Pulmonary Artery Pulsatility Index and Hemolysis during Impella-Incorporated Mechanical Circulatory Support

Evaluation of hemolysis in patients supported with Impella 5.5: a single center experience

BACKGROUND

Hemolysis, variably defined in mechanical circulatory support (MCS), is understudied in percutaneous left ventricular assist devices. We characterize hemolytic sequelae of Impella 5.5-supported patients in the largest series to date.

METHODS

All Impella 5.5 patients at our center from 2020 to 2023 were identified (n = 169) and retrospectively reviewed. Patients with a plasma free hemoglobin (PfHb) recorded (and not previously elevated) were included (n = 123). The top (high hemolysis [HH], n = 26) and bottom (low hemolysis [LH], n = 25) quintiles were categorized based on PfHb levels. Analysis between groups identified factors associated with hemolysis.

RESULTS

HH patients had higher admission SCAI stages (p = 0.008), more Impella 5.5 days (23.5 v 10.0, p = 0.001), more additional MCS (16/26 [61.5%] v 6/25 [24.0%], p = 0.015), and more transfusions of packed red blood cells (12.5 v 4.0, p = 0.001), fresh frozen plasma (2.5 v 0.0, p = 0.033), and platelets (3.0 v 0.0, p = 0.002). Logistic regression identified additional MCS (OR 10.82, p = 0.004) and more Impella days (OR 1.13 p = 0.006) as hemolysis risk factors. Eleven (44%) LH and 19/26 (73%) HH patients died, with no significant differences between postoperative complications. Compared with those who died, HH survivors had fewer platelet transfusions (2.0 vs. 5.0, p = 0.01) and less PfHb elevation days (3.0 v 6.0, p = 0.007).

CONCLUSIONS

Hemolysis in this high-risk cohort has a poor prognosis. HH patients spent more days on Impella 5.5, needed more MCS, and required more blood product transfusions.

Impact of inhaled nitric oxide therapy in patients with cardiogenic shock treated with veno-arterial extracorporeal membrane oxygenation combined with Impella: a retrospective cohort study

BACKGROUND

The mortality rate of patients with cardiogenic shock (CS) requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO) combined with Impella (ECPELLA) support remains high. Inhaled nitric oxide (iNO) improves right ventricular (RV) function, resulting in increased Impella flow, which may facilitate early withdrawal of VA-ECMO and improve survival. This study investigated the prognostic impact of iNO therapy in ECPELLA patients.

METHODS

We retrospectively analyzed the data of consecutive patients with CS supported by ECPELLA from September 2019 to March 2024 at our hospital. Changes in pulmonary artery pulsatility index (PAPi) and Impella flow over time were evaluated, and VA-ECMO withdrawal rate, time to withdrawal, and 30-day survival were compared between ECPELLA patients with and without iNO therapy.

RESULTS

Of the 48 ECPELLA patients, 25 were treated with iNO. There were no significant differences between the groups in baseline characteristics or lactate levels at mechanical circulatory support induction. Patients with iNO therapy demonstrated significant improvements in the PAPi over time and a trend toward increased Impella flow, as well as a significantly higher VA-ECMO withdrawal rate (88% vs. 48%, P = 0.002) and a shorter time to VA-ECMO withdrawal (5 [3-6] days vs. 7 [6-13] days, P = 0.0008) than those without iNO therapy. Kaplan-Meier analysis demonstrated that the 30-day survival rate was significantly higher in patients with iNO than in those without (76% vs. 26%, P = 0.0002).

CONCLUSIONS

iNO therapy in patients with CS requiring ECPELLA was associated with short-term prognosis by improving RV function and facilitating weaning from VA-ECMO. Trial registration Retrospectively registered in UMIN-CTR (Reference No. R00006352).

Impact of the spleen size on short-term prognosis in patients with cardiogenic shock receiving Impella-incorporated temporary mechanical circulatory support

The spleen size may be associated with mortality and morbidity in patients with heart failure, whereas its clinical implication in patients with cardiogenic shock receiving Impella-incorporated temporary mechanical circulatory support (MCS) remains unknown. Patients who received Impella-incorporated temporary MCS in our institute between March 2018 and August 2023 were eligible. The splenic volume index (SVI) was retrospectively calculated in all participants by measuring spleen size on the computed tomography obtained at the time of Impella placement. The impact of baseline SVI/central venous pressure (CVP) ratio on the 30-day mortality after Impella placement was evaluated. A total of 74 patients (70 years old, 62% men) were included. Median baseline SVI was 71.6 (50.3, 92.1) mL/m2. A lower SVI was associated with more decreased cardiac output and a higher SVI was associated with more elevated CVP (p < 0.05 for both). A lower SVI/CVP ratio was associated with higher 30-day mortality with an adjusted hazard ratio of 3.734 (95% confidence interval 1.397-9.981, p = 0.009). A baseline lower SVI/CVP ratio was associated with short-term mortality in patients receiving Impella-incorporated temporary MCS.

Computational fluid dynamics simulating of the FDA benchmark blood pump with different coefficient sets and scaler shear stress models used in the power-law hemolysis model

Hemolysis is the most important issue to consider in the design and optimization of blood-contacting devices. Although the use of Computational Fluid Dynamics (CFD) in hemolysis prediction studies provides convenience and has promising potential, it is an extremely challenging process. Hemolysis predictions with CFD depend on the mesh, implementation method, coefficient set, and scalar-shear-stress model. To this end, an attempt was made to find the combination that would provide the most accurate result in hemolysis prediction with the commonly cited power-law based hemolysis model. In the hemolysis predictions conducted using CFD on the Food and Drug Administration (FDA) benchmark blood pump, 3 different scalar-shear-stress models, and 5 different coefficient sets with the power-law based hemolysis model were used. Also, a mesh independence test based on hemolysis and pressure head was performed. The pressure head results of CFD simulations were compared with published pressure head of the FDA benchmark blood pump and a good agreement was observed. In addition, results of CFD-hemolysis predictions which are conducted with scalar-shear-stress model and coefficient set combinations were compared with experimental hemolysis data at three operating conditions such as 6-7 L/min flow rates at 3500 rpm rotational speeds and 6 L/min at 2500 rpm. One of the combinations of the scalar-shear-stress model and the coefficient set was found to be within the error limits of the experimental measurements, while all other combinations overestimated hemolysis.

Role of Mechanical Circulatory Support in Complex High-Risk and Indicated Percutaneous Coronary Intervention: Current Indications, Device Options, and Potential Complications

Improved expertise and technological advancements have enabled the safe and effective performance of complex and high-risk-indicated percutaneous coronary intervention (CHIP) in patients previously considered inoperable or high-risk. Mechanical circulatory support (MCS) devices play a crucial role in stabilizing hemodynamics during percutaneous coronary intervention (PCI) -related ischemia, thereby reducing the risk of major adverse events and achieving a more complete revascularization. However, the use of MCS devices in protected PCI is not without risks, including peri-procedural myocardial infarction (MI), bleeding, and access-related complications. Despite numerous observational studies, there is a significant lack of randomized clinical trials comparing different MCS devices in various CHIP scenarios and evaluating their long-term safety and efficacy profiles. This review aims to summarize the current evidence regarding the benefits of MCS devices during CHIPs, offer a practical guide for selecting appropriate devices based on clinical scenarios, and highlight the unanswered questions that future trials need to address.

Current Use and Impact of Pulmonary Artery Catheters on the Short-Term Outcomes in Patients With Cardiogenic Shock Treated With an Impella: Findings From the Japan Registry for Percutaneous Ventricular Assist Device (J-PVAD)

OBJECTIVES

This study aimed to investigate the current use and impact of pulmonary artery catheters (PACs) in patients with cardiogenic shock (CS) who underwent Impella support.

DESIGN

This was a prospective multicenter observational study between January 2020 and December 2021 that registered all patients with drug-refractory acute heart failure and in whom the placement of an Impella 2.5, CP, or 5.0 pump was attempted or successful in Japan.

SETTING

Cardiac ICUs in Japan.

PATIENTS

Between January 2020 and December 2021, a total of 3112 patients treated with an Impella were prospectively enrolled in the Japan registry for percutaneous ventricular assist device (J-PVAD). Among them, 2063 patients with CS were divided into two groups according to the PAC use.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the 30-day mortality, and the secondary endpoints were hemolysis, acute kidney injury, sepsis, major bleeding unrelated to the Impella, and ventricular arrhythmias within 30 days. PACs were used in 1358 patients (65.8%) who underwent an Impella implantation. The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) was significantly higher in the patients with PACs than in those without. Factors associated with PAC use were the prevalence of hypertension, out-of-hospital cardiac arrest, New York Heart Association classification IV, the lesser prevalence of a heart rate less than 50, and the use of any catecholamine. The primary and secondary endpoints did not significantly differ according to the PAC use. Focusing on the patients with VA-ECMO use, the 30-day mortality and hemolysis were univariately lower in the patients with PACs.

CONCLUSIONS

The J-PVAD findings indicated that PAC use did not have a significant impact on the short-term outcomes in CS patients undergoing Impella support. Further prospective studies are required to explore the clinical implications of PAC-guided intensive treatment strategies in these patients.

Cardiac Devices and Kidney Disease

A growing variety of cardiac devices are available to monitor or support cardiovascular function. The entwined nature of cardiovascular disease and kidney disease makes the relationship of these devices with kidney disease a multifaceted question relating to the use of these devices in individuals with kidney disease and to the effects of the devices and device placement on kidney health. Cardiac devices can be categorized broadly into cardiac implantable electronic devices, structural devices, and circulatory assist devices. Cardiac implantable electronic devices include devices for monitoring and managing cardiac electrical activity and devices for monitoring hemodynamics. Structural devices modify cardiac structure and include valve prostheses, valve repair clips, devices for treating atrial septal abnormalities, left atrial appendage closure devices, and interatrial shunt devices. Circulatory assist devices support the failing heart or support cardiac function during high-risk cardiac procedures. Evidence for the use of these devices in individuals with kidney disease, effects of the devices on kidney health and function, specific considerations with devices in kidney disease, and important knowledge gaps are surveyed in this article. With the growing prevalence of combined cardiorenal disease and the increasing variety of cardiac devices, kidney disease considerations are an important aspect of device therapy.

Monitoring a Mystery: The Unknown Right Ventricle during Left Ventricular Unloading with Impella in Patients with Cardiogenic Shock

Background: Right ventricular (RV) dysfunction or failure occurs in more than 30% of patients in cardiogenic shock (CS). However, the importance of timely diagnosis of prognostically relevant impairment of RV function is often underestimated. Moreover, data regarding the impact of mechanical circulatory support like the Impella on RV function are rare. Here, we investigated the effects of the left ventricular (LV) Impella on RV function. Moreover, we aimed to identify the most optimal and the earliest applicable parameter for bedside monitoring of RV function by comparing the predictive abilities of three common RV function parameters: the pulmonary artery pulsatility index (PAPi), the ratio of right atrial pressure to pulmonary capillary wedge pressure (RA/PCWP), and the right ventricular stroke work index (RVSWI). Methods: The data of 50 patients with CS complicating myocardial infarction, supported with different flow levels of LV Impella, were retrospectively analyzed. Results: Enhancing Impella flow (1.5 to 2.5 L/min ± 0.4 L/min) did not lead to a significant variation in PAPi (p = 0.717), RA/PCWP (p = 0.601), or RVSWI (p = 0.608), indicating no additional burden for the RV. PAPi revealed the best ability to connect RV function with global hemodynamic parameters, i.e., cardiac index (CI; p < 0.001, 95% CI: 0.181-0.663), pulmonary capillary wedge pressure (PCWP; p = 0.005, 95% CI: -6.721--1.26), central venous pressure (CVP; p < 0.001, 95% CI: -7.89-5.575), and indicators of tissue perfusion (central venous oxygen saturation (SvO2); p = 0.008, 95% CI: 1.096-7.196). Conclusions: LV Impella does not impair RV function. Moreover, PAPi seems to be to the most effective and valid predictor for early bedside monitoring of RV function.

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.