Mechanical Circulatory Support to Treat Pulmonary Embolism: Venoarterial Extracorporeal Membrane Oxygenation and Right Ventricular Assist Devices

Head-to-toe bedside ultrasound for adult patients on extracorporeal membrane oxygenation

Bedside ultrasound represents a well-suited diagnostic and monitoring tool for patients on extracorporeal membrane oxygenation (ECMO) who may be too unstable for transport to other hospital areas for diagnostic tests. The role of ultrasound, however, starts even before ECMO initiation. Every patient considered for ECMO should have a thorough ultrasonographic assessment of cardiac and valvular function, as well as vascular anatomy without delaying ECMO cannulation. The role of pre-ECMO ultrasound is to confirm the indication for ECMO, identify clinical situations for which ECMO is not indicated, rule out contraindications, and inform the choice of ECMO configuration. During ECMO cannulation, the use of vascular and cardiac ultrasound reduces the risk of complications and ensures adequate cannula positioning. Ultrasound remains key for monitoring during ECMO support and troubleshooting ECMO complications. For instance, ultrasound is helpful in the assessment of drainage insufficiency, hemodynamic instability, biventricular function, persistent hypoxemia, and recirculation on venovenous (VV) ECMO. Lung ultrasound can be used to monitor signs of recovery on VV ECMO. Brain ultrasound provides valuable diagnostic and prognostic information on ECMO. Echocardiography is essential in the assessment of readiness for liberation from venoarterial (VA) ECMO. Lastly, post decannulation ultrasound mainly aims at identifying post decannulation thrombosis and vascular complications. This review will cover the role of head-to-toe ultrasound for the management of adult ECMO patients from decision to initiate ECMO to the post decannulation phase.

High and intermediate risk pulmonary embolism in the ICU

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory: A State-of-the-Art Review

Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.

Mechanical Circulatory Support and Critical Care Management of High-Risk Acute Pulmonary Embolism

Hemodynamically significant pulmonary embolism (PE) remains a widely prevalent, underdiagnosed condition associated with mortality rates as high as 30%. The main driver of poor outcomes is acute right ventricular failure that remains clinically challenging to diagnose and requires critical care management. Treatment of high-risk (or massive) acute PE has traditionally included systemic anticoagulation and thrombolysis. Mechanical circulatory support, including both percutaneous and surgical approaches, are emerging as treatment options for refractory shock due to acute right ventricular failure in the setting of high-risk acute pulmonary embolism.

Surgical pulmonary embolectomy: state of the art

Acute pulmonary embolism is a significant cause of morbidity and mortality. Patients in life-threatening conditions require timely and effective interventions to improve pulmonary perfusion. The indications for surgical embolectomy in the thrombolysis era have been limited. This article discusses surgical techniques and outlines the position of surgical embolectomy concerning other treatment modalities.

Impact of Chronic Heart Failure on Acute Pulmonary Embolism in-Hospital Outcomes (From a Contemporary Study)

There is a paucity of evidence on the impact of chronic heart failure (HF) on acute pulmonary embolism (PE) hospitalization outcomes. The aim of this study was to evaluate the in-hospital outcomes of patients with chronic HF and acute PE. A total of 1,391,145 hospitalizations with acute PE from the National Inpatient Sample Database from 2011 to 2019 were included. The database was queried for relevant International Classification of Diseases, Ninth and Tenth Revisions procedural and diagnostic codes. Baseline characteristics and in-hospital outcomes for patients with acute PE were compared in patients with and without a history of chronic HF. Multivariate logistic regression analyses were performed, adjusting for age, race, gender, and statistically significant co-morbidities between cohorts. A p value <0.001 was considered significant. Overall, the mean age was 65.2±16 years; 50.9% of patients were women, and 230,875 patients (16.6%) had chronic HF. The patients in the chronic HF cohort were predominantly older (mean age 69.0 vs 61.4 years) and male (49.9% vs 48.3%). In the multivariate model, chronic HF was associated with increased all-cause mortality (odds ratio [OR] 1.6, 95% confidence interval [CI], 1.57 to 1.63, 10.4% vs 5.7%), acute respiratory distress (OR 1.7, 95% CI 1.70 to 1.74, 39.5% vs 22.1%), cardiac arrest (OR 1.4, 95% CI 1.40 to 1.49, 3.9% vs 2.2%), and cardiogenic shock (OR 3.0, 95% CI 2.85 to 3.06, 4.2% vs 1.2%). All p values were <0.001. In conclusion, patients with PE and chronicHF are associated with increased in-hospital complications compared with patients with PE and without chronic HF. Prospective studies are needed to evaluate optimal management strategies in this population at high risk.

Percutaneous oxygenated right ventricular assist device for pulmonary embolism: A case series

Acute right ventricular (RV) failure following massive pulmonary embolism (PE) can have significant hemodynamic consequences and is the mode of death. Temporary mechanical circulatory support can provide tissue perfusion required while thrombectomy or lysis-aimed therapies act to relieve the thrombotic obstruction. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) has conventionally been the first line MCS. A more selective approach to RV support has been advocated in the form of an extracorporeal right ventricular assist device (RVAD) as it mitigates some of the shortcomings of V-A ECMO. We present the first case series of four patients who received fully percutaneous RVAD, with an integrated oxygenator forming an Oxy-RVAD, for selective right heart support following massive PE, including the application of single-access dual-lumen right atrium to pulmonary artery cannula. All patients achieved RV recovery and were successfully weaned from oxy-RVAD support within 5-10 days demonstrating the feasibility of selective percutaneous right heart support in managing these challenging patients.

Temporary Right Ventricular Assist Device Support for Acute Right Heart Failure: A Single-Center Experience

INTRODUCTION

Severe right ventricular (RV) failure is associated with significant morbidity and mortality. Although right ventricular assist devices (RVADs) are increasingly used for refractory RV failure, there is limited data on their short- and long-term outcomes. Therefore, we undertook this study to better understand our experience with temporary RVADs.

METHODS

We conducted a retrospective review of all RVADS performed from 2017 to 2021. Patients supported with surgical RVADs, the Protek Duo device, and the Impella RP device were included. Patients were stratified by the type of RVAD and by etiology of RV failure. Survival was assessed by the Kaplan-Meier method and multivariable Cox proportional hazards regression models.

RESULTS

From 2017 to 2021, 42 patients underwent RVAD implantation: 32 with a Protek Duo, 6 with an Impella RP, and 4 with a surgical RVAD. Majority of patients were already supported with an alternate form of mechanical support. Most patients had impaired renal function, decreased hepatic function, and lactic acidosis at the time of cannulation. The median duration of RVAD support was 8.5 [5-19] d. Survival to decannulation was 68.4%, to discharge was 47.4%, and to 1-y was 40.2%. Multivariable analysis identified elevated total bilirubin levels to be associated with 30-d mortality while increased hemoglobin levels were protective. After RVAD cannulation, the median number of pressors and inotropes was lower (P < 0.01) and the lactic acidosis was less (P < 0.01).

CONCLUSIONS

In conclusion, RVAD support is associated with lower lactate levels, and decreased number of vasoactive medications, but is associated with significant morbidity and mortality.

VA-ECMO and thrombus aspiration in a pulmonary embolism patient with cardiac arrest and contraindications to thrombolytic therapy

Summary: A 57-year-old male patient with a history of proximal deep vein thrombosis on vitamin K antagonist therapy, suffered a recent hypertensive intracranial hemorrhage without significant neurological deficit. Three weeks later he presented with bilateral central pulmonary embolism. He had witnessed cardiac arrest and was put on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Endovascular thrombectomy with an Aspirex device led to a significant improvement of hemodynamics. VA-ECMO was terminated after one day, an IVC filter was inserted, and he was discharged from ICU after 15 days. In conclusion, VA-ECMO and endovascular therapy are rescue strategies in patients with contraindications for thrombolysis.

Efficacy and safety of Impella 5.0 in cardiogenic shock: an updated systematic review

Aim: The impact on safety and efficacy outcomes of Impella 5.0 in cardiogenic shock (CS) has not been systematically assessed. Materials & methods: We conducted a systematic review of the literature (PROSPERO protocol: CRD42020164680) to critically appraise available evidence on Impella 5.0 comparative safety, efficacy and effectiveness. Results: Of 244 retrieved citations, 17 original articles met the a priori defined inclusion criteria. All included studies had a retrospective study design and, overall, reported on, respectively, 52 and 67 different safety and efficacy/effectiveness outcomes. Thirty-day survival rates ranged from 40 to 94%, myocardial recovery from 18 to 93%. Conclusion: Impella 5.0 provides a full cardiac support, it is associated with a lower rate of vascular complications, it represents a valuable bridge-to-decision and allows for resolution of intercurrent clinical conditions. As available data suggest Impella 5.0 good performance in CS of various etiologies, more solid evidence will come from much-needed large-scale all-comer registries and prospective multicenter randomized trials.