Venoarterial extracorporeal membrane oxygenation is a viable option as a bridge to heart transplant.

OBJECTIVE: Venoarterial extracorporeal membrane oxygenation is a rescue therapy for patients in cardiogenic shock. We hypothesize that patients bridged to heart transplant with extracorporeal membrane oxygenation have decreased survival. METHODS: The United Network of Organ Sharing database was retrospectively reviewed from January 1, 1999, to March 31, 2018, for heart transplant recipients. Recipients bridged with any form of mechanical support and those without support were compared with recipients bridged with extracorporeal membrane oxygenation. The primary end point was restricted mean survival time through 16.7 years. RESULTS: Of 26,918 recipients, 15,076 required no pretransplant mechanical support (56.0%). Support patients included 9321 with left ventricular assist devices (34.6%), 53 with right ventricular assist devices (0.2%), 258 with total artificial hearts (1.0%), 686 with biventricular assist devices (2.6%), 1378 with intra-aortic balloon pumps (5.1%), and 146 who required extracorporeal membrane oxygenation (0.5%). In the first 16.7 years post-transplant, compared with recipients bridged with extracorporeal membrane oxygenation, estimated adjusted restricted mean survival time was higher in patients who required no mechanical support (16.6 months [14.0-19.4]) and patients with a left ventricular assist device (16.5 months [99% confidence interval, 13.9-19.2]), an intra-aortic balloon pump (11.2 months [8.3-14.7]), or a biventricular assist device (6.6 months [3.6-10.3]). Restricted mean survival time in patients with a right ventricular assist device or a total artificial heart was similar to patients with extracorporeal membrane oxygenation. CONCLUSIONS: Recipients bridged with extracorporeal membrane oxygenation were estimated to survive 16.6 months less than nonmechanical circulatory support recipients. Bridge to heart transplant with extracorporeal membrane oxygenation is a viable option, and these patients should be considered transplant candidates.

Advanced heart failure patients supported with ambulatory inotropic therapy: What defines success of therapy?

OBJECTIVE: The objective of this study was to describe the profiles and outcomes of a cohort of advanced heart failure patients on ambulatory inotropic therapy (AIT). BACKGROUND: With the growing burden of patients with end-stage heart failure, AIT is an increasingly common short or long-term option, for use as bridge to heart transplant (BTT), bridge to ventricular assist device (BTVAD), bridge to decision regarding advanced therapies (BTD) or as palliative care. AIT may be preferred by some patients and physicians to facilitate hospital discharge. However, counseling patients on risks and benefits is critically important in the modern era of defibrillators, durable mechanical support and palliative care. METHODS: We retrospectively studied a cohort of 241 patients on AIT. End points included transplant, VAD implantation, weaning of inotropes, or death. The primary outcomes were survival on AIT and ability to reach intended goal if planned as BTT or BTVAD. We also evaluated recurrent heart failure hospitalizations, incidence of ventricular arrhythmias (VT/VF) and indwelling line infections. Unintended consequences of AIT, such reaching unintended end point (e.g. VAD implantation in BTT patient) or worse than expected outcome after LVAD or HT, were recorded. RESULTS: Mean age of the cohort was 60.7 ± 13.2 years, 71% male, with Class III-IV heart failure (56% non-ischemic). Average ejection fraction was 19.4 ± 10.2%, pre-AIT cardiac index was 1.5 ± 0.4 L/min/m2 and 24% had prior ventricular arrhythmias. Overall on-AIT 1-year survival was 83%. Hospitalizations occurred in 51.9% (125) of patients a total of 174 times for worsening heart failure, line complication or ventricular arrhythmia. In the BTT cohort, only 42% were transplanted by the end of follow-up, with a 14.8% risk of death or delisting for clinical deterioration. For the patients who were transplanted, 1-year post HT survival was 96.7%. In the BTVAD cohort, 1-year survival after LVAD was 90%, but with 61.7% of patients undergoing LVAD as INTERMACS 1-2. In the palliative care cohort, only 24.5% of patients had a formal palliative care consult prior to AIT. CONCLUSIONS: AIT is a strategy to discharge advanced heart failure patients from the hospital. It may be useful as bridge to transplant or ventricular assist device, but may be limited by complications such as hospitalizations, infections, and ventricular arrhythmias. Of particular note, it appears more challenging to bridge to transplant on AIT in the new allocation system. It is important to clarify the goals of AIT therapy upfront and continue to counsel patients on risks and benefits of the therapy itself and potential unintended consequences. Formalized, multi-disciplinary care planning is essential to clearly define individualized patient, as well as programmatic goals of AIT.

Predicting post-LVAD outcome: Is there a role for cognition?

BACKGROUND: Cognition has been found to influence risk of stroke and death for a variety of patient groups but this association has not been examined in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implant. We aimed to study the relationship between cognition, stroke, and death in a cohort of patients who received LVAD therapy. It was hypothesized that cognitive test results obtained prior to LVAD placement would predict stroke and death after surgery. METHODS: We retrospectively identified 59 HF patients who had cognitive assessment prior to LVAD placement. Cognitive assessment included measures of attention, memory, language, and visualmotor speed and were averaged to produce one z-score variable per patient. Survival analyses, censored for transplant, evaluated predictors for stroke and death within a follow-up period of 900 days. RESULTS: For patients with stroke or death during the follow up period, the average cognitive z-score predicted post-LVAD stroke (HR = 0.513, 95% CI = 0.31-0.86, p = 0.012) and death (HR = 0.166, 95% CI = 0.06-0.47, p = 0.001). Cognitive performances were worse in the patients who suffered stroke or died. No other variable predicted stroke and death within the follow up period when the cognitive variable was in the model. CONCLUSION: Cognitive performance was predictive of post-LVAD risk of stroke and death. Results are consistent with findings from other studies in non-LVAD samples and may reflect early signs of neurologic vulnerability. Further studies are needed to clarify the relationship between cognition and LVAD outcomes in order to optimize patient selection, management, and advanced care planning.

Serially Measured Cytokines and Cytokine Receptors in Relation to Clinical Outcome in Patients With Stable Heart Failure.

In this prospective cohort study of 250 stable heart failure patients with trimonthly blood sampling, we investigated associations of 17 repeatedly measured cytokines and cytokine receptors with clinical outcome during a median follow-up of 2.2 (25th-75th percentile, 1.4-2.5) years. Sixty-six patients reached the primary end point (composite of cardiovascular mortality, heart failure hospitalization, heart transplantation, left ventricular assist device implantation). Repeatedly measured levels of 8 biomarkers correlated with clinical outcomes independent of clinical characteristics. Rates of change over time (slopes of biomarker evolutions) remained independently associated with outcome for 15 biomarkers. Thus, temporal patterns of cytokines and cytokine receptors, in particular tumour necrosis factor ligand superfamily member 13B and interleukin-1 receptor type 1, might contribute to personalized risk assessment.

A Case of TAVR Complicated by Severe Functional Mitral Regurgitation.

Mitral regurgitation (MR) is a known complication of transcatheter aortic valve replacement (TAVR). We report a case of a 90-year-old man with severe symptomatic aortic stenosis who underwent elective TAVR. The procedure was complicated by severe functional MR from left ventricular stunning and dilatation caused by hypotension throughout the procedure. An Impella CP (Abiomed, Inc, Danvers, MA) was inserted to unload the left ventricle and decrease its size with subsequent improvement in MR severity, which was sustained after Impella CP removal. In conclusion, we present the first case of successful management of post-TAVR severe functional MR with an Impella CP.

Insertion technique for the Impella 5.0 heart pump in the COVID-19 era.

We describe the insertion of the Impella 5.0, a peripherally placed mechanical cardiovascular microaxial pump, in a patient with ischemic left ventricular dysfunction. The Impella is a 7 Fr device capable of achieving a flow of 4.0-5.0 L/min; its use necessitates an open arterial cut-down. A subclavicular incision is used to access the right or left axillary artery. A 10-mm tube graft is anastomosed to the artery through which the Impella 5.0 is inserted. The device traverses the tube graft and is advanced via the aorta, across the aortic valve, to its final position (inflow toward the ventricular apex and outflow above the aorta). The device may remain in situ for 10 days until recovery or until further supports are instituted. Our goal is to demonstrate the insertion of the Impella 5.0 device in a patient with cardiogenic shock whose situation was further complicated by coronavirus disease 2019.

Usefulness of regional right ventricular and right atrial strain for prediction of early and late right ventricular failure following a left ventricular assist device implant: A machine learning approach.

BACKGROUND: Identifying candidates for left ventricular assist device surgery at risk of right ventricular failure remains difficult. The aim was to identify the most accurate predictors of right ventricular failure among clinical, biological, and imaging markers, assessed by agreement of different supervised machine learning algorithms. METHODS: Seventy-four patients, referred to HeartWare left ventricular assist device since 2010 in two Italian centers, were recruited. Biomarkers, right ventricular standard, and strain echocardiography, as well as cath-lab measures, were compared among patients who did not develop right ventricular failure (N = 56), those with acute-right ventricular failure (N = 8, 11%) or chronic-right ventricular failure (N = 10, 14%). Logistic regression, penalized logistic regression, linear support vector machines, and naïve Bayes algorithms with leave-one-out validation were used to evaluate the efficiency of any combination of three collected variables in an "all-subsets" approach. RESULTS: Michigan risk score combined with central venous pressure assessed invasively and apical longitudinal systolic strain of the right ventricular-free wall were the most significant predictors of acute-right ventricular failure (maximum receiver operating characteristic-area under the curve = 0.95, 95% confidence interval = 0.91-1.00, by the naïve Bayes), while the right ventricular-free wall systolic strain of the middle segment, right atrial strain (QRS-synced), and tricuspid annular plane systolic excursion were the most significant predictors of Chronic-RVF (receiver operating characteristic-area under the curve = 0.97, 95% confidence interval = 0.91-1.00, according to naïve Bayes). CONCLUSION: Apical right ventricular strain as well as right atrial strain provides complementary information, both critical to predict acute-right ventricular failure and chronic-right ventricular failure, respectively.

Mechanical circulatory support in the context of coronary artery bypass grafting.

PURPOSE OF REVIEW: With the continuous innovation in mechanical circulatory support as an option for the management of patients in cardiogenic shock from myocardial infarction, it is important to understand the current evidence and recommendations for the use of these devices for patients who require or underwent coronary artery bypass surgery. RECENT FINDINGS: The use of mechanical circulatory support (MCS) in patients with cardiogenic shock who require or underwent coronary artery bypass surgery has not been well studied. Observational studies have shown that the use of intra-aortic balloon pump or percutaneous ventricular assist devices prior to revascularization lead to better survival. Extracorporeal membrane oxygenation (ECMO) still carries significant risk of mortality and complications; the use of additional MCS devices for left ventricular unloading during ECMO improves outcomes. SUMMARY: MCS will continue to play an important role in coronary artery surgery patients. Multidisciplinary Cardiac Shock Team can assist in proper patient selection and device choice, whereas prospective clinical trials are required to provide evidence-based guidance towards the management of these patients.

An in vitro analysis of the PediMag and CentriMag for right-sided failing Fontan support.

OBJECTIVE: Right-sided mechanical circulatory support for failing Fontan physiology has been largely unsuccessful due to inherent hemodynamic differences between these patients and the target populations for most assist devices. This study uses advanced benchtop modeling of Fontan physiology to examine the use of PediMag and CentriMag to improve failing Fontan hemodynamics. METHODS: Each device was attached to a compliance-matched, patient-specific total cavopulmonary connection in vitro model that used resistances, compliances, and programmable waveforms to establish "failing Fontan" baseline hemodynamics (cardiac output [CO] = 3.5 L/min and central venous pressure ∼17 mm Hg). The ability of the assist devices to improve failing Fontan hemodynamics (reduce inferior vena cava pressure and augment CO) was investigated. RESULTS: Requiring complete Fontan pathway restriction, PediMag reduced inferior vena cava pressure by ∼10 mm Hg and supported CO augmentation up to 5 L/min. This was accompanied by an increase in superior vena cava pressure of ∼6 mm Hg. CentriMag produced similar hemodynamic changes without the need for pathway restriction or an increase in superior vena cava pressure. CONCLUSIONS: PediMag and CentriMag right-sided support led to a decrease in inferior vena cava pressure and augmentation of cardiac output. In the case of CentriMag, this is accomplished without an increase in superior vena cava pressure or the need for restrictive banding. This work provides further data to help with the optimal design of a Fontan assist device to ameliorate the growing need.

Venous perfusion assist system has no additional effect compared to simple elevation on post-operative edema in patients with distal radial fracture treated with volar locking plate fixation: A randomized controlled trial.

BACKGROUND: While limb elevation and other methods for reducing hand edema are commonly used in clinical practice, alternative methods, such as compression and venous perfusion assist system (VPAS), have emerged. This study compared the efficacy of VPAS to limb elevation in decreasing hand edema after surgery for distal radial fracture (DRF) treated by a volar locking plate (VLP). METHODS: A randomized controlled trial was conducted in 102 patients to compare VPAS and elevation methods for edema reduction following VLP fixation for DRF. Changes in edema were measured using the tape measure method along with other parameters on the next day and at one, three, six, and 12 weeks postoperatively. RESULTS: There were no significant differences in edema reduction or other factors between the VPAS and elevation groups at any measurement point. CONCLUSIONS: VPAS appears to confer no measurable advantage over management with elevation for edema reduction after VLP fixation of DRF. TRIALS REGISTRY: This study was registered at the University Hospital Medical Information Network Clinical Trials Registry (UMIN000015640).

Video capsule endoscopy is safe and effective in suspected small bowel bleeding among left ventricular assist device recipients.

INTRODUCTION:: Suspected small bowel bleeding is frequently encountered in left ventricular assist device recipients and the identification of the culprit lesion may be challenging. Data regarding the safety and yield of small bowel capsule in the investigation of suspected small bowel bleeding are limited. We aimed to evaluate the safety and efficacy of small bowel video capsule endoscopy for the investigation of suspected small bowel bleeding among left ventricular assist device recipients. METHODS:: Patients with left ventricular assist device who underwent video capsule endoscopy for the investigation of suspected small bowel bleeding were identified. Suspected small bowel bleeding was defined as the presence of overt bleeding at least 30 days following left ventricular assist device implantation with no identifiable cause in upper and lower endoscopy. RESULTS:: A total of 10 patients with left ventricular assist device associated suspected small bowel bleeding performed 12 small bowel capsule endoscopies between January 2008 and December 2015 at our tertiary medical care facility. There were no cases of capsule retention or any other serious adverse events during the exams. A significant finding was identified in 8 out of 10 patients, including 3 cases of small bowel angioectasia, 2 cases of small bowel ulcers, 1 case of cecal polyp, and 2 cases of active bleeding with no apparent bleeding source. Small bowel enteroscopy identified and treated bleeding angioectasia in the latter two cases. CONCLUSION:: Small bowel capsule endoscopy is safe and effective in the investigation of left ventricular assist device associated suspected small bowel bleeding.

Bloodstream infections in mechanical circulatory support device recipients in the International Society of Heart and Lung Transplantation Mechanically Assisted Circulation Support Registry: Epidemiology, risk factors, and mortality.

BACKGROUND: We used multicenter international data from the International Society of Heart and Lung Transplantation Mechanically Assisted Circulation Support (IMACS) registry to determine bloodstream infection (BSI) event rate, independent risk factors, and association with mortality. METHODS: Included were patients registered in IMACS from January 2013 through December 2015, assessed BSI event rate of mechanical circulatory support (MCS) and non-MCS-related BSIs, and conducted univariate and multivariate analyses between BSI with baseline characteristics and mortality. RESULTS: We documented 1,606 BSIs in 1,231 of 10,171 MCS recipients (12%), with an event rate of 2.43 BSIs/100 patient-months within 3 months after implant (early onset) and 1.03 BSIs/100 patient-months after 3 months (late onset). Of these episodes, 1,378 (85.8%) were non- MCS-related BSI. Increasing body mass index and bilirubin were independent correlates of MCS-related BSI. Independent correlates of non-MCS-related BSI included older age, higher body mass index, previous cardiac surgery, baseline chronic renal disease and dialysis, pre-implant frailty, presence of biventricular assist device, total artificial heart or right ventricular assist device, and Interagency Registry for Mechanically Assisted Circulatory Support category 1. Survival after 3 months after implant of patients who developed early-onset BSI was 56.9% at 24 months vs 77.4% in patients without early-onset BSI (p < 0.001). Early-onset BSI was an independent correlate of mortality at 3 months after implantation (hazard ratio, 2.56; 95% confidence interval, 2.09-3.15; p < 0.001). CONCLUSIONS: Early-onset BSI was associated with significantly increased 24-month mortality. More than 85% of these BSIs were not device related. There is an opportunity for infection prevention practices to decrease the BSI event rate, which may affect 24-month survival. These data can also serve as benchmarking for individual institutions.

A Novel Idea to Improve Cardiac Output of Mechanical Circulatory Support Devices by Optimizing Kinetic Energy Transfer Available in Forward Moving Aortic Blood Flow.

Mechanical circulatory support devices (MCSDs) have gained widespread clinical acceptance as an effective heart failure (HF) therapy. The concept of harnessing the kinetic energy (KE) available in the forward aortic flow (AOF) is proposed as a novel control strategy to further increase the cardiac output (CO) provided by MCSDs. A complete mathematical development of the proposed theory and its application to an example MCSDs (two-segment extra-aortic cuff) are presented. To achieve improved device performance and physiologic benefit, the example MCSD timing is regulated to maximize the forward AOF KE and minimize retrograde flow. The proof-of-concept was tested to provide support with and without KE control in a computational HF model over a wide range of HF test conditions. The simulation predicted increased stroke volume (SV) by 20% (9 mL), CO by 23% (0.50 L/min), left ventricle ejection fraction (LVEF) by 23%, and diastolic coronary artery flow (CAF) by 55% (3 mL) in severe HF at a heart rate (HR) of 60 beats per minute (BPM) during counterpulsation (CP) support with KE control. The proposed KE control concept may improve performance of other MCSDs to further enhance their potential clinical benefits, which warrants further investigation. The next step is to investigate various assist technologies and determine where this concept is best applied. Then bench-test the combination of kinetic energy optimization and its associated technology choice and finally test the combination in animals.

Mechanical circulatory support in patients with severe aortic stenosis and left ventricular dysfunction undergoing percutaneous coronary intervention.

Management of obstructive coronary artery disease in patients with aortic stenosis and severe left ventricular dysfunction is challenging. Mechanical circulatory support at the time of percutaneous coronary interventions may be necessary in these extreme-risk patients. We present a case in which the TandemHeart was used to support a patient with severe aortic stenosis, severe protected left main and circumflex disease, and severe cardiomyopathy and review the literature on this subject.

In vivo evaluation of centrifugal blood pump for cardiopulmonary bypass-Spiral Pump.

The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base. Worm gears provide axial motion to the blood column, and the rotational motion of the conically shaped impeller generates a centrifugal pumping effect, improving pump efficiency without increasing hemolysis. In vitro tests were performed to evaluate the SP's hydrodynamic performance, and in vivo experiments were performed to evaluate hemodynamic impact during usual CPB. A commercially available centrifugal blood pump was used as reference. In vivo experiments were conducted in six male pigs weighing between 60 and 90 kg, placed on CPB for 6 h each. Blood samples were collected just before CPB (T0) and after every hour of CPB (T1-T6) for hemolysis determination and laboratory tests (hematological and biochemical). Values of blood pressure, mean flow, pump rotational speed, and corporeal temperature were recorded. Also, ergonomic conditions were recorded: presence of noise, difficulty in removing air bubbles, trouble in installing the pump in the drive module (console), and difficulties in mounting the CPB circuit. Comparing the laboratory and hemolysis results for the SP with those of the reference pump, we can conclude that there is no significant difference between the two devices. In addition, reports made by medical staff and perfusionists described a close similarity between the two devices. During in vivo experiments, the SP maintained blood flow and pressure at physiological levels, consistent with those applied in cardiac surgery with CPB, without presenting any malfunction. Also, the SP needed lower rotational speed to obtain average blood flow and pressure, compared with the reference pump.

Long-term mechanical circulatory support (destination therapy): on track to compete with heart transplantation?

OBJECTIVES: Average 2-year survival after cardiac transplantation is approximately 80%. The evolution and subsequent approval of larger pulsatile and, more recently, continuous flow mechanical circulatory support (MCS) technology for destination therapy (DT) offers the potential for triage of some patients awaiting cardiac transplantation to DT. METHODS: The National Heart, Lung, and Blood Institute Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) is a national multi-institutional study of long-term MCS. Between June 2006 and December 2011, 127 pulsatile and 1160 continuous flow pumps (24% of total primary left ventricular assist devices [LVADs]) carried an initial strategy of DT therapy. RESULTS: By multivariable analysis, risk factors (P < .05) for mortality after DT included older age, larger body mass index, history of cancer, history of cardiac surgery, INTERMACS level I (cardiogenic shock), dialysis, increased blood urea nitrogen, use of a pulsatile flow device, and use of a right ventricular assist device (RVAD). Among patients with a continuous flow LVAD who were not in cardiogenic shock, a particularly favorable survival was associated with no cancer, patients not in cardiogenic shock, and blood urea nitrogen less than 50 mg/dL, resulting in 1- and 2-year survivals of 88% and 80%. CONCLUSIONS: (1) Evolution from pulsatile to continuous flow technology has dramatically improved 1- and 2-year survivals; (2) DT is not appropriate for patients with rapid hemodynamic deterioration or severe right ventricular failure; (3) important subsets of patients with continuous flow DT now enjoy survival that is competitive with heart transplantation out to about 2 years.

Mechanical circulatory support for infants and small children.

The development of mechanical circulatory support devices for infants and small children with heart failure has significantly lagged behind the development of devices for adults. In the United States, there was really very little activity focused on the development and implementation of durable mechanical assist devices for small children until the early part of this millennium. At present, the Berlin Heart EXCOR Pediatric ventricular assist device (Berlin Heart Inc., The Woodlands, TX) is currently the only device available to provide long-term support to small children awaiting cardiac transplantation; this device is only available through either compassionate use solicitation or within the confines of an ongoing investigation device exemption trial. There are several other devices being developed at this time, but it will be years before they are tested in clinical trials. In this article, we will review the current status of mechanical circulatory support devices and therapy strategies for infants and small children presenting in acute heart failure.