation into current ESC (Class IIa, evidence C) and AHA/ACC (Class IIa, evidence B-NR) guidelines is based nearly exclusively on observational results. Despite these recommendations and increasing application, current evidence from randomized controlled trials has not provided clear mortality benefit. Thus, reflection on current evidence is hereby justified.

Axillary artery access considerations in Impella 5.5 insertion: Insights from exclusive axillary approach for successful support.

BACKGROUND: The Impella 5.5® is commonly inserted via the axillary artery (AX) in patients with cardiogenic shock. The right AX has traditionally been preferred to avoid crossing the aortic arch, and a minimum diameter of 7 mm has been recommended to accommodate the device (21 Fr). There is limited data on choice of laterality of access and AX size required, both in terms of technicality of the procedure as well as outcomes. METHODS: We performed a single-center retrospective cohort analysis of patients who underwent Impella 5.5® implantation between December 2020 and February 2024 (N = 75). Data including demographics and outcomes were stratified both by diameter (small, <7 mm vs. normal, ≥7 mm) and laterality of access (right vs. left). Adverse events included stroke, limb ischemia, procedural bleeding or infection, and unplanned explant due to complications. Delivery time was defined as time from advancing the first wire to activation of the device. RESULTS: AX approach was attempted in all (N = 74) but one requiring innominate access, with a technical success rate of 95.9% (N = 71/74). The mean age was 58.8 ± 13.3 years, with 81.1% males. The median delivery time was 7.0 (25th, 75th percentiles: 4.0, 11.5) min with a median support duration of 13 (7.7, 24) days. Ten patients (13.5%) had a small AX, with a mean diameter of 6.3 ± 0.5 mm and were more likely to be younger compared to the normal AX group. Fifty-nine patients (79.7%) had insertion via the right AX. Median delivery time was comparable across all groups (small, 5.4 [3.5, 10.9] vs. normal, 7 [4.0, 12.1] min, p = 0.59) and (right, 10.4 [5.3, 15.2] vs. left, 6 [3.7, 10.4] min, p = 0.35). There was no difference between the rates of stroke, ischemia, bleeding, or infection when comparing by size or laterality. Survival to discharge was 59.5%, with 21.1% mortality on support, all in patients with a normal AX diameter, but with no difference between right versus left. CONCLUSION: In our study, laterality and a small diameter of AX access did not affect outcomes of Impella 5.5®, with a similar safety profile.

Stroke outcomes following durable left ventricular assist device implant in patients bridged with micro-axial flow pump: Insights from a large registry.

BACKGROUND: Stroke after durable left ventricular assist device (d-LVAD) implantation portends high mortality. The incidence of ischemic and hemorrhagic stroke and the impact on stroke outcomes of temporary mechanical circulatory support (tMCS) management among patients requiring bridge to d-LVAD with micro-axial flow-pump (mAFP, Abiomed) is unsettled. METHODS: Consecutive patients, who underwent d-LVAD implantation after being bridged with mAFP at 19 institutions, were retrospectively included. The incidence of early ischemic and hemorrhagic stroke after d-LVAD implantation (<60 days) and association of pre-d-LVAD characteristics and peri-procedural management with a specific focus on tMCS strategies were studied. RESULTS: Among 341 patients, who underwent d-LVAD implantation after mAFP implantation (male gender 83.6%, age 58 [48-65] years, mAFP 5.0/5.5 72.4%), the early ischemic stroke incidence was 10.8% and early hemorrhagic stroke 2.9%. The tMCS characteristics (type of mAFP device and access, support duration, upgrade from intra-aortic balloon pump, ECMELLA, ECMELLA at d-LVAD implantation, hemolysis, and bleeding) were not associated with ischemic stroke after d-LVAD implant. Conversely, the device model (mAFP 2.5/CP vs. mAFP 5.0/5.5: HR 5.6, 95%CI 1.4-22.7, p = 0.015), hemolysis on mAFP support (HR 10.5, 95% CI 1.3-85.3, p = 0.028) and ECMELLA at d-LVAD implantation (HR 5.0, 95% CI 1.4-18.7, p = 0.016) were associated with increased risk of hemorrhagic stroke after d-LVAD implantation. Both early ischemic (HR 2.7, 95% CI 1.9-4.5, p < 0.001) and hemorrhagic (HR 3.43, 95% CI 1.49-7.88, p = 0.004) stroke were associated with increased 1-year mortality. CONCLUSIONS: Among patients undergoing d-LVAD implantation following mAFP support, tMCS characteristics do not impact ischemic stroke occurrence, while several factors are associated with hemorrhagic stroke suggesting a proactive treatment target to reduce this complication.

Hemocompatibility-related Adverse Events in Patients With Temporary Mechanical Circulatory Support: The Scoring Haemostasis Events and Assessment for Risk (SHEAR) Score.

Evaluation of treatment outcomes in patients supported by temporary mechanical circulatory support (tMCS) currently relies mainly on mortality, which may not sufficiently address other patient benefits or harms. Bleeding and thrombosis are major contributors to mortality. Still, current bleeding scores are not designed for critically ill patients undergoing tMCS, only consider selected populations, and do not account for the high heterogeneity among bleeding and thrombotic adverse events. To improve clinical management, a group of European experts has proposed a revised scoring system based on the MOMENTUM 3 Hemocompatibility Score and the Society of Cardiac Angiography and Interventions (SCAI)classification of cardiogenic shock. The new system termed the Scoring Haemostasis Events and Assessment for Risk (SHEAR) score, is divided into a baseline characterization stage and four escalating scoring stages encompassing all aspects of clinical relevance. This report summarizes the literature on hemocompatibility-related adverse events associated with tMCS, including bleeding, stroke, vascular access complications, hemolysis, thrombosis, and device failure. The SHEAR score provides a simple and rapid bedside scoring system aiming to provide a univocal tool to increase physician awareness of hemocompatibility complications at baseline and beyond, improve clinical research, and enable the capture of device-related complications that will inform relevant outcomes beyond mortality.

Comparison of Intraoperative Blood Product Use During Heart Transplantation in Patients Bridged with Impella 5.5 versus Durable Left Ventricular Assist Devices.

OBJECTIVE: To determine if the intraoperative transfusion requirements differ based on the mechanical circulatory device used as a bridge to heart transplantation. DESIGN: A single-center retrospective analysis of intraoperative transfusion requirements in all patients undergoing heart or heart/kidney transplantation between November 2018 and July 2021 who were bridged with a temporary (Impella 5.5) or durable left ventricular assist device (LVAD). SETTING: A tertiary care hospital. PARTICIPANTS: Forty-three adult patients bridged to heart or heart/kidney transplantation with a temporary or durable LVAD between 2018 and 2021 INTERVENTIONS: Recording of baseline characteristics and intraoperative transfusion requirements, including packed red blood cells, fresh frozen plasma, cryoprecipitate, autologous blood salvage, and platelets. The difference in cardiopulmonary bypass times, intensive care unit length of stay, and the vasoactive inotrope score following transplantation were also recorded. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the volume of blood products transfused intraoperatively. Patients who underwent bridge to transplantation using the Impella 5.5 had statistically significant lower median transfusions of cryoprecipitate (155 mL versus 200 mL, p = 0.015), autologous blood salvage (675 mL versus 1,125 mL, p ≤ 0.01), and platelets (412 mL versus 675 mL, p ≤ 0.01). Additionally, there was a trend toward lower transfusion of intraoperative packed red blood cells (4.5 units versus 6.5 units, p = 0.29) and fresh frozen plasma (675 mL versus 800 mL, p = 0.11), but these were not statistically significant. CONCLUSIONS: The results suggest a reduction in certain intraoperative transfusion requirements in patients undergoing heart transplantation bridged with the Impella 5.5 versus durable left ventricular assist device.

Contemporary optimal therapeutic strategy with escalation/de-escalation of temporary mechanical circulatory support in patients with cardiogenic shock and advanced heart failure in Japan.

The utilization of temporary mechanical circulatory support (MCS) in the management of cardiogenic shock is experiencing a notable surge. Acute myocardial infarction remains the predominant etiology of cardiogenic shock, followed by heart failure. Recent findings from the DanGer Shock trial indicate that the percutaneous micro-axial flow pump support, in conjunction with standard care, significantly reduced 6-month mortality in patients with acute myocardial infarction-related cardiogenic shock compared to those receiving standard care alone. However, real-world registry data reveal that the 30-day mortality among patients with acute myocardial infarction-related cardiogenic shock, who received concomitant veno-arterial extracorporeal membrane oxygenation support along with micro-axial flow pump, remain suboptimal. The persistent challenge in the field is how to incorporate, escalate, and de-escalate these temporary MCS to further improve clinical outcomes in such clinical scenarios. This review aims to elucidate the current practices surrounding the escalation and de-escalation of temporary MCS in real-world clinical settings and proposes considerations for future advancements in this critical area.

Impella support for refractory cardiogenic shock accompanied by diabetic ketoacidosis: a case report.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are strongly recommended in patients with heart failure, regardless of the presence of diabetes mellitus. A 74 year-old woman with a reduced left ventricular ejection fraction and diabetes mellitus (the types were unknown), receiving insulin and SGLT2 inhibitor, was hospitalized for altered consciousness with systemic hypotension. Upon admission, she was diagnosed with cardiogenic shock due to diabetic ketoacidosis. Intensive fluid resuscitation under Impella CP support successively improved her metabolic acidosis, preventing worsening pulmonary congestion by mechanically unloading the heart. After hemodynamic stabilization, she was diagnosed with type 1 diabetes mellitus for the first time. She was discharged on day 54 and was followed for 6 months without any recurrences. We must remain vigilant regarding the risk of diabetic ketoacidosis in patients using SGLT2 inhibitors, particularly those on insulin therapy or with diabetes mellitus of unknown types. Impella device shows promise as a circulatory support system in alleviating the left ventricle's workload and averting exacerbated pulmonary congestion, especially in cases where patients necessitate aggressive fluid replacement therapy, such as in the treatment of diabetic ketoacidosis concurrent with compromised cardiac function.

Usefulness of bicarbonate-based Impella purge solution in a patient with heparin-induced thrombocytopenia: the first case report of long-term management in Japan.

Percutaneous mechanical circulatory support utilizing micro-axial flow pumps, such as the Impella group of devices, has become a life-saving technique in the treatment of refractory cardiogenic shock, with ever-increasing success rates. A 30-year-old man presented with acute decompensated heart failure and a severely reduced left ventricular ejection fraction (17%). Despite initial treatment with inotropic drugs and intra-aortic balloon pump support, his hemodynamic status remained unstable. Transition to Impella CP mechanical circulatory support was made on day 6 owing to persistently low systolic blood pressure. A significant decline in platelet count prompted suspicion of heparin-induced thrombocytopenia (HIT), later confirmed by positive platelet-activated anti-platelet factor 4/heparin antibody and a 4Ts score of 6 points. Argatroban was initially used as the purge solution, but owing to complications, a switch to Impella 5.0 and a bicarbonate-based purge solution (BBPS) was performed. Despite additional veno-arterial extracorporeal membrane oxygenation support on day 24, the patient, aiming for ventricular assist device treatment and heart transplantation, died from infection and multiple organ failure. Remarkably, the Impella CP continued functioning normally until the patient's demise, indicating stable Impella pump performance using BBPS. This case highlights the usefulness of BBPS as an alternative to conventional Impella heparin purge solution when HIT occurs.

Prevalence of bleeding events in real-world Japanese registry for Percutaneous Ventricular Assist Device.

PURPOSE: Bleeding complication is a critical risk factor for outcomes of acute heart failure patients requiring mechanical circulatory support (MCS), including percutaneous catheter-type heart pumps (Impella). The Japanese registry for Percutaneous Ventricular Assist Device (J-PVAD) is an ongoing, large-scale, real-world registry to characterize Japanese patients requiring Impella. Here we analyzed bleeding complication profiles in patients who received Impella. METHODS: All consecutive Japanese patients who received Impella from October 2017 to January 2020 were enrolled. The 30-day survival and bleeding complications were analyzed. RESULTS: A total of 1344 patients were included: 653 patients received Impella alone, 685 patients received a combination of veno-arterial extracorporeal membrane oxygenation and Impella (ECPELLA), and 6 patients had failed Impella delivery. Overall 30-day survival was 67.0%, with Impella alone at 81.9% and ECPELLA at 52.7%. Overall bleeding/hematoma adverse events with a relation or not-excluded relation to Impella was 6.92%. Among them, the rates of hematoma and bleeding from medical device access sites were 1.41% and 4.09%, respectively. There was no difference between etiologies for these events. CONCLUSION: This study represents the first 3-year survival and the safety profile focused on bleeding adverse events from the J-PVAD registry. The results show that the real-world frequency of bleeding adverse events for patients who received Impella was an expected range from previous reports, and future real-world studies should aim to expand this data set to improve outcomes and adverse events.

Feasibility of an animal model for long-term mechanical circulatory support with Impella 5.5 implanted through carotid artery access in sheep.

Impella is a mechanical circulatory support device of a catheter-based intravascular microaxial pump for left ventricular support and unloading. However, nonclinical studies assessing the effects of the extended duration of left ventricular unloading on cardiac recovery are lacking. An animal model using Impella implanted with a less invasive procedure to enable long-term support is required. This study aimed to evaluate the feasibility of an animal model for long-term support with Impella 5.5 implanted through carotid artery access in sheep.Impella 5.5 was implanted in four sheep through the proximal region of the left carotid artery without a thoracotomy, and myocardial injuries were induced by coronary microembolization. Support by Impella 5.5 was maintained for 4 weeks, and the animals were observed. The position of Impella 5.5 and cardiac function was evaluated using cardiac computer tomography at 2 and 4 weeks after implantation.All four animals completed the 4-week study without major complications. The discrepancy in the Impella 5.5 flow rate between the conscious and anesthetized states was observed depending on the device's position. Animals in whom the inflow was above the left ventricular papillary muscle had a relatively high flow rate under the maximum performance level without a suction alarm during the conscious state. Pathological changes in the aortic valve were observed. Cardiac function under the minimum performance level was observed with no remarkable deterioration.The animal model with myocardial injuries supported for 4 weeks by Impella 5.5 implanted through carotid artery access in sheep was feasible.

Mechanical Circulatory Support for High-Risk Percutaneous Coronary Intervention.

PURPOSE OF REVIEW: This review will focus on the indications of mechanical circulatory support (MCS) for high-risk percutaneous coronary intervention (PCI) and then analyze in detail all MCS devices available to the operator, evaluating their mechanisms of action, pros and cons, contraindications, and clinical data supporting their use. RECENT FINDINGS: Over the last decade, the interventional cardiology arena has witnessed an increase in the complexity profile of the patients and lesions treated in the catheterization laboratory. Patients with significant comorbidity burden, left ventricular dysfunction, impaired hemodynamics, and/or complex coronary anatomy often cannot tolerate extensive percutaneous revascularization. Therefore, a variety of MCS devices have been developed and adopted for high-risk PCI. Despite the variety of MCS available to date, a detailed characterization of the patient requiring MCS is still lacking. A precise selection of patients who can benefit from MCS support during high-risk PCI and the choice of the most appropriate MCS device in each case are imperative to provide extensive revascularization and improve patient outcomes. Several new devices are being tested in early feasibility studies and randomized clinical trials and the experience gained in this context will allow us to provide precise answers to these questions in the coming years.

Left Ventricular Unloading in Extracorporeal Membrane Oxygenation: A Clinical Perspective Derived from Basic Cardiovascular Physiology.

PURPOSE OF REVIEW: To present an abridged overview of the literature and pathophysiological background of adjunct interventional left ventricular unloading strategies during veno-arterial extracorporeal membrane oxygenation (V-A ECMO). From a clinical perspective, the mechanistic complexity of such combined mechanical circulatory support often requires in-depth physiological reasoning at the bedside, which remains a cornerstone of daily practice for optimal patient-specific V-A ECMO care. RECENT FINDINGS: Recent conventional clinical trials have not convincingly shown the superiority of V-A ECMO in acute myocardial infarction complicated by cardiogenic shock as compared with medical therapy alone. Though, it has repeatedly been reported that the addition of interventional left ventricular unloading to V-A ECMO may improve clinical outcome. Novel approaches such as registry-based adaptive platform trials and computational physiological modeling are now introduced to inform clinicians by aiming to better account for patient-specific variation and complexity inherent to V-A ECMO and have raised a widespread interest. To provide modern high-quality V-A ECMO care, it remains essential to understand the patient's pathophysiology and the intricate interaction of an individual patient with extracorporeal circulatory support devices. Innovative clinical trial design and computational modeling approaches carry great potential towards advanced clinical decision support in ECMO and related critical care.

Left ventricular unloading in patients supported with veno-arterial extra corporeal membrane oxygenation; an international EuroELSO survey.

INTRODUCTION: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) improves end-organ perfusion in cardiogenic shock but may increase afterload, which can limit cardiac recovery. Left ventricular (LV) unloading strategies may aid cardiac recovery and prevent complications of increased afterload. However, there is no consensus on when and which unloading strategy should be used. METHODS: An online survey was distributed worldwide via the EuroELSO newsletter mailing list to describe contemporary international practice and evaluate heterogeneity in strategies for LV unloading. RESULTS: Of 192 respondents from 43 countries, 53% routinely use mechanical LV unloading, to promote ventricular recovery and/or to prevent complications. Of those that do not routinely unload, 65% cited risk of complications as the reason. The most common indications for unplanned unloading were reduced arterial line pulsatility (68%), pulmonary edema (64%) and LV dilatation (50%). An intra-aortic balloon pump was the most frequently used device for unloading followed by percutaneous left ventricular assist devices. Echocardiography was the most frequently used method to monitor the response to unloading. CONCLUSIONS: Significant variation exists with respect to international practice of ventricular unloading. Further research is required that compares the efficacy of different unloading strategies and a randomized comparison of routine mechanical unloading versus unplanned unloading.

Science of left ventricular unloading.

The concept of left ventricular unloading has its foundation in heart physiology. In fact, the left ventricular mechanics and energetics represent the cornerstone of this approach. The novel sophisticated therapies for acute heart failure, particularly mechanical circulatory supports, strongly impact on the mechanical functioning and energy consuption of the heart, ultimately affecting left ventricle loading. Notably, extracorporeal circulatory life support which is implemented for life-threatening conditions, may even overload the left heart, requiring additional unloading strategies. As a consequence, the understanding of ventricular overload, and the associated potential unloading strategies, founds its utility in several aspects of day-by-day clinical practice. Emerging clinical and pre-clinical research on left ventricular unloading and its benefits in heart failure and recovery has been conducted, providing meaningful insights for therapeutical interventions. Here, we review the current knowledge on left ventricular unloading, from physiology and molecular biology to its application in heart failure and recovery.

Structured Weaning From the Impella Left Ventricular Micro-Axial Pump in Acute Myocardial Infarction With Cardiogenic Shock and Protected Percutaneous Coronary Intervention: Experience From a Non-Cardiac Surgical Centre.

BACKGROUND: The Impella (Abiomed, Danvers, MA, USA) temporary percutaneous left ventricular assist device is increasingly used as mechanical circulatory support in patients with acute myocardial infarction-cardiogenic shock (AMICS) or those undergoing high-risk protected percutaneous coronary intervention (PCI). The optimal weaning regimen remains to be defined. METHOD: We implemented a structured weaning protocol in a series of 10 consecutive patients receiving Impella support for protected PCI or AMICS treated with PCI in a high volume non-cardiac surgery centre. Weaning after revascularisation was titrated to native heart recovery using both haemodynamic and echocardiographic parameters. RESULTS: Ten patients (eight male, two female; aged 43-70 years) received Impella support for AMICS (80%) or protected PCI (20%). Cardiogenic shock was of Society for Cardiac Angiography & Interventions grade C-E of severity in 80%, and median left ventricular end-diastolic pressure was 31 mmHg. Protocol implementation allowed successful weaning in eight of 10 patients with a median support time of 29 hours (range, 4-48 hours). Explantation was associated with an increase in heart rate (81 vs 88 bpm; p=0.005), but no significant change in Cardiac Index (2.9 vs 2.9 L/min/m2), mean arterial pressure (79 vs 82 mmHg), vasopressor requirement (10% vs 10%), or serum lactate (1.0 vs 1.0). Median durations of intensive care and hospital stay were 3 and 6 days, respectively. At 30 days, the mortality rate was 20%, with median left ventricular ejection fraction of 40%. CONCLUSIONS: A structured and dynamic weaning protocol for patients with AMICS and protected PCI supported by the Impella device is feasible in a non-cardiac surgery centre. Larger studies are needed to assess generalisability of such a weaning protocol.