Left ventricular assist devices: an alternative to medical therapy for end-stage heart failure

Impact of Fried Frailty Phenotype on Postoperative Outcomes After Durable Contemporary Mechanical Circulatory Support: A Single-Center Experience

Background

Frailty is prevalent in advanced heart failure patients and may help distinguish patients at risk of worse outcomes. However, the effect of frailty on postoperative clinical outcomes is still understudied. Therefore, we aim to study the relationship between frailty and postoperative clinical outcomes in patients undergoing long-term mechanical circulatory support (MCS).

Methods

Forty-six patients undergoing durable MCS (left ventricular assist device and total artificial heart) placement at our medical center were assessed for frailty pre-implant. Frailty was defined as ≥ 3 physical components of the Fried frailty phenotype. Our primary endpoint is 1 year of survival post-implant. Secondary endpoints include 30-day all-cause rehospitalization, pump thrombosis, neurological event (stroke/transient ischemic attack), gastrointestinal bleeding, and driveline infection within 12 months post-MCS support.

Results

Of the 46 patients, 32 (69%) met the criteria for frailty according to Fried. The cohort's median age was 67.0 years. The frail group had statistically significant lower left ventricular ejection fraction (LVEF) (11% vs. 20%, P = 0.017) and lower albumin (3.5 vs. 4.0 g/dL, P = 0.021). The frail cohort also had significantly higher rates of comorbid chronic kidney disease (47% vs. 7%, P = 0.016). There were no differences between the frail vs. non-frail group in terms of 30-day readmission rates (40% vs. 39%, P = 0.927) and 1-year post-intervention survival (log-rank, P = 0.165). None of the other secondary endpoints reached statistical significance, although the incidence of gastrointestinal bleed (24% vs. 16%, P = 0.689) and pump thrombosis (8% vs. 0%, P = 0.538) were higher in the frail group.

Conclusions

Preoperative Fried frailty was not associated with readmission at 30 days, mortality at 365 days, and other postoperative outcomes in long-term durable MCS patients. Findings may need further validation in larger studies.

Impact of Ischaemic and Dilated Cardiomyopathy on Short-Term and Long-Term Survival After Ventricular Assist Device Implantation: A Single-Centre Experience

BACKGROUND

Prognosis of patients with end-stage heart failure is known to be impacted by the aetiology of heart failure (HF). Ischaemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) are the most frequent pathologies necessitating ventricular assist device (VAD) support in these patients. However, the specific impact of ICM and DCM in clinical outcomes after VAD implantation remains unclear. Therefore, this study aimed to analyse clinical differences in ICM and DCM patients after LVAD surgery from the current institution.

METHODS

All consecutive patients from the LVAD centre were included in this retrospective study. To analyse specific differences in in-hospital outcomes, patients were divided into two groups: ICM and DCM. Long-term follow-up was calculated by Kaplan-Meier estimation of survival.

RESULTS

Between January 2010 and July 2020, 60 consecutive patients underwent LVAD implantation at the institution: 36 patients (60%) were supported due to end-stage ICM and 24 patients (40%) in regard of therapy-refractory DCM. Baseline characteristics showed no between-group differences. The ICM patients showed a clear trend to higher amount of additional cardiac procedures during VAD surgery (36% ICM vs. 12% DCM; p=0.052). In-hospital mortality was comparable between ICM and DCM patients (36% ICM vs. 21% DCM; p=0.206). A trend towards higher frequency of pump thrombosis was seen in DCM patients (p=0.080). Long-term survival was comparable between the groups.

CONCLUSION

The aetiology of heart failure did not impact short-term or long-term clinical outcomes after VAD surgery. Multicentre registry data are necessary to substantiate these findings.

Heartech® left ventricular partitioning device improves left ventricular systolic function of patients with chronic heart failure post-myocardial infarction at 1-year follow-up

OBJECTIVES

This study presents 1-year follow-up data of echocardiographic outcomes in patients who received the Heartech® left ventricular (LV) partitioning device (LVPD) (Xinrui Medical Equipment Co. Ltd., Shanghai, China).

BACKGROUND

Our first-in-man study of the Heartech® LVPD confirmed its safety and efficacy in patients with chronic heart failure (HF) post-myocardial infarction (MI) 1 month post-implantation. This subsequent study reports the echocardiographic outcomes of these patients at 1 year of follow-up.

METHODS

Fifteen patients with HF post-MI from three cardiac intervention centers in China were successfully implanted with the Heartech® LVPD via percutaneous ventricular restoration procedures. Echocardiographic parameters-including LV systolic function, diastolic function, two-dimensional speckle-tracking analysis, and right ventricular systolic function-were obtained before device implantation and at 1 month and 1 year postoperatively.

RESULTS

There was no deterioration of LV diastolic function, specific strain parameters, or right ventricular function at 1 year. Relative to the echocardiographic parameters recorded before the procedure, the LV ejection fraction (32.47 ± 6.98% vs. 42.5 ± 7.41%; p = .001) was significantly improved at 1 year, while the LV end-diastolic volume index (106.29 ± 28.01 vs. 83.30 ± 31.71; p = .005) and end-systolic volume index were significantly reduced (72.47 ± 22.77 vs. 50.00 ± 19.70; p = .001).

CONCLUSIONS

One-year echocardiographic follow-up results confirmed that no deterioration of LV diastolic function or specific strain parameters was observed and LV systolic function was significantly improved in patients with HF post-MI who were implanted with the Heartech® LVPD.

Percutaneous ventricular restoration using the parachute device in patients with ischemic heart failure: three-year outcomes of the PARACHUTE first-in-human study

BACKGROUND

Left ventricle remodeling after anterior wall myocardial infarction leads to increased left ventricle volumes, myocardial stress, and ultimately heart failure (HF). Treatment options are limited for these high-risk HF patients. A study was conducted to assess safety and feasibility of a percutaneous ventricular restoration therapy using the Parachute device in subjects with HF because of a cardiac ischemic event.

METHODS AND RESULTS

Thirty-nine subjects with New York Heart Association class II to IV ischemic HF, ejection fraction between 15% and 40%, and dilated akinetic or dyskinetic anterior-apical wall without the need to be revascularized were enrolled in a prospective, nonrandomized, multicenter investigation testing percutaneous ventricular restoration using the Parachute device. The safety primary end point was defined as successful procedure without device-related major adverse cardiac events during 6 months. Clinical and echocardiographic outcomes were obtained at 6, 12, 24, and 36 months post-treatment. Echocardiographic and end point data were adjudicated independently. Of the 39 subjects enrolled, device implantation was attempted in 34 and successful in 31 patients. Twenty-three subjects reached 3 years post-treatment with the device implanted. New York Heart Association symptom class was improved or maintained in 85% of subjects. Left ventricle end-diastolic volume index and end-systolic volume index were reduced from 128.4±22.1 and 94.9±22.3 mL/m(2) preimplant to 115.2±23.1 and 87.3±18.7 mL/m(2) at 3-year follow-up (end-diastolic volume index, P=0.0056; end-systolic volume index, P=0.4719). The cumulative incidence of HF hospitalization or death was 16.1%, 32.3%, and 38.7% at 12, 24, and 36 months, respectively. By 3-year follow-up, 2 (6.5%) of 31 patients with successful implant had died from cardiac reasons, with no cardiac deaths occurring past 6 months post-treatment.

CONCLUSIONS

The first series of ischemic HF patients treated with percutaneous ventricular restoration using the Parachute device demonstrates feasibility and safety of the device ≤3 years post-treatment.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifiers: NCT00573560 (US patients) and NCT01286116 (EU patients).

The PARACHUTE IV trial design and rationale: percutaneous ventricular restoration using the parachute device in patients with ischemic heart failure and dilated left ventricles

BACKGROUND

Left ventricle (LV) remodeling after anterior wall myocardial infarction leads to increased LV volumes, myocardial stress, and, ultimately, heart failure (HF). Patients have high morbidity and mortality risk, and treatment remains limited. Percutaneous ventricular restoration (PVR) therapy using the Parachute device, a fluoropolymer membrane stretched over a nitinol conical frame, is a novel approach to partition off the damaged myocardium. In the European and United States PARACHUTE feasibility trials, the observed rates of death or rehospitalization for HF were <17% at 12 months. These data compare favorably with historical data and support the need of a randomized trial to determine the clinical efficacy of PVR on outcomes for patients with ischemic HF.

OBJECTIVE

To determine the safety and efficacy of PVR utilizing a LV partitioning device, Parachute, in a randomized clinical trial compared with optimal medical therapy.

METHODS

This US pivotal trial is approved by the Food and Drug Administration (ClinicalTrials.gov Identifier: NCT01286116) and will randomly assign (1:1) 478 patients with New York Heart Association class III-IV ischemic HF, akinetic or dyskinetic LV wall abnormality, and ejection fraction between 15% and 35% to optimal medical therapy (control) versus Parachute device implantation in approximately 65 hospitals. The primary endpoint is death or rehospitalization for worsening HF. Sample size calculation assumes constant hazards and follow-up ≥12 months using an event-driven trial design.

CONCLUSIONS

We reported the rational and design of the first multicenter randomized trial to test the efficacy of PVR using the Parachute device to treat patients with ischemic HF and dilated LV.

Cardiac CT: Imaging of and Through Cardiac Devices

For patients with cardiac devices, cardiac computed tomography (CT) remains the mainstay for imaging due to its superior resolution as compared with echocardiography and nuclear studies and no contraindication to metal as with cardiac magnetic resonance imaging. This review focuses on the evaluation and pitfalls of coronary arterial imaging in patients with devices, such as pacemakers, implantable defibrillators, cardiac resynchronization therapy (CRT), as well as complications such as lead perforation and safety concerns of CT interference. We discuss both pre- and post-procedural CRT assessment for coronary venous imaging and pre-procedural myocardial scar assessment to localize regions of scar and peri-infarct zone to facilitate ventricular tachycardia ablation in patients with devices. We describe potential new research on dyssynchrony and integration with myocardial scar and site of latest activation for patients with or being considered for CRT. We detail the utility of CT for the assessment of proper function and complications in patients with left ventricular assist device implantation.

Surgical Therapy of End-Stage Heart Failure: Understanding Cell-Mediated Mechanisms Interacting with Myocardial Damage

Worldwide, cardiovascular disease results in an estimated 14.3 million deaths per year, giving rise to an increased demand for alternative and advanced treatment. Current approaches include medical management, cardiac transplantation, device therapy, and, most recently, stem cell therapy. Research into cell-based therapies has shown this option to be a promising alternative to the conventional methods. In contrast to early trials, modern approaches now attempt to isolate specific stem cells, as well as increase their numbers by means of amplifying in a culture environment. The method of delivery has also been improved to minimize the risk of micro-infarcts and embolization, which were often observed after the use of coronary catheterization. The latest approach entails direct, surgical, transepicardial injection of the stem cell mixture, as well as the use of tissue-engineered meshes consisting of embedded progenitor cells.

Location and density of alpha- and beta-adrenoreceptor sub-types in myocardium after mechanical left ventricular unloading

BACKGROUND

We hypothesized that not all subtypes of alpha- and beta-adrenoreceptors undergo similar upregulation and redistribution in human myocardium after mechanical unloading with an assist device.

METHODS

We obtained core biopsy samples of the left ventricle in 19 patients before and after removal of a Jarvik or Thoratec left ventricular assist device (LVAD) to study the effect of mechanical unloading on the distribution of alpha- and beta-adrenoreceptors. Fresh, embedded tissue sections were incubated with receptor blockers and antibodies before the fluorescent labeling of receptors. Images were obtained by fluorescence deconvolution microscopy, and composite tissue renditions were made from the stacked images. Multiple adrenoreceptor subtypes were studied.

RESULTS

We saw a reversal of myocyte hypertrophy in all patients, but the upregulation of receptors was not seen in all post-LVAD tissue samples. Furthermore, we noted receptor relocalization from an initial punctate/clumped pattern to a normal homogeneous distribution in many patients. Significant differences were seen in the distribution of beta(2)- and alpha(1)-receptors and in alpha(1A) subtypes.

CONCLUSIONS

In this study we show not only the expected reversal of myocyte hypertrophy and the increase in adrenoreceptors after ventricular unloading, but also the relocalization of specific receptor subtypes.

Hypoxemia Complicating LVAD Insertion: Novel Application of the Amplatzer PFO Occlusion Device

We report a case of profound systemic hypoxemia complicating left ventricular assist device (LVAD) insertion due to right to left shunting through a patent foramen ovale (PFO) in association with a Chiari network. The patient was successfully managed with percutaneous closure of the interatrial defect using an Amplatzer PFO occlusion device and judicious reduction in LVAD flows.

Left Ventricular Assist Device Therapy for End‐Stage Congestive Heart Failure: From REMATCH to the Future

Therapy for patients with end-stage cardiomyopathy continues to evolve, but clearly it must now involve left ventricular assist device therapy as either bridge-to-transplantation or destination therapy. Patients who are selected for left ventricular assist device support must be able to undergo the surgical implantation procedure safely and avoid common complications such as right heart failure. Adequate patient selection is essential and can typically be accomplished using simple hemodynamic measures. As left ventricular assist device technology evolves, pulsatile devices will likely be replaced by their newer axial flow counterparts, which offer decided advantages. In the future, therapy for end-stage heart failure will involve aggressive use of mechanical assist device therapy and, as more patients are supported with these devices and the technology improves, this will become a burgeoning field for cardiologists and cardiovascular surgeons.

An emerging role for calcium sensitisation in the treatment of heart failure

Heart failure occurs in 2 - 3% of the adult population in the developed world. With decompensation of cardiac function, haemodynamic stability can be achieved by using intravenous vasodilators, diuretics and inotropes. Unlike traditional inotropes, Ca2+ sensitisers enhance cardiac function without significantly increasing cardiac oxygen consumption, promoting arrhythmia or impairing lusitropy. The most promising drug in this new class is levosimendan, which has a unique dual mechanism; it enhances cardiac output through a Ca(2+)-dependent stabilisation of cardiac myofilaments and exhibits vasodilatory effects by opening ATP-dependent K(+) channels. Clinical trials have demonstrated the beneficial haemodynamic effects of levosimendan, and prospective trials are currently underway to confirm its potential benefits on long-term prognosis. Updated guidelines from the European Society of Cardiology advise on how to incorporate levosimendan into care for patients who have acute heart failure.

Stem cell therapy for cardiac diseases

PURPOSE OF REVIEW

This review examines the knowledge that researchers have gained during the past year regarding some fundamental questions about stem cell therapy. These questions concern patient selection and safety, the optimal type of stem cells, the best route for their delivery, the fate of the transplanted cells, and the mechanism by which this therapy works.

RECENT FINDINGS

So far, candidates for cardiac stem cell therapy have been limited to patients with acute myocardial infarction and chronic ischemic heart failure. Currently, bone marrow stem cells seem to be the most attractive cell type for these patients. The cells may be delivered by means of direct surgical injection, intracoronary infusion, retrograde venous infusion, and transendocardial injection. Stem cells may directly increase cardiac contractility or passively limit infarct expansion and remodeling. This therapy is generally well tolerated, but the potential for accelerated atherogenesis remains a concern. Eventually, cell therapy may be combined with gene therapy to treat ischemic myocardium.

SUMMARY

Stem cell therapy for cardiac disease is a rapidly evolving field. Most of the evidence accumulated so far, including preclinical and clinical findings, confirms the potential of this novel therapy. However, most of the fundamental knowledge needed to guide the application of stem cell therapy in cardiac disease is still lacking.

Left ventricular assist devices: evolving devices and indications for use in ischemic heart disease

PURPOSE OF REVIEW

The mortality with end-stage heart failure is extremely high, especially when patients become refractory to conventional medical therapy and require frequent hospitalization. Ischemic heart disease remains the primary cause of advanced heart failure. Mechanical pumps or devices have been developed called ventricular assist devices and are being used to support an increasing number of patients with refractory heart failure.

RECENT FINDINGS

The use of ventricular assist devices has evolved from initially only support of patients unable to be weaned from a heart-lung machine after cardiac surgery to use now as a bridge to a heart transplant, including patients with acute myocardial infarction and shock and severe pulmonary hypertension. More recently, they have been proven as a definitive alternative for patients not eligible for heart transplantation. There are new devices being examined in clinical trials, including a change from pusher-plate to devices with axial flow technology that are much smaller and easier to implant. Outcomes with their use are improving rapidly as the devices become more reliable and more is learned about the importance of candidate selection.

SUMMARY

This review describes current indications for the use of these devices, the types of pumps now available, criteria for initiating ventricular assist device support, complications of their use, and new applications such as a platform for stem cell therapy for treatment of end-stage heart failure.

Left Ventricular Assist Devices as Destination Therapy

Although an estimated 16,500 Americans annually could benefit from a heart transplant, in 1999 only 2184 heart transplants were performed in the United States. These statistics emphasize the severity of the shortage of available hearts for transplantation. Circulatory support provided by an implantable Left Ventricular Assist Device (LVAD) that meets Food and Drug Administration approval as destination therapy is a promising alternative that impacts patient survival. As medical technology creates smaller implantable battery-powered circulatory assist devices that allow patients to safely live independently in the community, nursing's role must change in response. Long-term LVAD patients require strategic, anticipatory planning for extended care and emergency preparedness for mechanical support. Therefore, practitioners must familiarize themselves with these devices as they care for larger numbers of patients with implanted LVADs who require assessment and treatment of noncardiac problems during their lengthened lifespan.