Persistent blood stream infection in patients supported with a continuous-flow left ventricular assist device is associated with an increased risk of cerebrovascular accidents

In search of similarity in adverse events journeys of patients with left ventricular assist devices

OBJECTIVE

The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Event data set contains an expansive collection of longitudinal evidence of the course of adverse events (AEs) of >15,000 patients who have received a left ventricular assist device (LVAD). Buried in the huge Event data set is knowledge that can provide a deeper understanding of the patterns of the "AE journey" of patients with LVAD. Thus, the goal of this study was to examine the Event data set from a comprehensive perspective to identify unique relationships and patterns of AEs, alert potential challenges, and suggest future research directions.

METHODS

A sequential pattern mining algorithm called SPADE (ie, Sequential PAttern Discovery using Equivalence classes) was applied to 86,912 recorded AEs of 15,820 patients with a continuous-flow LVAD between 2008 and 2016, extracted from the publicly accessible INTERMACS registry. The patterns of AE journey were investigated by posing 5 descriptive research questions about most common types of AE, concomitant AEs, AE sequences, AE subsequences, and interesting relations between AEs.

RESULTS

The analysis revealed several characteristics of patterns of the AE journey of patients who received an LVAD that accounts for the types and temporal ordering of successive AEs, combinations of AEs, and their timing after surgery.

CONCLUSIONS

The high diversity and sparsity of the types and timing of AE occurrences make the AE journeys of patients dissimilar from each other, impeding the discovery of highly-patterned AE journeys among the patients. This study suggests 2 salient directions for future studies to tackle this issue using cluster analysis to cluster patients into more similar groups and translate these results into a practical clinical tool to forecast the next AE based on the history of previous AEs.

18F-FDG PET/CT in left ventricular assist device infections: In-depth characterization and clinical implications

BACKGROUND

Previous retrospective studies suggest a good diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/computed tomography (CT) in left ventricular assist device (LVAD) infections. Our aim was to prospectively evaluate the role of PET/CT in the characterization and impact on clinical management of LVAD infections.

METHODS

A total of 40 patients (aged 58 [53-62] years) with suspected LVAD infection and 5 controls (aged 69 [64-71] years) underwent 18F-FDG-PET/CT. Four LVAD components were evaluated: exit site and subcutaneous driveline (peripheral), pump pocket, and outflow graft. The location with maximal uptake was considered the presumed site of infection. Infection was confirmed by positive culture (exit site or blood) and/or surgical findings.

RESULTS

Visual uptake was present in 40 patients (100%) in the infection group vs 4 (80%) control subjects. For each individual component, the presence of uptake was more frequent in the infection than in the control group. The location of maximal uptake was most frequently the pump pocket (48%) in the infection group and the peripheral components (75%) in the control group. Maximum standard uptake values (SUVmax) were higher in the infection than in the control group: SUVmax (average all components): 6.9 (5.1-8.5) vs 3.8 (3.7-4.3), p = 0.002; SUVmax (location of maximal uptake): 10.6 ± 4.0 vs 5.4 ± 1.9, p = 0.01. Pump pocket infections were more frequent in patients with bacteremia than without bacteremia (79% vs 31%, p = 0.011). Pseudomonas (32%) and methicillin-susceptible Staphylococcus aureus (29%) were the most frequent pathogens and were associated with pump pocket infections, while Staphylococcus epidermis (11%) was associated with peripheral infections. PET/CT affected the clinical management of 83% of patients with infection, resulting in surgical debridement (8%), pump exchange (13%), and upgrade in the transplant listing status (10%), leading to 8% of urgent transplants.

CONCLUSIONS

18F-FDG-PET/CT enables the diagnosis and characterization of the extent of LVAD infections, which can significantly affect the clinical management of these patients.

Bleeding and thrombotic complications and their impact on mortality in patients supported with left ventricular assist device for cardiogenic shock

INTRODUCTION

Thrombosis and bleeding are major complications in patients supported with left ventricular assist devices (LVADs). We aimed to assess the incidence of bleeding and thrombosis in patients supported with a HeartWare left ventricular assist device (HVAD), their predictive factors and their impact on mortality.

METHODS

A single centre retrospective observational study of patients supported with HVAD over 5 years from January 2015 to October 2020.

RESULTS

A total 139 patients (median age 52.5, 72.1% male) were included for analysis. The probability of 1-year survival was 73.1%. Advanced age (>60 years) and EuroSCORE II score (>20%) were independently associated with reduced survival. Major bleeding and thrombosis occurred in 46.8% and 35.3% respectively. Secondary mechanical circulatory support (MCS) increased likelihood of experiencing major bleeding (HR: 2.76, 95%1.65-4.62, p < 0.0001) whilst patients receiving aspirin were protected from bleeding and thrombosis (HR: 0.34 95% CI 0.19-0.58, p < 0.001). Pre-operative anaemia (HR: 3.02, 95% CI: 1.6-5.7, p = 0.014) and use of a secondary MCS device (HR: 2.78, 95% CI: 1.2-6.3, p = 0.001) were associated with an increased risk of thrombosis. Patients with any major bleeding (with or without thrombosis) had a 7.68-fold (95% CI 3.5-16.8) increased risk of death compared to those without. In contrast, 'thrombosis only' patients had 4.23-fold (95% CI 1.8-10.2) increased risk of death compared to those without thrombosis. The risk of mortality was increased in patients with any thrombosis and the risk of death was highest in patients with major bleeding and thrombosis (HR: 16.49 [95% CI 7.7-35.3]).

CONCLUSIONS

Major bleeding and thrombosis significantly increase the 1-year mortality. Optimal perioperative haemostasis and anticoagulation remains crucial in patients supported with HVAD.

Mortality following durable left ventricular assist device implantation by timing and type of first infection

OBJECTIVE

Although infections are common after left ventricular assist device implantation, the relationship between timing and type of first infection with regard to mortality is less well understood.

METHODS

The Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support patients receiving a primary left ventricular assist device from April 2012 to May 2017 were included. The primary exposure was defined 3 ways: any infection, timing of first infection (early: ≤90 days; intermediate: 91-180 days; late: >180 days), and type (ventricular assist device specific, ventricular assist device related, non-ventricular assist device). The association between first infection and all-cause mortality was estimated using Cox regression.

RESULTS

The cohort included 12,957 patients at 166 centers (destination therapy: 47.4%, bridge-to-transplant: 41.2%). First infections were most often non-ventricular assist device (54.2%). Rates of first infection were highest in the early interval (10.7/100 person-months). Patients with any infection had a significantly higher adjusted hazard of death (hazard ratio, 2.63; 2.46-2.86). First infection in the intermediate interval was associated with the largest increase in adjusted hazard of death (hazard ratio, 3.26; 2.82-3.78), followed by late (hazard ratio, 3.13; 2.77-3.53) and early intervals (hazard ratio, 2.37; 2.16-2.60). Ventricular assist device-related infections were associated with the largest increase in hazard of death (hazard ratio, 3.02; 2.69-3.40), followed by ventricular assist device specific (hazard ratio, 2.92; 2.57-3.32) and non-ventricular assist device (hazard ratio, 2.42; 2.20-2.65).

CONCLUSIONS

Relative to those without infection, patients with any postimplantation infection had an increased risk of death. Ventricular assist device-related infections and infections occurring in the intermediate interval were associated with the largest increase in risk of death. After left ventricular assist device implantation, infection prevention strategies should target non-ventricular assist device infections in the first 90 days, then shift to surveillance/prevention of driveline infections after 90 days.

Infections in Patients With Left Ventricular Assist Devices: Current State and Future Perspectives

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment.

Hypoxic-Ischemic Brain Injury in ECMO: Pathophysiology, Neuromonitoring, and Therapeutic Opportunities

Extracorporeal membrane oxygenation (ECMO), in conjunction with its life-saving benefits, carries a significant risk of acute brain injury (ABI). Hypoxic-ischemic brain injury (HIBI) is one of the most common types of ABI in ECMO patients. Various risk factors, such as history of hypertension, high day 1 lactate level, low pH, cannulation technique, large peri-cannulation PaCO2 drop (∆PaCO2), and early low pulse pressure, have been associated with the development of HIBI in ECMO patients. The pathogenic mechanisms of HIBI in ECMO are complex and multifactorial, attributing to the underlying pathology requiring initiation of ECMO and the risk of HIBI associated with ECMO itself. HIBI is likely to occur in the peri-cannulation or peri-decannulation time secondary to underlying refractory cardiopulmonary failure before or after ECMO. Current therapeutics target pathological mechanisms, cerebral hypoxia and ischemia, by employing targeted temperature management in the case of extracorporeal cardiopulmonary resuscitation (eCPR), and optimizing cerebral O2 saturations and cerebral perfusion. This review describes the pathophysiology, neuromonitoring, and therapeutic techniques to improve neurological outcomes in ECMO patients in order to prevent and minimize the morbidity of HIBI. Further studies aimed at standardizing the most relevant neuromonitoring techniques, optimizing cerebral perfusion, and minimizing the severity of HIBI once it occurs will improve long-term neurological outcomes in ECMO patients.

Added value of semi-quantitative analysis of [18F]FDG PET/CT for the diagnosis of device-related infections in patients with a left ventricular assist device

AIMS

Left ventricular assist devices (LVADs) improve quality of life and survival in patients with advanced heart failure, but device-related infections (DRIs) remain cumbersome. We evaluated the diagnostic capability of [18F]FDG PET/CT, factors affecting its accuracy, and the additive value of semi-quantitative analysis for the diagnosis of DRI.

METHODS AND RESULTS

LVAD recipients undergoing [18F]FDG PET/CT between 2012 and 2020 for suspected DRI were retrospectively included. [18F]FDG PET/CT was performed and evaluated in accordance with EANM guidelines. The final diagnosis of DRI, based on multidisciplinary consensus and findings during surgery, whenever performed, was used as the reference for diagnosis. 41 patients were evaluated for 59 episodes of suspected DRI. The clinical evaluation established driveline infection in 32 (55%) episodes, central device infection in 6 (11%), and combined infection in 2 (4%). Visual analysis of [18F]FDG PET/CT achieved a sensitivity and specificity for driveline infections of 0.79 and 0.71, respectively, whereas semi-quantitative analysis achieved a sensitivity and specificity of 0.94 and 0.83, respectively. For central device component infection, visual analysis of [18F]FDG PET/CT achieved a sensitivity and specificity of 0.75 and 0.60, respectively. Semi-quantitative analysis using SUVratio achieved a sensitivity and specificity of 1.0 and 0.8, respectively. The increase of specificity for central component infection was statistically significant (P = 0.05).

CONCLUSIONS

[18F]FDG PET/CT reliably predicts the presence of DRI in LVAD recipients. Semi-quantitative analysis may increase the specificity of [18F]FDG PET/CT for the analysis of central device component infection and should be considered in equivocal cases after visual analysis.

Infection calls for thrombosis: Fact or superstition?

Despite all the efforts, pump thrombosis and thromboembolic complications still remain among the most dreadful complications after long-term ventricular assist device implantation. There is growing evidence that infections, especially blood stream infections predispose to a prothrombotic state despite anticoagulation, and frequently leads to thrombosis and/or embolic events as a consequence. In this short comment, the article by Bouzas et al with heterodox, if not unsettling, conclusions is discussed.

HFSA Expert Consensus Statement on the Medical Management of Patients on Durable Mechanical Circulatory Support

The medical management of patients supported with durable continuous flow left ventricular assist device (LVAD) support encompasses pharmacologic therapies administered in the preoperative, intraoperative, postoperative and chronic LVAD support stages. As patients live longer on LVAD support, the risks of LVAD-related complications and progression of cardiovascular and other diseases increase. Using existing data from cohort studies, registries, randomized trials and expert opinion, this Heart Failure Society of America Consensus Document on the Medical Management of Patients on Durable Mechanical Circulatory Support offers best practices on the management of patients on durable MCS, focusing on pharmacological therapies administered to patients on continuous flow LVADs. While quality data in the LVAD population are few, the utilization of guideline directed heart failure medical therapies (GDMT) and the importance of blood pressure management, right ventricular preload and afterload optimization, and antiplatelet and anticoagulation regimens are discussed. Recommended pharmacologic regimens used to mitigate or treat common complications encountered during LVAD support, including arrhythmias, vasoplegia, mucocutaneous bleeding, and infectious complications are addressed. Finally, this document touches on important potential pharmacological interactions from anti-depressants, herbal and nutritional supplements of relevance to providers of patients on LVAD support.

Neurologic Complications in Patients With Left Ventricular Assist Devices

Left ventricular assist device (LVAD) use has revolutionised the care of patients with advanced heart failure, allowing more patients to survive until heart transplantation and providing improved quality for patients unable to undergo transplantation. Despite these benefits, improvements in device technology, and better clinical care and experience, LVADs are associated with neurologic complications. This review provides information on the incidence, risk factors, and management of neurologic complications among LVAD patients. Although scant guidelines exist for the evaluation and management of neurologic complications in LVAD patients, a high index of suspicion can prompt early detection of neurologic complications which may improve overall neurologic outcomes. A better understanding of the implications of continuous circulatory flow on systemic and cerebral vasculature is necessary to reduce the common occurrence of neurologic complications in this population.

Molecular Imaging of Valvular Diseases and Cardiac Device Infection

The use of positron emission tomography imaging with 18F-fluorodeoxyglucose in the diagnostic workup of patients with suspected prosthetic valve endocarditis and cardiac device infection (implantable electronic device and left ventricular assist device) is gaining momentum in clinical practice. However, in the absence of prospective randomized trials, guideline recommendations about 18F-fluorodeoxyglucose positron emission tomography in this setting are currently largely based on expert opinion. Measurement of aortic valve microcalcification occurring as a healing response to valvular inflammation using 18F-sodium fluoride positron emission tomography represents another promising clinical approach, which is associated with both the risk of native valve stenosis progression and bioprosthetic valve degeneration in research trials. In this review, we consider the role of molecular imaging in cardiac valvular diseases, including aortic stenosis and valvular endocarditis, as well as cardiac device infections.

Infections in LVAD patients

Infections in LVAD patients continue to be a major cause of morbidity and mortality. One needs to separate between early infections which are mostly driven by the general state of the patient before implant, and infections during long term support, mostly related to drive line issues. A diligent risk stratification before implant and close follow up after implant will help to reduce the incidence of infection.

Infections in LVAD patients

Infections in left ventricular assist device (LVAD) patients remain common. Differentiating into device related and non-device related infection is crucial. The incidence of non-device related infections seems to be more determined by the overall condition of the LVAD recipient. Device related infections can be treated by innovative surgical approaches or by transplant. Infection increases the risk of mortaility while on LVAD.

Endovascular therapy for intracranial infectious aneurysms associated with a left ventricular assist device: illustrative case

BACKGROUND

Cerebrovascular events and infection are among the most common complications of left ventricular assist device (LVAD) therapy. The authors reported on a patient with an infectious intracranial aneurysm (IIA) associated with LVAD infection that was successfully occluded by endovascular therapy.

OBSERVATIONS

A 37-year-old man with severe heart failure received an implantable LVAD. He was diagnosed with candidemia due to driveline infection 44 months after LVAD implantation, and empirical antibiotic therapy was started. After 4 days of antibiotic treatment, the patient experienced sudden dizziness. Computed tomography (CT) revealed subarachnoid hemorrhage in the right frontal lobe, and CT angiography revealed multiple aneurysms in the peripheral lesion of the anterior cerebral artery (ACA) and middle cerebral artery. Two weeks and 4 days after the first bleeding, aneurysms on the ACA reruptured. Each aneurysm was treated with endovascular embolization using n-butyl cyanoacrylate. Subsequently, the patient had no rebleeding of IIAs. The LVAD was replaced, and bloodstream infection was controlled. He received a heart transplant and was independent 2 years after the heart transplant.

LESSONS

LVAD-associated IIAs have high mortality and an increased risk of surgical complications. However, endovascular obliteration may be safe and thus improve prognosis.

Does infection predispose to thrombosis during long term ventricular assist device support?

BACKGROUND

Infections and thrombotic events remain life-threatening complications in patients with ventricular assist devices (VAD).

METHODS

We describe the relationship between both events in our cohort of patients (n=220) supported with the HeartWare VAD (HVAD). This is a retrospective analysis of patients undergoing HVAD implantation between July 2009 and March 2019 at the Freeman Hospital, Newcastle upon Tyne, United Kingdom.

RESULTS

Infection was the most common adverse event in HVAD patients, with 125 patients (56.8%) experiencing ≥ one infection (n=168, 0.33 event-per-person-year-EPPY), followed by pump thrombosis (PT) in 61 patients (27.7%, 0.16 EPPY). VAD-specific infections were the largest group of infections. Of the 125 patients who had an infection, 66 (53%) had a thrombotic event. Both thrombotic events and infections were related to the duration of support, though there was only limited evidence that infections predispose to thrombosis. Those with higher than median levels of CRP during the infection were more likely to have an ischaemic stroke (IS) (34.5% vs 16.7%, p=0.03), though not PT or a combined thrombotic event (CTE: first PT or IS). However, in multivariate analysis there was no significant effect of infection predisposing to CTE.

CONCLUSIONS

Infection and thrombotic events are significant adverse events related to the duration of support in patients receiving HVADs. Infections do not clearly predispose to thrombotic events.

Intracranial Mycotic Aneurysm after Left Ventricular Assist Device Implantation Treated with Trans-arterial Embolization via the Brachial Artery: A Case Report

Implantation of left ventricular assist device (LVAD) is widely performed in patients with end-stage chronic heart failure. Infection and stroke are major complications after LVAD implantation. However, the incidence of intracranial mycotic aneurysm after LVAD implantation is rare, and with no standard of care. In this study, we describe a case of an intracranial mycotic aneurysm after LVAD implantation that was successfully treated with trans-arterial embolization (TAE) with N-butyl 2-cyanoacrylate (NBCA) via the brachial artery. A 49-year-old man with a history of implantation of LVAD for ischemic cardiomyopathy was admitted to our institution. He had infectious endocarditis and was administered systemic antibiotics. At 3 weeks after admission, intracranial mycotic aneurysm of the left posterior parietal artery was detected during a diagnostic examination for asymptomatic intracranial hemorrhage. Anticoagulant therapy was administered to prevent thromboembolic complications of LVAD implantation. Under local anesthesia, TAE with NBCA was performed via the brachial artery because of the tortuous anatomy of the origin of the innominate artery and implant of the aortic arch. The aneurysm was completely obliterated. The patient was discharged without neurological deficits. TAE using NBCA could be an effective modality for the treatment of intracranial mycotic aneurysm after LVAD implantation.

Effect of Ventricular Assist Device Self-care Simulation-Based Mastery Learning on Driveline Exit Site Infections: A Pilot Study

BACKGROUND

Ventricular assist device simulation-based mastery learning (SBML) results in better patient and caregiver self-care skills compared with usual training.

OBJECTIVE

The aim of this study was to evaluate the effect of SBML on driveline exit site infections.

METHODS

We compared the probability of remaining infection free at 3 and 12 months between patients randomized to SBML or usual training.

RESULTS

The SBML-training group had no infections at 3 months and 2 infections at 12 months, yielding a Kaplan-Meier estimate of the probability of remaining infection free of 0.857 (95% confidence interval [CI], 0.692-1.00) at 12 months. The usual-training group had 6 infections at 3 months with no additional infections by 12 months. Kaplan-Meier estimates of remaining infection free at 3 and 12 months were 0.878 (95% CI, 0.758-1.00) and 0.748 (95% CI, 0.591-0.946), respectively. Time-to-infection distributions for SBML versus usual training showed a difference in 12-month infection rates of 0.109 (P = .07).

CONCLUSIONS

Ventricular assist device self-care SBML resulted in fewer 12-month infections.

Heart Failure Association of the European Society of Cardiology position paper on the management of left ventricular assist device-supported patients for the non-left ventricular assist device specialist healthcare provider: Part 2: at the emergency department

The improvement in left ventricular assist device (LVAD) technology and scarcity of donor hearts have increased dramatically the population of the LVAD‐supported patients and the probability of those patients to present to the emergency department with expected and non‐expected device‐related and patient–device interaction complications. The ageing of the LVAD‐supported patients, mainly those supported with the ‘destination therapy’ indication, increases the risk for those patients to suffer from other co‐morbidities common in the older population. In this second part of the trilogy on the management of LVAD‐supported patients for the non‐LVAD specialist healthcare provider, definitions and structured approach to the LVAD‐supported patient presenting to the emergency department with bleeding, neurological event, pump thrombosis, chest pain, syncope, and other events are presented. The very challenging issue of declaring death in an LVAD‐supported patient, as the circulation is artificially preserved by the device despite no other signs of life, is also discussed in detail.

Cerebral Microvascular Injury in Patients with Left Ventricular Assist Device: a Neuropathological Study

Strokes are common among patients with left ventricular devices (LVAD). We hypothesize that there is ongoing cerebral microvascular injury with LVAD support and aim to describe this among LVAD-implanted patients through post-mortem neuropathologic evaluation. We identified and reviewed medical records of LVAD patients who underwent brain autopsy between January 2006 and December 2019 at a tertiary center. Cerebral injury was defined as both gross and microscopic injuries within the intracranial space including cerebral infarct (CI), hypoxic-ischemic brain injury (HIBI), intracranial hemorrhage (ICH), and cerebral microvascular injury. Cerebral microvascular injury was defined as microscopic brain intraparenchymal or perivascular hemorrhage, perivascular hemosiderin deposition, and perivascular inflammation. Twenty-one patients (median age = 57 years, 67% male) had autopsy after LVAD support (median LVAD support = 51 days). The median time from death to autopsy was 19 h. All 21 patients had cerebral injuries and 19 (90%) patients had cerebral microvascular injuries. Fourteen patients (78%) harbored more than one type of cerebral injury. On gross examination, 8 patients (38%) had CI, and 6 patients (29%) had ICH. On microscopic exam, 12 patients (57%) had microscopic intraparenchymal hemorrhage, 3 patients (14%) had perivascular hemorrhage, 11 patients (43%) had perivascular hemosiderin deposition, 5 patients (24%) had meningeal hemorrhage, 13 patients had chronic perivascular inflammation (62%), and 2 patients had diffuse HIBI (10%). Among patients with LVAD, there is a high prevalence of subclinical microvascular injuries and cerebral microbleeds (CMBs), which may provide some insights to the cause of frequent cerebral injury in LVAD population.

Cerebrovascular Events in Patients With Centrifugal-Flow Left Ventricular Assist Devices: Propensity Score-Matched Analysis From the Intermacs Registry

BACKGROUND

Ischemic and hemorrhagic cerebrovascular accidents remain common among patients with centrifugal-flow left ventricular assist devices, despite improvements in survival and device longevity. We compared the incidence of neurologic adverse events (NAEs) associated with 2 contemporary centrifugal-flow left ventricular assist devices: the Abbott HeartMate3 (HM3) and the Medtronic HeartWare HVAD (HVAD).

METHODS

Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a centrifugal-flow left ventricular assist device as a primary isolated implant between January 1, 2017, and September 30, 2019. Major NAEs were defined as transient ischemic attack, ischemic cerebrovascular accident, or hemorrhagic cerebrovascular accident. The association of HVAD with risk of NAE in the first year after implant was evaluated using propensity score matching to balance for preimplant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data-driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase.

RESULTS

Of 6205 included patients, 3129 (50.4%) received the HM3 and 3076 (49.6%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD, respectively). Patients receiving HVAD had more major NAEs (16.4% versus 6.4%, P<0.001) as well as each subtype (transient ischemic attack: 3.3% versus 1.0%, P<0.001; ischemic cerebrovascular accident: 7.7% versus 3.4%, P<0.001; hemorrhagic cerebrovascular accident: 7.2% versus 2.0%, P<0.001) than did patients receiving HM3. A propensity-matched cohort balanced for preimplant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE 82% versus 92%, P<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio, 5.71 [CI, 3.90-8.36]).

CONCLUSIONS

HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early postimplantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Cerebrovascular Events in Patients with Centrifugal-Flow Left Ventricular Assist Devices: A Propensity Score Matched Analysis from the Intermacs Registry

Background: Ischemic and hemorrhagic cerebrovascular accidents (ICVA and HCVA, respectively) remain common among patients with centrifugal-flow left ventricular assist devices (CF-LVADs), despite improvements in survival and device longevity. Therefore, the incidence of neurological adverse events (NAEs) associated with two contemporary CF-LVADs, the Abbott HeartMate3^® (HM3) and the Medtronic HeartWare^™ HVAD^® (HVAD), were compared. Methods: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a CF-LVAD as a primary isolated implant between 1/1/2017 and 9/30/2019. Major NAEs were defined as transient ischemic attack (TIA), ICVA, and HCVA. The association of HVAD with risk of NAE in the first year post implant was evaluated using propensity score matching to balance for pre-implant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. Results: Of 6,205 included patients, 3,076 (49.6%) received the HM3 and 3,129 (50.4%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD). HVAD patients had more major NAEs (16.4% vs. 6.4%, p<0.001), as well as each subtype (TIA: 3.3% vs. 1.0%, p<0.001; ICVA: 7.7% vs. 3.4%, p<0.001; and HCVA: 7.2% vs. 2.0%, p<0.001), than did HM3 patients. A propensity-matched cohort balanced for pre-implant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE: 82% vs. 92%, p<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio: 5.71, confidence interval: 3.90-8.36). Conclusions: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early post-implantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

An Integrative Study of Aortic mRNA/miRNA Longitudinal Changes in Long-Term LVAD Support

Studying the long-term impact of continuous-flow left ventricular assist device (CF-LVAD) offers an opportunity for a complex understanding of the pathophysiology of vascular changes in aortic tissue in response to a nonphysiological blood flow pattern. Our study aimed to analyze aortic mRNA/miRNA expression changes in response to long-term LVAD support. Paired aortic samples obtained at the time of LVAD implantation and at the time of heart transplantation were examined for mRNA/miRNA profiling. The number of differentially expressed genes (Pcorr < 0.05) shared between samples before and after LVAD support was 277. The whole miRNome profile revealed 69 differentially expressed miRNAs (Pcorr < 0.05). Gene ontology (GO) analysis identified that LVAD predominantly influenced genes involved in the extracellular matrix and collagen fibril organization. Integrated mRNA/miRNA analysis revealed that potential targets of miRNAs dysregulated in explanted samples are mainly involved in GO biological process terms related to dendritic spine organization, neuron projection organization, and cell junction assembly and organization. We found differentially expressed genes participating in vascular tissue engineering as a consequence of LVAD duration. Changes in aortic miRNA levels demonstrated an effect on molecular processes involved in angiogenesis.

Characteristics and Outcomes of Left Ventricular-Assist Device-Associated Cerebrovascular Events in Setting of Infectious Intracranial Aneurysms

Background and purpose: The study aims to identify the characteristics and neurological outcomes of the left ventricular-assist device (LVAD)-associated cerebrovascular events (CVE) and infections, particularly in the setting of infectious intracranial aneurysms (IIA).

Methods: A single-center retrospective review of patients having undergone LVAD implantation between 2011 and 2017 was conducted using institutional registries and screened for CVE. Patients with CVE were assessed for concurrent bacteremia; neurovascular imaging was then used to isolate patients with IIA. A review of comorbidities, imaging characteristics, and management were performed to determine predictors of neurological outcomes, as defined by the 90-day modified Rankin scale (mRS) scores.

Results: Of the 383 HeartMate II LVAD implantations performed, 43 all-cause stroke events were identified across 35 (9%) patients. The majority of the events were hemorrhagic CVE (n=28) with 21 events complicated by bacteremia. Of patients with hemorrhagic CVE and bacteremia, Staphylococcus aureus (n=10) and Pseudomonas aeruginosa (n= 8) infection were the most frequently associated organisms. Severe disability or death (90-day mRS > 4) was observed in 15 patients (63%). Seven patients had confirmed findings of IIA on diagnostic cerebral angiogram and were associated with distal middle cerebral artery (MCA) territory involvement (n=6; 86%) with concurrent Staphylococcus (n=5, 71%) and/or Pseudomonas (n=4, 57%) infections. Overall, a higher incidence of acute and chronic bacteremia was observed in the hemorrhagic CVE subgroup compared to the ischemic CVE subgroup (74% vs 36% & 71% vs 29%, respectively; p <0.05). Despite endovascular and/or surgical intervention in patients with IIA, four patients failed management and elected for comfort measures.

Conclusion: Our results indicate that P. aeruginosa and S. aureus bacteremia are associated with a greater incidence of intracranial hemorrhage and worse neurological outcomes. Future management considerations may include pre-implantation cerebrovascular imaging to assess vascular pathology including prior aneurysms and intracranial atherosclerotic disease burden as a screen for higher-risk patients, as well as more aggressive antibiotic therapy at bacteremia onset.

Brain Injury in Extracorporeal Membrane Oxygenation: A Multidisciplinary Approach

Extracorporeal membrane oxygenation (ECMO) represents an established technique to provide temporary cardiac and/or pulmonary support. ECMO, in veno-venous, veno-arterial or in extracorporeal carbon dioxide removal modality, is associated with a high rate of brain injuries. These complications have been reported in 7 to 15% of adults and 20% of neonates, and are associated with poor survival. Thromboembolic events, loss of cerebral autoregulation, alteration of the blood-brain barrier, and hemorrhage related to anticoagulation represent the main causes of severe brain injury during ECMO. The most frequent forms of acute neurological injuries in ECMO patients are intracranial hemorrhage (2-21%), ischemic stroke (2-10%), seizures (2-6%), and hypoxic-ischemic brain injury; brain death may also occur in this population. Other frequent complications are infarction (1-8%) and cerebral edema (2-10%), as well as neuropsychological and psychiatric sequelae, including posttraumatic stress disorder.

A Comprehensive Review of Risk Factor, Mechanism, and Management of Left Ventricular Assist Device-Associated Stroke

The use of left ventricular assist devices (LVADs) has been increasing in the last decade, along with the number of patients with advanced heart failure refractory to medical therapy. Ischemic stroke and intracranial hemorrhage remain the leading causes of morbidity and mortality in LVAD patients. Despite the common occurrence and the significant outcome impact, underlying mechanisms and management strategies of stroke in LVAD patients are controversial. In this article, we review our current knowledge on pathophysiology and risk factors of LVAD-associated stroke, outline the diagnostic approach, and discuss treatment strategies.

Neurocritical Care of Mechanical Circulatory Support Devices

PURPOSE OF REVIEW

Mechanical circulatory support (MCS) devices have demonstrated improved survival outcomes in otherwise refractory cardiopulmonary failure but are associated with significant neurologic morbidity and mortality. This review aims to characterize MCS-associated brain injury and discuss the neurocritical care of this population.

RECENT FINDINGS

We found no practice guidelines or specific management strategies for the neurocritical care of patients with MCS devices. Acute brain injury was commonly observed in short-term and durable MCS devices. There is emerging evidence that a standardized neurological monitoring and management algorithm for MCS device-associated brain injury is feasible and potentially improves neurological outcomes. While MCS devices are associated with significant neurologic morbidity and mortality, there is scant evidence regarding optimal neuromonitoring and neurocritical care. With the increase in use of MCS devices for both short-term and durable applications, improved outcomes will depend on early identification and intervention of neurologic complications and further research into their pathophysiology.

Antiplatelet and anticoagulation strategies for left ventricular assist devices

Left ventricular assist devices (LVAD) have revolutionized the management of advanced heart failure. However, complications rates remain high, among which hemorrhagic and thrombotic complications are the most important. Antiplatelet and anticoagulation strategies form a cornerstone of LVAD management and may directly affect LVAD complications. Concurrently, LVAD complications influence anticoagulation and anticoagulation management. A thorough understanding of device, patient, and management, including anticoagulation and antiplatelet therapies, are important in optimizing LVAD outcomes. This article provides a comprehensive state of the art review of issues related to antiplatelet and anticoagulation management in LVADs. We start with a historical overview, the epidemiology and pathophysiology of bleeding and thrombotic complications in LVADs. We then discuss platelet and anticoagulation biology followed by considerations prior to, during, and after LVAD implantation. This is followed by discussion of anticoagulation and the management of thrombotic and hemorrhagic complications. Specific problems, including management of heparin-induced thrombocytopenia, anticoagulant reversal, novel oral anticoagulants, artificial heart valves, and noncardiac surgeries are covered in detail.

The Joint Association of Septicemia and Cerebrovascular Diseases with In-Hospital MortalityAmong Patients with Left Ventricular Assist Device in the United States

OBJECTIVES

Left ventricular assist device (LVAD) is associated with complications such as cerebrovascular diseases (CEVD) as well as septicemia which is often preventable. With their use increasing in the U.S., identifying patients with LVAD who are at high risk for short-term mortality is essential for targeted effective patient management strategies to prevent adverse outcomes. We investigated the individual and joint association of CEVD and septicemia with the risk of in-hospital mortality in patients with LVAD in the U.S.

MATERIALS AND METHODS

We used data from the National Inpatient Sample from 2004 to 2015 to identify patients ≥18 years of age who underwent LVAD implantation by means of International Classification of Disease, 9th Revision, codes. Multivariable hierarchical negative binomial regression models were used to estimate risk ratios (RR) and 95% confidence intervals (CI) for in-hospital mortality by CEVD-septicemia status.

RESULTS

The mean age of the 4638 patients was 56 years, and 23% of them were women. Approximately 13% of patients had septicemia; 7% had CEVD and 2% had both conditions. In models adjusted for demographic, lifestyle/behavior factors and comorbid conditions, the risk of in-hospital mortality was almost threefold higher among patients with septicemia alone (RR=2.84, CI:2.24-3.60); two-and-half fold higher among patients with CEVD alone (RR=2.53, CI:1.85-3.48); and almost fourfold among patients with both septicemia and CEVD (RR=3.76, CI: 2.38-5.94, P_interaction = <0.001) CONCLUSION: The presence of both septicemia and CEVD was associated with a substantially higher risk of in-hospital mortality among LVAD patients when compared to septicemia or CEVD alone.

Diagnosis and Image-guided Therapy of Cardiac Left Ventricular Assist Device Infections

Due to limited availability of donor hearts, more and more end stage heart failure patients are dependent on left ventricular assist device (LVAD) as their destination therapy rather than the original intended use as a bridge for heart transplantation. While LVADs improve life expectancy in these patients, infection emerges as one of the major adverse events. Early and accurate localization of LVAD infection is critical, as it can significantly influence clinical management decisions and ultimately impact patient outcome. Although the International Society of Heart and Lung Transplantation has defined 3 categories for LVAD infection: (1) LVAD-specific infection, (2) LVAD-related infection, and (3) non-LVAD infection, there is still lack of standardized criteria for diagnosing these 3 types of LVAD infections. Morphologically based imaging tools such as transesophageal echocardiogram and cardiac computed tomography (CT) or CT angiogram have limited roles in diagnosing LVAD infections due to their nonspecific findings, often affected by significant streaking and beam hardening artifacts from the metal device. In contrast, ¹⁸F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET)/CT has repeatedly shown a high sensitivity and specificity for LVAD infection diagnosis, albeit in small number of subjects. Beyond its accuracy for detecting infection, FDG PET/CT can predict clinical outcome based on the location of LVAD infection. As a functional imaging tool, FDG PET/CT can demonstrate the extent and severity of LVAD infection, as well as infectious embolism and potential extra-cardiac source of infection, which are all critical for providing optimal patient care, justifying its judicious and precise use in the workup of LVAD infection.

Clinically Silent Brain Injury and Perioperative Neurological Events in Patients With Left Ventricular Assist Device: A Brain Autopsy Study

Current studies underestimate the prevalence of brain injury in patients with left ventricular assist devices (LVADs), as CT scans are not sensitive in detecting cerebral ischemia. Using postmortem neuropathological evaluation, we sought to characterize the types and risk factors of brain injury in LVAD patients. We reviewed 24 LVAD patients who underwent brain autopsy with gross and microscopic examinations from 1993 through 2019 at a single tertiary center. Patients who expired less than 7 days after implantation or who underwent explantation more than 7 days before death were excluded. Our study demonstrated that all LVAD nonsurvivors developed brain injury. The most common brain injury was hemorrhage (71%), followed by infarct (42%) and hypoxic ischemic brain injury (HIBI) (33%), and 10 patients (42%) presented with more than 1 brain injury. Cerebral microbleeds (CMBs) and intracranial hemorrhage were present in 33% and 42%, respectively. In those with intracranial hemorrhage, subarachnoid hemorrhage (25%) and intracerebral hemorrhage (25%) were more common than subdural hematoma (4%). Intracranial hemorrhage was associated with driveline infection (P = 0.047), and HIBI was associated with prior history of chronic obstructive pulmonary disease (P = 0.037). Fourteen (60%) had clinically silent brain injury with 65% of hemorrhages and 70% of infarcts being silent. However, the impact of silent brain injury on neurologic outcome and mortality remains unclear. Standardized neurologic monitoring and surveillance are recommended to better detect these clinically silent brain injury.

National Landscape of Hospitalizations in Patients with Left Ventricular Assist Device. Insights from the National Readmission Database 2010-2015

The number of patients with left ventricular assist devices (LVAD) has increased over the years and it is important to identify the etiologies for hospital admission, as well as the costs, length of stay and in-hospital complications in this patient group. Using the National Readmission Database from 2010 to 2015, we identified patients with a history of LVAD placement using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code V43.21. We aimed to identify the etiologies for hospital admission, patient characteristics, and in-hospital outcomes. We identified a total of 15,996 patients with an LVAD, the mean age was 58 years and 76% were males. The most common cause of hospital readmission after LVAD was heart failure (HF, 13%), followed by gastrointestinal (GI) bleed (11.8%), device complication (11.5%), and ventricular tachycardia/fibrillation (4.2%). The median length of stay was 6 days (3-11 days) and the median hospital costs was $12,723 USD. The in-hospital mortality was 3.9%, blood transfusion was required in 26.8% of patients, 20.5% had acute kidney injury, 2.8% required hemodialysis, and 6.2% of patients underwent heart transplantation. Interestingly, the most common cause of readmission was the same as the diagnosis for the preceding admission. One in every four LVAD patients experiences a readmission within 30 days of a prior admission, most commonly due to HF and GI bleeding. Interventions to reduce HF readmissions, such as speed optimization, may be one means of improving LVAD outcomes and resource utilization.

Cerebrovascular events in children on intracorporeal continuous-flow left ventricular assist devices

Continuous-flow intracorporeal left ventricular assist devices (CF-LVAD) are used more frequently in the pediatric population. One of the major complications of CF-LVAD is cerebrovascular events (CVEs). Limited information is available on this complication in pediatric patients. We hereby present our experience on CVEs in children under CF-LVAD support in our institution. A retrospective, single center review of 21 patients younger than 19 years of age who underwent CF-LVAD implantation between June 2014 and September 2018 was performed. Patients on biventricular support and extracorporeal devices were excluded. Cerebrovascular accidents (CVAs)-ischemic or hemorrhagic-were investigated. CVE was confirmed by brain computed tomographic scan. Of 21 pediatric patients, 11 were male. Mean BSA was 1.05 ± 0.41 m² and mean age was 11.05 ± 4.07 years. Dilated cardiomyopathy was the leading cause of heart failure. The patients were implanted with HeartWare hVAD (n = 19), HeartMate II (n = 1), and HeartMate 3 (n = 1). Mean support time was 421 ± 448 (18-1460) days. Target international normalized ratio was between 2.5 and 3.0. Nine (43%) patients underwent transplantation, one patient recovered with subsequent device explantation. Four (17%) patients were still on support. One patient (5%) died in the early postoperative period and six (28%) patients died on VAD support after a mean duration of 194 days. There were overall five cerebral hemorrhagic strokes in four patients (0.2 events per patient-year). CVA occurred between 250 and 1320 days (mean 600 days). No ischemic stroke was documented. Only one (20%) patient died after hemorrhagic stroke; the other three patients recovered and were discharged from the hospital with minor sequelae. Incidence of CVE in children on CF-LVAD is relatively low compared with adults on VAD and severity of stroke is milder than adult population.

The value of 18F-FDG PET/CT for the diagnosis of device-related infections in patients with a left ventricular assist device: a systematic review and meta-analysis

Background

Left ventricular assist devices (LVADs) are increasingly used for the treatment of advanced heart failure. LVADs improve quality of life and decrease mortality, but the driveline carries substantial risk for major infections. These device-related LVAD and driveline infections are difficult to diagnose with conventional imaging. We reviewed and analysed the current literature on the additive value of ¹⁸F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) imaging for the diagnosis of LVAD-related infections.”

Materials/methods

We performed a systematic literature review using several databases from their inception until the 31st of December, 2019. Studies investigating the diagnostic performance of FDG-PET/CT in patients with suspected LVAD infection were retrieved. After a bias risk assessment using QUADAS-2, a study-aggregate meta-analysis was performed on a per examination-based analysis.

Results

A total of 10 studies were included in the systematic review, eight of which were also eligible for study-aggregate meta-analysis. For the meta-analysis, a total of 256 FDG-PET/CT scans, examining pump/pocket and/or driveline infection, were acquired in 230 patients. Pooled sensitivity of FDG-PET/CT was 0.95 (95% confidence interval (CI) 0.89–0.97) and pooled specificity was 0.91 (95% CI 0.54–0.99) for the diagnosis of device-related infection. For pump/pocket infection, sensitivity and specificity of FDG-PET/CT were 0.97 (95%CI 0.69–1.00) and 0.93 (95%CI 0.64–0.99), respectively. For driveline infection, sensitivity and specificity were 0.96 (95%CI 0.88–0.99) and 0.99 (95%CI 0.13–1.00) respectively. Significant heterogeneity existed across studies for specificity, mostly caused by differences in scan procedures. Predefined criteria for suspicion of LVAD and/or driveline infection were lacking in all included studies.

Conclusions

FDG-PET/CT is a valuable tool for assessment of device-related infection in LVAD patients, with high sensitivity and high, albeit variable, specificity. Standardization of FDG-PET/CT procedures and criteria for suspected device-related LVAD infections are needed for consistent reporting of FDG-PET/CT scans.

Electronic supplementary material

The online version of this article (10.1007/s00259-020-04930-8) contains supplementary material, which is available to authorized users.

Blood stream infection and outcomes in recipients of a left ventricular assist device

OBJECTIVES

METHODS

We retrospectively analysed all adult recipients of a continuous-flow LVAD between 2006 and 2016 at the Division of Cardiac Surgery, Medical University of Vienna (n = 257; devices: Medtronic HeartWare® HVAD®, Abbott HeartMate II®, Abbott HeartMate 3™). The primary outcome was all-cause mortality during follow-up. Secondary outcomes included the risk of stroke and pump thrombus during follow-up as well as the probability of heart transplantation (HTx). Risk factors for the development of ≥1 positive BC were evaluated additionally.

RESULTS

The incidence of ≥1 positive BC during the first year of LVAD support was 32.1% [95% confidence interval (CI) 26.4–37.9]. Multivariable Cox proportional cause-specific hazards regression analysis showed that a positive BC was associated with significantly increased all-cause mortality [hazard ratio (HR) 5.51, 95% CI 3.57–8.51; P &lt; 0.001]. Moreover, a positive BC was associated with a significantly increased risk of stroke (HR 2.41, 95% CI 1.24–4.68; P = 0.010). There was no association with the risk of pump thrombus or the probability of HTx. Independent risk factors for a positive BC included preoperative albumin and extracorporeal membrane oxygenation/intra-aortic balloon pump support.

CONCLUSIONS

Blood stream infection is common and associated with a significantly increased risk of all-cause mortality and stroke at any given time during LVAD support. Effective strategies of prevention and treatment are necessary.

Stroke Risk Following Infection in Patients with Continuous-Flow Left Ventricular Assist Device

BACKGROUND

Infection has been associated with stroke in patients with left ventricular assist devices (LVAD); however, little data exist on the timing, type and mortality impact of infection-related stroke.

METHODS

Prospectively collected data of HeartMate II (N = 332) and HeartWare (N = 70) LVAD patients from a single center were reviewed. Only strokes (ischemic or hemorrhagic) that occurred within 6 weeks following a LVAD infection were considered in analyses. The association between LVAD infections (wound, pump pocket, driveline and/or bloodstream infection [BSI]), specific pathogens and ischemic and hemorrhagic strokes was evaluated using multivariable logistic regression analysis. The impact of infection-related stroke on cumulative survival was assessed using Kaplan-Meier analysis.

RESULTS

Of 402 patients, LVAD infection occurred in 158 (39%) including BSI in 107 (27%), driveline infection in 67 (17%), wound infection in 31 (8%) and pump pocket infection in 24 (6%). LVAD infection-related stroke occurred in 20/158 (13%) patients in a median of 4 days (0-36 days) from documented infection. In multivariable analysis, ischemic stroke was associated with wound infection (aOR 9.0, 95% CI 2.4-34.0, P = 0.001) and BSI (aOR 7.7, 95% CI 0.9-66.0, P = 0.064), and hemorrhagic stroke was associated with BSI in 100% of cases (P = 0.01). There was no association with driveline or pump pocket infection. The cumulative survival rate among patients with infection-related stroke was significantly lower compared to those with LVAD infection but no stroke (log-rank P < 0.001). There was a trend toward shorter stroke-free survival among patients with LVAD infection.

CONCLUSIONS

LVAD infections, particularly BSI, are significantly associated with stroke, and infection-related stroke conferred significantly lower cumulative survival.

In Full Flow: Left Ventricular Assist Device Infections in the Modern Era

With the rising prevalence of heart disease in the United States, there is increasing reliance on durable mechanical circulatory support (MCS) to treat patients with end-stage heart failure. Left ventricular assist devices (LVADs), the most common form of durable MCS, are implanted mechanical pumps that connect to an external power source through a transcutaneous driveline. First-generation LVADs were bulky, pulsatile pumps that were frequently complicated by infection. Second-generation LVADs have an improved design, though infection remains a common and serious complication due to the inherent nature of implanted MCS. Infections can affect any component of the LVAD, with driveline infections being the most common. LVAD infections carry significant morbidity and mortality for LVAD patients. Therefore, it is paramount for the multidisciplinary team of clinicians caring for these patients to be familiar with this complication. We review the epidemiology, prevention, diagnosis, treatment, and outcomes of LVAD infections.

Cerebral Microembolization in Left Ventricular Assist Device Associated Ischemic Events

INTRODUCTION

The significance of microembolic signals (MES) detected by transcranial Doppler ultrasound emboli monitoring (TCD-e) in patients supported with left ventricular assist devices (LVAD) remains unclear. We aimed to investigate the relationship between cerebral microembolization detected by TCD-e and acute ischemic events in LVAD patients.

METHODS

We reviewed consecutive patients with acute ischemic stroke or transient ischemic attack (TIA) in a prospectively collected database of LVAD patients. TCD-e exams consisted of monitoring the middle cerebral arteries for microembolic signals (MES) over 30 minutes.

RESULTS

Of 515 persons with LVAD, 41 TCD-e studies were performed in 35 patients with acute ischemic stroke or transient ischemic attack (TIA) in a median of 1 day (Interquartile range [IQR]: 0-2) after the event. MES were present in 15 (44%) TCD-e studies with a median MES count of 4 (IQR: 2-15.5). Bloodstream infections were more common in patients with MES (38% versus 8%, P = .039). There were trends for lower international normalized ratio (1.39 versus 1.69, P = .214), lower activated partial thromboplastin (33.2 versus 36.6, P = .577), higher lactate dehydrogenase (531 versus 409, P = .323) and a higher frequency of pump thrombosis (13% versus 8%, P = .637) in patients with MES compared with those without MES.

CONCLUSIONS

LVAD patients with acute ischemic stroke or TIA have a high prevalence of MES on TCD-e, which may serve as a marker for a prothrombotic state. Further study of MES in LVAD patients is warranted.

Understanding risk factors and predictors for stroke subtypes in the ENDURANCE trials

BACKGROUND

Stroke is a devastating morbidity associated with left ventricular assist device (LVAD) support. We report a comprehensive analysis of stroke subtypes in the ENDURANCE destination therapy (DT) and ENDURANCE Supplemental (DT2) trials.

METHODS

Patients in the combined HeartWare LVAD (HVAD) cohorts of the DT and DT2 trials were included. Neurologic events included ischemic stroke (ischemic cerebrovascular accident [ICVA]), hemorrhagic stroke (hemorrhagic cerebrovascular accident [HCVA]), and transient ischemic attack (TIA). Peri-operative strokes were defined as occurring within 2 weeks of the implant.

RESULTS

A total of 604 patients received an HVAD in the DT (n = 296) and DT2 (n = 308) trials. Over 2 years, 178 (29.5%) had at least 1 cerebrovascular accident (CVA). Forty-four (7.3%) had HCVAs, 116 (19.2%) had ICVAs, and 44 (7.3%) had TIAs. Thirty (5.0%) had peri-operative stroke. In multivariable analysis, sub-therapeutic international normalized ratio (INR) values were independently associated with peri-operative stroke. Supra- and/or sub-therapeutic INR values, peripheral vascular disease, and presence of left ventricular thrombus were independently associated with ICVA. No aspirin and supra- and/or sub-therapeutic INR values were independently associated with TIA. No aspirin, supra- and/or sub-therapeutic INR values, and prior stroke and/or TIA were associated with HCVA. In further analysis, mean arterial pressure (MAP) was higher in the ICVA (86.8mm Hg, p = 0.002 4) and TIA (88.8mm Hg, p<0.0001) groups, but not in HCVA, than in the No-CVA group (81.4mm Hg). Time in therapeutic range for INR was 65.3% for the No-CVA group, 62.9% (p = 0.59) for HCVA, 65.1% (p = 0.97) for ICVA, and 63.2% (p = 0.62) for TIA.

CONCLUSIONS

Supra- and sub-therapeutic INR values at the time of CVA were associated with all stroke subtypes >14 days post-implant. MAP was higher among those with ICVA and TIA but not with HCVA compared to without CVA. Our study demonstrates the challenges of anti-thrombotic therapy and blood pressure management in LVAD population.

Left Ventricular Assist Devices 101: Shared Care for General Cardiologists and Primary Care

Ambulatory patients with a left ventricular assist device (LVAD) are increasing in number, and so is their life expectancy. Thus, there is an increasing need for care of these patients by non-LVAD specialists, such as providers in the emergency department, urgent care centers, community-based hospitals, outpatient clinics, etc. Non-LVAD specialists will increasingly come across LVAD patients and should be equipped with the knowledge and skills to provide initial assessment and management for these complex patients. These encounters may be for LVAD-related or unrelated issues. However, there are limited data and guidelines to assist non-LVAD specialists in caring for these complex patients. The aim of our review, targeting primary care providers (both inpatient and outpatient), general cardiologists, and other providers is to describe the current status of durable LVAD therapy in adults, patient selection, management strategies, complications and to summarize current outcome data.

Cerebrovascular Events After Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

Cerebrovascular events (CVE) are among the most common and serious complications after implantation of continuous-flow left ventricular assist devices (CF-LVAD). We studied the incidence, subtypes, anatomical distribution, and pre- and post-implantation risk factors of CVEs as well as the effect of CVEs on outcomes after CF-LVAD implantation at our institution.

METHODS

Retrospective analysis of clinical and neuroimaging data of 372 patients with CF-LVAD between May 2005 and December 2013 using standard statistical methods.

RESULTS

CVEs occurred in 71 patients (19%), consisting of 35 ischemic (49%), 26 hemorrhagic (37%), and 10 ischemic+hemorrhagic (14%) events. History of coronary artery disease and female gender was associated with higher odds of ischemic CVE (OR 2.84 and 2.5, respectively), and diabetes mellitus was associated with higher odds of hemorrhagic CVE (OR 3.12). While we found a higher rate of ischemic CVEs in patients not taking any antithrombotic medications, no difference was found between patients with ischemic and hemorrhagic CVEs. Occurrence of CVEs was associated with increased mortality (HR 1.62). Heart transplantation was associated with improved survival (HR 0.02). In patients without heart transplantation, occurrence of CVE was associated with decreased survival.

CONCLUSIONS

LVADs are associated with high rates of CVE, increased mortality, and lower rates of heart transplantation. Further investigations to identify the optimal primary and secondary stroke prevention measures in post-LVAD patients are warranted.

Bloodstream infection is associated with subarachnoid hemorrhage and infectious intracranial aneurysm in left ventricular assist device

Bloodstream infection is the leading cause of mortality in left ventricular assist device. Bloodstream infection is a risk factor for intracranial hemorrhage. We report three left ventricular assist device recipients who presented with bloodstream infection and developed subarachnoid hemorrhage. Case 1, a 37-year-old male with non-ischemic cardiomyopathy with HeartMate II, presented with confusion and found to have serratia bloodstream infection and left frontal lobe subarachnoid hemorrhage. Cerebral angiogram showed a right M3/M4 branch infectious intracranial aneurysm. He was treated with coil embolization and underwent device exchange. Case 2, a 41-year-old male with non-ischemic cardiomyopathy with HeartMate II presented with confusion and found to have methicillin-resistant staphylococcus aureus bloodstream infection and bilateral frontal convexity subarachnoid hemorrhage. Cerebral angiogram showed left M3 and left A3 infectious intracranial aneurysms, which were treated with antibiotics alone. Case 3, a 58-year-old female with ischemic cardiomyopathy with HeartMate II presented with fever, found to have candida albicans bloodstream infection and a parieto-occipital enhancing lesion concerning for cerebral abscess. Repeat computed tomography brain a week later showed a new right frontal subarachnoid hemorrhage. Cerebral angiogram showed a M4/M5 junction infectious intracranial aneurysm; patient was not a surgical candidate and was transitioned to hospice. This case series emphasizes that left ventricular assist device-associated subarachnoid hemorrhage may be caused by infectious intracranial aneurysms when acute bloodstream infections are present.

Ventricular assist device-related infections and solid organ transplantation-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

The Infectious Diseases Community of Practice of the American Society of Transplantation has published evidenced-based guidelines on the prevention and management of infectious complications in SOT recipients since 2004. This updated guideline reviews the epidemiology of ventricular assist device (VAD) infections and provides recommendations for the management and prevention of these infections. Almost one half of those awaiting heart transplantation are supported with VADs. Despite advances in device technologies, VAD infections commonly complicate mechanical circulatory support and remain typified by common components and anatomic locations. These infections have important implications for transplant candidates, most notably increased wait-list mortality. Strategic management of these infections is crucial for successful transplantation. Coincidentally, explantation of all VAD components at the time of transplantation is often the definitive cure for the device-associated infection. Highlighted in this updated guideline is the reported success of transplantation in patients with a variety of pre-existing VAD infections and guidance on post-transplant management strategies.

Ventricular Assist Device Patients Have Different Clinical Outcomes and Altered Patterns of Bleeding with Intracranial Hemorrhage

Intracranial hemorrhage (ICH) is one of the most feared complications of left ventricular assist device (LVAD) support. However, outcomes in this group have not been well described. We therefore sought to examine clinical outcomes in this patient population in comparison to those with heart failure (HF) and no LVAD, as well as those without HF or LVAD. The National Inpatient Sample database, years 2002-2012, was queried to classify patients into 3 groups: any ICH (group 1), any HF with any ICH (group 2), and any LVAD with any ICH (group 3). Clinical outcomes, hemorrhage type, neurosurgical intervention rates, and hospital factors were collected and analyzed. Group 1 consisted of 419,264 patients, group 2 had 41,186, and group 3 had 118 patients. Group 3 patients were more likely to be in large, academic medical centers, with longer length of stay and higher hospital charges. Inpatient mortality was highest in this group at 39%; however, 46.2% were ultimately discharged to home. Patients in group 3 were more likely to have a subarachnoid or intracerebral hemorrhage versus a subdural or epidural hemorrhage. Neurosurgical intervention rates did not differ between the groups. Although LVAD patients with ICH have worse clinical outcomes, the majority survived their event and nearly half were able to be discharged home. Left ventricular assist device patients also have a distinct pattern of bleeding with ICH. Additional study is required to understand risk factors for the development of ICH in this population and ideal management strategies.