Results of mechanical circulatory support in France

Temporary assist device support for the right ventricle: pre-implant and post-implant challenges

Severe right ventricular (RV) failure is more likely reversible than similar magnitudes of left ventricular (LV) failure and, because reversal of both adaptive remodeling and impaired contractility require most often only short periods of support, the use of temporary RV assist devices (t-RVADs) can be a life-saving therapy option for many patients. Although increased experience with t-RVADs and progresses made in the development of safer devices with lower risk for complications has improved both recovery rate of RV function and patient survival, the mortality of t-RVAD recipients can still be high but it depends mainly on the primary cause of RV failure (RVF), the severity of end-organ dysfunction, and the timing of RVAD implantation, and much less on adverse events and complications related to RVAD implantation, support, or removal. Reduced survival of RVAD recipients should therefore not discourage appropriate application of RVADs because their underuse further reduces the chances for RV recovery and patient survival. The article reviews and discusses the challenges related to the pre-implant and post-implant decision-making processes aiming to get best possible therapeutic results. Special attention is focused on pre-implant RV assessment and prediction of RV improvement during mechanical unloading, patient selection for t-RVAD therapy, assessment of unloading-promoted RV recovery, and prediction of its stability after RVAD removal. Particular consideration is also given to prediction of RVF after LVAD implantation which is usually hampered by the complex interactions between the different risk factors related indirectly or directly to the RV potential for reverse remodeling and functional recovery.

An early analysis of cost-utility of baroreflex activation therapy in advanced chronic heart failure in Germany

Background

This study aimed to evaluate cost-utility of baroreflex activation therapy (BAT) using the Barostim neo™ device (CVRx Inc., Minneapolis, MN, USA) compared with optimized medical management in patients with advanced chronic heart failure (NYHA class III) who were not eligible for treatment with cardiac resynchronization therapy, from a statutory health insurance perspective in Germany over a lifetime horizon.

Methods

A decision analytic model was developed using the combination of a decision tree and the Markov process. The model included transitions between New York Heart Association (NYHA) health states, each of which is associated with a risk of mortality, hospitalization, cost, and quality of life. The effectiveness of BAT was projected through relative risks for mortality (obtained by application of patient-level data to the Meta-analysis Global Group in Chronic Heart Failure risk prediction model) and hospitalization owing to worsening of heart failure (obtained from BAT Randomized Clinical Trial). All patients were in NYHA class III at baseline.

Results

BAT led to an incremental cost of €33,185 (95% credible interval [CI] €24,561–38,637) and incremental benefits of 1.78 [95% CI 0.45–2.71] life-years and 1.19 [95% CI 0.30–1.81] quality-adjusted life-years (QALYs). This resulted in an incremental cost-effectiveness ratio of €27,951/QALY (95% CI €21,357–82,970). BAT had a 59% probability of being cost-effective at a willingness-to-pay threshold of €35,000/QALY (but 84% at a threshold of €52,000/QALY).

Conclusions

BAT can be cost-effective in European settings in those not eligible for cardiac resynchronization therapy among patients with advanced heart failure.

Experience with the SynCardia total artificial heart in a Canadian centre

BACKGROUND

The SynCardia total artificial heart (TAH) provides complete circulatory support by replacing both native ventricles. Accepted indications include bridge to transplantation and destination therapy. We review our experience with TAH implantation during a period when axial flow pump became available.

METHODS

We retrospectively analyzed the demographics, clinical characteristics and survival of all patients receiving the TAH.

RESULTS

From September 2004 to November 2016, 13 patients (12 men, mean age 45 ± 13 yr) received the TAH for refractory cardiogenic shock secondary to idiopathic (56%) or ischemic (17%) cardiomyopathy and to other various causes (33%). Before implantation, mean ejection fraction was 14% ± 4%, 7 (54%) patients had previous cardiac surgery, 4 (31%) were on mechanical ventilation, and 3 (23%) patients were on dialysis. The mean duration of TAH support was 46 ± 40 days. Three (23%) patients died while on support after a mean of 15 days. Actuarial survival on support was 77% ± 12% at 30 days after implantation. Complications on support included stroke (n = 1, 8%), acute respiratory distress syndrome requiring prolonged intubation (n = 5, 38%) and acute renal failure requiring temporary dialysis (n = 5, 38%). Ten (77%) patients survived to be transplanted after a mean of 52 ± 42 days of support. Actuarial survival rates after transplant were 67% ± 16% at 1 month and 56% ± 17% at 1 year after transplantation.

CONCLUSION

The TAH provides an alternative with low incidence of neurologic events in extremely fragile and complex patients waiting for heart transplantation. Complex and unusual anatomic conditions explained the current use of TAH.

Extracorporeal life support for refractory ventricular tachycardia

Extracorporeal life support (ECLS) is a very effective bridging therapy in patients with refractory ventricular tachycardia (VT) associated with cardiogenic shock. A moribund patient in extremis, is not amenable to optimization by standard ACC/AHA guidelines. New approaches and novel salvage techniques are necessary to improve outcomes in patients with refractory clinical settings such as malignant ventricular arrhythmias, cardiac arrest, cardiogenic shock and/or pulmonary failure until further management options are explored. Data base searches were done using key words such as ECLS, VT, cardiac arrest, VT ablation, venoarterial extra-corporeal membrane oxygenation (VA-ECMO). The use of ECLS has been described in a few case reports to facilitate VT ablation for incessant VT refractory to medical therapy. For patients with, out-of- hospital ventricular fibrillation (VF) and VT, Minnesota Resuscitation Consortium has implemented emergent advanced perfusion and reperfusion strategy, followed by coronary angiography and primary coronary intervention to improve outcome. The major indications for ECLS are cardiogenic shock related to acute myocardial infarction, myocarditis, post embolic acute cor pulmonale, drug intoxication and post cardiac arrest syndrome with the threat of multi-organ failure. ECLS permits the use of negative inotropic antiarrhythmic drug therapy, facilitates the weaning of catecholamine administration, thereby ending the vicious cycle of catecholamine driven electric storm. ECLS provides hemodynamic support during ablation procedure, while mapping and induction of VT is undertaken. ECLS provides early access to cardiac catheterization laboratory in patients with cardiac arrest due to shockable rhythm. The current evidence from literature, supports the use of ECLS to ensure adequate vital organ perfusion in patients with refractory VT. ECLS is a safe, feasible and effective therapeutic option when conventional therapies are insufficient to support cardiopulmonary function. A highly driven multidisciplinary team approach is essential to accomplish this task.

Minimally-invasive LVAD Implantation: State of the Art

Nowadays, the worldwide number of left ventricular assist devices (LVADs) being implanted per year is higher than the number of cardiac transplantations. The rapid developments in the field of mechanical support are characterized by continuous miniaturization and enhanced performance of the pumps, providing increased device durability and a prolonged survival of the patients. The miniaturization process enabled minimally-invasive implantation methods, which are associated with generally benefitting the overall outcome of patients. Therefore, these new implantation strategies are considered the novel state of the art in LVAD surgery.

In this paper we provide a comprehensive review on the existing literature on minimally-invasive techniques with an emphasis on the different implantation approaches and their individual surgical challenges.

Early clinical outcomes of new pediatric extracorporeal life support system (Endumo (2000) in neonates and infants

We investigated early clinical outcomes of a new extracorporeal life support (ECLS) system (Endumo 2000, Heiwa Bussan, Tokyo, Japan), which consists of a ROTAFLOW centrifugal pump, a BIOCUBE oxygenator with plasma-leakage-tight polymer fibers, and a biocompatible coating (T-NCVC coating), in pediatric patients <1 year old. From 2008 to 2011, 31 patients required ECLS. Except for 1 patient who was instituted with a transitional ECLS device, a conventional ECLS system (pediatric Emersave, TERUMO, Saitama, Japan) was initiated in 14 patients before December 2009 (6 boys, 63.4 ± 87.1 days old, 3.1 ± 1.0 kg), and the Endumo 2000 was initiated in 16 patients after December 2009 (8 boys, 43.9 ± 78.5 days old, 3.2 ± 0.7 kg). Primary reasons for the institution of ECLS were intraoperative low output syndrome in 11 patients, post-cardiotomy cardiopulmonary collapse in 9 patients, and other reasons in 10 patients. The median support period was 21.7 ± 20.7 days and the total number of circuit exchanges was 83. The median first circuit durability was significantly longer in the Endumo group [8.0 days (range 5.9-13.2) vs. 4.4 days (1.9-8.3)] (p = 0.020). Significant cranial hemorrhage occurred in only 1 patient, who received the Emersave system. The success rate for weaning from ECLS was 14.3% in the Emersave group and 56.3% in the Endumo group. Univariate analysis showed that usage of the Endumo 2000 was a predictor for successful weaning from the ECLS (p = 0.017) as well as survival at discharge (p = 0.032). The Endumo 2000 system provided safe and effective cardiopulmonary support without complications.

Is anti-platelet therapy needed in continuous flow left ventricular assist device patients? A single-centre experience

OBJECTIVES

We report our 5-year experience of continuous flow left ventricular assist device (LVAD) implantation without the use of anti-platelet therapy.

METHODS

Between February 2006 and September 2011, 27 patients (26 men; 1 woman) were implanted with a continuous flow LVAD (HeartMate II, Thoratec Corporation, Pleasanton, CA, USA). The mean age was 55.7 ± 9.9 years. The mean duration of support was 479 ± 436 (1-1555) days with 35.4 patient-years on support. Twenty-one patients were implanted as a bridge to transplantation and 6 for destination therapy. The anticoagulation regimen was fluindione for all patients, with aspirin for only 4 patients. At the beginning of our experience, aspirin was administered to 4 patients for 6, 15, 60 and 460 days. Due to gastrointestinal (GI) bleeding and epistaxis, aspirin was discontinued, and since August 2006, no patients have received anti-platelet therapy.

RESULTS

At 3 years, the survival rate during support was 76%. The most common postoperative adverse event was GI bleeding (19%) and epistaxis (30%) (median time: 26 days) for patients receiving fluindione and aspirin. The mean International Normalized Ratio (INR) was 2.58 ± 0.74 during support. Fifteen patients have been tested for acquired Von Willebrand disease. A diminished ratio of collagen-binding capacity and ristocetin cofactor activity to Von Willebrand factor antigen was observed in 7 patients. In the postoperative period, 2 patients presented with ischaemic stroke at 1 and 8 months. One of these 2 patients had a previous history of carotid stenosis with ischaemic stroke. There were no patients with haemorrhagic stroke, transient ischaemic attack or pump thrombosis. The event rate of stroke (ischaemic and haemorrhagic) per patient-year was 0.059 among the patients without aspirin with fluindione regimen only.

CONCLUSIONS

A fluindione regimen without aspirin in long-duration LVAD support appears to not increase thromboembolic events and could lead to a diminished risk of haemorrhagic stroke.