Role Of Mechanical Circulatory Support Research Articles

Decision-making in advanced heart failure patients requiring LVAD insertion: Can preoperative simulation become the way forward? A case study

Clinical practice heavily relies on results from randomized controlled trials, which may not reflect completely individual patients. Patient-specific modelling has received increasing attention in recent years. Although still far from clinical application on a daily basis, the potential of this approach is significant. The treatment of advanced heart failure may benefit from a modelling framework to guide device treatment and predict outcome. The role of mechanical circulatory support as a long-term solution is increasing in view of the evolving technology and worsening heart failure patient population. Therefore, a preoperative strategy with the ability to predict the course of events in a simulation setting may be justified. Here we present a heart failure patient discussed at a multidisciplinary team meeting whose outcome was compared with simulations carried out with CARDIOSIM$^{©}$ software to investigate the role of this approach as a planning strategy to guide intervention and predict outcome. The clinical decision process is complex and many factors are involved. Patient-specific modelling may have a role to play as part of a preoperative planning strategy with more quantitative evaluation to smooth decision-making.

Ten-year Experience With CentriMag Ventricular Assist Device Use in Acute Myocardial Infarction and Cardiogenic Shock

The role of mechanical circulatory support has dramatically increased for patients with acute myocardial infarction (AMI) and cardiogenic shock. We analyzed our ten-year experience with CentriMag (St. Jude Medical Inc., St. Paul, Minnesota) ventricular assist devices (VAD) in patients for the treatment of AMI and cardiogenic shock.

Cardiac Transplantation and Mechanical Circulatory Support in Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

Cardiac transplantation is the ultimate therapy for refractory arrhythmias or heart failure in ARVC patients. The study aim was to evaluate outcomes of cardiac transplantation in ARVC as well the role of mechanical circulatory support (MCS).

The Role of Mechanical Circulatory Support During Percutaneous Coronary Intervention in Patients Without Severely Depressed Left Ventricular Function

Currently, there are no data on the use of mechanical circulatory support (MCS) in patients without severely depressed left ventricular ejection fraction (LVEF) during high-risk percutaneous coronary intervention (PCI). We analyzed data from the global catheter-based ventricular assist device (cVAD) registry on the clinical use of MCS in high-risk PCI in patients without severely depressed LVEF, defined as LVEF > 35%. Patients without cardiogenic shock from the catheter-based ventricular assist device registry, who underwent elective or urgent PCI with an Impella 2.5 or Impella CP, were included. Patients who received MCS after the start of the PCI were excluded. A total of 891 patients were included, of whom 661 had LVEF ≤ 35% and 230 had LVEF > 35%. Patients with LVEF > 35% compared with patients with LVEF ≤ 35% were older (72.12 ± 11.70 years vs 68.68 ± 11.01 years; p <0.001), had more extensive coronary artery disease with more diseased vessels (1.90 ± 0.71 vs 1.73 ± 0.79; p = 0.005), more multivessel intervention (1.74 ± 0.69 vs 1.55 ± 0.73; p <0.001), and more use of rotational atherectomy (21.21% vs 14.90%; p = 0.046), respectively. Additionally, they had a high prevalence of high-risk clinical features such as renal failure (24.89%) and diabetes mellitus (45.37%). Despite these high-risk features, the major adverse cardiovascular and cerebral event rates were favorable overall, with no differences between the 2 groups (3.48% vs 4.54%; p = 0.574). Despite having LVEF > 35%, this selected group of patients had severe co-morbidities and complex angiographic features; hence, PCI with hemodynamic support was deemed necessary. In addition, PCI with elective MCS was feasible and safe in this patient population.

The role of mechanical circulatory support as destination therapy for ambulatory heart failure.

Continuous flow technology has dramatically improved patient survival during ventricular assist device (VAD) therapy in recent years. Health-related quality of life is improved by at least two years. Despite remarkable progress in this field, major adverse events during VAD support limit the effectiveness of this therapy and present major barriers to its extension to ambulatory advanced heart failure patients. The pace of progress will depend on improvements in both the adverse event profile and development of semi-quantitative methodology to calculate and display a composite of survival and health-related quality of life.

Mechanical circulatory support in heart failure.

The increasing number of end-stage heart failure patients eligible for heart transplant and the disproportionately low number of donor hearts have led to increased interest in ventricular assist devices (VAD). These devices can be used as a bridge to decision, bridge to recovery, or bridge to candidacy. The main advantage of mechanical circulatory support (MCS) is the improvement of organ perfusion and function, which leads to better quality of life and survival. The MCS can also be used as a destination therapy in end-stage heart failure patients who are not eligible for heart transplant. It should be remembered that, despite the tangible benefits, VAD implantation may also be associated with the risk of serious complications, such as bleeding, infection, arrhythmias, blood clots, right ventricular failure, and cardiovascular events. This study presents an up-to-date overview of the current knowledge on the role of MCS in modern medicine.

Management of Advanced Heart Failure due to Cancer Therapy: the Present Role of Mechanical Circulatory Support and Cardiac Transplantation.

Rapid improvement in antineoplastic therapy is increasing not only cancer survivorship but also the incidence of end-stage heart failure among breast and childhood cancer survivors. Anthracyclines and newer targeted therapies, including trastuzumab and tyrosine kinase inhibitors, are important agents implemented in clinical practice that carry cardiotoxic risk. While acute heart failure is often self-limited and reversible, delayed-onset heart failure significantly reduces survival. Extremes of age, renal dysfunction, pre-existing coronary artery disease, HER2 positivity, and multi-drug therapy are predictors of irreversible heart failure after chemotherapy. Left ventricular assist device (LVAD) implantation and cardiac transplantation can be performed safely in patients with end-stage heart failure (HF) from chemotherapy. However, co-existing right ventricular dysfunction, hepatic congestion, and increased risk of bleeding make LVAD therapy challenging and dependent on careful patient selection. Cardiac transplantation in patients with chemotherapy-induced heart failure can be performed with good 10-year survival, but requires 5years of cancer freedom and post-transplant infections remain a problem. Improvements in LVAD therapy and the expanding role of the total artificial heart and other durable biventricular support devices will likely provide more reliable surgical options for the management of end-stage HF after chemotherapy.

Important role of mechanical circulatory support in acute myocardial infarction complicated by cardiogenic shock.

Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) remains associated with significant mortality despite the widespread application of early revascularization strategies. Recent evidence suggests that the use of intra-aortic balloon pump (IABP) counterpulsation does not improve mortality in this cohort of patients. We summarize our experience with mechanical circulatory support (MCS) therapy for AMI/CS. This is a retrospective review of 61 patients who received MCS therapy for AMI/CS at our institution between March 2007 and March 2013. Mean age was 60.2 ± 10.3 years; mean ejection fraction was 24 ± 15% and 29% of patients were receiving active cardiopulmonary resuscitation at the time of support initiation. Prior to the initiation of MCS, 70.5% of patients had an IABP. Mean arterial pressure improved significantly with MCS (63 mmHg prior to MCS, 82 mmHg after MCS, P ≤ 0.01). Mean length of support was 9.5 ± 11.0 days, and overall survival to 30 days was 59.0%. Among 30-day survivors, 44.4% required device exchange to a durable MCS device. Ultimately, only 31% (52.8% of patients who survived to 30 days) achieved myocardial recovery. Short-term MCS therapy with subsequent aggressive use of durable MCS device may improve the unacceptably high mortality rate in AMI/CS. Rigorous prospective studies of MCS therapy in AMI/CS are warranted.

Transplantation in end-stage pulmonary hypertension (Third International Right Heart Failure Summit, part 3).

The Third International Right Heart Summit was organized for the purpose of bringing an interdisciplinary group of expert physician-scientists together to promote dialogue involving emerging concepts in the unique pathophysiology, clinical manifestation, and therapies of pulmonary vascular disease (PVD) and right heart failure (RHF). This review summarizes key ideas addressed in the section of the seminar entitled "Transplantation in End-Stage Pulmonary Hypertension." The first segment focused on paradigms of recovery for the failing right ventricle (RV) within the context of lung-alone versus dual-organ heart-lung transplantation. The subsequent 2-part section was devoted to emerging concepts in RV salvage therapy. A presentation of evolving cell-based therapy for the reparation of diseased tissue was followed by a contemporary perspective on the role of mechanical circulatory support in the setting of RV failure. The final talk highlighted cutting-edge research models utilizing stem cell biology to repair diseased tissue in end-stage lung disease-a conceptual framework within which new therapies for PVD have potential to evolve. Together, these provocative talks provided a novel outlook on how the treatment of PVD and RHF can be approached.

Veno-arterial extracorporeal membrane oxygenation for adult cardiovascular failure.

To examine the utility and technical challenges of applying veno-arterial extracorporeal membrane oxygenation for acute cardiovascular failure in adults with acute and chronic causes of heart failure. The role of mechanical circulatory support in acute cardiovascular continues to evolve as technology and clinical experience develop. There is increasing interest in the role of veno-arterial extracorporeal membrane oxygenation as a bridging therapy and as an adjunct to conventional cardiopulmonary resuscitation. Veno-arterial extracorporeal membrane oxygenation is an expensive, complex, resource intensive support. It is essential that its future use be guided by evidence obtained from centres that have demonstrated timely, safe support.

Left Ventricular Outflow Tract Occluding Thrombus After Biventricular Mechanical Circulatory Support as a Bridge to Recovery

The role of mechanical circulatory support for cardiopulmonary failure is expanding. Anticoagulation in the setting of static blood, hypercoagulable states, extracorporeal circuits, and surgery presents an intricate and delicate balance. We present a patient with large, biventricular thrombi during and succeeding biventricular mechanical support. Management of the thrombi and device selection in this patient are discussed.

Cardiogenic shock in ACS. Part 2: role of mechanical circulatory support

This Review explores contemporary circulatory support in profound postinfarction cardiogenic shock. Frequently, death is the only alternative to implantation of a blood pump, so prospective randomized trials of device versus medical treatment are unacceptable and evidence is derived from clinical experience. Irrespective of ACC/AHA and European guidelines, no study has shown survival benefit for the intra-aortic balloon pump in patients with established shock. In the past 10 years, the safety and durability of mechanical blood pumps has improved considerably. New temporary and long-term rotary pumps have transformed outcomes for patients with acute heart failure. For urgent resuscitation, outreach salvage, and transportation extracorporeal membrane oxygenation (ECMO) is a reliable, but time limited, first step. ECMO decompresses the venous system, provides flow, and ensures oxygenation, but does not unload the failing left ventricle. Myocardial stunning takes days, and sometimes weeks, to recover. Effective ventricular unloading is best achieved by surgical implantation of a temporary rotary or volume-displacement pump. After cardiopulmonary resuscitation, hemodynamic stabilization allows assessment of cerebral injury and prognosis. Published series demonstrate that 50-75% of patients with profound shock can be salvaged either through native heart recovery, urgent transplantation, or switch to a long-term pump.

Mechanical Circulatory Support for End-Stage Heart Failure in Repaired and Palliated Congenital Heart Disease

Approximately one in one hundred children is born with congenital heart disease. Most can be managed with corrective or palliative surgery but a small group will develop severe heart failure, leaving cardiac transplantation as the ultimate treatment option. Unfortunately, due to the inadequate number of available donor organs, only a small number of patients can benefit from this therapy, and mortality remains high for pediatric patients awaiting heart transplantation, especially compared to adults. The purpose of this review is to describe the potential role of mechanical circulatory support in this context and to review current experience. For patients with congenital heart disease, ventricular assist devices are most commonly used as a bridge to cardiac transplantation, an application which has been shown to have several important advantages over medical therapy alone or support with extracorporeal membrane oxygenation, including improved survival to transplant, less exposure to blood products with less immune sensitization, and improved organ function. While these devices may improve wait list mortality, the chronic shortage of donor organs for children is likely to remain a problem into the foreseeable future. Therefore, there is great interest in the development of mechanical ventricular assist devices as potential destination therapy for congenital heart disease patients with end-stage heart failure. This review first discusses the experience with the currently available ventricular assist devices in children with congenital heart disease, and then follows to discuss what devices are under development and may reach the bedside soon.

The 2011 Canadian Cardiovascular Society Heart Failure Management Guidelines Update: Focus on Sleep Apnea, Renal Dysfunction, Mechanical Circulatory Support, and Palliative Care

The 2011 Canadian Cardiovascular Society Heart Failure (HF) Guidelines Focused Update reviews the recently published clinical trials that will potentially impact on management. Also reviewed is the less studied but clinically important area of sleep apnea. Finally, patients with advanced HF represent a group of patients who pose major difficulties to clinicians. Advanced HF therefore is examined from the perspectives of HF complicated by renal failure, the role of palliative care, and the role of mechanical circulatory support (MCS). All of these topics are reviewed from a perspective of practical applications. Important new studies have demonstrated in less symptomatic HF patients that cardiac resynchronization therapy will be of benefit. As well, aldosterone receptor antagonists can be used with benefit in less symptomatic HF patients. The important role of palliative care and the need to address end-of-life issues in advanced HF are emphasized. Physicians need to be aware of the possibility of sleep apnea complicating the course of HF and the role of a sleep study for the proper assessment and management of the conditon. Patients with either acute severe or chronic advanced HF with otherwise good life expectancy should be referred to a cardiac centre capable of providing MCS. Furthermore, patients awaiting heart transplantation who deteriorate or are otherwise not likely to survive until a donor organ is found should be referred for MCS.

Mechanical circulatory support in the ICCU

The mortality of acute heart failure (AHF) remains high despite advances in treatment. Mechanical circulatory support (MCS) can be applied in AHF, refractory to conventional measures, to improve outcomes. This article aims to describe the current and the prospective role of MCS in the treatment of AHF. The support strategies and the indications of MCS are continuously evolving, including situations considered as contraindications in the past. Appropriate patient selection, advanced device technology and improved patient management have contributed to the substantially improved results. Evolution in device technology results in evolution of the clinical applications of MCS. Earlier application of MCS, with novel, flexible and individualized support strategies is now feasible. Bridging to recovery is the most intriguing support strategy and bridging to future treatments is feasible with long-term support. The progressively expanding role of MCS in the treatment of heart failure is not reflected in the existing guidelines. Being reserved for refractory heart failure, MCS has been applied to the sickest patients who were less amenable to randomization. This explains the lack of robust evidence, but also highlights the value of the progressively improving results. The anticipated wider application of MCS should be better defined, systematically recorded, and guided.

Current Mechanical Circulatory Support Devices for End Stage Heart Failure

Mechanical circulatory support is necessary when heart failure becomes refractory to medical support. It is typically instituted when organ dysfunction occurs as a result of hypoperfusion. Enthusiasm has recently developed for the role of mechanical circulatory support in the ever-growing population of heart failure patients. Indeed, efforts in developing this technology have allowed for the relatively recent development of a variety of complete circulatory support devices. The use of left ventricular assist devices (LVADs) in patients with advanced heart failure results in a clinically meaningful survival benefit and an improved quality of life, and LVADs could be an acceptable alternative therapy for selected patients who are not candidates for cardiac transplantation. (Korean Circ J 2009; 39:1-10)

Acute myocardial infarction complicated by cardiogenic shock: role of mechanical circulatory support

Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is the leading cause of in-hospital death for patients admitted with acute coronary syndromes. Expert guidelines for the care of AMI-CS patients recommend early revascularization with intra-aortic balloon pump support. Ventricular assist devices (VADs) offer the advantages of providing greater and longer-term cardiac support than an intra-aortic balloon pump and may improve outcomes when inserted early after heart failure symptoms begin. Pulsatile VADs are versatile and can provide biventricular support but are associated with a higher incidence of serious complications. The newer percutaneous VADs can normalize cardiac index and can be implanted without surgery. Therefore, early implementation of percutaneous VADs and early revascularization may reduce the high mortality of AMI-CS. However, access to revascularization and VAD support, including percutaneous VADs, is currently limited and must improve to more effectively treat AMI-CS patients.

Ventricular-assist devices for the treatment of chronic heart failure

The role of ventricular-assist devices in the management of end-stage heart failure is growing. Initially developed as a ‘bridge to transplantation’, they are now implanted permanently in patients who need cardiac replacement but are not candidates for cardiac transplantation (‘destination therapy’). Furthermore, observations from expert centers indicate that a significant proportion of patients under long-term mechanical assistance can be weaned from mechanical circulatory support after significant functional recovery of their native heart (‘bridge to recovery’). This review discusses the emerging roles of mechanical circulatory support and their direct implications in clinical practice. Evolution of devices, important aspects of candidate selection, challenging issues in the management of ventricular-assist device patients (infection, device malfunction, anticoagulation–thromboembolic complications, psychosocial issues and cost) and ongoing research targeting sustained myocardial recovery are discussed.

Left ventricular assist devices as destination therapy for end-stage heart failure

In the therapy of advanced heart failure, left ventricular assist devices represent an exciting new option. The role of mechanical circulatory support is currently limited predominantly by factors related to device durability. The population for whom mechanical circulatory support can be considered as permanent therapy is defined by those for whom improvement in survival and clinical function is expected from current devices. Reported device survival in the range of 50% at 1 year limits the present candidate population to those with greater than 50% mortality at 1 year, who are not eligible for cardiac transplantation, after which survival is 50% at 10 years. Even as we learn to identify these patients who are "sick enough" to warrant device placement and yet "well enough" to survive surgery, the devices and surgical techniques are evolving so that the outcomes are improving and the candidate population is expanding.

Postcardiotomy mechanical circulatory support in the elderly

The role of mechanical circulatory support after cardiac operations in elderly patients is not clearly established. Between November 1985 and July 1989, 18 patients 65 years of age or older (mean age, 71 years; range, 65 to 82 years) were treated after cardiotomy with a centrifugal vortex or pneumatic mechanical ventricular assist device. This group comprised 1.9% of the 926 patients 65 years of age or older undergoing cardiac surgical procedures and 69% of the 26 patients requiring postcardiotomy support during this interval. Before institution of mechanical support, all patients were receiving maximal inotropic support and 16 patients had intraaortic balloon pumps inserted. Univentricular support was used in 9 patients (6 left, 3 right) and biventricular support in 9 patients. The mean duration of support was 45 hours (range, 8 to 118 hours). Twelve patients (67%) were successfully weaned, 8 (44%) were discharged from the hospital, and 6 (33%) remain alive 11 to 31 months postoperatively. Four of the 6 survivors are in New York Heart Association class I, 1 is in class II, and 1 is in class IV. The Combined Registry for ventricular assist device support has recently reported an overall survival rate of 12% in patients 65 to 70 years of age and 6% in those older than 70 years. Our results are comparable with those reported for younger patients and justify the use of postcardiotomy ventricular assist device support in the elderly.