Effects of Impella on Coronary Perfusion in Patients With Critical Coronary Artery Stenosis

Cardioprotection in cardiovascular surgery

Since the invention of cardiopulmonary bypass, cardioprotective strategies have been investigated to mitigate ischemic injury to the heart during aortic cross-clamping and reperfusion injury with cross-clamp release. With advances in cardiac surgical and percutaneous techniques and post-operative management strategies including mechanical circulatory support, cardiac surgeons are able to operate on more complex patients. Therefore, there is a growing need for improved cardioprotective strategies to optimize outcomes in these patients. This review provides an overview of the basic principles of cardioprotection in the setting of cardiac surgery, including mechanisms of cardiac injury in the context of cardiopulmonary bypass, followed by a discussion of the specific approaches to optimizing cardioprotection in cardiac surgery, including refinements in cardiopulmonary bypass and cardioplegia, ischemic conditioning, use of specific anesthetic and pharmaceutical agents, and novel mechanical circulatory support technologies. Finally, translational strategies that investigate cardioprotection in the setting of cardiac surgery will be reviewed, with a focus on promising research in the areas of cell-based and gene therapy. Advances in this area will help cardiologists and cardiac surgeons mitigate myocardial ischemic injury, improve functional post-operative recovery, and optimize clinical outcomes in patients undergoing cardiac surgery.

Restoration of Epicardial Blood Flow After Left Ventricular Unloading With the Impella CP Heart Pump in a Patient With STEMI Treated With Surgical Revascularization

Left main occlusion presenting as ST-segment elevation myocardial infarction is an exceedingly morbid condition. This article reports a case of cardiac arrest in a patient after a treadmill stress test. Coronary angiography revealed 100% occlusion of the left main coronary artery. Left ventricular unloading with the Impella CP heart pump (ABIOMED/Johnson & Johnson MedTech) was used, after which epicardial blood flow was restored without angioplasty. The patient underwent surgical revascularization. Despite a prolonged revascularization time, there was no evidence of severe myocardial injury postoperatively.

Cardioprotective Strategies After Ischemia-Reperfusion Injury

Acute myocardial infarction (AMI) is associated with high morbidity and mortality worldwide. Although early reperfusion is the most effective strategy to salvage ischemic myocardium, reperfusion injury can develop with the restoration of blood flow. Therefore, it is important to identify protection mechanisms and strategies for the heart after myocardial infarction. Recent studies have shown that multiple intracellular molecules and signaling pathways are involved in cardioprotection. Meanwhile, device-based cardioprotective modalities such as cardiac left ventricular unloading, hypothermia, coronary sinus intervention, supersaturated oxygen (SSO2), and remote ischemic conditioning (RIC) have become important areas of research. Herein, we review the molecular mechanisms of cardioprotection and cardioprotective modalities after ischemia-reperfusion injury (IRI) to identify potential approaches to reduce mortality and improve prognosis in patients with AMI.

Coronary perfusion pressure is associated with adverse outcomes in advanced heart failure

BACKGROUND

Myocardial perfusion is an important determinant of cardiac function. We hypothesized that low coronary perfusion pressure (CPP) would be associated with adverse outcomes in heart failure. Myocardial perfusion impacts the contractile efficiency thus a low CPP would signal low myocardial perfusion in the face of increased cardiac demand as a result of volume overload.

METHODS

We analyzed patients with complete hemodynamic data in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial using Cox Proportional Hazards regression for the primary outcome of the composite risk of death, heart transplantation, or left ventricular assist device [(LVAD). DT × LVAD] and the secondary outcome of the composite risk of DT × LVAD and heart failure hospitalization (DT × LVADHF). CPP was calculated as the difference between diastolic blood pressure and pulmonary artery wedge pressure. Heart failure categories (ischemic vs non-ischemic) were also stratified based on CPP strata.

RESULTS

The 158 patients (56.7 ± 13.6 years, 28.5% female) studied had a median CPP of 40 mmHg (IQR 35-52 mmHg). During 6 months of follow-up, 35 (22.2%) had the composite primary outcome and 109 (69.0%) had the composite secondary outcome. When these outcomes were then stratified based on the median, CPP was associated with these outcomes. Increasing CPP was associated with lower risk of both the primary outcome of DT × LVAD (HR 0.96, 95% CI 0.94-0.99 p = .002) and as well as the secondary outcome of DT × LVADHF (p = .0008) There was significant interaction between CPP and ischemic etiology (p = .04).

CONCLUSION

A low coronary artery perfusion pressure below (median) 40mmHg in patients with advanced heart failure undergoing invasive hemodynamic monitoring with a pulmonary artery catheter was associated with adverse outcomes. CPP could useful in guiding risk stratification of advanced heart failure patients and timely evaluation of advanced heart failure therapies.

Impact of Impella on Coronary Flow Assessed by Transthoracic Doppler Echocardiography

A 66-year-old male patient presented with anterior ST-elevated myocardial infarction and cardiogenic shock. After placement of the Impella device (Abiomed, Danvers, Massachusetts), the patient successfully underwent percutaneous coronary intervention for lesions in the left anterior descending artery (LAD) and left circumflex artery. Coronary flow in the LAD according to the support setting was evaluated using transthoracic Doppler echocardiography during Impella weaning.

Impella-Supported Optical Coherence Tomography-Guided Aggressive Rotational Atherectomy for Heavily Calcified Lesions in Left Main Trunk Bifurcation in a Patient with Severe Left Ventricular Systolic Dysfunction

The Impella, a percutaneous left ventricular assist device, has been reported to minimize the risk of hemodynamic compromise and improve clinical outcomes during percutaneous coronary intervention (PCI) in complex high-risk indicated patients (CHIPs). Optical coherence tomography (OCT) provides information on calcified plaque thickness, which is helpful in determining the indication and endpoint of atherectomy during PCI for calcified lesions. However, there are few reports on OCT-guided aggressive rotational atherectomy with Impella assistance in CHIPs. A 71-year-old man on dialysis for end-stage renal failure was admitted for congestive heart failure. Transthoracic echocardiography revealed severe left ventricular systolic dysfunction, and coronary angiography performed after improvement of heart failure showed severe stenosis with heavily calcified lesions in the left main trunk (LMT) bifurcation and right coronary artery. The patient refused coronary artery bypass surgery and was revascularized using PCI. PCI was started with prophylactic Impella CP insertion because of the high risk of hemodynamic collapse. After OCT-guided rotational atherectomy with 1.5- and 2.0-mm burr toward the left anterior descending artery and left circumflex artery, respectively, double-kissing culotte stenting was performed in the LMT, and good dilation was obtained. Impella CP was removed immediately after PCI without hemodynamic compromise, and the procedure was completed.

Haemodynamic impact of aortic balloon occlusion combined with percutaneous left ventricular assist device during cardiopulmonary resuscitation in a swine model of cardiac arrest

AIM

To investigate the effect of tandem use of transient balloon occlusion of the descending aorta (AO) and percutaneous left ventricular assist device (pl-VAD) during cardiopulmonary resuscitation in a large animal model of prolonged cardiac arrest.

METHODS

Ventricular fibrillation was induced and left untreated for 8 minutes followed by 16 minutes of mechanical CPR (mCPR) in 24 swine, under general anesthesia. Animals were randomized to 3 treatment groups (n = 8 per group): A) pL-VAD (Impella CP®) B) pL-VAD+AO, and C) AO. Impella CP® and the aortic balloon catheter were inserted via the femoral arteries. mCPR was continued during treatment. Defibrillation was attempted 3 times starting at minute 28 and then every 4 minutes. Haemodynamic, cardiac function and blood gas measurements were recorded for up to 4 hours.

RESULTS

Coronary perfusion pressure (CoPP) in the pL-VAD+AO Group increased by a mean (SD) of 29.2(13.94) mmHg compared to an increase of 7.1(12.08) and 7.1(5.95) mmHg for groups pL-VAD and AO respectively (p = 0.02). Similarly, cerebral perfusion pressure (CePP) in pL-VAD+AO increased by a mean (SD) of 23.6 (6.11), mmHg compared with 0.97 (9.07) and 6.9 (7.98) mmHg for the other two groups (p < 0.001). The rate of return of spontaneous heartbeat (ROSHB) was 87.5%, 75%, and 100% for pL-VAD+AO, pL-VAD, and AO.

CONCLUSION

Combined AO and pL-VAD improved CPR hemodynamics compared to either intervention alone in this swine model of prolonged cardiac arrest.

Clinical expert consensus document on the use of percutaneous left ventricular assist devices during complex high-risk PCI in India using a standardised algorithm

Over the past decade, percutaneous left ventricular assist devices (pLVAD), such as the Impella microaxial flow pump (Abiomed), have been increasingly used to provide haemodynamic support during complex and high-risk revascularisation procedures to reduce the risk of intraprocedural haemodynamic compromise and to facilitate complete and optimal revascularisation. A global consensus on patient selection for the use of pLVADs, however, is currently lacking. Access to these devices is different across the world, thus, individual health care environments need to create and refine patient selection paradigms to optimise the use of these devices. The Impella pLVAD has recently been introduced in India and is being used in several centres in the management of high-risk percutaneous coronary intervention (PCI) and cardiogenic shock. With this increasing utilisation, there is a need for a standardised evaluation protocol to guide Impella use that factors in the unique economic and infrastructural characteristics of India's health care system to ensure that the needs of patients are optimally managed. In this consensus document, we present an algorithm to guide Impella use in Indian patients: to establish a standardised patient selection and usage paradigm that will allow both optimal patient outcomes and ongoing data collection.

Novel therapeutic strategies to reduce reperfusion injury after acute myocardial infarction

For almost 30 years, urgent revascularization termed primary percutaneous coronary intervention (pPCI) has been a cornerstone of modern care for acute myocardial infarction (AMI). It lowers mortality and improved cardiovascular outcome compared to conservative therapy including thrombolysis. Reperfusion injury, which occurs after successful re-opening of the formerly occluded coronary artery, had been exploited as a potential therapeutic target. When revascularisation became faster and pPCI was successfully performed within 60-90 minutes of symptom onset, the interest in a potential additive effect of targeting reperfusion injury vanished. More recently, several meta-analyses indicated that limiting reperfusion injury prevents microvascular obstruction and reduces final infarct size, thereby lowering the probability of heart failure events and improving quality of life in AMI survivors. Here, we describe the current strategies to limit reperfusion injury and to improve post-AMI outcomes such as systemic or intracoronary hypothermia, left-ventricular unloading, intracoronary infusion of super-saturated oxygen, intermittent coronary sinus occlusion, and C-reactive protein apharesis.

Impella versus Venoarterial Extracorporeal Membrane Oxygenation for Acute Myocardial Infarction Cardiogenic Shock: A Systematic Review and Meta-Analysis

Objectives: Despite an increase in the use of mechanical circulatory support (MCS) devices for acute myocardial infarction cardiogenic shock (AMI-CS), there is currently no randomised data directly comparing the use of Impella and veno-arterial extra-corporeal membrane oxygenation (VA-ECMO). Methods: Electronic databases of MEDLINE, EMBASE and CENTRAL were systematically searched in November 2021. Studies directly comparing the use of Impella (CP, 2.5 or 5.0) with VA-ECMO for AMI-CS were included. Studies examining other modalities of MCS, or other causes of cardiogenic shock, were excluded. The primary outcome was in-hospital mortality. Results: No randomised trials comparing VA-ECMO to Impella in patients with AMI-CS were identified. Six cohort studies (five retrospective and one prospective) were included for systematic review. All studies, including 7093 patients, were included in meta-analysis. Five studies reported in-hospital mortality, which, when pooled, was 42.4% in the Impella group versus 50.1% in the VA-ECMO group. Impella support for AMI-CS was associated with an 11% relative risk reduction in in-hospital mortality compared to VA-ECMO (risk ratio 0.89; 95% CI 0.83–0.96, I² 0%). Of the six studies, three studies also adjusted outcome measures via propensity-score matching with reported reductions in in-hospital mortality with Impella compared to VA-ECMO (risk ratio 0.72; 95% CI 0.59–0.86, I² 35%). Pooled analysis of five studies with 6- or 12-month mortality data reported a 14% risk reduction with Impella over the medium-to-long-term (risk ratio 0.86; 95% CI 0.76–0.97, I² 0%). Conclusions: There is no high-level evidence comparing VA-ECMO and Impella in AMI-CS. In available observation studies, MCS with Impella was associated with a reduced risk of in-hospital and medium-term mortality as compared to VA-ECMO.

Risk Stratification by Coronary Perfusion Pressure in Left Ventricular Systolic Dysfunction Patients Undergoing Revascularization: A Propensity Score Matching Analysis

Background

Coronary perfusion pressure (CPP) and coronary artery stenosis are responsible for myocardial perfusion. However, how CPP-related survival outcome affects revascularization is unclear.

Objective

The aim of this study is to investigate the prognostic role of CPP in patients with left ventricular systolic dysfunction (LVSD) undergoing percutaneous coronary intervention (PCI) with complete revascularization (CR) or reasonable incomplete revascularization (RIR).

Methods

We retrospectively screened 6,076 consecutive patients in a registry. The residual synergy between percutaneous coronary intervention with Taxus and cardiac surgery (SYNTAX) score (rSS) was used to define CR (rSS = 0) and RIR (0<rSS≤8). Propensity score matching was performed to reduce bias between RIR and CR. The primary endpoint was all-cause mortality.

Results

In total, 816 patients with LVSD who underwent CR or RIR were enrolled. After a mean follow-up of 4.6 years, 134 patients died. Both CPP and RIR independently predicted mortality in the total population. After 1:1 matching, 175 pairs of RIR and CR were found in patients with CPP > 42 mmHg. Moreover, 101 pairs of RIR and CR were present in patients with CPP ≤ 42 mmHg. In patients with CPP > 42 mmHg, RIR was not significantly different from CR in long-term mortality [hazard ratio (HR) 1.20; 95% confidence interval (CI):0.70–2.07; p = 0.513]; However, in patients with CPP≤42 mmHg, RIR had a significantly higher mortality risk than CR (HR 2.39; 95% CI: 1.27–4.50; p = 0.007).

Conclusions

The CPP had a risk stratification role in selecting different revascularization strategies in patients with LVSD. When patients with LVSD had CPP > 42 mmHg, RIR was equivalent to CR in survival. However, when patients with LVSD had CPP ≤ 42 mmHg, RIR had a significantly higher mortality risk than CR.

The Use of Mechanical Circulatory Assist Devices for ACS Patients with Cardiogenic Shock and High-Risk PCI

PURPOSE OF REVIEW

There has been a significant expansion of the use of mechanical circulatory support (MCS) devices for patient with acute coronary syndromes (ACS) with cardiogenic shock (CS) and in patients undergoing high-risk percutaneous interventions (PCI). The purpose of this review is to provide an overview of the indications and outcomes of these devices in high-risk cardiac patients.

RECENT FINDINGS

Early revascularization of the culprit-lesion is the immediate goal in ACS patients with CS and the use of pulmonary artery catheters has been associated with improved outcomes in patients with cardiogenic shock. The MCS devices that are used for myocardial support include the intra-aortic balloon pump (IABP), the left ventricle (LV) to aorta pumps, left atrium (LA) to arterial pumps, and right atrial (RA) to arterial pumps. This review provides an overview on the use of these devices in patients with ACS and CS and those undergoing high-risk PCI. Attention is focused on the IABP, the Impella (LV-aorta pump), the TandemHeart (LA-arterial pump), and veno-arterial extracorporeal membrane oxygenation (RA-arterial pump). The indications, evidence, and complications of each device are reviewed. Each device varies in its physiological effect on native heart function, complexity in insertion, and complications. The use of MCS devices for high-risk PCI and CS has increased in recent years and have demonstrated efficacy in supporting a vulnerable myocardium. Although recommendations can be made for use of each device in certain clinical scenarios, further evidence through registries and clinical trials is necessary to guide appropriate device utilization.

Perioperative Management of Patients Receiving Short-term Mechanical Circulatory Support with the Transvalvular Heart Pump

Use of the transvalvular heart pump to provide short-term circulatory support in the perioperative setting is growing. The considerations for the perioperative management of patients receiving transvalvular heart pump support are reviewed for the anesthesiologist.

Impella in Transport: Physiology, Mechanics, Complications, and Transport Considerations

Cardiogenic shock (CS) represents a spectrum of hemodynamic deficits in which the cardiac output is insufficient to provide adequate tissue perfusion. The Impella (Abiomed Inc, Danvers, MA) device, a contemporary percutaneous ventricular support, is most often indicated for classic, deteriorating, and extremis Society for Coronary Angiography and Intervention stages of CS, which describe CS that is not responsive to optimal medical management and conventional treatment measures. Impella devices are an evolving field of mechanical support that is used with increasing frequency. Critical care transport medicine crews are required to transport patient support by the Impella device with increasing frequency. It is important that critical care transport medicine crews are familiar with the Impella device and are able to troubleshoot complications that may arise in the transport environment. This article reviews many aspects of the Impella device critical to the transport of this complex patient population.

The role of mechanical support devices during percutaneous coronary intervention

The practice of interventional cardiology has changed dramatically over the last four decades since Andreas Gruentzig carried out the first balloon angioplasty. The obvious technological improvements in stent design and interventional techniques have facilitated the routine treatment of a higher risk cohort of patients, including those with complex coronary artery disease and poor left ventricular function, and more often in the setting of cardiogenic shock (CS) complicating acute myocardial infarction (AMI). The use of mechanical cardiac support (MCS) in these settings has been the subject of intense interest, particularly over the past decade . A number of commercially available devices now add to the interventional cardiologist’s armamentarium when faced with the critically unwell or high-risk patient in the cardiac catheter laboratory. The theoretical advantage of such devices in these settings is clear- an increase in cardiac output and hence mean arterial pressure, with variable effects on coronary blood flow. In doing so, they have the potential to prevent the downward cascade of ischaemia and hypoperfusion, but there is a paucity of evidence to support their routine use in any patient subset, even those presenting with cardiogenic shock. This review will discuss the use and haemodynamic effect of MCS devices during percutaneous coronary intervention (PCI), and also examine the clinical evidence for their use in patients with cardiogenic shock, and those undergoing ‘high risk’ PCI

Increased and continuous coronary arterial flow was induced by LV uncoupling condition using combined treatment of a microaxial heart pump and venoarterial extracorporeal membrane oxygenation

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.

Trends in the Outcomes of High-risk Percutaneous Ventricular Assist Device-assisted Percutaneous Coronary Intervention, 2008-2018

Percutaneous ventricular assist devices (pVAD) are frequently utilized in high-risk percutaneous coronary intervention (HR-PCI) to provide hemodynamic support in patients with complex cardiovascular disease and/or multiple comorbidities who are poor candidates for surgical revascularization. Using the National Inpatient Sample we identified pVAD-assisted PCI (excluding intra-aortic balloon pump) in patients without cardiogenic shock from January 2008 to December 2018. We evaluated the trends in patient and procedural characteristics, and complication rates across the 11-year study period. A total of 26,661 pVAD-PCI was performed. From 2008 to 2018 there has was a 27-fold increase in the number of pVAD-PCIs performed annually. There has also been an increase in the proportion of procedures performed in small to medium sized hospitals. The use of atherectomy, image-guided PCI, FFR/iFR, drug-eluting stents, and multi-vessel intervention has significantly increased. Patients undergoing pVAD-PCI had a higher burden of comorbidities, without a significant difference in mortality over time. There were decreased rates of acute stroke and blood transfusions over time, while vascular complications and acute kidney injury (AKI) requiring dialysis remained mostly unchanged. In conclusion, the use of pVAD for HR-PCI has increased significantly, along with adjunctive PCI techniques such as atherectomy, intravascular imaging, and physiologic lesion assessment. With increasing use of this device, there appeared to be lower rates of peri-procedural stroke, and blood transfusions. Despite a higher burden of comorbidities, adjusted mortality remained stable over time.

Joint EAPCI/ACVC expert consensus document on percutaneous ventricular assist devices

There has been a significant increase in the use of short-term percutaneous ventricular assist devices (pVADs) as acute circulatory support in cardiogenic shock and to provide haemodynamic support during interventional procedures, including high-risk percutaneous coronary interventions. Although frequently considered together, pVADs differ in their haemodynamic effects, management, indications, insertion techniques, and monitoring requirements. This consensus document summarizes the views of an expert panel by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) and the Association for Acute Cardiovascular Care (ACVC) and appraises the value of short-term pVAD. It reviews the pathophysiological context and possible indications for pVAD in different clinical settings and provides guidance regarding the management of pVAD based on existing evidence and best current practice.

Effect of Atrioventricular Dyssynchrony on Impella Hemodynamics: Mechanism and Its Clinical Implications

The physiologic importance of atrial systole and atrioventricular (AV) synchrony in maintaining cardiac performance is well established. However, the role of AV synchrony in maintaining adequate Impella output has not been fully evaluated. Despite the common belief that AV dyssynchrony does not affect Impella output, given that Impella is a continuous flow device, recent reports indicate that AV dyssynchrony can lead to low Impella output in patients with cardiogenic shock complicated by complete heart block. Temporary transvenous pacing without establishing AV synchrony may fail to improve Impella hemodynamics; therefore, understanding the mechanism of low Impella output in AV dyssynchrony and promptly restoring AV synchrony may improve Impella output in such cases and lead to better outcomes.

Ability of a novel shock index that incorporates invasive hemodynamics to predict mortality in patients with ST-elevation myocardial infarction

OBJECTIVE

To determine whether the use of invasively measured hemodynamics improves the prognostic ability of a shock index (SI).

BACKGROUND

SI such as Admission-SI, Age-SI, Modified SI (MSI), and Age-MSI predict short-term mortality in ST-elevation myocardial infarction (STEMI).

METHODS

Single-center study of 510 patients who underwent primary percutaneous coronary intervention. STEMI SI was defined as age × heart rate (HR) divided by coronary perfusion pressure (CPP).

RESULTS

The mean age was 62 ± 14 years, 66% were males with hypertension (69%), tobacco use (38%), diabetes (28%) and chronic kidney disease (6%). The mean HR, systolic blood pressure (SBP), and CPP were 81 ± 18 bpm, 124 ± 28 mmHg, and 52.8 ± 16.3 mmHg, respectively. Patients with STEMI SI ≥182 (n = 51) were more likely to experience a cardiac arrest in the catheterization laboratory (9.8% vs. 2.0%; p = .001), require mechanical circulatory support (47.1% vs. 8.5%; p < .0001) and be treated with vasopressors (56.9% vs. 10.7%; p < .0001) compared to STEMI SI < 182 (n = 459). After multivariate adjustment, patients with STEMI SI ≥182 were 10, 10.1 and 4.8 times more likely to die during hospitalization, at 30 days and at 5 years, respectively. The C statistic of STEMI SI was 0.870, similar to GRACE score (AUC = 0.902; p = .29) and TIMI STEMI score (AUC = 0.895; p = .36).

CONCLUSION

STEMI SI is an easy to calculate risk score that identifies STEMI patients at high risk of in-hospital death.

Joint EAPCI/ACVC expert consensus document on percutaneous ventricular assist devices

There has been a significant increase in the use of short-term percutaneous ventricular assist devices (pVADs) as acute circulatory support in cardiogenic shock and to provide haemodynamic support during interventional procedures, including high-risk percutaneous coronary interventions. Although frequently considered together, pVADs differ in their haemodynamic effects, management, indications, insertion techniques, and monitoring requirements. This consensus document summarizes the views of an expert panel by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) and the Association for Acute Cardiovascular Care (ACVC) and appraises the value of short-term pVAD. It reviews the pathophysiological context and possible indications for pVAD in different clinical settings and provides guidance regarding the management of pVAD based on existing evidence and best current practice.

Mechanical Circulatory Support in Cardiogenic Shock due to Structural Heart Disease

Despite advances in cardiovascular care, managing cardiogenic shock caused by structural heart disease is challenging. Patients with cardiogenic shock are critically ill upon presentation and require early disease recognition and rapid escalation of care. Temporary mechanical circulatory support provides a higher level of care than current medical therapies such as vasopressors and inotropes. This review article focuses on the role of hemodynamic monitoring, mechanical circulatory support, and device selection in patients who present with cardiogenic shock due to structural heart disease. Early initiation of appropriate mechanical circulatory support may reduce morbidity and mortality.

The Role of Hemodynamic Support in High-risk Percutaneous Coronary Intervention

Patients with advanced age, complex coronary anatomy, and multiple comorbidities are often unsuitable for surgical revascularization. In this setting, hemodynamic support devices are used as an adjunct to percutaneous coronary intervention to maintain hemodynamic stability and enable optimal revascularization. This article provides an overview of percutaneous hemodynamic support devices currently used in clinical practice for high-risk percutaneous coronary intervention. These include the intra-aortic balloon pump, centrifugal pumps (TandemHeart, venous arterial extracorporeal membrane oxygenation), and micro-axial Impella pump. The hemodynamic effects, clinical evidence supporting improved outcomes and recovery of heart function, and associated complications with these devices are highlighted, with a special focus on Impella pumps.

Effects of intraaortic balloon counterpulsation on translesional coronary hemodynamics

The intraaortic balloon pump (IABP) provides counterpulsation by displacing a 40-50 cc blood volume during diastole augmenting diastolic pressure. The rapid deflation of the balloon timed to the initiation of systole reduces the afterload of ventricular ejection and thus peak systolic pressure. As a direct result, IABP increases mean arterial pressure (MAP) and peak diastolic pressure while reducing systolic pressure and myocardial work. IABP increases coronary flow velocity in non-obstructed vessels, but does not increase flow across a severe obstruction as shown by intracoronary Doppler flow studies (Kern et al., Circulation, 1993;87:500-511 and Kern et al., Circulation 1991;84:II-485). There are few studies using pressure sensor guidewires to confirm these responses. We present a case illustrating the translesional hemodynamics using an angioplasty sensor pressure wire across a severe stenosis and the unique influence of the IABP.

Novel Porcine Model of Coronary Dissection Reveals the Impact of Impella on Dissected Coronary Arterial Hemodynamics

Background: Coronary artery dissection (CAD) sometimes accompanies unstable hemodynamics and requires mechanical cardiac support. Meanwhile, mechanical cardiac support may influence coronary hemodynamics in CAD. No study has examined the impact of Impella left ventricular (LV) support on CAD. Materials and Methods: CAD was induced in eight Yorkshire pigs by injuring the left anterior descending artery (LAD) using a 0.018-in. stiff guidewire and/or deep engagement of a blunt-cut coronary guiding catheter. After the creation of CAD, hemodynamic parameters, coronary pressure, and flow as well as coronary angiograms were acquired before and after maximum LV support using the Impella CP. Result: CADs with a large flap were successfully created by deep engagement of a blunt-tip guiding catheter with forceful contrast injection. One animal (#8) exhibited thrombolysis in myocardial infarction (TIMI)-1 flow, while the others (animals #1-#7) showed TIMI-2/3 flow. In TIMI-2/3 animals, maximal Impella support increased mean coronary pressure (108.4 ± 22.5 to 124.7 ± 28.0 mmHg, P < 0.001) with unchanged mean coronary flow velocity (63.50 ± 28.66 to 48.32 ± 13.30 cm/s, P = 0.17) of the LAD distal to the dissection. The LV end-diastolic pressure (20.6 ± 6.6 vs. 12.0 ± 3.4 mmHg, P = 0.032), LV end-diastolic volume (127 ± 32 vs. 97 ± 26 ml, P = 0.015), stroke volume (68 ± 16 vs. 48 ± 14 ml, P = 0.003), stroke work (5,744 ± 1,866 vs. 4,424 ± 1,650 mmHg·ml, P = 0.003), and heart rate (71.4 ± 6.6 vs. 64.9 ± 9.3/min, P = 0.014) were all significantly reduced by Impella support, indicating effective unloading of the LV. In the TIMI-1 animal (animal #8), maximal Impella support resulted in further delay in angiographic coronary flow and reduced distal coronary pressure (22.9-17.1 mmHg), together with increased false-lumen pressure. Conclusion: Impella support effectively unloaded the LV and maintained the hemodynamics in a novel porcine model of CAD. Coronary pressure distal to the dissection was increased in TIMI-2/3 animals after Impella support but decreased in the animal with initial TIMI-1 flow.

Acute myocardial infarction and cardiogenic shock: Should we unload the ventricle before percutaneous coronary intervention?

Despite early reperfusion and coordinated systems of care, cardiogenic shock (CS) remains the number one cause of morbidity and in-hospital mortality following acute myocardial infarction (AMI). CS is a complex clinical syndrome that begins with hemodynamic instability and can progress to multi-organ failure and profound hemo-metabolic compromise. To improve outcomes, a clear understanding of the treatment objectives in CS and developing time-sensitive management strategies aimed at stabilizing hemodynamics and restoring myocardial perfusion are critical. Left ventricular (LV) load has been identified as an independent predictor of heart failure and mortality following AMI. Decades of preclinical and clinical research have identified several effective LV unloading strategies. Recent initiatives from single and multi-center registries and more recently the Door to Unload (DTU)-STEMI pilot study have provided valuable insight to developing a standardized treatment approach to AMI, based on early invasive hemodynamics and tailored circulatory support to unload the LV. To follow is a review of the pathophysiology and prevalence of shock, limitations of current therapies, and the pre-clinical and translational basis for incorporating LV unloading into contemporary AMI and shock care.