Interaction of a Ventricular Assist Device With Patient-Specific Cardiovascular Systems: In-Silico Study With Bidirectional Coupling.

Heart failure has become one of the fastest growing cardiovascular diagnoses, with estimates as high as 500 000 new cases per year.1,2 This growth is in part a result of the reductions in death from acute coronary syndromes, increased use of implantable cardioverter defibrillators, and improved survival with most cardiovascular interventions, which have led to this continued increase in the number of patients who develop progressive heart failure (HF). The estimated number of people in the United States with the diagnosis of HF may exceed 7 million, based on the estimated average prevalence of 2.6%,3,4 and a census of >300 million population (Figure 1).5,6 HF is clearly age related,1,–,4 with prevalence as low as 0.5% in those 65 years of age.2 This is an important demographic, because it is estimated that the number of people >65 years of age will double in the next 20 to 30 years.4,–,7 HF is not a homogeneous condition. Based primarily on data from recent hospital registries8,9 and other studies,10 nearly half of all patients have HF with preserved systolic function, and the other half have varying degrees of severity of HF with reduced systolic function. Although the prevalence of HF is higher in males at <70 years of age, overall HF is equally common in men and women. Unfortunately, the average survival of patients with either preserved or reduced systolic function is only 40% at 5 years after diagnosis,10,11 and may be as high as 80% when it reaches a refractory stage.12 One study of 3500 patients in Minnesota suggested that there is …

Recurrent orthostatic syncope due to left atrial and left ventricular collapse after a continuous-flow left ventricular assist device implantation

Cost-effectiveness analysis in cardiac surgery: A review of its concepts and methodologies

"I Guess I'm On Alert All The Time": Dyadic Symptom Appraisal In Heart Failure With And Without An LVAD

Left ventricular assist devices (LVADs) are frequently used as a bridge to cardiac transplantation and may be useful as long-term therapy. The purpose of this study was to compare the exercise performance of LVAD patients with that of ambulatory heart failure patients. Exercise testing with hemodynamic and respiratory gas measurements was performed in 65 congestive heart failure (CHF) patients (age 53+/-10 years) and 20 LVAD patients (age 49+/-8 years). Peak Vo2 was significantly higher in the LVAD than the CHF patients (CHF, 12+/-3; LVAD, 15. 9+/-3.8 mL . kg-1 . min-1; P<0.001), as was the Vo2 at the anaerobic threshold (CHF, 8.1+/-2.1; LVAD, 12.2+/-2.9 mL . kg-1 . min-1; P<0.001). At rest, mean arterial blood pressure (CHF, 87+/-11; LVAD, 94+/-9 mm Hg) and cardiac output (CHF, 4+/-1; LVAD, 4. 9+/-0.9 L/min) were increased, whereas mean pulmonary artery pressure (CHF, 28+/-11; LVAD, 18+/-4 mm Hg) and pulmonary artery wedge pressure (CHF, 16+/-10; LVAD 5+/-3 mm Hg) were reduced (all P<0.01). At peak exercise, heart rate (CHF,125+/-24; LVAD, 148+/-24 bpm), blood pressure (CHF, 87+/-14; LVAD,96+/-12 mm Hg), and cardiac output (CHF, 7.6+/-2.2; LVAD, 11.2+/-2.6 L/min) were higher (all P<0. 01), whereas mean pulmonary artery pressure (CHF, 48+/-12; LVAD, 30+/-5 mm Hg) and mean pulmonary capillary wedge pressure (CHF, 31+/-11; LVAD, 14+/-6 mm Hg) were lower in the LVAD group (both P<0. 001). In the LVAD patients, Fick cardiac output was higher than LVAD flow sensor value measurements (Fick, 11.6+/-2.5; LVAD, 8.1+/-1.2 L/min; P<0.001). Hemodynamic measurements at rest and during exercise are significantly improved in patients with devices compared with those in ambulatory heart failure patients awaiting cardiac transplantation. Similarly, the exercise capacity of device patients is better than that of transplant candidates and in the majority of patients is similar to that of patients with mild CHF.

Introduction: The role of left ventricular assist devices (LVAD) in advanced heart failure (HF) patients (pts) not dependent on intravenous inotropes is unclear. We hypothesize that the benefits of LVAD vs optimal medical management (OMM) are more pronounced in INTERMACS profile 4 (IM4) than profiles 5-7 (IM5-7). Methods: ROADMAP is a prospective, 41-center, non-randomized study of 200 pts. The objective was to evaluate the effectiveness and relative risks of HeartMate II LVAD support vs OMM in ambulatory NYHA Class IIIB/IV pts who met FDA indications for LVAD destination therapy but were non-inotrope dependent. The primary composite endpoint was survival with improvement in 6MWD ≥ 75m at 1 yr. Results: There were more LVAD pts in IM4 than IM5-7 (Table). Among IM4 pts, LVAD was 4.6X more likely than OMM to meet the primary endpoint, and 1 yr event-free survival as treated on original therapy was significantly greater for LVAD pts (Figure). The most frequent adverse event (AE) was bleeding for LVAD pts and worsening HF for OMM. For IM4 and IM5-7, LVAD pts had a higher composite of AEs compared to OMM, but freedom from rehospitalizations was similar for IM4. In OMM pts, 33% of IM4 and 15% of IM5-7 received delayed LVADs within 1 yr. Health related quality of life (HRQoL), severity of depression (PHQ-9), and NYHA class improved more at 1 yr with LVADs than OMM. Conclusions: Survival with improved functional status was better with LVADs compared to OMM in IM4 pts. HRQoL and depression improved more in all IM profiles with LVADs in spite of AEs being more frequent with LVADs. Results support the use of the HMII LVAD in functionally limited non-inotrope dependent HF patients, particularly those in IM4 profile.

TEMPORAL TRENDS OF ISCHEMIC AND HEMORRHAGIC STROKE AFTER LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION IN THE UNITED STATES (2017-2019)

Relevance. Left ventricular assist device (LVAD) is an alternative treatment for heart failure (HF) patients which improves patient’s quality of life at their end-stage. Despite to the improvement LVAD is beleaguered with thrombosis/bleeding complications in 70% of HF patients after implantation. An anticoagulant treatment of warfarin is usually prescribed to reduce thrombosis complications. However, due to the incorrect dosage of the treatment thrombosis/ bleeding complications still happen. Warfarin dose could be identified by genetic variants of vitamin K-epoxide reductase complex (VKORC1) and the cytochrome P450-2C9 (CYP2C9) which account for 50% of dose variability. Aim. The aim of our investigation is to identify variability of warfarin dose according to the genotype polymorphisms of genes and their difference from the clinical dosage in HF patients. Materials and methods. The case series study included 98 HF patients (without complications – 74 patients, with complications – 24 patients) with prescribed warfarin treatment after device implantation. Clinical warfarin dosage difference was identified between genotype polymorphisms of rs9923231, rs9934438 in VKORC1 gene. Furthermore, warfarin dosage was calculated according to the genetic test results and compared with clinical dosage. Results. Warfarin dosage according to the clinical protocol between three genotypes of polymorphisms in VKORC1gene showed significant difference. HF patients were prescribed with higher warfarin dosage with wild type genotype polymorphism of rs9934438 in VKORC1 gene than with mutant genotype &lt; 2.5mg (3.88 ± 1.25 vs. 2.44 ± 0.81, p = 0.00005). Conclusion. Genotype-guided warfarin dosing may estimate accurate dose and potentially improve outcomes in LVAD patients. Введение. Вспомогательное механическое устройство левого желудочка (Left ventricular assist device, LVAD) является альтернативным методом лечения пациентов с сердечной недостаточностью (СН), которое улучшает качество жизни пациентов на терминальной стадии. Несмотря на улучшение, LVAD сопровождается тромбозами/кровотечениями у 70% пациентов с СН после имплантации. Антикоагулянтное лечение варфарином обычно назначают для уменьшения осложнений тромбоза. Однако из-за неправильной дозировки лечения осложнения тромбоза/кровотечения все же случаются. Дозу варфарина можно определить по генетическим вариантам комплекса витамин К-эпоксидредуктазы (VKORC1) и цитохрома P450-2C9 (CYP2C9), которые влияет на вариабельности дозы на 50%. Цель. Целью нашего исследования является выявление вариабельности дозы варфарина в зависимости от генетических полиморфизмов генов и их отличия от клинической дозы у больных СН. Материалы и методы. В исследование серии случаев включены 98 пациентов с СН (без осложнений – 74 пациента, с осложнениями – 24 пациента), получавших лечение варфарином после имплантации устройства. Выявлена клиническая разница в дозировке варфарина между полиморфизмами генотипов rs9923231, rs9934438 гена VKORC1. Кроме того, дозировка варфарина рассчитывалась по результатам генетического теста и сравнивалась с клинической дозировкой. Результаты. Дозировка варфарина согласно клиническому протоколу между тремя генотипами полиморфизмов гена VKORC1 показала значительную разницу. Пациентам с СН назначали более высокие дозы варфарина при диком типе полиморфизма rs9934438 гена VKORC1, чем при мутантном генотипе &lt;2,5 мг (3,88 ± 1,25 против 2,44 ± 0,81, p = 0,00005). Выводы. Дозирование варфарина с учетом генотипа может дать точную оценку дозы и потенциально улучшить исходы у пациентов с LVAD. Өзектілігі. Сол жақ қарыншаның көмекші механикалық құрылғысы (Left ventricular assist device, LVAD) жүрек жеткіліксіздігі (ЖЖ) бар науқастарға арналған балама емдеу әдісі болып табылады, ол соңғы сатыдағы пациенттердің өмір сапасын жақсартады. Жақсарғанына қарамастан, 70% ЖЖ пациенттерінде тромбоз/ қан кету асқынулары пайда болады LVAD имплантациясынан кейін. Тромбоздың асқынуын азайту үшін антикоагулянттық емдеу варфаринмен әдетте тағайындалады. Дегенмен, тромбоз/қан кету асқынулары емдеудің дұрыс емес дозасынан туындайды. Дозаның өзгергіштігіне 50%-ға әсер ететін, К витаминінің эпоксид-редуктаза кешенінің (VKORC1) және P450-2C9 цитохромының (CYP2C9) генетикалық нұсқалары арқылы варфариннің дозасын анықтауға болады. Мақсаты. Біздің зерттеуіміздің мақсаты гендік полиморфизмге байланысты варфарин дозасының өзгергіштігін және олардың жүрек жеткіліксіздігі бар науқастардағы клиникалық дозадан айырмашылығын анықтау болып табылады. Материалдар мен әдістер. Жағдайлар сериясына зерттеуге LVAD құрылғысы имплантациясынан кейін варфаринмен емделген 98 ЖЖ пациенттері (асқынулары жоқ – 74 пациент, асқынулары бар - 24 пациент ) қамтылды. Варфарин дозасының клиникалық айырмашылығы VKORC1 генінде полиморфизмдерінің rs9923231 және rs9934438 генотиптерінің арасында анықталды. Сонымен қатар, варфариннің дозасы генетикалық сынақ нәтижелері бойынша есептелді және клиникалық дозамен салыстырылды. Нәтижелер. VKORC1 гендік полиморфизмінің үш генотипі арасындағы варфарин клиникалық дозасы айтарлықтай айырмашылықты көрсетті. ЖЖ бар емделушілер VKORC1 генінің rs9934438 полиморфизмінде, мутантты генотипке қарағанда (&lt;2,5 мг) жабайы типте варфариннің жоғары дозасын қабылдады, (3,88 ± 1,25 қарсы 2,44 ± 0,81, p= 0,00005). Қорытынды. Варфариннің генотипі бойынша дозаның нақты дозасын анықтауға және LVAD пациенттеріндегі нәтижелерді жақсартуы мүмкін.

Left Ventricular Assist Device Flow Pattern Analysis Utilizing a Novel Computational Fluid Dynamics Model: Using Physics and Physiology to Better Define the Pump-Patient Interaction

Heart failure is associated with prolonged stress and inflammation characterized by elevated levels of cortisol and circulating catecholamines. Persistent sympathetic stimulation secondary to the stress of heart failure causes an induced insulin resistance, which creates a need for higher doses of insulin to adequately manage hyperglycemia in this patient population. We hypothesized that cortisol and catecholamine levels would be elevated in end-stage heart failure patients, however, would be reduced after the implantation of a left ventricular assist device (LVAD). Insulin requirements would therefore be reduced post LVAD implant and control of diabetes improved as compared with pre-implant. Pre- and postoperative cortisol, catecholamine, glycated hemoglobin, and blood glucose levels were evaluated retrospectively in 99 LVAD patients at a single center from January 2007 through November 2011. Serum was collected before LVAD implantation and monthly after implantation for 12 months consecutively. Results were evaluated and compared to insulin requirements, if any, before and after implant. Plasma levels were measured by ELISA. There were a total of 99 patients (81 men and 18 women). Two patients were implanted twice due to pump dysfunction. Mean age was 59 years, ± 10, with a median of 63 years. Of those patients, 64 had ischemic cardiomyopathy and 35 had dilated cardiomyopathy. The total patient years of LVAD support were 92.5 years. All patients received a continuous flow left ventricular assist device. Type II diabetes mellitus was diagnosed in 28 patients. Of those patients, 24 required daily insulin with an average dose of 45 units/day. Average preoperative glycated hemoglobin (HbA1c) levels were 6.8% with fasting blood glucose measurements of 136 mg/dL. Mean cortisol levels were measured at 24.3 μg/dL before LVAD implantation, with mean plasma catecholamine levels of 1824 μg/mL. Post operatively, average HbA1c levels were 5.38% with fasting blood glucose measurements of 122 mg/dL. Mean cortisol levels were measured at 10.9 μg/dL with average plasma catecholamine levels were 815 μg/mL. There was a significant decrease in both cortisol levels post LVAD implant (P = 0.012) as well as catecholamine levels (P = 0.044). The average insulin requirements post LVAD implant were significantly reduced to 13 units/day (P = 0.001). Six patients no longer required any insulin after implant. Implantation of nonpulsatile LVADs has become a viable option for the treatment of end-stage heart failure, helping to improve patient quality of life by decreasing clinical symptoms associated with poor end-organ perfusion. Frequently, diabetes is a comorbid condition that exists among heart failure patients and with the reduction of the systemic inflammatory and stress response produced by the support of a nonpulsatile LVAD, many patients may benefit from a reduction in their blood glucose levels, as well as insulin requirements.

Left ventricular assist devices (LVADs) are increasingly being used to treat patients in end-stage heart failure (HF) as bridge-to-transplantation, lifetime support or destination therapy. However, the importance of this newer technique for chronic cardiac support compared to heart transplantation is still open to discussion. To date, there are few studies that extensively explore the psychological and cognitive profiles of patient with ventricular assist devices (VADs). We studied the psychological aspects, quality of life (QOL) and cognitive profiles of 19 patients with HF before VAD implantation and then at two, five and 16 months post-implantation. Our results showed that after VAD implantation, patients did not show any psychopathological problems such as anxiety and/or depression. More interestingly, despite the constant risk of neurological events determined by the continuous-blood-flow pump (CBFP), patients' cognitive functioning did not worsen. In fact, significant enhancements were observed over time. Psychological and cognitive deficits are common in advanced HF and often worsen over time. Appropriately designed and randomized studies are needed to demonstrate whether earlier VAD implantation is warranted to arrest cognitive decline and encourage better post-implantation adaptation.

Left ventricular assist devices (LVAD) are increasingly being used to treat patients in end-stage heart failure to facilitate survival to cardiac transplant or as a bridge to myocardial recovery. The technical innovation of the LVAD has a significant benefit on the patients' physical functioning. However, within the United Kingdom, there has been no systematic evaluation of the psychological adjustment and quality of life (QoL) of patients currently living with an LVAD, or of the differences in QoL for patients who are either explanted or transplanted. To assess the differences in QoL and psychological adjustment for current LVAD patients, patients who have been transplanted from an LVAD and patients in whom the device has been explanted. Twenty-two patients involved in an LVAD programme were recruited (18 men and four women; age range 18-60). Eight patients had an LVAD in situ, six patients had the LVAD explanted and eight had undergone transplantation. QoL and psychological functioning were assessed using previously validated measures. Although there were no significant differences between the three groups, there was a trend for the LVAD patients to have higher levels of anxiety and depression and a lower QoL compared with transplanted or explanted patients. For patients with an LVAD in situ, there was a trend for QoL and psychological functioning to be poorer than for transplanted and explanted patients. Larger studies will be needed to confirm these findings, but psychological assessment and interventions to reduce psychological morbidity and improve QoL will be important in these patients, particularly in view of the increasing numbers of LVADs being implanted and the possibility of their use for long-term "destination" therapy.

Successful Robotic Sleeve Gastrectomy in a Patient with Left Ventricular Assist Device

Summary : Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium is a novel drug that breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. In this study, the authors prescribed alagebrium (200 mg daily) or placebo combined with aerobic exercise training or contact control in healthy, sedentary older individuals for 1 year. The authors evaluated overall cardiac function by the use of several modalities, including invasive pressure–volume measurements, exercise testing, and cardiac MRI before and after the training. To the authors’ knowledge, this is the first study to evaluate the effects of alagebrium and exercise training in healthy aged humans. After intervention, exercise training significantly increased exercise capacity, LV mass, and LV end-diastolic volume. Conversely, alagebrium had little effect on exercise capacity or LV geometry. However, alagebrium showed a modest improvement in LV stiffness compared with placebo. This favorable effect of alagebrium on LV stiffness was most prominent in individuals with combined alagebrium and exercise training. Conclusions : Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening.1 Summary : Maximum oxygen consumption (peak VO2) and efficiency of ventilation (VE) during exercise (VE/VCO2 slope) are known to stratify adults in heart failure for 1-year survival. On the basis of adult data, a recent American Heart Association scientific statement suggested that peak VO2<50% predicted for age and sex should be considered substantial impairment in exercise performance in children with heart disease and therefore a class I indication for heart transplant listing. This single-center study examined the association of …

Geriatric Nutrition Risk Index is Associated with LVAD Recipient Survival with Cutoff Value of 92.68