The spectrum of complications following left ventricular assist device placement

Real-world safety and effectiveness of inhaled nitric oxide therapy for pulmonary hypertension during the perioperative period of cardiac surgery: a post-marketing study of 2817 patients in Japan

OBJECTIVE

To evaluate the real-world safety and effectiveness of inhaled nitric oxide (INOflo® for Inhalation 800 ppm) for perioperative pulmonary hypertension associated with cardiac surgery in Japan.

METHODS

This was a prospective, non-interventional, all-case, post-marketing study of pediatric and adult patients who received perioperative INOflo with cardiac surgery from November 2015-December 2020. Safety and effectiveness were monitored from INOflo initiation to 48 h after treatment completion or withdrawal. Safety outcomes included adverse drug reactions, blood methemoglobin concentrations, and inspired nitrogen dioxide concentrations over time. Effectiveness outcomes included changes in central venous pressure among pediatrics, mean pulmonary arterial pressure among adults, and the partial pressure of arterial oxygen/fraction of inspired oxygen ratio (PaO2/FiO2) in both populations.

RESULTS

The safety analysis population included 2,817 Japanese patients registered from 253 clinical sites (pediatrics, n = 1375; adults, n = 1442). INOflo was generally well tolerated; 15 and 20 adverse drug reactions were reported in 14 pediatrics (1.0%) and 18 adults (1.2%), respectively. No clinically significant elevations in blood methemoglobin and inspired nitrogen dioxide concentrations were observed. INOflo treatment was associated with significant reductions in both central venous pressure among pediatrics and mean pulmonary arterial pressure among adults, and significant improvements in PaO2/FiO2 among pediatrics and adults with PaO2/FiO2 ≤ 200 at baseline.

CONCLUSIONS

Perioperative INOflo treatment was a safe and effective strategy to improve hemodynamics and oxygenation in patients with pulmonary hypertension during cardiac surgery. These data support the use of INOflo for this indication in Japanese clinical practice.

Stroke and Mechanical Circulatory Support in Adults

PURPOSE OF THE REVIEW

Short-term and durable mechanical circulatory support (MCS) devices represent life-saving interventions for patients with cardiogenic shock and end-stage heart failure. This review will cover the epidemiology, risk factors, and treatment of stroke in this patient population.

RECENT FINDINGS

Short-term devices such as intra-aortic balloon pump, Impella, TandemHeart, and Venoatrial Extracorporal Membrane Oxygenation, as well as durable continuous-flow left ventricular assist devices (LVADs), improve cardiac output and blood flow to the vital organs. However, MCS use is associated with high rates of complications, including ischemic and hemorrhagic strokes which carry a high risk for death and disability. Improvements in MCS technology have reduced but not eliminated the risk of stroke. Mitigation strategies focus on careful management of anti-thrombotic therapies. While data on therapeutic options for stroke are limited, several case series reported favorable outcomes with thrombectomy for ischemic stroke patients with large vessel occlusions, as well as with reversal of anticoagulation for those with hemorrhagic stroke. Stroke in patients treated with MCS is associated with high morbidity and mortality. Preventive strategies are targeted based on the specific form of MCS. Improvements in the design of the newest generation device have reduced the risk of ischemic stroke, though hemorrhagic stroke remains a serious complication.

Titanium is a potent inducer of contact activation: implications for intravascular devices

BACKGROUND

Titanium (Ti) and its alloys are widely used in manufacturing medical devices because of their strength and resistance to corrosion. Although Ti compounds are considered compatible with blood, they appear to support plasma contact activation and may be thrombogenic.

OBJECTIVES

The objective of this study was to compare Ti and titanium nitride (TiN) with known activators of contact activation (kaolin and silica) in plasma-clotting assays and to assess binding and activation of factor XII, (FXII), factor XI (FXI), prekallikrein, and high-molecular-weight kininogen (HK) with Ti/TiN.

METHODS

Ti-based nanospheres and foils were compared with kaolin, silica, and aluminum in plasma-clotting assays. Binding and activation of FXII, prekallikrein, HK, and FXI to surfaces was assessed with western blots and chromogenic assays.

RESULTS

Using equivalent surface amounts, Ti and TiN were comparable with kaolin and superior to silica, for inducing coagulation and FXII autoactivation. Similar to many inducers of contact activation, Ti and TiN are negatively charged; however, their effects on FXII are not neutralized by the polycation polybrene. Antibodies to FXII, prekallikrein, or FXI or coating Ti with poly-L-arginine blocked Ti-induced coagulation. An antibody to FXII reduced FXII and PK binding to Ti, kallikrein generation, and HK cleavage.

CONCLUSION

Titanium compounds induce contact activation with a potency comparable with that of kaolin. Binding of FXII with Ti shares some features with FXII binding to soluble polyanions but may have unique features. Inhibitors targeting FXII or FXI may be useful in mitigating Ti-induced contact activation in patients with titanium-based implants that are exposed to blood.

Preoperative atrial fibrillation predicts worse outcomes after LVAD implantation

Introduction: Left ventricular assist device (LVAD) implantation is a common therapy for end-stage heart failure. Heart failure patients often present with atrial fibrillation (AF). The purpose of this study was to evaluate the influence of preoperative AF as well as vascular complications on outcome in LVAD patients. Methods: Between 01/2010 and 12/2017, 168 patients (141 male) with end-stage heart failure underwent LVAD implantation at a single center. Patient outcome was retrospectively studied by using the Kaplan-Meier method for analyzing crude survival as well as Cox regression for analyzing risk factors. Results: Sixty-two patients suffered from preoperative atrial fibrillation at LVAD implantation. Mean age was 56.8±11.9 years (range: 22–79) and 141 (84%) were male. Postoperative vascular or visceral surgical management due to malperfusion was needed in 27 patients (16.1%) and did not correlate with postoperative mortality (P=0.121, HR=1.587, CI=0.885–2.845). Patients with preoperative AF had a worse outcome in the Kaplan-Meier analysis (P=0.069). In contrast, cox regression showed that postoperative AF could not to be considered to be an independent predictor of mortality in this study group. Conclusion: Our data suggest that preoperative AF may be a potential predictor of mortality and impaired long-term outcome in LVAD patients. In contrast, preoperative ECLS and vascular or visceral surgery after LVAD implantation did not represent limiting factors with regard to mortality after LVAD implantation.

Left ventricular assist devices: A historical perspective at the intersection of medicine and engineering

Over the last half-century, left ventricular assist device (LVAD) technology has progressed from conceptual therapy for failed cardiopulmonary bypass weaning to an accepted destination therapy for advanced heart failure. The history of LVAD engineering is defined by an initial development phase, which demonstrated the feasibility of such an approach, to the more recent three major generations of commercial devices. In this review, we explore the engineering challenges of LVADs, how they were addressed over time, and the clinical outcomes that resulted from each major technological development. The first generation of commercial LVADs were pulsatile devices, which lacked the appropriate durability due to their number of moving components and hemocompatibility. The second generation of LVADs was defined by replacement of complex, pulsatile pumps with primarily axial, continuous-flow systems with an impeller in the blood passageway. These devices experienced significant commercial success, but the presence of excessive trauma to the blood and in-situ bearing resulted in an unacceptable burden of adverse events. Third generation centrifugal-flow pumps use magnetically suspended rotors within the pump chamber. Superior outcomes with this newest generation of devices have been observed, particularly with respect to hemocompatibility-related adverse events including pump thrombosis, with fully magnetically levitated devices. The future of LVAD engineering includes wireless charging foregoing percutaneous drivelines and more advanced pump control mechanisms, including synchronization of the pump flow with the native cardiac cycle, and varying pump output based on degree of physical exertion using sensor or advanced device-level data triggers.

Role of left atrial appendage occlusion in patients with HeartMate 3

OBJECTIVES

Left atrial appendage occlusion (LAAO) at the time of implantation may reduce thromboembolic events (TEs) during continuous-flow left ventricular assist device support. The HeartMate 3 (HM3) reduces TEs overall, but the efficacy of LAAO in HM3 is unknown.

METHODS

Adults receiving first HM3 implantation from November 2014 through December 2019 at a single, large medical centre were retrospectively reviewed. TEs included device thrombosis and ischaemic stroke. Patients were classified by whether they received LAAO or not. Incidence of TEs was compared between groups using cumulative incidence curves with competing risks (death and heart transplant) and risk factors for TEs were assessed with Fine and Gray competing risk regression.

RESULTS

A total of 182 patients received HM3, of whom 99 (54%) received LAAO versus 83 (46%) who did not. There were 14 TEs, including 13 strokes (7%) and 1 pump thrombosis (0.5%). No significant difference in the incidence of TEs in each group was found (Gray's test: P = 0.35). LAAO was not associated with TEs in multivariable Fine-Gray analysis (P = 0.10) and no significant risk factors for TEs were found. There were zero disabling strokes in those who received LAAO compared to 6 (7%) in those who did not receive LAAO (P = 0.008).

CONCLUSIONS

A low number of TEs was observed in HM3 recipients. LAAO did not further reduce the overall rate of TEs in this patient population, though its use may be beneficial in preventing disabling ischaemic strokes after HM3 implantation.

Mock circulatory loops used for testing cardiac assist devices: A review of computational and experimental models

Heart failure is a major health risk, and with limited availability of donor organs, there is an increasing need for developing cardiac assist devices (CADs). Mock circulatory loops (MCL) are an important in-vitro test platform for CAD's performance assessment and optimisation. The MCL is a lumped parameter model constructed out of hydraulic and mechanical components aiming to simulate the native cardiovascular system (CVS) as closely as possible. Further development merged MCLs and numerical circulatory models to improve flexibility and accuracy of the system; commonly known as hybrid MCLs. A total of 128 MCLs were identified in a literature research until 25 September 2020. It was found that the complexity of the MCLs rose over the years, recent MCLs are not only capable of mimicking the healthy and pathological conditions, but also implemented cerebral, renal and coronary circulations and autoregulatory responses. Moreover, the development of anatomical models made flow visualisation studies possible. Mechanical MCLs showed excellent controllability and repeatability, however, often the CVS was overly simplified or lacked autoregulatory responses. In numerical MCLs the CVS is represented with a higher order of lumped parameters compared to mechanical test rigs, however, complex physiological aspects are often simplified. In hybrid MCLs complex physiological aspects are implemented in the hydraulic part of the system, whilst the numerical model represents parts of the CVS that are too difficult to represent by mechanical components per se. This review aims to describe the advances, limitations and future directions of the three types of MCLs.

Ablation therapy for ventricular arrhythmias in patients with LVAD: Multiple faces of an electrophysiological challenge

Left ventricular assist device implantation is a recognized treatment option for patients with advanced heart failure refractory to medical therapy and can be used both as bridge to transplantation and as destination therapy. The risk of ventricular arrhythmias is common after left ventricular assist device implantation and is influenced by pre-, peri and post-operative determinants. The management of ventricular arrhythmias can be a challenge when they become refractory to medication or to device therapy and their impact on prognosis can be detrimental despite the mechanical support. In this setting, catheter ablation is being increasingly recognized as a feasible option for patients in which standard therapeutic strategies fail, but also with preventive purpose. Catheter ablation is being increasingly considered for the management of ventricular arrhythmias in patients with left ventricular assist device despite complex clinical and technical peculiarities due to the characteristics of the mechanical support. Much conflicting data exist regarding the predictors of success of the procedure and the rate of recurrence. In this review we discuss the latest evidences regarding catheter ablation of ventricular arrhythmias in this subset of patients, focusing on clinical characteristics, arrhythmia etiology, technical aspects and postprocedural features which must be considered by the electrophysiologist.

Contemporary outcomes of continuous-flow left ventricular assist devices-a systematic review

Background

End stage heart failure is a major cause of morbidity and mortality, and its prevalence is expected to rise with the ageing population. For suitable patients, orthotopic heart transplantation remains the gold standard therapy, however, a paucity of donor organs has led to the development of left ventricular assist devices (LVAD). These devices can be utilized as either a bridge-to-transplant (BTT) or as an alternative to heart transplantation. While these devices can prolong life and improve quality of life, they are associated with a significant number of adverse events. We aim to systematically review the literature to quantify survival and the incidence of adverse events following implantation of continuous-flow LVADs (cf-LVAD).

Methods

A systematic review was performed to determine outcomes following implantation of a cf-LVAD. Primary outcomes were survival and frequency of adverse events (such as bleeding, infection, thrombosis, stroke and right ventricular failure). Secondary outcomes included quality of life and assessment of functional status.

Results

Sixty-three studies reported clinical outcomes of 9,280 patients. Survival after cf-LVAD varied between studies. Industry-funded trials generally reported better overall survival than the single- and multi-center case series, which showed significant variation. The largest registry report documented twelve, twenty-four and forty-eight-month survival rates of 82%, 72% and 57% respectively. The most commonly reported adverse events were gastrointestinal bleeding (GIB), device-related infection, neurological events and right heart failure (RHF). Bleeding, RHF and infection were the most frequent complications experienced by those supported with cf-LVAD, occurring in up to 35%, 40% and 55% of patients, respectively. Quality of life as measured using the Kansas City Cardiomyopathy Questionnaire (KCCQ) and functional status as measured with the 6-minute walk test (6MWT) improved after cf-LVAD implantation with no decline evident two years after implantation.

Conclusions

The paucity of donor hearts has led to the development of left-ventricular assist devices as a BTT or as a destination therapy (DT). Outcomes after cf-LVAD implantation are excellent, with short-term survival comparable to heart transplantation, but long-term survival remains limited due to the incidence of post-implantation adverse events. Despite these complications, quality of life and functional status improve significantly post-implantation and remain improved over the long-term. This study demonstrates the potential benefits of cf-LVAD therapy whilst also identifying adverse events as an area of increased morbidity and mortality.

Ventricular Assist Device-Specific Infections

Ventricular assist device (VAD)-specific infections, in particular, driveline infections, are a concerning complication of VAD implantation that often results in significant morbidity and even mortality. The presence of a percutaneous driveline at the skin exit-site and in the subcutaneous tunnel allows biofilm formation and migration by many bacterial and fungal pathogens. Biofilm formation is an important microbial strategy, providing a shield against antimicrobial treatment and human immune responses; biofilm migration facilitates the extension of infection to deeper tissues such as the pump pocket and the bloodstream. Despite the introduction of multiple preventative strategies, driveline infections still occur with a high prevalence of ~10-20% per year and their treatment outcomes are frequently unsatisfactory. Clinical diagnosis, prevention and management of driveline infections are being targeted to specific microbial pathogens grown as biofilms at the driveline exit-site or in the driveline tunnel. The purpose of this review is to improve the understanding of VAD-specific infections, from basic "bench" knowledge to clinical "bedside" experience, with a specific focus on the role of biofilms in driveline infections.

Incidence and impact of acute kidney injury on patients with implantable left ventricular assist devices: a Meta-analysis

Background: We aimed to evaluate the acute kidney injury (AKI) incidence and its associated risk of mortality in patients with implantable left ventricular assist devices (LVAD).Methods: A systematic literature search in Ovid MEDLINE, EMBASE, and Cochrane Databases was conducted through January 2020 to identify studies that provided data on the AKI incidence and AKI-associated mortality risk in adult patients with implantable LVADs. Pooled effect estimates were examined using random-effects, generic inverse variance method of DerSimonian-Laird.Results: Fifty-six cohort studies with 63,663 LVAD patients were enrolled in this meta-analysis. The pooled incidence of reported AKI was 24.9% (95%CI: 20.1%-30.4%) but rose to 36.9% (95%CI: 31.1%-43.1%) when applying the standard definition of AKI per RIFLE, AKIN, and KDIGO criteria. The pooled incidence of severe AKI requiring renal replacement therapy (RRT) was 12.6% (95%CI: 10.5%-15.0%). AKI incidence did not differ significantly between types of LVAD (p = .35) or indication for LVAD use (p = .62). While meta-regression analysis did not demonstrate a significant association between study year and overall AKI incidence (p = .55), the study year was negatively correlated with the incidence of severe AKI requiring RRT (slope = -0.068, p < .001). The pooled odds ratios (ORs) of mortality at 30 days and one year in AKI patients were 3.66 (95% CI, 2.00-6.70) and 2.22 (95% CI, 1.62-3.04), respectively. The pooled ORs of mortality at 30 days and one year in severe AKI patients requiring RRT were 7.52 (95% CI, 4.58-12.33) and 5.41 (95% CI, 3.63-8.06), respectively.Conclusion: We found that more than one-third of LVAD patients develop AKI based on standard definitions, and 13% develop severe AKI requiring RRT. There has been a potential improvement in the incidence of severe AKI requiring RRT for LVAD patients. AKI in LVAD patients was associated with increased 30-day and 1 year mortality.

Is it Safe for Patients with Left Ventricular Assist Devices to Undergo Non-Cardiac Surgery?

Background and Objectives: Since the first use of ventricular assist devices (VADs) as bridge to recovery and bridge to cardiac transplantation in the early 1990s, significant technological advances have transformed VAD implantation into a routine destination therapy. With improved survival, many patients present for cardiac surgery for conditions not directly related to their permanent mechanical circulatory support. The aim of this study was to analyze the indications and outcomes of non-cardiac surgeries (NCSs) of left ventricular assist device (LVAD) patients in tertiary center. Material and Methods: We present a single-center experience after 151 LVAD implantations in 138 consecutive patients between 2012–2019 who had to undergo NCS during a follow-up period of 37 +/− 23.4 months on left ventricular assist device (LVAD). Results: A total of 105 procedures was performed in 63 LVAD recipients, resulting in peri-operative mortality of 3.8%. Twenty-five (39.7%) of patients underwent multiple surgeries. We found no significant difference in cumulative survival associated with the performed surgical interventions (p = 0.469). Conclusion: We demonstrated good overall clinical outcomes in LVAD patients undergoing NCS. With acceptable peri-operative mortality, NCS can be safely performed in LVAD patients on long-term support.

Cost savings for pVAD compared to ECMO in the management of acute myocardial infarction complicated by cardiogenic shock: An episode-of-care analysis

BACKGROUND

Acute myocardial infarction complicated by cardiogenic shock (AMICS) occurs in up to 10% of acute myocardial infarction admissions and is associated with high mortality, frequent adverse outcomes, prolonged hospitalizations, extensive medical resource utilization, and major cost. Using hospital cost data for Medicare Fee-for-Service (FFS) patients with AMICS, we sought to evaluate in hospital and 45-day outcomes and cost, comparing patients treated with percutaneous ventricular assist device (pVAD) versus extracorporeal membrane oxygenation (ECMO). The goal of this study was to better understand clinical and economic outcomes of AMICS to help clinicians and hospitals optimize outcomes most economically for AMICS patients.

METHODS

A retrospective claims analysis identified patients from the full census Medicare Standard Analytic Files compiled by the Center for Medicare and Medicaid (CMS) including: Inpatient, Outpatient, Skilled Nursing Facility and Home Health files for Medicare FFS beneficiaries. Study costs were defined as the total costs incurred by providers for treating a population with AMICS. Medicare FFS beneficiaries who experienced an inpatient admission during the index period (January 1, 2015 to March 31, 2017) with a diagnosis of AMICS were eligible for study inclusion and were identified by the presence of appropriate International Classification of Diseases, Ninth and Tenth Versions (ICD-9 and ICD-10) diagnosis and procedure codes. To create a matched sample and control for any baseline differences, a 1:1 Propensity Score Matching (PSM) was performed based on criteria such as age, gender, race, geographic distribution, and 11 high-cost comorbidities (e.g., congestive HF, coronary artery disease, diabetes, etc.). Index length of stay (LOS), index costs, discharge disposition (including mortality), post-index utilization, and episode-of-care (EOC) costs were reviewed. EOC was defined as index admission for all patients plus a 45-day post index period for patients who survived the index admission.

RESULTS

Each cohort included 338 patients. Index in-hospital mortality rates were 53% for pVAD versus 64% for ECMO (178 vs. 217; p = .0023), and total EOC in-hospital mortality rates were 66% for pVAD versus 74% for ECMO (222 vs. 250; p = .0160). Index LOS for pVAD was 27% lower versus ECMO (12.12 vs. 16.59; p = .0006). The index LOS for patients discharged alive was 25% lower for pVAD versus ECMO (17.73 vs. 23.62; p = .0016). For patients that experienced in-hospital mortality during their index stay, pVAD had a 44% lower LOS compared to ECMO (7.08 vs. 12.66; p < .0001). Following index hospitalization, the average cost savings with additional inpatient care was 31% lower for pVAD patients ($62,188 vs. $90,087; p = NS). During the EOC, pVAD patients incurred 32% lower costs compared to ECMO patients ($117,849 vs. $172,420; <.0001).

CONCLUSIONS

This study of Medicare FFS patients demonstrates that hospitals utilizing pVAD for appropriately selected AMICS patients have reduced mortality rates and reduced index LOS with lower index facility costs and lower post index 45-day costs. The study results offer hospitals and clinicians an opportunity to improve clinical outcomes and reduce total EOC costs in treating patients with AMI complicated by CS.

Comprehensive review of hemolysis in ventricular assist devices

Ventricular assist devices (VADs) have played an important role in altering the natural history of end-stage heart failure. Low-grade hemolysis has been traditionally described in patients with VADs, indicating effective device functionality. However, clinically significant hemolysis could be crucial in terms of prognosis, calling for prompt therapeutic actions. The absence of solid and widely approved diagnostic criteria for clinically significant hemolysis, render the utilization of hemolysis laboratory markers challenging. Hemolysis incidence varies (5%-18%) depending on definition and among different VAD generations, being slightly higher in continuous-flow devices than in pulsatile devices. Increased shear stress of red blood cells and underlying device thrombosis appear to be the main pathogenetic pathways. No certain algorithm is available for the management of hemolysis in patients with VADs, while close clinical and laboratory monitoring remains the cornerstone of management. Imaging examinations such as echocardiography ramp test or computed tomography scan could play a role in revealing the underlying cause. Treatment should be strictly personalized, including either pharmacological (antithrombotic treatment) or surgical interventions.

Ventricular arrhythmias following continuous-flow left ventricular assist device implantation: A systematic review

Ventricular arrhythmias (VA) are not uncommon after continuous-flow left ventricular assist device (CF-LVAD) implantation. In this systematic review, we sought to identify the patterns of VA that occurred following CF-LVAD implantation and evaluate their outcomes. An electronic search was performed to identify all articles reporting the development of VA following CF-LVAD implantation. VA was defined as any episode of ventricular fibrillation (VF) or sustained (>30 seconds) ventricular tachycardia (VT). Eleven studies were pooled for the analysis that included 393 CF-LVAD patients with VA. The mean patient age was 57 years [95%CI: 54; 61] and 82% [95%CI: 73; 88] were male. Overall, 37% [95%CI: 19; 60] of patients experienced a new onset VA after CF-LVAD implantation, while 60% [95%CI: 51; 69] of patients had a prior history of VA. Overall, 88% of patients [95%CI: 78; 94] were supported on HeartMate II CF-LVAD, 6% [95%CI: 3; 14] on HeartWare HVAD, and 6% [95%CI: 2; 13] on other CF-LVADs. VA was symptomatic in 47% [95%CI: 28; 68] of patients and in 50% [95%CI: 37; 52], early VA (<30 days from CF-LVAD) was observed. The 30-day mortality rate was 7% [95%CI: 5; 11]. Mean follow-up was 22.9 months [95%CI: 4.8; 40.8], during which 27% [95%CI: 17; 39] of patients underwent heart transplantation. In conclusion, approximately a third of patients had new VA following CF-LVAD placement. VA in CF-LVAD patients is often symptomatic, necessitates treatment, and carries a worse prognosis.

Rapid Development of Bleeding Esophageal Varices after Placement of Continuous Flow Left Ventricular Assist Device

We describe a patient with compensated cirrhosis and portal hypertension who underwent continuous flow LVAD implantation. Shortly after LVAD implantation, the patient developed new onset bleeding esophageal varices and ultimately had a fatal outcome. Our experience suggests that even well-compensated cirrhotic patients with significant portal hypertension are at risk of variceal bleeding after LVAD placement.

Effects of Systemic and Device-Related Complications in Patients Bridged to Transplantation With Left Ventricular Assist Devices

BACKGROUND

The use of left ventricular assist devices (LVADs) as a bridge to heart transplantation has increased rapidly over the last 2 decades. We aim to explore the effect of pretransplant systemic and device-related complications on posttransplant survival for patients bridged with LVADs.

MATERIALS AND METHODS

The United Network of Organ Sharing (Organ Procurement and Transplantation Network) database was queried for all adult heart transplant recipients (aged ≥ 18 y) transplanted from April 1, 2015, to June 31, 2018. Device-related complications included thrombosis, device infection, device malfunction, life-threatening arrhythmia, and other device complications. Systemic complications included a new dialysis need or ventilator dependence between the time of listing and transplantation, transfusion, or systemic infection requiring treatment with intravenous antibiotics within 2 wk of transplantation.

RESULTS

A total of 2131 patients were identified as requiring LVAD support before transplantation. LVAD patients had high rates of preoperative systemic complications (53%) and high rates of device-related complications (42.7% experienced at least one device-related complication). Kaplan-Meier analysis revealed a significantly decreased 1-y survival for LVAD patients bridged to transplantation who experienced a pretransplant systemic complication (P = 0.041). Interestingly, preoperative device-related complications had no effect on 1-y posttransplantation survival (P = 0.93). Multivariate Cox modeling revealed that systemic complications were associated with a significantly increased risk of posttransplant mortality for LVAD patients (hazard ratio 1.45; P = 0.033).

CONCLUSIONS

Recipients who suffered a systemic complication while awaiting heart transplantation experienced higher short-term mortality rates. Device-related complications do not appear to impact posttransplantation outcomes.

Early signatures of bleeding and mortality in patients on left ventricular assist device support: novel methods for personalized risk-stratification

Background: Left ventricular assist devices (LVADs) provide support for patients with end-stage heart failure. The aims of this study were to determine whether baseline analysis and early trends in routine laboratory data, platelet activity, and thromboinflammatory biomarkers following LVAD implantation reveal trends that predict personalized risks of one-year gastrointestinal (GI) bleeding, stroke, pump thrombosis, drive-line infections and mortality in patients on LVAD support. Methods: We performed an observational study at the University of Kentucky with 61 participants who underwent first-time LVAD implantation. Blood was collected at baseline and post-op days 0, 1, 3 and 6 as well as clinical follow-up. Demographics, clinical characteristics, one-year adverse events and routine laboratory data were collected from electronic medical records. Platelet function and plasma biomarkers were profiled. Results: Evaluation of routine laboratory results revealed that sustained thrombocytopenia and increased mean platelet volume (MPV) were associated with development of GI bleeding and mortality. Platelet function at follow-up visit predicted one-year bleeding events. Thrombotic biomarker sCD40L strongly predicted one-year GI bleeding at baseline before implantation and within the first week following LVAD implant. Conclusions: Early trends in routine bloodwork and platelet function may serve as novel signatures of patients at risk to experience adverse events.

Outcomes of Acute Inpatient Rehabilitation of Patients With Left Ventricular Assist Devices and Subsequent Stroke

OBJECTIVE

The aim of the study was to examine the functional outcomes and medical complications of patients with left ventricular assist device implantation and subsequent stroke during comprehensive inpatient rehabilitation.

DESIGN

Retrospective cohort study of 21 patients admitted to an inpatient rehabilitation facility between 2009 and 2015. Main outcome measurements include admission and discharge Functional Independence Measure, length of stay, and Functional Independence Measure efficiency.

RESULTS

The study included 17 male and 4 female patients aged 32-75 yrs. Eleven patients (52%) required transfer to an acute care hospital for evaluation. Fifteen patients completed inpatient rehabilitation with median [interquartile range] length of stay 26 [13.5-34] days (range = 7-59 days), median [interquartile range] Functional Independence Measure gain of 18 [12.5-32], and median [interquartile range] Functional Independence Measure efficiency of 1.0 [0.6-1.44]. Patients who required transfer to acute care during their course but ultimately completed inpatient rehabilitation (n = 5) demonstrated larger median [interquartile range] Functional Independence Measure gain (40 [23-42]) and longer median [interquartile range] length of stay (35 [35-42]) compared with patients who completed inpatient rehabilitation without transfer (Functional Independence Measure gain = 15 [9.25-26.5]; length of stay = 14.5 [11.5-26.25]).

CONCLUSIONS

Patients with left ventricular assist device implantation and subsequent stroke demonstrate functional gains during acute inpatient rehabilitation programs. A large percent of patients required transfer to acute care.

The Rehabilitation of Patients With Advanced Heart Failure After Left Ventricular Assist Device Placement: A Narrative Review

Because more patients with advanced heart failure are receiving a left ventricular assist device (LVAD) as destination therapy or a bridge to transplantation, there is increasing attention on functional outcomes and quality of life after LVAD implantation. Rehabilitation providers in the acute inpatient rehabilitation setting increasingly will treat patients with an LVAD and should understand the exercise physiology, medical management, rehabilitation considerations, and outcomes after rehabilitation for patients with an LVAD. The purpose of this article is to provide the physiatrist with a comprehensive understanding of the rehabilitation of patients with advanced heart failure and LVAD implantation. Changes in relevant organ system physiology and exercise physiology after LVAD are summarized. Safety of rehabilitation and program considerations for acute inpatient rehabilitation are reviewed. Recommendations for medical management and prevention of secondary complications seen in patients with an LVAD are outlined. A discussion of outcomes after acute inpatient rehabilitation, the dual diagnosis of stroke and LVAD placement, and long-term cognitive, functional, and quality-of-life outcomes after LVAD placement is presented.

Mechanical circulatory support costs in children bridged to heart transplantation - analysis of a linked database

BACKGROUND

Pediatric mechanical circulatory support (MCS) has evolved considerably over the past decade. Though marked improvements in waitlist survival have been realized, costs have not been reassessed. This project aimed to assess contemporary MCS costs in children bridged to heart transplant (HT).

METHODS

All pediatric HT recipients (2002-2016) were identified from a unique, linked PHIS/SRTR dataset. Costs were calculated from hospital charges, inflated to 2016 Dollars and adjusted for patient-specific characteristics using generalized linear mixed-effects models. Costs and length of stay (LOS) were compared across support strategies at the time of HT (no MCS, VAD, or ECMO) with select subgroup analyses.

RESULTS

A total of 2873 pediatric HT recipients were included; no MCS: 2268 (78.9%), VAD: 470 (16.4%), and ECMO: 135 (4.7%). Both VAD and ECMO were associated with greater total hospitalization costs compared to no MCS ($755,345 and $808,771 vs. $457,086; P < .001). Total costs and LOS were similar between VAD and ECMO groups; however, costs and LOS were greatest for VAD-supported patients in the pre-HT period and greatest for ECMO-supported patients post-HT. Post-HT costs and LOS were similar between patients who did not require MCS and those supported with a VAD ($324,887 and 18 days vs. $329,198 and 18 days respectively, p = NS). Outpatients with VAD support at HT demonstrated significantly lower total costs compared to those who were inpatient with continuous flow devices ($552,222 vs. $663,071, P = .003).

CONCLUSIONS

MCS as a bridge to HT in children is associated with greater total costs. While costs are similar between VAD and ECMO groups, the majority of costs associated with VAD support is incurred pre-HT while ECMO costs are incurred primarily post-HT. Discharging patients on VAD support awaiting HT may represent a strategy to reduce costs in this population.

Successful treatment of ventricular arrhythmic storm with percutaneous coronary intervention and catheter ablation in a patient with left ventricular assist device

INTRODUCTION

Ventricular arrhythmias are common in patients with advanced heart failure, which may also persist after sufficient intensive therapy for heart failure even with a left ventricular assist device. Although most ventricular arrhythmias have no hemodynamic relevance during left ventricular assist device support, some patients suffer from right ventricular decompensation due to ventricular arrhythmias resulting in severe hemodynamic deterioration and poor clinical outcomes.

METHODS

We describe herein an left ventricular assist device patient with refractory ventricular arrhythmic storm early after left ventricular assist device implantation.

RESULTS

The patient was admitted to our department after stenting of left anterior descending artery with subsequent polymorphic ventricular tachycardia and cardiogenic shock with ongoing multi-organ failure. After 6 days of extracorporeal life-support, a permanent left ventricular assist device was implanted. With postoperatively ongoing tachycardias, a subtotal right coronary artery occlusion was recanalized utilizing a drug-eluting stent. On the first post-intervention day, an additional catheter ablation was successfully performed. No further ventricular tachycardias were detected during the entire hospital stay and the further postoperative course was uneventful. The patient was transferred to a physiotherapy unit to improve his daily physical activities. He is currently at home and doing well 6 months after discharge.

CONCLUSIONS

Our case report demonstrates the feasibility of a successful therapeutic approach with a combination of interventional therapies such as coronary stenting and catheter ablation in a patient with persistent ventricular arrhythmias after assist device implantation.

Diagnosis of LVAD Thrombus using a High-Avidity Fibrin-Specific 99mTc Probe

Treatment of advanced heart failure with implantable LVADs is increasing, driven by profound unmet patient need despite potential serious complications: bleeding, infection, and thrombus. The experimental objective was to develop a sensitive imaging approach to assess early thrombus accumulation in LVADs under operational high flow and high shear rates.

Methods: A monomeric bifunctional ligand with a fibrin-specific peptide, a short spacer, and ^99mTc chelating amino acid sequence (F1A) was developed and compared to its tetrameric PEG analogue (F4A).

Results: ^99mTc attenuation by LVAD titanium (1 mm) was 23%. ^99mTc-F1A affinity to fibrin was K_d ~10 µM, whereas, the bound ^99mTc-F4A probe was not displaced by F1A (120,000:1). Human plasma interfered with ^99mTc-F1A binding to fibrin clot (p<0.05) in vitro, whereas, ^99mTc-F4A targeting was unaffected. The pharmacokinetic half-life of ^99mTc-F4A was 28% faster (124±41 min) than ^99mTc-F1A (176±26 min) with both being bioeliminated through the urinary system with negligible liver or spleen biodistribution. In mice with carotid thrombus, ^99mTc-F4A binding to the injured carotid was much greater (16.3±3.3 %ID/g, p=0.01) than that measured with an irrelevant negative control, ^99mTc-I4A (3.4±1.6 %ID/g). In an LVAD mock flow-loop (1:1, PBS:human plasma:heparin) operating at maximal flow rate, ^99mTc-F4A bound well to phantom clots in 2 min (p<0.05), whereas ^99mTc-F1A had negligible targeting. Excised LVADs from patients undergoing pump exchange or heart transplant were rewired, studied in the mock flow loop, and found to have spatially variable fibrin accumulations in the inlet and outlet cannulas and bearings.

Conclusions:^99mTc-F4A is a high-avidity prototype probe for characterizing thrombus in LVADs that is anticipated to help optimize anticoagulation, reduce thromboembolic events, and minimize pump exchange.

Intermediate-Term Risk of Stroke Following Cardiac Procedures in a Nationally Representative Data Set

Background

Studies on stroke risk following cardiac procedures addressed only perioperative and long‐term risk following limited higher‐risk procedures, were poorly generalizable, and often failed to stratify by stroke type. We calculated stroke risk in the intermediate risk period following cardiac procedures compared with common noncardiac surgeries and medical admissions.

Methods and Results

The Nationwide Readmissions Database contains readmission data for 49% of US admissions in 2013. We compared age‐adjusted stroke readmission rates up to 90 days postdischarge. We used Cox regression to calculate hazard ratios, up to 1 year, of stroke risk comparing transcatheter aortic valve replacement versus surgical aortic valve replacement and coronary artery bypass graft versus percutaneous coronary intervention. Procedures and diagnoses were identified by International Classification of Disease, Ninth Revision, Clinical Modification codes. After cardiac procedures, 90‐day ischemic stroke readmission rate was highest after transcatheter aortic valve replacement (2.05%); 90‐day hemorrhagic stroke rate was highest after left ventricular assist device placement (0.09%). The hazard ratio for ischemic stroke after transcatheter aortic valve replacement, compared with surgical aortic valve replacement, in fully adjusted Cox models was 1.86 (95% confidence interval, 1.12–3.08; P=0.016) and 6.17 (95% confidence interval, 1.97–19.33; P=0.0018) for hemorrhagic stroke. There was no difference between coronary artery bypass graft and percutaneous coronary intervention.

Conclusions

We demonstrated elevated readmission rates for ischemic and hemorrhagic stroke in the intermediate 30‐, 60‐, and 90‐day risk periods following common cardiac procedures. Furthermore, we found an elevated risk of stroke after transcatheter aortic valve replacement compared with surgical aortic valve replacement up to 1 year.

Arrhythmias in Patients with Cardiac Implantable Electrical Devices after Implantation of a Left Ventricular Assist Device

Utilization of continuous-flow left ventricular assist devices (CF-LVADs) for advanced heart failure is increasing, and the role of cardiac implantable electrical devices (CIED) is unclear. Prior studies of the incidence of arrhythmias and shocks are frequently limited by ascertainment. One hundred and seventy-eight patients were examined with a previous CIED who were implanted with a CF-LVAD. Medical history, medications, and CIED data from device interrogations were gathered. A cardiac surgery control group (n = 38) was obtained to control for surgical factors. Several clinically significant events increased after LVAD implantation: treated-zone ventricular arrhythmias (VA; p < 0.01), monitored-zone VA (p < 0.01), antitachycardia pacing (ATP)-terminated episodes (p < 0.01), and shocks (p = 0.01), although administered shocks later decreased (p < 0.01). Presence of a preimplant VA was associated with postoperative VA (odds ratio [OR]: 4.31; confidence interval [CI]: 1.5-12.3, p < 0.01). Relative to cardiac surgery, LVAD patients experienced more perioperative events (i.e., monitored VAs and shocks, p < 0.01 and p = 0.04). Neither implantable cardioverter defibrillator (ICD) shocks before implant nor early or late postimplant arrhythmias or shocks predicted survival (p = 0.07, p = 0.55, and p = 0.55). Our experience demonstrates time-dependent effects on clinically significant arrhythmias after LVAD implantation, including evidence that early LVAD-related arrhythmias may be caused by the unique arrhythmogenic effects of VAD implant.

Percutaneous transcatheter balloon dilatation and stenting to the inflow cannula stenosis of a left ventricular assist device

Left ventricular assist devices (LVAD) improve survival in patients with advanced heart failure but are prone to various complications causing mechanical failure. Inflow cannula stenosis presents a particular challenge often requiring invasive surgical repair. We present a novel transcatheter approach for stent delivery to successfully restore hemodynamic function in a patient with inflow cannula stenosis of a HeartMate II LVAD. © 2017 Wiley Periodicals, Inc.

Current status of mechanical circulatory support for treatment of advanced end-stage heart failure: successes, shortcomings and needs

INTRODUCTION

Heart failure (HF) remains a major global burden in terms of morbidity and mortality. Despite advances in pharmacological and resynchronization device therapy, many patients worsen to end-stage HF. Although the gold-standard treatment for such patients is heart transplantation, there will always be a shortage of donor hearts. Areas covered: A left ventricular assist device (LVAD) is a valuable option for these patients as a bridge measure (to recovery, to candidacy for transplant, or to transplant itself) or as destination therapy. This review describes the current indications for and complications of the most commonly implanted LVADs. In addition, we review the potential and promising new LVADs, including the HeartMate 3, MVAD, and other LVADs. Studies investigating each were identified through a combination of online database and direct extraction of studies cited in previously identified articles. Expert commentary: The goal of LVADs has been to fill the gap between patients with end-stage HF who would likely not benefit from heart transplantation and those who could benefit from a donor heart. As of now, the use of LVADs has been limited to patients with end-stage HF, but next-generation LVAD therapy may improve both survival and quality of life in less sick patients.

Benefits of ultra-fast-track anesthesia in left ventricular assist device implantation: a retrospective, propensity score matched cohort study of a four-year single center experience

BACKGROUND

The use of left ventricular assist devices (LVADs) has gained significant importance for treatment of end-stage heart failure. Fast-track procedures are well established in cardiac surgery, whereas knowledge of their benefits after LVAD implantation is sparse. We hypothesized that ultra-fast-track anesthesia (UFTA) with in-theater extubation or at a maximum of 4 h. after surgery is feasible in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level 3 and 4 patients and might prevent postoperative complications.

METHODS

From March, 2010 to March, 2012, 53 LVADs (50 Heart Mate II and 3 Heart Ware) were implanted in patients in our department. UFTA was successfully performed (LVAD _ultra ) in 13 patients. After propensity score matching, we compared the LVAD _ultra group with a matched group (LVAD _match ) receiving conventional anesthesia management.

RESULTS

Patients in the LVAD _ultra group had significantly lower incidences of pneumonia (p = 0.031), delirium (p = 0.031) and right ventricular failure (RVF) (p = 0.031). They showed a significantly higher cardiac index in the first 12 h. (p = 0.017); a significantly lower central venous pressure during the first 24 h. postoperatively (p = 0.005) and a significantly shorter intensive care unit (ICU) stay (p = 0.016). Kaplan-Meier analysis after four years of follow-up showed no significant difference in survival.

CONCLUSION

In this pilot study, we demonstrated the feasibility of ultra-fast-track anesthesia in LVAD implantation in selected patients with INTERMACS level 3-4. Patients had a lower incidence of postoperative complications, better hemodynamic performance, shorter length of ICU stay and lower incidence of RVF after UFTA. Prospective randomized investigations should examine the preservation of right ventricular function in larger numbers and identify appropriate selection criteria.

Asymptomatic Sustained Polymorphic Ventricular Tachycardia in a Patient with a Left Ventricular Assist Device: Case Report and what the Emergency Physician Should Know

BACKGROUND

Left ventricular assist devices (LVADs) are a viable treatment option for patients with end-stage heart failure. LVADs can improve survival, quality of life, and functional status. The indications for LVAD placement to support left ventricular function are temporary support, a bridge to transplantation, or destination therapy.

CASE REPORT

A 61-year-old man with past medical history significant for advanced congestive heart failure from ischemic cardiomyopathy, status post LVAD (HeartMate II; Thoratec Corporation, Pleasanton, CA) placement 2009 as destination therapy, presented to the Emergency Department (ED) with implantable cardiac defibrillators firing four times that morning. While in the care of Emergency Medical Services, he was in ventricular tachycardia, and they gave him a bolus of amiodarone 150 mg intravenously prior to arrival in the ED. He was reportedly alert and oriented without any chest pain on arrival to the ED, where an electrocardiogram was obtained showing polymorphic ventricular tachycardia. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians must be familiar with the atypical presentations of potentially lethal dysrhythmias in this patient population. They must also be familiar with the major adverse events after LVAD implantation. These include device malfunction, cardiac dysrhythmias, bleeding, thromboembolism, neurological events, and infection. The causes of device malfunction can include thrombus formation with hemolysis, mechanical failure of the impeller, and driveline lead fractures with electric failure. Although time is critical in the heart failure patient with an LVAD failure or complication, expert consultation with cardiology or the LVAD specialist should occur when possible.

New Management Strategies in Heart Failure

Despite >100 clinical trials, only 2 new drugs had been approved by the US Food and Drug Administration for the treatment of chronic heart failure in more than a decade: the aldosterone antagonist eplerenone in 2003 and a fixed dose combination of hydralazine-isosorbide dinitrate in 2005. In contrast, 2015 has witnessed the Food and Drug Administration approval of 2 new drugs, both for the treatment of chronic heart failure with reduced ejection fraction: ivabradine and another combination drug, sacubitril/valsartan or LCZ696. Seemingly overnight, a range of therapeutic possibilities, evoking new physiological mechanisms, promise great hope for a disease that often carries a prognosis worse than many forms of cancer. Importantly, the newly available therapies represent a culmination of basic and translational research that actually spans many decades. This review will summarize newer drugs currently being used in the treatment of heart failure, as well as newer strategies increasingly explored for their utility during the stages of the heart failure syndrome.

Physiologic effects of continuous-flow left ventricular assist devices

BACKGROUND

Within the past 10 years, continuous-flow left ventricular assist devices (LVADs) have replaced pulsatile-flow LVADs as the standard of care for both destination therapy and bridging patients to heart transplantation. Despite the rapid clinical adoption of continuous-flow LVADs, an understanding of the effects of continuous-flow physiology, as opposed to more natural pulsatile-flow physiology, is still evolving.

MATERIALS AND METHODS

A thorough review of the relevant scientific literature regarding the physiological and clinical effects of continuous-flow physiology was performed. These effects were analyzed on an organ system basis and include an evaluation of the cardiovascular, respiratory, hematologic, gastrointestinal, renal, hepatic, neurologic, immunologic, and endocrine systems.

RESULTS

Continuous-flow physiology is, generally speaking, well tolerated over the long term. However, several changes are manifest at the organ system level. Although many of these changes are without appreciable clinical significance, other changes, such as an increased rate of gastrointestinal bleeding, appear to be associated with continuous-flow physiology.

CONCLUSIONS

Continuous-flow LVADs confer a significant advantage over their pulsatile-flow counterparts with regard to size and durability. From a physiological standpoint, continuous-flow physiology has limited clinical effects at the organ system level. Although improved over previous generations, challenges with this technology remain. Approaching these problems with a combination of clinical and engineering solutions may be needed to achieve continued progression in the field of durable mechanical circulatory support.

Fully Magnetically Levitated Left Ventricular Assist System for Treating Advanced HF: A Multicenter Study

BACKGROUND

The HeartMate 3 left ventricular assist system (LVAS) is intended to provide long-term support to patients with advanced heart failure. The centrifugal flow pump is designed for enhanced hemocompatibility by incorporating a magnetically levitated rotor with wide blood-flow paths and an artificial pulse.

OBJECTIVES

The aim of this single-arm, prospective, multicenter study was to evaluate the performance and safety of this LVAS.

METHODS

The primary endpoint was 6-month survival compared with INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support)-derived performance goal. Patients were adults with ejection fraction ≤ 25%, cardiac index ≤ 2.2 l/min/m(2) without inotropes or were inotrope-dependent on optimal medical management, or listed for transplant.

RESULTS

Fifty patients were enrolled at 10 centers. The indications for LVAS support were bridge to transplantation (54%) or destination therapy (46%). At 6 months, 88% of patients continued on support, 4% received transplants, and 8% died. Thirty-day mortality was 2% and 6-month survival 92%, which exceeded the 88% performance goal. Support with the fully magnetically levitated LVAS significantly reduced mortality risk by 66% compared with the Seattle Heart Failure Model-predicted survival of 78% (p = 0.0093). Key adverse events included reoperation for bleeding (14%), driveline infection (10%), gastrointestinal bleeding (8%), and debilitating stroke (modified Rankin Score > 3) (8%). There were no pump exchanges, pump malfunctions, pump thrombosis, or hemolysis events. New York Heart Association classification, 6-min walk test, and quality-of-life scores showed progressive and sustained improvement.

CONCLUSIONS

The results show that the fully magnetically levitated centrifugal-flow chronic LVAS is safe, with high 30-day and 6-month survival rates, a favorable adverse event profile, and improved quality of life and functional status. (HeartMate 3™ CE Mark Clinical Investigation Plan [HM3 CE Mark]; NCT02170363).

Inhaled Nitric Oxide Augments Left Ventricular Assist Device Capacity by Ameliorating Secondary Right Ventricular Failure

Clinical right ventricular (RV) impairment can occur with left ventricular assist device (LVAD) use, thereby compromising the therapeutic effectiveness. The underlying mechanism of this RV failure may be related to induced abnormalities of septal wall motion, RV distension and ischemia, decreased LV filling, and aberrations of LVAD flow. Inhaled nitric oxide (NO), a potent pulmonary vasodilator, may reduce RV afterload, and thereby increase LV filling, LVAD flow, and cardiac output (CO). To investigate the mechanisms associated with LVAD-induced RV dysfunction and its treatment, we created a swine model of hypoxia-induced pulmonary hypertension and acute LVAD-induced RV failure and assessed the physiological effects of NO. Increased LVAD speed resulted in linear increases in LVAD flow until pulse pressure narrowed. Higher speeds induced flow instability, LV collapse, a precipitous fall of both LVAD flow and CO. Nitric oxide (20 ppm) treatment significantly increased the maximal achievable LVAD speed, LVAD flow, CO, and LV diameter. Nitric oxide resulted in decreased pulmonary vascular resistance and RV distension, increased RV ejection, promoted LV filling and improved LVAD performance. Inhaled NO may thus have broad utility for the management of biventricular disease managed by LVAD implantation through the effects of NO on LV and RV wall dynamics.

Singularity now: using the ventricular assist device as a model for future human-robotic physiology

In our 21^st century world, human-robotic interactions are far more complicated than Asimov predicted in 1942. The future of human-robotic interactions includes human-robotic machine hybrids with an integrated physiology, working together to achieve an enhanced level of baseline human physiological performance. This achievement can be described as a biological Singularity. I argue that this time of Singularity cannot be met by current biological technologies, and that human-robotic physiology must be integrated for the Singularity to occur. In order to conquer the challenges we face regarding human-robotic physiology, we first need to identify a working model in today's world. Once identified, this model can form the basis for the study, creation, expansion, and optimization of human-robotic hybrid physiology. In this paper, I present and defend the line of argument that currently this kind of model (proposed to be named "IshBot") can best be studied in ventricular assist devices - VAD.

Outcomes after stroke complicating left ventricular assist device

BACKGROUND

Stroke is one of the leading complications during continuous flow-left ventricular assist device (CF-LVAD) support. Risk factors have been well described, although less is known regarding treatment and outcomes. We present a large single-center experience on stroke outcome and transplant eligibility by stroke sub-type and severity in CF-LVAD patients.

METHODS

Between January 1, 2008, and April 1, 2015, 301 patients underwent CF-LVAD (266 HeartMate II [HM I], Thoratec Corp, Pleasanton, CA; 35 HeartWare [HVAD], HeartWare International Inc, Framingham, MA). Stroke was defined as a focal neurologic deficit with abnormal neuroimaging. Intracerebral hemorrhage (ICH) definition excluded sub-dural hematoma and hemorrhagic conversion of an ischemic stroke (IS). Treatment in IS included intra-arterial embolectomy when appropriate; treatment in ICH included reversal of coagulopathy. Stroke severity was measured using the National Institutes of Health Stroke Scale (NIHSS). Outcomes were in-hospital mortality and transplant status.

RESULTS

Stroke occurred in 40 patients: 8 ICH (4 HM II, 4 HVAD) and 32 IS (26 HM II, 6 HVAD). Among 8 ICH patients, there were 4 deaths (50%), with NIHSS of 18.8 ± 13.7 vs 1.8 ± 1.7 in survivors (p = 0.049). Among 32 IS patients, 12 had hemorrhagic conversion and 5 were treated with intra-arterial embolectomy. There were 9 deaths (28%), with NIHSS of 16.2 ± 10.8 vs 7.0 ± 7.6 in survivors (p = 0.011). Among the 32 IS patients, 12 underwent transplant, and 1 is awaiting transplant. No ICH patients received a transplant.

CONCLUSIONS

In-hospital mortality after stroke is significantly affected by the initial neurologic impairment. Patients with IS appear to benefit the most from in-hospital treatment and often make sufficient recovery to be able to progress to transplant.

A randomized controlled pilot trial to improve advance care planning for LVAD patients and their surrogates

OBJECTIVES

To examine feasibility, acceptability and preliminary effects of an advance care planning (ACP) intervention, SPIRIT-HF, in LVAD patients and their surrogates.

BACKGROUND

LVADs may improve HF symptoms but they are not curative. Thus, ACP is needed to prepare patients and surrogates for end-of-life (EOL) decision-making.

METHODS

Bridge to transplant and destination therapy LVAD patient-surrogate dyads were randomized to either SPIRIT-HF or usual care. Percentages of eligible dyads who were enrolled and completed the study determined feasibility. Analysis of interviews with SPIRIT dyads determined acceptability. Group comparisons of dyad congruence, patient's decisional conflict, and surrogate's decision-making confidence determined preliminary effects.

RESULTS

Of 38 eligible dyads, 29 (76%) were enrolled, randomized, and completed the study. The 14 intervention dyads characterized SPIRIT-HF as beneficial. All dyads demonstrated improvement in outcomes. However, SPIRIT-HF dyads tended toward greater congruence on patient EOL treatment goals.

CONCLUSIONS

SPIRIT-HF is feasible and acceptable. Results will inform future trials.

Hemodynamic changes and retrograde flow in LVAD failure

In the event of left ventricular assist device (LVAD) failure, we hypothesized that rotary blood pumps will experience significant retrograde flow and induce adverse physiologic responses. Catastrophic LVAD failure was investigated in computer simulation with pulsatile, axial, and centrifugal LVAD, mock flow loop with pulsatile (PVAD) and centrifugal (ROTAFLOW), and healthy and chronic ischemic heart failure bovine models with pulsatile (PVAD), axial (HeartMate II), and centrifugal (HVAD) pumps. Simulated conditions were LVAD "off" with outflow graft clamped (baseline), LVAD "off" with outflow graft unclamped (LVAD failure), and LVAD "on" (5 L/min). Hemodynamics (aortic and ventricular blood pressures, LVAD flow, and left ventricular volume), echocardiography (cardiac volumes), and end-organ perfusion (regional blood flow microspheres) were measured and analyzed. Retrograde flow was observed with axial and centrifugal rotary pumps during LVAD failure in computer simulation (axial = -3.4 L/min, centrifugal = -2.8 L/min), mock circulation (pulsatile = -0.1 L/min, centrifugal = -2.7 L/min), healthy (pulsatile = -1.2 ± 0.3 L/min, axial = -2.2 ± 0.2 L/min, centrifugal = -1.9 ± 0.3 L/min), and ischemic heart failure (centrifugal = 2.2 ± 0.7 L/min) bovine models for all test conditions (p < 0.05). Differences between axial and centrifugal LVAD were statistically indiscernible. Retrograde flow increased ventricular end-systolic and end-diastolic volumes and workload, and decreased myocardial and end-organ perfusion during LVAD failure compared with baseline, LVAD support, and pulsatile LVAD failure.

National Trends in Utilization, Mortality, Complications, and Cost of Care After Left Ventricular Assist Device Implantation From 2005 to 2011

BACKGROUND

Left ventricular assist devices (LVADs) have shown survival benefit in end-stage heart failure patients. LVAD technology has evolved considerably with the development of continuous-flow devices.

METHODS

The Nationwide Inpatient Sample was queried from 2005 to 2011 using International Classification of Diseases, 9th Edition procedure code 37.66, Insertion of Implantable Heart System, in any procedure field. Patients with primary diagnosis of orthotopic heart transplant or use of temporary mechanical circulatory support devices were excluded. Procedural complications were identified using International Classification of Diseases, 9th Edition codes and patient safety indicators. Cochran-Armitage and Cuzick tests for trend were used to identify time trends for categorical and continuous variables, respectively.

RESULTS

There were 2,038 LVAD implantations from 2005 to 2011. LVAD use increased from 127 procedures in 2005 to 506 procedures in 2011, and in-hospital mortality declined from 47.2% to 12.7% (p < 0.001), with sharp inflection points in the year 2008. Average length of stay decreased from 44 days in the pulsatile-flow era (2005 to 2007) to 36 days in the continuous-flow era (2008 to 2011). Cost of hospitalization increased from $194,380 in 2005 to $234,808 in 2011 but remained constant from 2008 to 2011. There was a trend of increased incidence of major bleeding and thromboembolism and decreased incidence of infectious and iatrogenic cardiac complications in the continuous-flow era.

CONCLUSIONS

LVAD use has increased and in-hospital mortality and LOS after LVAD implantation have declined. These changes coincide with United States Food and Drug Administration (FDA) approval of continuous-flow devices in 2008.

Neurologic aspects of cardiac emergencies

In this review, cardiac arrest is discussed, with a focus on neuroprognostication and the emerging data, with regard to identifying more accurate predictors of neurologic outcomes in the era of therapeutic hypothermia. Topics discussed include recent controversies with regard to targeted temperature management in comatose survivors of cardiac arrest; neurologic complications associated with surgical disease and procedures, namely aortic dissection, infective endocarditis, left ventricular assist devices, and coronary artery bypass grafting; and the cause, pathogenesis, and management of neurogenic stunned myocardium.

Advances in the understanding and management of heart transplantation

Cardiac transplantation represents one of the great triumphs in modern medicine and remains the cornerstone in the treatment of advanced heart failure. In this review, we contextualize pivotal developments in our understanding and management of cardiac transplant immunology, histopathology, rejection surveillance, drug development and surgery. We also discuss current limitations in their application and the impact of the left ventricular assist devices in bridging this gap.