Results following implantation of mechanical circulatory support systems: The Montreal Heart Institute experience

BACKGROUND:

Mechanical circulatory support systems (MCSS) have been available in Canada since 1986. Accepted indications include bridging to transplantation or recovery. The present study reviewed the results following MCSS implantation at the Montreal Heart Institute (Montreal, Quebec).

METHODS:

From September 1987 to September 2006, 43 MCSS were implanted (32 Thoratec [Thoratec Corporation, USA], nine Cardio West TAH [SynCardia Systems Inc, USA], two Novacor [World Heart Corporation, Canada]) in 43 patients (mean [± SD] age 44±13 years; range 19 to 64 years). Indications for implantation included cardiogenic shock due to ischemic (n=19), viral (n=10) or other types of cardiomyopathies (n=14).

RESULTS:

The mean ejection fraction before implantation was 17.6±6.5% (range 10% to 45%). Before MCSS implantation, most patients showed signs of end-organ failure, including mechanical ventilation (77%), central venous pressure higher than 16 mmHg (44%), oliguria (35%) and hepatic dysfunction (19%). The mean duration of MCSS support was 22.8±32.8 days (range one to 158 days). Survival to transplantation or recovery was 74%. Only one patient was successfully bridged to recovery. Complications were common during MCSS support. They included re-exploration for bleeding (47%), respiratory failure (44%), renal failure requiring temporary dialysis (40%), infection (33%) and neurological events (16%). Only one patient had device failure. In patients successfully bridged to transplantation, early actuarial survival (one month) following transplantation averaged 71±8% and was 57±9% at one year.

CONCLUSION:

MCSS support with a left ventricular assist device or a total artificial heart provides an effective means of bridging terminally ill patients to transplantation or recovery. Early survival after transplantation shows satisfactory results. However, these results come at the expense of frequent device-related complications, and device failure remains a constant threat.     

Heart transplantation after short-term mechanical circulatory support

IntroductionShort-term ventricular assist device (VAD) implantation is a life-saving procedure in patients with refractory cardiogenic shock. The present paper provides our experience with patients we were able to bridge from this critical condition directly to heart transplantation.MethodOur group comprises 11 patients implanted a Levitronix CentriMag short-term ventricular assist device from April 2009 to October 2012 as a bridge to heart transplantation. Six (55%) patients received a biventricular assist device while five (45%) had a left-ventricular assist device implanted. The mean age of patients was 41.2 years (20–63 years). Our group of patients included eight men (73%). The underlying diagnoses included dilated cardiomyopathy (5 patients), coronary heart disease (4 patients), infective endocarditis, and primary graft failure (1 patient each). Prior to implantation, all patients received high doses of inotropes, and eight (73%) patients had mechanical ventilatory support. Six (55%) patients showed laboratory signs of liver and kidney failure, and metabolic acidosis.ResultsThe mean time from VAD implantation to putting the patient on the urgent waiting list for heart transplantation was 7.6 days (1–54 days) depending on organ function recovery. The mean duration of mechanical circulatory support was 26.7 days (8–72 days). The mean time from inclusion into the waiting list to transplantation was 19.1 days (4–52 days). One-month, six-months and one-year survivals post-transplant were 91%, 82%, and 73%, respectively.ConclusionImplantation of the CentriMag short-term ventricular assist device in patients with refractory cardiogenic shock and otherwise grim prognosis markedly increases their chances for survival. Given the relatively short waiting time in the Czech Republic, the CentriMag ventricular assist device can thus serve as a direct bridge to heart transplantation.     

Mechanical circulatory support of the critically ill child awaiting heart transplantation

The majority of children awaiting heart transplantation require inotropic support, mechanical ventilation, and/or extracorporeal membrane oxygenation (ECMO) support. Unfortunately, due to the limited pool of organs, many of these children do not survive to transplant. Mechanical circulatory support of the failing heart in pediatrics is a new and rapidly developing field world-wide. It is utilized in children with acute congestive heart failure associated with congenital heart disease, cardiomyopathy, and myocarditis, both as a bridge to transplantation and as a bridge to myocardial recovery. The current arsenal of mechanical assist devices available for children is limited to ECMO, intra-aortic balloon counterpulsation, centrifugal pump ventricular assist devices, the DeBakey ventricular assist device Child; the Thoratec ventricular assist device; and the Berlin Heart. In the spring of 2004, five contracts were awarded by the National Heart, Lung and Blood Institute to support preclinical development for a range of pediatric ventricular assist devices and similar circulatory support systems. The support of early development efforts provided by this program is expected to yield several devices that will be ready for clinical trials within the next few years. Our work reviews the current international experience with mechanical circulatory support in children and summarizes our own experience since 2005 with the Berlin Heart, comparing the indications for use, length of support, and outcome between these modalities.     

Management of acute severe perioperative failure of cardiac allografts: a single-centre experience with a review of the literature

BACKGROUND: Early graft failure is associated with high mortality and is the main cause of death within the first 30 days after transplantation. The purpose of the present study was to examine the investigators' experience of severe perioperative acute graft failure and to review the literature. METHODS: Nine of 385 cardiac transplants (2.3%) performed from 1984 through 2005 developed severe perioperative acute graft failure either in the operating room or within 24 h after cardiac transplantation. Four patients had primary graft failure, two had right heart failure secondary to pulmonary hypertension, one had hyperacute rejection, one had accelerated acute rejection and one possibly sustained a particulate coronary embolus intraoperatively. RESULTS: All except the two patients who had right heart failure secondary to pulmonary hypertension received mechanical circulatory support. Three patients were supported with total artificial hearts, two patients received a left ventricular assist device, one patient was supported with extracorporeal life support followed by a right ventricular assist device when the left ventricle recovered, and one patient was supported for several hours with cardiopulmonary bypass. Three patients were retransplanted after mechanical circulatory support, but only one survived. Only one of the nine patients (11%) survived; this patient was supported with a total artificial heart followed by retransplantation. CONCLUSION: The outcome of severe perioperative acute graft failure is very poor. Mechanical circulatory support and retransplantation are not as successful as in other situations. Due to the shortage of donors and poor outcomes, retransplantation for hyperacute rejection is not advisable.     

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.     

Interprovincial spoke-to-hub transport using the Impella Recover LP 5.0 left ventricular assist device as a bridge to long-term circulatory support

Current hospital administrative practices categorize health care centres in a network of  'spokes' (primary care centres) and 'hubs' (tertiary care centres). For the treatment of cardiogenic shock, long-term left ventricular assist devices (LVADs) and transplant therapies are only used at a few hub centres nationwide and are, thus, only available to patients living in close proximity to these centres. The relatively lower technical requirements of the Impella Recover LP 5.0 LVAD (ABIOMED Inc, USA) translate into greater use by spoke centres for the short-term treatment of cardiogenic shock, and facilitate appropriate stabilization and subsequent transportation to a suitable hub centre. Based on a review of the literature, the present report describes the first case demonstrating successful use of the Impella Recover LP 5.0 LVAD, implanted under local anesthetic, for the purposes of interprovincial spoke-to-hub transport in a bridge-to-bridge-to-transplant procedure. By providing an economical and technically straightforward alternative to traditional extracorporeal membrane oxygenation, the present case demonstrates that less invasive LVADs are valuable to the spoke-and-hub model for delivery of specialized cardiac care.     

Mechanical circulatory support with impella to facilitate percutaneous coronary intervention for post‐TAVI bilateral coronary obstruction

One of the potential complications of transcatheter aortic valve implantation (TAVI) is coronary obstruction (CO), which can occur by displacement of heavily calcified native valve cusps against the coronary ostium. Treatment mandates immediate percutaneous coronary intervention (PCI) to restore coronary flow and improve hemodynamics and if unsuccessful, urgent implementation of circulatory support, commonly extracorporeal, with subsequent surgical revascularization. We report a case of post‐TAVI CO for which successful emergent deployment of Impella percutaneous mechanical circulatory support to restore hemodynamic stability facilitated definitive treatment with bilateral PCI. Impella support represents an expeditious, effective, and widely available therapy to complement and facilitate PCI in the treatment of CO complicating TAVI, and may diminish requirement for urgent coronary artery bypass surgery. © 2015 Wiley Periodicals, Inc.     

Use of mechanical circulatory support in patients with non-ischaemic cardiogenic shock

Aims

Despite its high incidence and mortality risk, there is no evidence-based treatment for non-ischaemic cardiogenic shock (CS). The aim of this study was to evaluate the use of mechanical circulatory support (MCS) for non-ischaemic CS treatment.

Methods and results

In this multicentre, international, retrospective study, data from 890 patients with non-ischaemic CS, defined as CS due to severe de-novo or acute-on-chronic heart failure with no need for urgent revascularization, treated with or without active MCS, were collected. The association between active MCS use and the primary endpoint of 30-day mortality was assessed in a 1:1 propensity-matched cohort. MCS was used in 386 (43%) patients. Patients treated with MCS presented with more severe CS (37% vs. 23% deteriorating CS, 30% vs. 25% in extremis CS) and had a lower left ventricular ejection fraction at baseline (21% vs. 25%). After matching, 267 patients treated with MCS were compared with 267 patients treated without MCS. In the matched cohort, MCS use was associated with a lower 30-day mortality (hazard ratio 0.76, 95% confidence interval 0.59–0.97). This finding was consistent through all tested subgroups except when CS severity was considered, indicating risk reduction especially in patients with deteriorating CS. However, complications occurred more frequently in patients with MCS; e.g. severe bleeding (16.5% vs. 6.4%) and access-site related ischaemia (6.7% vs. 0%).

Conclusion

In patients with non-ischaemic CS, MCS use was associated with lower 30-day mortality as compared to medical therapy only, but also with more complications. Randomized trials are needed to validate these findings.     

Percutaneous bi‐atrial extracorporeal membrane oxygenation for acute circulatory support in advanced heart failure

Veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) may improve survival after cardiac arrest by providing cardiopulmonary support. However, VA‐ECMO increases left ventricular (LV) afterload, which can promote progressive LV distension and often requires a secondary approach to reduce LV pressure and volume in patients with left heart failure. We report a case of biventricular unloading via biatrial cannulation in the presence of LV thrombus using a TandemHeart percutaneous trans‐septal cannula for VA‐ECMO in an adult patient with refractory ventricular fibrillation. © 2014 Wiley Periodicals, Inc.     

Percutaneous left ventricular support in cardiogenic shock and severe aortic regurgitation

Severe aortic regurgitation (AR) is a well‐established contraindication to intra‐aortic balloon counterpulsation therapy. We report two cases of medically refractory cardiogenic shock in patients with severe AR who were successfully bridged to surgical left ventricular assist device implantation by percutaneous left atrial to femoral artery mechanical bypass. Further investigation into the clinical utility of percutaneous mechanical support in the setting of AR and shock is required. © 2012 Wiley Periodicals, Inc.     

机械循环辅助装置治疗围手术期急性心肺功能衰竭

目的:观察心室辅助(VAD)、体外膜式氧合(ECMO)及主动脉内气囊反搏(IABP)等机械循环辅助装置治疗围手术期急性心肺功能衰竭的疗效。方法:回顾2005年1月至2006年12月我院心脏外科监护病房224例围手术期进行循环辅助患者临床资料,VAD4例、ECMO47例及IABP173例。结果:VAD死亡2例(50%),ECMO死亡23例(48.9%),IABP死亡49例(28.3%)。并发症为感染27例、肾功能衰竭需要透析26例、出血23例、下肢缺血15例及脑并发症7例。结论:机械辅助是救治围手术期急性心肺功能衰竭的有效方法,应根据患者病情选择适合的辅助方式并及早放置,防治并发症对提高成功率非常重要。     

Mechanical circulatory support for acute right ventricular failure in the setting of pulmonary embolism

Background

Right ventricular (RV) failure due to pulmonary embolism (PE) increases morbidity and mortality and contributes to prolonged hospital length of stay and higher costs of care. RV mechanical circulatory support (MCS) including Impella RP devices have been increasingly used in hemodynamically compromised PE patients who are refractory to intravascular volume expansion and inotropic therapy. However, effectiveness and safety of Impella RP, in hemodynamically unstable PE patients is unknown.

Methods

We included consecutive patients who presented to Detroit Medical Center between November 3, 2015 and October 2, 2017 with acute PE and had evidence of hemodynamic compromise indicating Impella RP.

Results

Total of five cases were identified. All patients met the shock definition due to massive or submassive PE and therefore received Impella RP on admission. Cardiac index was improved from mean of 1.69/min/m^2, (0.88‐2.15 L/min/m²), to 2.5 L/min/m² (range 1.88‐3.4), after 24 h of treatment. Similarly, mean heart rate reduced to 92 beats per minute (79‐105), and mean systolic blood pressure increased to 140 mmHg (115‐179). No significant changes were found in renal function, hemoglobin and platelets level during device use. One patient experienced hemoglobin drop from 13.7 to 7.3 g/dL but did not require blood transfusion. All patients survived to discharge.

Conclusion

In patients with PE and RV shock, Impella RP device resulted in immediate hemodynamic benefit with reversal of shock and favorable survival to discharge.

     

Myocardial recovery with mechanical circulatory support

Mechanical circulatory support (MCS) is instituted in patients with advanced heart failure, some of who may experience sufficient recovery in cardiac function to allow withdrawal of mechanical support. The incidence of left ventricular recovery with MCS is unclear as reported series in the literature demonstrate widely divergent rates. A number of clinical parameters (including echocardiographic, haemodynamic and physiological) are used to indicate likely left ventricular recovery during pump speed reduction but no internationally agreed definition exists. Withdrawal of MCS is not without risk and so robust clinical and biochemical definitions are important to minimize patient morbidity and mortality. Here we review our current understanding of left ventricular recovery with MCS.     

Severe mitral regurgitation and biventricular heart failure successfully treated with biventricular percutaneous axial flow pumps as a bridge to mitral valve surgery

Prompt recognition of acute right ventricular failure is essential in order to provide timely hemodynamic support. We report a case of a patient with severe mitral regurgitation complicated by cardiogenic shock that failed to improve with left ventricular support alone. The recognition of concomitant right ventricular failure led to the addition of a right ventricular support device, resulting in dramatic hemodynamic improvement. © 2016 Wiley Periodicals, Inc.     

Feasibility study of the use of the TandemHeart percutaneous ventricular assist device for treatment of cardiogenic shock.

BACKGROUND: The mortality of cardiogenic shock (CGS) remains high despite currently available pharmacological and mechanical treatment options. The standard of care in medically refractory situations has been the insertion of an intra-aortic balloon pump. The purpose of this study was to investigate the feasibility, safety, and hemodynamic impact of the TandemHeart percutaneous left ventricular assist device (pVAD) in CGS. METHODS: Thirteen patients from five centers in the US with the diagnosis of CGS were enrolled in the study. Hemodynamic measurements, including cardiac index (CI), mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), and central venous pressure (CVP) were performed presupport, during support and after device removal. Patients were monitored for 6 months. RESULTS: The pVAD was successfully implanted in all 13 patients, with duration of support averaging 60 +/- 44 hr. During support, CI increased from 2.09 +/- 0.64 at baseline to 2.53 +/- 0.65 (P = 0.02), MAP increased from 70.6 +/- 11.1 to 81.7 +/- 14.6 (P = 0.01), PCWP decreased from 27.2 +/- 12.2 to 16.5 +/- 4.8 (P = 0.01), and CVP from 12.9 +/- 3.7 to 12.6 +/- 3.6 (P = NS). Ten patients survived to device explant, 6 of whom were bridged to another therapy. Seven patients survived to hospital discharge and were all alive at 6 months. The two most common adverse events were distal leg ischemia (n = 3) and bleeding from the cannulation site (n = 4). CONCLUSION: The TandemHeart PTVA System may be a useful complementary treatment for patients with CGS, especially as a bridge to another treatment. Further study is needed to definitively establish safety and efficacy.