Complications and Outcomes of Impella Treatment in Cardiogenic Shock Patients With and Without Acute Myocardial Infarction

CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) in 2024

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST-segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018 and updated in 2022. Recently, the European Society of Cardiology (ESC) published the guidelines for the management of acute coronary syndrome in 2023. Major new updates in the 2023 ESC guideline include: (1) intravascular imaging should be considered to guide PCI (Class IIa); (2) timing of complete revascularization; (3) antiplatelet therapy in patient with high-bleeding risk. Reflecting rapid advances in the field, the Task Force on Primary PCI of the CVIT group has now proposed an updated expert consensus document for the management of ACS focusing on procedural aspects of primary PCI in 2024 version.

Infections in Patients with Mechanical Circulatory Support

Patients on mechanical circulatory support are at heightened risk for infection given the invasive nature of the devices with internal and external components, the surgical implantation of the devices, and the presence of foreign material susceptible to biofilm formation. This review discusses the new International Society for Heart and Lung Transplantation mechanical circulatory support device infection definitions, inclusive of durable and acute mechanical circulatory support infections, and describes their epidemiology, diagnosis, and management. A multidisciplinary approach is essential for optimal management. Timing of transplantation in the context of active infection is addressed, and areas of future research are highlighted.

Safety and efficacy of covered stent grafts in the treatment of emergent access related complications

BACKGROUND

Large bore percutaneous access is becoming increasingly common. Parallel to this, we observe an increase in vascular access site complications such as bleeding, dissection, thrombosis or pseudo-aneurysms. This study was aimed to evaluate safety and efficacy of covered stent grafts for fixing large bore vascular access injuries.

METHODS

A total of 147 Viabahn or Viabahn VBX (WL Gore) stent grafts which were placed across the inguinal ligament in emergent settings in 136 patients, were retrospectively analyzed. The two endpoints were the technical success rate, defined by complete arterial repair, and long-term stent graft patency. We also looked at the need for open conversion, wound infections, and in hospital and 30-day mortality. We followed the patients using duplex ultrasound and computed tomography angiogram to assess for arterial patency, freedom from intervention, stent kinking and clinical symptoms.

RESULTS

30 Viabahn and 117 Viabahn VBX (WL Gore) stent grafts were placed in the distal external iliac artery and into the proximal common femoral artery of 136 patients. Indications for intervention were bleeding in 92 patients (68 %), flow limiting dissection in 41 patients (30 %) and symptomatic AVF in 3 patients (2 %). Primary technical success rate was 100 %. Limited 3-year follow up (101/136 patients) showed 99 % patency with no evidence of stent fracture, stenosis or kinking except in one patient who needed target lesion revascularization due to neointimal hyperplasia.

CONCLUSIONS

Covered stent grafts can be placed safely, efficiently, and effectively in the distal external iliac and common femoral arteries across the inguinal ligament. These stent grafts can be used as an alternative therapeutic option to open surgery in patients with large bore vascular access injuries.

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.

Volume-Outcome Relationships for Intra-Aortic Balloon Pump in Acute Myocardial Infarction

BACKGROUND

Acute myocardial infarction (AMI) is a major scenario for the use of an intra-aortic balloon pump (IABP), particularly when complicated by cardiogenic shock, although the utilization of mechanical circulatory support devices varies widely per hospital. We evaluated the relationship, at the hospital level, between the volume of IABP use and mortality in AMI.

METHODS AND RESULTS

Using a Japanese nationwide administrative database, 26,490 patients with AMI undergoing primary percutaneous coronary intervention (PCI) from 154 hospitals were included in this study. The primary endpoint was the observed-to-predicted in-hospital mortality ratio. Predicted mortality per patient was calculated using baseline variables and averaged for each hospital. The associations among PCI volume for AMI, observed and predicted in-hospital mortality, and observed and predicted IABP use were assessed per hospital. Of 26,490 patients, 2,959 (11.2%) were treated with IABP and 1,283 (4.8%) died during hospitalization. The annualized number of uses of IABP per hospital in AMI was 4.5. In lower-volume primary PCI centers, IABP was more likely to be underused than expected, and the observed-to-predicted in-hospital mortality ratio was higher than in higher-volume centers.

CONCLUSIONS

A lower annual number of IABP use was associated with an increased mortality risk at the hospital level, suggesting that IABP use can be an institutional quality indicator in the setting of AMI.

Bailout Procedure Utilizing Balloon Dilatation for a Percutaneous Micro-axial Flow Pump Entrapped Within a Significantly Calcified Subclavian Artery

The IMPELLA 5.5 (Abiomed Inc., Danvers, Massachusetts, United States) is a catheter-based, micro-axial blood pump designed to enhance organ perfusion in patients with cardiogenic shock. Despite its superior hemodynamic support, vascular complications are a significant concern, with many patients needing to discontinue IMPELLA therapy due to these issues. Patients may even require surgical intervention to address device-related vascular injuries. The IMPELLA 5.5 implantation in vessels with severe calcification is particularly associated with complications such as vascular calcification, stenosis, vascular tortuosity, and the use of larger sheaths are risk factors following endovascular therapy and IMPELLA implantation. In this report, we present a case of severe calcification in the right subclavian artery, in which the IMPELLA 5.5 was lodged. The calcifications protruded into the vascular lumen, becoming lodged between the IMPELLA motor and the cannula, complicating extraction despite the vessel having sufficient diameter. We successfully removed the device using a balloon dilation technique, ensuring safe extraction. No vascular complications such as pseudoaneurysm or dissection were observed in the right subclavian artery one month after extraction. This case highlights a potential approach for managing similar complications and vascular access for IMPELLA insertion.

Intra-aortic balloon pump is associated with the lowest whereas Impella with the highest inpatient mortality and complications regardless of severity or hospital types

Impella and intra-aortic balloon pumps (IABP) are commonly utilized in patients with cardiogenic shock. However, the effect on mortality remains controversial. The goal of this study was to evaluate the effect of Impella and IABP on mortality in patients with cardiogenic shock the large Nationwide Inpatient Sample (NIS) database was utilized to study any association between the use of IABP or Impella on outcome. ICD-10 codes for Impella, IABP, and cardiogenic shock for available years 2016-2020 were utilized. A total of 844,020 patients had a diagnosis of cardiogenic shock. A total of 101,870 patients were treated with IABP and 39645 with an Impella. Total inpatient mortality without any device was 34.2% vs only 25.1% with IABP use (OR = 0.65, CI 0.62-0.67) but was highest at 40.7% with Impella utilization (OR = 1.32, CI 1.26-1.39). After adjusting for 47 variables, Impella utilization remained associated with the highest mortality (OR: 1.33, CI 1.25-1.41, p < 0.001), whereas IABP remained associated with the lowest mortality (OR: 0.69, CI 0.66-0.72, p < 0.001). Separating rural vs teaching hospitals revealed similar findings. In patients with cardiogenic shock, the use of Impella was associated with the highest whereas IABP was associated with the lowest in-hospital mortality regardless of comorbid condition.

Percutaneous Microaxial Ventricular Assist Device Versus Intra-Aortic Balloon Pump for Nonacute Myocardial Infarction Cardiogenic Shock

BACKGROUND

Evidence on the comparative outcomes following percutaneous microaxial ventricular assist devices (pVAD) versus intra-aortic balloon pump for nonacute myocardial infarction cardiogenic shock is limited.

METHODS AND RESULTS

We included 704 and 2140 Medicare fee-for-service beneficiaries aged 65 to 99 years treated with pVAD and intra-aortic balloon pump, respectively, for nonacute myocardial infarction cardiogenic shock from 2016 to 2020. Patients treated using pVAD compared with those treated using intra-aortic balloon pump were more likely to be concurrently treated with mechanical ventilation, renal replacement therapy, and blood transfusions. We computed propensity scores for undergoing pVAD using patient- and hospital-level factors and performed a matching weight analysis. The use of pVAD was associated with higher 30-day mortality (adjusted odds ratio, 1.92 [95% CI, 1.59-2.33]) but not associated with in-hospital bleeding (adjusted odds ratio, 1.00 [95% CI, 0.81-1.24]), stroke (adjusted odds ratio, 0.91 [95% CI, 0.56-1.47]), sepsis (OR, 0.91 [95% CI, 0.64-1.28]), and length of hospital stay (adjusted mean difference, +0.4 days [95% CI, -1.4 to +2.3]). A quasi-experimental instrumental variable analysis using the cross-sectional institutional practice preferences showed similar patterns, though not statistically significant (adjusted odds ratio, 1.38; 95% CI, 0.28-6.89).

CONCLUSIONS

Our investigation using the national sample of Medicare beneficiaries showed that the use of pVAD compared with intra-aortic balloon pump was associated with higher mortality in patients with nonacute myocardial infarction cardiogenic shock. Providers should be cautious about the use of pVAD for nonacute myocardial infarction cardiogenic shock, while adequately powered high-quality randomized controlled trials are warranted to determine the clinical effects of pVAD.

Diagnosis and Management of Vasoplegia in Temporary Mechanical Circulatory Support: A Narrative Review

Refractory vasodilatory shock, or vasoplegia, is a pathophysiologic state observed in the intensive care unit and operating room in patients with a variety of primary diagnoses. Definitions of vasoplegia vary by source but are qualitatively defined clinically as a normal or high cardiac index and low systemic vascular resistance causing hypotension despite high-dose vasopressors in the setting of euvolemia. This definition can be difficult to apply to patients undergoing mechanical circulatory support (MCS). A large body of mostly retrospective literature exists on vasoplegia in the non-MCS population, but the increased use of temporary MCS justifies an examination of vasoplegia in this population. MCS, particularly extracorporeal membrane oxygenation, adds complexity to the diagnosis and management of vasoplegia due to challenges in determining cardiac output (or total blood flow), lack of clarity on appropriate dosing of noncatecholamine interventions, increased thrombosis risk, the difficulty in determining the endpoints of adequate volume resuscitation, and the unclear effects of rescue agents (methylene blue, hydroxocobalamin, and angiotensin II) on MCS device monitoring and function. Care teams must combine data from invasive and noninvasive sources to diagnose vasoplegia in this population. In this narrative review, the available literature is surveyed to provide guidance on the diagnosis and management of vasoplegia in the temporary MCS population, with a focus on noncatecholamine treatments and special considerations for patients supported by extracorporeal membrane oxygenation, transvalvular heart pumps, and other ventricular assist devices.

Comparison of Outcomes in Patients Requiring Mechanical Circulatory Support Who Received Cangrelor in Addition to Anticoagulation Versus Anticoagulation Alone

OBJECTIVES

To evaluate the safety of cangrelor administered concurrently with heparin or bivalirudin in patients on mechanical circulatory support.

DESIGN

A single-center, retrospective cohort study of adult patients consecutively admitted between January 2016 and October 2020.

SETTING

A tertiary medical center.

PARTICIPANTS

Adult patients admitted to the cardiovascular intensive care unit put on mechanical circulatory support for acute myocardial infarction (AMI) or non-AMI indications. Patients who received cangrelor underwent percutaneous coronary intervention with stenting during the index event or within the last year.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of major bleeding, defined by the Extracorporeal Life Support Organization criteria, in patients with mechanical circulatory support receiving cangrelor plus anticoagulation with heparin or bivalirudin with or without aspirin versus patients who did not receive cangrelor. Sixty-eight patients were included in the study. Twenty-nine patients received cangrelor, and 39 did not. Cangrelor was not associated with an increase in major bleeding; however, the CI was wide (adjusted hazard ratio 1.93, 95% CI 0.61-6.11; p = 0.262).

CONCLUSIONS

Patients receiving cangrelor did not appear to be at higher risk of major bleeding compared to patients not receiving cangrelor. Larger trials should be conducted to better evaluate the safety of cangrelor in patients with mechanical circulatory support.

Volume-outcome relationships for extracorporeal membrane oxygenation in acute myocardial infarction

Acute myocardial infarction (MI) is one of the major scenarios of extracorporeal membrane oxygenation (ECMO) use. The utilization of mechanical circulatory support systems including ECMO varies widely at the hospital level, while whether ECMO volume per hospital is associated with outcomes in acute MI is unclear. Using a Japanese nationwide administrative database, a total of 26,913 patients with acute MI undergoing percutaneous coronary intervention from 154 hospitals were included. The relations among PCI volume for acute MI, observed and predicted in-hospital mortality, and observed and predicted rates of ECMO use were evaluated at the hospital level. Of 26,913 patients, 423 (1.6%) were treated with ECMO, and 1561 (5.8%) died during the hospitalization. Median ECMO use per hospital per year was 0.5. An observed rate of ECMO use was linearly correlated with the predicted probability of ECMO use and was not associated with the observed/predicted in-hospital mortality ratio. The observed/predicted mortality ratio was lowest in hospitals with the observed/predicted ECMO use ratio of around one. In conclusion, ECMO was infrequently used in a setting of acute MI at each hospital annually. An observed rate of ECMO use was not associated with observed/predicted in-hospital mortality ratio, while the observed/predicted in-hospital mortality ratio was lowest when ECMO was used as predicted, suggesting that standardized ECMO use may be an institutional quality indicator in acute MI.

Intracerebral Hematoma in Patients With Impella Ventricular Assist Device Placement for Cardiogenic Shock: Report of Three Cases

Despite the clear benefits of Impella in patients with cardiogenic shock, bleeding is a possible complication. Herein, we report three cases of intracerebral hemorrhage in patients with Impella implantation for cardiogenic shock, which were treated with hematoma evacuation. We present the clinical features, diagnosis, and management (hematoma evacuation) of patients with the Impella device (Abiomed, Danvers, Massachusetts) who developed intracerebral hemorrhage. Case one was a 56-year-old man who presented with chest pain and loss of consciousness, was diagnosed with acute myocardial infarction, and underwent urgent percutaneous coronary intervention and Impella placement. After eight days, the patient developed anisocoria. Computed tomography revealed a left intracerebral hemorrhage. An emergency hematoma evacuation was successfully performed (intraoperative blood loss: 2600 mL). Case two was a 54-year-old male who presented with persistent chest pain and loss of consciousness, was diagnosed with acute myocardial infarction, and underwent an emergency percutaneous coronary intervention with Impella implantation and venoarterial extracorporeal membrane oxygenation. The patient developed intracerebral hemorrhage after 26 days. Hematoma evacuation was successfully performed (intraoperative blood loss: 380 mL). Case three was a 52-year-old male who presented with dyspnea and hypotension, was diagnosed with dilated cardiomyopathy, and underwent Impella implantation and venoarterial extracorporeal membrane oxygenation, followed by which the patient developed subcortical hematoma. An emergency hematoma evacuation was performed (intraoperative blood loss: 3205 mL). The patient died 14 days after admission. Intracerebral hemorrhage is a potential cause of morbidity associated with Impella placement. Although hematoma evacuation is optimal, the bleeding tends to increase.