Gastrointestinal Bleeding Following LVAD Placement from Top to Bottom

How to Select Patients for Left Ventricular Assist Devices? A Guide for Clinical Practice

In recent years, a significant improvement in left ventricular assist device (LVAD) technology has occurred, and the continuous-flow devices currently used can last more than 10 years in a patient. Current studies report that the 5-year survival rate after LVAD implantation approaches that after a heart transplant. However, the outcome is influenced by the correct selection of the patients, as well as the choice of the optimal time for implantation. This review summarizes the indications, the red flags for prompt initiation of LVAD evaluation, and the principles for appropriate patient screening.

Gastrointestinal Bleeding in Patients Supported with Left Ventricular Assist Devices: The Journey from Bridging to Destination

End-stage heart failure is a prevalent and fatal cardiovascular disease. Almost 1 in 4 cases of mortality in the United States is attributed to heart failure. Left ventricular assist devices (LVADs) have emerged as a safe destination therapy or bridge to transplant. Despite remarkable results, LVAD is associated with significant adverse events, such as gastrointestinal bleeding (GIB). In this review, we aimed to understand the incidence and prevalence, pathophysiologic mechanisms, predictors, diagnostic mechanisms, management, and preventative measures of GIB in patients with an LVAD. GIB is a common adverse event in patients with an LVAD with an incidence of 15% to 25%. The exact pathogenesis of GIB is poorly understood. However, different mechanisms of bleeding have been described, such as arteriovenous malformations, acquired von Willebrand syndrome, coagulopathy, and treatment with antithrombotic therapy. Upper GIB is the most common site of GIB in patients with an LVAD. The management of GIB in patients with LVAD includes ensuring hemodynamic stability, holding or reversing antithrombotic therapy, and investigating and controlling the source of GIB through diagnostic and interventional endoscopic and radiologic means. Prophylactic medication use (e.g., danazol, octreotide, and bevacizumab) can decrease the risk of GIB in patients with an LVAD by decreasing arteriovenous malformations. Despite that the overall risk of GIB has decreased with new advancements in LVAD technology, further studies are needed regarding predictors, risk stratification, and optimal antithrombotic therapy to minimize the morbidity and mortality in patients with an LVAD. In conclusion, prompt diagnosis and management in a multidisciplinary team approach are crucial and lifesaving in such a life-threatening condition.

Temporal trends and risk factors of gastrointestinal bleeding in patients with left ventricular assist devices: a nationwide analysis 2008-2017

Background

Left ventricular assist devices (LVADs) are indicated for patients with end-stage heart failure and require systemic anticoagulation. Gastrointestinal (GI) bleeding is a major adverse event following LVAD implantation. There is paucity of data on healthcare resource utilization in patients with LVAD and the risk factors of associated bleeding, despite the increase in GI bleeding. We investigated the in-hospital outcomes of GI bleeding in patients with continuous-flow (CF) LVAD.

Methods

This was a serial cross-sectional study of the Nationwide Inpatient Sample (NIS) in the CF-LVAD era from 2008-2017. All adults admitted to hospital with a primary diagnosis of GI bleeding were included. GI bleeding was diagnosed by ICD-9/ICD-10 codes. Patients with CF-LVAD (cases) and without CF-LVAD (controls) were compared using univariate and multivariate analyses.

Results

A total of 3,107,471 patients were discharged with a primary diagnosis of GI bleeding during the study period. Of these, 6569 (0.21%) had CF-LVAD-related GI bleeding. Overall, bleeding angiodysplasia accounted for the majority (69%) of LVAD-related GI bleeding. There was no statistical difference in mortality, but the length of hospital stay increased by 2.53 days (95% confidence interval [CI] 1.78-2.98; P<0.001) and the mean hospital charge per stay increased by $25,980 (95%CI 21,267-29,874; P<0.001) in 2017 compared to 2008. The results were consistent after propensity score matching.

Conclusion

Our study highlights that patients with LVAD admitted to the hospital for GI bleeding experience longer hospital stays and greater healthcare costs that warrant risk-based patient evaluation and careful implementation of management strategies.

Gastrointestinal bleeding in patients with continuous-flow left ventricular assist devices: A comprehensive review

BACKGROUND

Gastrointestinal bleeding is a major cause of morbidity that plagues the quality of life of patients supported on contemporary continuous-flow left ventricular assist devices (CF-LVADs). Despite benefits in survival and the nearly 50% reduction in complications provided by CF-LVADs, bleeding remains one of the most frequent adverse events with CF-LVAD implants. The CF-LVADs cause an increased risk of bleeding mainly due to the activation of the coagulation cascade.

METHODS

A literature search was done using PubMed and Google Scholar from Inception to February 2022. Qualitative analyses of the articles retrieved were used to construct this review. This review attempts to provide a comprehensive summary of the epidemiology, pathophysiology, risk stratification, and management of gastrointestinal bleeding as a complication of CF-LVAD as well as propose an algorithm for diagnosis and treatment.

RESULTS

Bleeding can occur at different sites in the gastrointestinal tract, the most common underlying pathology being arteriovenous malformations located in the upper gastrointestinal tract The increased prevalence of gastrointestinal (GI) bleeding in CF-LVAD patients has been attributed to the physiology of the LVAD itself, the use of anticoagulants, as well as patient comorbidities. Management involves pharmacologic and nonpharmacologic strategies.

CONCLUSIONS

CF-LVAD-supported patients have a significant risk of GI bleeding that is mainly caused by arteriovenous malformations located in the upper GI tract. The increased prevalence of GI bleeding in CF-LVAD patients is attributed to several etiologies that include factors attributed to the device itself and extrinsic factors such as the use of anticoagulation.

ADAMTS13 inhibition to treat acquired von Willebrand syndrome during mechanical circulatory support device implantation

BACKGROUND

Acquired von Willebrand syndrome (aVWS) is common in patients with mechanical circulatory support (MCS) devices. In these patients, the high shear stress in the device leads to increased shear-induced proteolysis of von Willebrand factor (VWF) by A Disintegrin And Metalloprotease with Thrombospondin type 1 repeats, number 13 (ADAMTS13). As a result, the high molecular weight (HMW) VWF multimers are lost, leading to a decreased VWF function and impaired hemostasis that could explain the bleeding complications that are frequently observed in these patients. To counteract this abnormal VWF degradation by ADAMTS13, we developed a novel targeted therapy, using an anti-ADAMTS13 monoclonal antibody (mAb) that inhibits the shear-induced proteolysis of VWF by ADAMTS13.

METHODS

Human or bovine blood was circulated through in vitro MCS device systems with either inhibitory anti-ADAMTS13 mAb 3H9 or 17C7 (20 μg/ml) or control anti-ADAMTS13 mAb 5C11 or phosphate buffered saline (PBS). VWF multimers and function (collagen binding activity) were determined at different time points. Next, Impella pumps were implanted in calves and the calves were injected with PBS and subsequently treated with mAb 17C7. VWF, ADAMTS13, and blood parameters were determined.

RESULTS

We demonstrated that blocking ADAMTS13 could prevent the loss of HMW VWF multimers in in vitro MCS device systems. Importantly, our antibody could reverse aVWS in a preclinical Impella-induced aVWS calf model.

CONCLUSION

Hence, inhibition of ADAMTS13 could become a novel therapeutic strategy to manage aVWS in MCS device patients.

Acquired platelet defects are responsible for nonsurgical bleeding in left ventricular assist device recipients

BACKGROUND

Left ventricular assist devices (LVADs) have been used as a standard treatment option for patients with advanced heart failure. However, these devices are prone to adverse events. Nonsurgical bleeding (NSB) is the most common complication in patients with continuous flow (CF) LVADs. The development of acquired von Willebrand syndrome (AVWS) in CF-LVAD recipients is thought to be a key factor. However, AVWS is seen across a majority of LVAD patients, not just those with NSB. The purpose of this study was to examine the link between acquired platelet defects and NSB in CF-LVAD patients.

METHODS

Blood samples were collected from 62 CF-LVAD patients at pre- and 4 post-implantation timepoints. Reduced adhesion receptor expression (GPIbα and GPVI) and activation of platelets (GPIIb/IIIa activation) were used as markers for acquired platelet defects.

RESULTS

Twenty-three patients experienced at least one NSB episode. Significantly higher levels of platelet activation and receptor reduction were seen in the postimplantation blood samples from bleeders compared with non-bleeders. All patients experienced the loss of high molecular weight monomers (HMWM) of von Willebrand Factor (vWF), but no difference was seen between the two groups. Multivariable logistic regression showed that biomarkers for reduced platelet receptor expression (GPIbα and GPVI) and activation (GPIIb/IIIa) have more predictive power for NSB, with the area under curve (AUC) values of 0.72, 0.68, and 0.62, respectively, than the loss of HMWM of vWF (AUC: 0.57).

CONCLUSION

The data from this study indicated that the severity of acquired platelet defects has a direct link to NSB in CF-LVAD recipients.

A Multicenter Study of Left Ventricular Assist Device-Related Gastrointestinal Bleeding

INTRODUCTION

Continuous left ventricular assist devices (LVADs) offer hemodynamic support in advanced and decompensated heart failure but are often complicated by gastrointestinal bleeding (GIB) in medically fragile patients.

METHODS

We performed a retrospective analysis of 475 consecutive patients who underwent LVAD implantation at the Massachusetts General Hospital and Tufts Medical Center from 2008 to 2019 and identified 128 patients with clinically significant GIB. Clinical characteristics of each bleeding event, including procedures and interventions, were recorded. We examined LVAD patients with overt and occult presentations to determine diagnostic endoscopic yield and analyzed predictors of recurrent GIB.

RESULTS

We identified 128 unique patients with LVAD implantation complicated by GIB. No significant difference was observed based on study center, underlying cardiomyopathy, race/ethnicity, serum indices, and medications used. Overt bleeders presented more commonly during LVAD implantation admission ( P = 0.001) than occult bleeders. Occult bleed presentations had only 1 lower and no middle GI bleed source identified, despite similar workups to overt bleeds. Destination therapy (e.g., among nontransplant candidates) LVAD implantation (odds ratio 2.38, 95% confidence interval 1.05-5.58) and a history of GIB (odds ratio 3.85, 95% confidence interval 1.29-12.7) were independently associated with an increased risk of recurrent GIB-related hospitalization.

DISCUSSION

Our findings confirm a high rate of GIB, especially in destination LVAD patients, and show a low diagnostic yield for colonoscopy and middle GI bleed assessments in LVAD patients with occult bleeds. Overt bleeding was more common and associated with vascular malformations. Although endoscopic interventions stopped active hemorrhage, GIB often recurred.

Incidence and Outcomes of Gastrointestinal Bleeding in Patients With Percutaneous Mechanical Circulatory Support Devices

Percutaneous mechanical circulatory support (pMCS) devices are increasingly used in patients with cardiogenic shock as a bridge to recovery or bridge to decision to advanced heart failure therapies. Gastrointestinal bleeding (GIB) is a common complication that can be catastrophic. Because of the paucity of data describing the association of GIB with pMCS, we analyzed this population using the United States National Inpatient Sample database. We performed a retrospective study in patients with pMCS devices who had GIB during the index hospitalization using the National Inpatient Sample. Multivariate logistic regression analysis was performed to determine independent predictors of GIB in these patients. A total of 466,627 patients were included. We observed an overall increase in the incidence of adjusted GIB from 2.9% to 3.5% (p = 0.0025) from 2005 to 2014. In comparison to patients without GIB, those with GIB had significantly higher in-hospital mortality, length of stay, and hospitalization cost. In addition to the usual co-morbid conditions, the presence of small bowel and colonic ischemia, colon cancer, diverticulosis, chronic liver disease, and peptic ulcer disease were noted to be significant predictors of GIB for all (p <0.001). In conclusion, patients with pMCS and GIB have higher in-hospital mortality, longer length of stay, and higher cost of hospitalization. Awareness of patient risk factors for bleeding and gastrointestinal disorders are important before the use of mechanical circulatory support devices because they are associated with a substantially higher risk for bleeding.

An external validation study of the Utah Bleeding Risk Score

OBJECTIVES

Gastrointestinal bleeding in patients with continuous-flow left ventricular assist devices (CF-LVAD) impairs quality of life and increases hospitalization rate. The Utah Bleeding Risk Score (UBRS) has been created to predict gastrointestinal bleeding (GIB) in patients on left ventricular assist device. We here aimed to externally validate UBRS on our cohort of CF-LVAD patients.

METHODS

Utah Bleeding Risk Score was calculated, GIB events summarized on follow-up and patients stratified into 3 risk groups. Predictive ability of UBRS was examined at 3 years and during whole support time and person time incidence rates correlated to UBRS. In a sub-analysis, single effects of UBRS variables on freedom from GIB were assessed.

RESULTS

A total of 111 CF-LVAD patients were included. The median UBRS was 2 (3-1). Receiver operating characteristic curve analysis showed an area under the curve of 0.519 (P = 0.758, 95% confidence interval = 0.422-0.615) at 3 years and an area under the curve of 0.515 (P = 0.797, 95% confidence interval = 0.418-0.611) during whole support time. No significant difference was observed in UBRS between bleeders and non-bleeders (P = 0.80). No significant difference in freedom from GIB was observed (P3 years = 0.7; Psupport-time = 0.816) and no independent significance regarding the freedom from bleeding at 3 years for any variable was observed. Coronary artery disease was associated with higher risk of GIB beyond the 3rd year (P = 0.048).

CONCLUSIONS

UBRS was not able to predict GIB and therefore not applicable in our cohort of patients. Coronary artery disease could lead to a higher risk for GIB during support time. An additional validation in a larger cohort is advisable.

The role of renin-angiotensin system in patients with left ventricular assist devices

End-stage heart failure is a condition in which the up-regulation of the systemic and local renin-angiotensin-aldosterone system (RAAS) leads to end-organ damage and is largely irreversible despite optimal medication. Left ventricular assist devices (LVADs) can downregulate RAAS activation by unloading the left ventricle and increasing the cardiac output translating into a better end-organ perfusion improving survival. However, the absence of pulsatility brought about by continuous-flow devices may variably trigger RAAS activation depending on left ventricular (LV) intrinsic contractility, the design and speed of the pump device. Moreover, the concept of myocardial recovery is being tested in clinical trials and in this setting LVAD support combined with intense RAAS inhibition can promote recovery and ensure maintenance of LV function after explantation. Blood pressure control on LVAD recipients is key to avoiding complications as gastrointestinal bleeding, pump thrombosis and stroke. Furthermore, emerging data highlight the role of RAAS antagonists as prevention of arteriovenous malformations that lead to gastrointestinal bleeds. Future studies should focus on the role of angiotensin receptor inhibitors in preventing myocardial fibrosis in patients with LVADs and examine in greater details the target blood pressure for these patients.

Initial endoscopic intervention is not associated with reduced risk of recurrent gastrointestinal bleeding in left ventricular assist device patients

Background

Left ventricular assist devices (LVADs) are increasingly used for mechanical support of end-stage heart failure. Gastrointestinal bleeding (GIB) confers a significant morbidity in LVAD patients, with rates of up to 30% at 5 years. We assessed predictors of index and recurrent GIB (rGIB) in LVAD patients to risk stratify patients and evaluate if endoscopic approach and intervention at index GIB impacted rGIB.

Methods

A retrospective chart review of all LVAD patients at our institution from 01/01/2006 to 31/10/2016 was completed. Predictors for index and recurrent GIB were analyzed. Multivariate logistic regression analysis was created using only statistically significant dependent variables and adjusted for demographic variables.

Results

A total of 77/214 (36%) patients developed GIB, and 38/214 (17.8%) developed rGIB. Destination therapy (P=0.01), longer duration of LVAD (P=0.03), and low albumin (<3.5 g/dL) (P<0.001) were associated with increased risk of index GIB. Charlson Comorbidity Index, heart failure etiology, and Medicare were predictors of index GIB on univariate analysis, but this was not seen on multivariate analysis. Performing an endoscopy with/without intervention, non- angioectasia lesions, and location of bleeding were not statistically significant predictors of rGIB. Longer duration of hospitalization appeared to be protective for rGIB on univariate analysis.

Conclusions

Index endoscopy and intervention is not associated with reduced risk of rGIB in LVAD patients. Several independent factors are associated with the risk of index GIB. Albumin is a potentially modifiable risk factor, and likely contributes to bleeding through poor nutrition. It is a surrogate marker for systemic illness, and may have pharmacologic implications.

In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept

Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.

Does endoscopic intervention prevent subsequent gastrointestinal bleeding in patients with left ventricular assist devices? A retrospective study

BACKGROUND

Patients with left ventricular assist devices (LVADs) are at increased risk for recurrent gastrointestinal bleeding (GIB) and repeat endoscopic procedures. We assessed the frequency of endoscopy for GIB in patients with LVADs and the impact of endoscopic intervention on preventing a subsequent GIB.

AIM

To evaluate for an association between endoscopic intervention and subsequent GIB. Secondary aims were to assess the frequency of GIB in our cohort, describe GIB presentations and sources identified, and determine risk factors for recurrent GIB.

METHODS

We conducted a retrospective cohort study of all patients at a large academic institution who underwent LVAD implantation from January 2011 – December 2018 and assessed all hospital encounters for GIB through December 2019. We performed a descriptive analysis of the GIB burden and the outcome of endoscopic procedures performed. We performed multivariate logistic regression to evaluate the association between endoscopic intervention and subsequent GIB.

RESULTS

In the cohort of 295 patients, 97 (32.9%) had at least one GIB hospital encounter. There were 238 hospital encounters, with 55.4% (132/238) within the first year of LVAD implantation. GIB resolved on its own by discharge in 69.8% (164/235) encounters. Recurrent GIB occurred in 55.5% (54/97) of patients, accounting for 59.2% (141/238) of all encounters. Of the 85.7% (204/238) of encounters that included at least one endoscopic evaluation, an endoscopic intervention was performed in 34.8% (71/204). The adjusted odds ratio for subsequent GIB if an endoscopic intervention was performed during a GIB encounter was not significant (odds ratio 1.18, P = 0.58).

CONCLUSION

Patients implanted with LVADs whom experience recurrent GIB frequently undergo repeat admissions and endoscopic procedures. In this retrospective cohort study, adherence to endoscopic guidelines for performing endoscopic interventions did not significantly decrease the odds of subsequent GIB, thus suggesting the uniqueness of the LVAD population. A prospective study is needed to identify patients with LVAD at risk of recurrent GIB and determine more effective management strategies.

Device-induced platelet dysfunction in patients after left ventricular assist device implantation

BACKGROUND

Non-surgical bleeding (NSB) is a major complication after left ventricular assist device (LVAD) implantation. It has been reported that non-physiological shear stress caused by LVADs could alter platelet receptor expression, which leads to bleeding disorders caused by coagulation dysfunctions.

OBJECTIVES

Because bleeding diathesis could be multifactorial, we focused on the combined characterization of platelet receptor expression patterns and oxidative stress to compare patients with NSB and patients without coagulation disorder in a monocentric, prospective study.

METHODS

Blood samples were obtained from LVAD patients with NSB (bleeder group, n = 19) and without NSB (non-bleeder group, n = 20). The platelet receptors platelet endothelial cell adhesion molecule-1 (PECAM-1), glycoprotein (GP)Ibα, P-selectin, CD63, and GPIIb/IIIa, as well as the production of intraplatelet reactive oxygen species (ROS) were quantified by flow cytometry. Aggregation capacity was evaluated by aggregometry.

RESULTS

The surface expression level of P-selectin and GPIbα on platelets was decreased in bleeders (P-selectin: 465 ± 72 U; GPIbα: 435 ± 41 U) compared to non-bleeders (P-selectin: 859 ± 115 U, P < .01; GPIbα: 570 ± 49 U, p = .04). Additionally, the mean fluorescence intensity of ADP-stimulated P-selectin and PECAM-1 expressing platelets were reduced in bleeders (P-selectin: 944 ± 84 U; PECAM-1: 6722 ± 419 U) compared to non-bleeders (P-selectin: 1269 ± 130 U, P = .04; PECAM-1: 8542 ± 665 U, P = .03). Bleeders showed a higher amount of ROS formation in platelets (88.0 ± 2.6%) than non-bleeders (81.5 ± 2.1%, P = .05).

CONCLUSIONS

These findings suggested that changes of three platelet receptors (GPIbα, P-selectin, and PECAM-1) and elevated oxidative stress may play a role in patients with bleeding complications following LVAD implantation. These results might help to explain the high incidence of spontaneous hemorrhage during LVAD support through an altered platelet function.

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.

Association between digoxin use and gastrointestinal bleeding in contemporary continuous flow left ventricular assist device support

BACKGROUND

Assess the association between digoxin use and gastrointestinal bleeding (GIB) in a multicenter continuous flow left ventricular assist device (LVAD) cohort.

METHODS

Patients implanted with continuous flow LVADs with data on GIB and digoxin use from two centers were included in the analysis (n = 649). GIB events were captured up to 2 years of follow-up. Digoxin use was defined as digoxin prescribed at discharge or within the first 3 months after LVAD implantation. A negative binomial regression model was performed to determine the association between digoxin use and number of GIB events over the follow-up period.

RESULTS

Mean age of the cohort was 57 years (±14) and 45% (293/649) were bridge to transplant (BTT). Digoxin was prescribed in 33% of patients. Digoxin use was associated with an unadjusted 32% reduction in the incidence of rate of all cause GIB (IRR 0.68, 95% CI 0.46-0.99, p = 0.049). After adjusting for age, sex, Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile, renal function, and implanting center there was still a 34% reduction in the incidence rate (IRR 0.67, 95% CI 0.45-0.99, p = 0.048). When limiting the analysis to those with likely arteriovenous malformation associated GIB, the association strengthened (unadjusted: IRR 0.48, 95 % CI 0.26-0.89, p = 0.02, adjusted: IRR 0.47, 95 % CI 0.25-0.9, p = 0.022).

CONCLUSIONS

In this multicenter study, inclusive of contemporary devices, digoxin use was associated with reduced GIB events. Prospective data will be required to confirm this association.

Laser interstitial thermotherapy (LITT) for the treatment of tumors of the brain and spine: a brief review

INTRODUCTION

Laser Interstitial Thermotherapy (LITT; also known as Stereotactic Laser Ablation or SLA), is a minimally invasive treatment modality that has recently gained prominence in the treatment of malignant primary and metastatic brain tumors and radiation necrosis and studies for treatment of spinal metastasis has recently been reported.

METHODS

Here we provide a brief literature review of the various contemporary uses for LITT and their reported outcomes.

RESULTS

Historically, the primary indication for LITT has been for the treatment of recurrent glioblastoma (GBM). However, indications have continued to expand and now include gliomas of different grades, brain metastasis (BM), radiation necrosis (RN), other types of brain tumors as well as spine metastasis. LITT is emerging as a safe, reliable, minimally invasive clinical approach, particularly for deep seated, focal malignant brain tumors and radiation necrosis. The role of LITT for treatment of other types of tumors of the brain and for spine tumors appears to be evolving at a small number of centers. While the technology appears to be safe and increasingly utilized, there have been few prospective clinical trials and most published studies combine different pathologies in the same report.

CONCLUSION

Well-designed prospective trials will be required to firmly establish the role of LITT in the treatment of lesions of the brain and spine.

Carotid artery structure and hemodynamics and their association with adverse vascular events in left ventricular assist device patients

Left ventricular assist devices (LVADs) are associated with major vascular complications including stroke and gastrointestinal bleeding (GIB). These adverse vascular events may be the result of widespread vascular dysfunction resulting from pre-LVAD abnormalities or continuous flow during LVAD therapy. We hypothesized that pre-existing large artery atherosclerosis and/or abnormal blood flow as measured in carotid arteries using ultrasonography are associated with a post-implantation composite adverse outcome including stroke, GIB, or death. We retrospectively studied 141 adult HeartMate II patients who had carotid ultrasound duplex exams performed before and/or after LVAD surgery. Structural parameters examined included plaque burden and stenosis. Hemodynamic parameters included peak-systolic, end-diastolic, and mean velocity as well as pulsatility index. We examined the association of these measures with the composite outcome as well as individual subcomponents such as stroke. After adjusting for established risk factors, the composite adverse outcome was associated with pre-operative moderate-to-severe carotid plaque (OR 5.08, 95% CI 1.67-15.52) as well as pre-operative internal carotid artery stenosis (OR 9.02, 95% CI 1.06-76.56). In contrast, altered hemodynamics during LVAD support were not associated with the composite outcome. Our findings suggest that pre-existing atherosclerosis possibly in combination with LVAD hemodynamics may be an important contributor to adverse vascular events during mechanical support. This encourages greater awareness of carotid morphology pre-operatively and further study of the interaction between hemodynamics, pulsatility, and structural arterial disease during LVAD support.

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.

Gastrointestinal Bleeding as a Complication in Continuous Flow Ventricular Assist Devices: A Systematic Review With Meta-Analysis

Background

The use of ventricular assist devices (VADs) has become predominant in this era of medicine. It is commonly used as a bridge to transplant, recovery and as a destination therapy for patients with severe heart failure, who are not responsive to maximum optimal management or ineligible for transplant. However, several complications are known to occur with the use of these devices. In this research, we will compare gastrointestinal bleeding in patients who used centrifugal flow versus axial flow VADs. We hope that the result of this meta-analysis and the review presented provide adequate information to future researchers, physicians and other healthcare professionals who are interested in this topic.

Methods

Published articles evaluated for inclusion were obtained from MEDLINE (PubMed), Cochrane, EBSCO, clinicaltrials.gov, and international clinical trials registry. This research was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Procured articles were reviewed by two independent reviewers. Only randomized control trials and observational studies were used. Quality assessment was done with Cochrane Collaboration’s tool (RoB.2 with visualization through robviz) and Newcastle-Ottawa Scale (NOS). Data analysis was carried out with the use of R data analysis tool (version 4.0.0; release date: April 24th, 2020).

Results

At the end of this meta-analysis, the occurrence of gastrointestinal bleeding was not significantly different between both groups; with odds ratio (OR): 0.81; 95% confidence interval (CI): 0.65 - 1.00; P value = 0.05. Between-study variance (Tau-squared) was zero (0), standard error (SE) = 0.06. The degree of heterogeneity measured with I-squared statistic was 0% (minimal). Egger’s regression test was not statistically significant, P = 0.93. Symmetry of distribution was observed on the funnel plot. Trim and fill analysis showed no missing studies on the left; SE = 1.68.

Conclusions

The result obtained from this research indicates that the occurrence of gastrointestinal bleeding is not significantly different in both groups of patients, irrespective of the type of continuous flow VAD used. Although, the study sample used in this meta-analysis was limited.

Thalidomide Use Reduces Risk of Refractory Gastrointestinal Bleeding in Patients with Continuous Flow Left Ventricular Assist Devices

Gastrointestinal (GI) bleeding is a common complication seen in patients with implanted continuous flow left ventricular assist devices (CF-LVAD), often attributed to arteriovenous malformations (AVMs). Whether thalidomide reduces recurrent GI bleeding risk in CF-LVAD patients has been incompletely evaluated. We conducted a retrospective review of all CF-LVAD patients at our institution with GI bleeding from AVMs who had a trial both off and on thalidomide. The primary endpoint was time to rebleed, while secondary endpoints included overall GI bleeding events, packed red blood cell (PRBC) transfusion requirements, and adverse events related to thalidomide. We report on 24 patients with recurrent AVM-associated GI bleeding who met criteria for and received thalidomide therapy, of which 17 had sufficient follow-up to be ultimately included for final analysis. We found the risk of rebleeding was significantly reduced in those on thalidomide therapy versus off (hazard ratio = 0.23, p = 0.022). The median number of GI bleeds per year was reduced from 4.6 to 0.4 (p = 0.0008) and the PRBC requirement was lower (36.1 vs. 0.9 units per year, p = 0.004) in those on thalidomide therapy. The adverse event rate with thalidomide was 59%, with symptoms resolution in most following dose reduction without increased bleeding. Thalidomide reduced the risk of AVM-associated GI rebleeding, number of bleeding events, and PRBC requirements in CF-LVAD patients. When initiating therapy, potential side effects and overall clinical context should be considered.

Anticoagulation strategy in a patient on the HeartMate III® left ventricular assist device with acquired von Willebrand syndrome and recurring gastrointestinal bleeding episodes: sometimes less is more

Acquired von Willebrand syndrome is a frequently encountered complication of continuous flow ventricular assist devices, which may lead to clinically relevant bleeding in up to 30% of patients after continuous flow ventricular assist device implantation. As standard anticoagulation strategies may be detrimental, individualized treatment is called for, as described in our patient on the HeartMate III® left ventricular assist device.

Outcomes of gastrointestinal bleeding in patients with left ventricular assist devices: a tertiary care experience

Background and study aims  Left ventricular assist device (LVAD) placement is a therapeutic modality for patients with end-stage heart failure. Gastrointestinal bleeding is a common complication following LVAD implantation. The aim of this study was to report our experience in management and outcomes of gastrointestinal bleeding in a large cohort of patients with LVADs. Patients and methods  We performed a retrospective review of all patients who underwent LVAD implantation at the University of Rochester Medical Center from January 2008 to June 2017. Data were collected on patient characteristics, clinical aspects of gastrointestinal bleeding events, and procedural interventions. A Cox proportional hazard model was utilized to identify potential risk factors for a gastrointestinal bleeding event. Results  During the study period, 345 patients underwent LVAD implantation. Of these, 125 patients (36.2 %) experienced 297 gastrointestinal bleeding events resulting in 533 endoscopic procedures. The diagnostic yield of endoscopy in determining a bleeding source was 49.5 %. If required, therapeutic interventions were successful in achieving homeostasis in 96.2 % of procedures. Our 30-day overall post-procedure adverse event (AE) rate was 6.6 %. Procedure-related (bleeding, infection, and perforation) AEs were very minimal (2.8 %). A Cox proportional hazard model indicated that older age at implant, female sex, African-American race, diabetes mellitus, and pulmonary hypertension were statistically significant predictors of a gastrointestinal bleeding event following LVAD implantation. Conclusions  LVAD patients have a high risk of gastrointestinal bleeding. Endoscopy was able to safely locate a bleeding lesion in approximately half of our patients and was successful in treating bleeding lesions in a majority of the cases.

The Predicament of Gastrointestinal Bleeding in Patients With a Continuous-Flow Left Ventricular Assist Device: Pathophysiology, Evaluation, and Management

Heart failure affects over 5 million Americans, with numbers expected to rise. While heart transplantation is the most effective long-term strategy for end-stage heart failure, there is a limited cardiac donor pool, and these organs are often unavailable at the time of need. Left ventricular assist devices, therefore, continue to be used to bridge this gap. Originally implanted as a bridge to transplant, these devices are now additionally utilized as destination therapy for patients ineligible for transplant. With the widespread applicability of these devices for not just temporary measures, but also for prolonged use, the short- and long-term impact on other organ systems has become more evident. For example, gastrointestinal (GI) bleeding, with an incidence approaching 30%, is one such complication post-continuous-flow left ventricular assist device implantation. This high incidence of GI bleeding is thought to stem from a combination of factors, including the need for concomitant anticoagulant and antiplatelet therapy, and intrinsic device-related properties resulting in acquired Von Willebrand disease and arteriovenous malformations. Due to the significant morbidity associated with these GI bleeding events, a standardized protocol optimizing medical and endoscopic management, alongside close coordination between the gastroenterology and cardiology services, should be advocated for and ultimately employed.

Noncardiac surgery in patients with a left ventricular assist device

Left ventricular assist devices are implanted in patients with chronic left heart failure refractory to maximal medical therapy. These devices were initially meant as bridge-to-transplant therapy, but with technological advances they are now also used as destination therapy. With improved survival, many patients with implanted devices need noncardiac surgery. We present three representative cases of noncardiac surgery in such patients to highlight the issues involved in their management. We also review the contemporary literature on various aspects of perioperative management. Anesthesia for noncardiac surgery in these patients was initially the domain of cardiac anesthesiologists, but with an increasing number of such patients needing surgery, general anesthesiologists are frequently tasked to provide anesthetic care. An understanding of left ventricular assist device physiology and issues unique to these patients is essential for safe management of these cases.

Clinical Approach to Manage Gastrointestinal Bleeding with a Left Ventricular Assist Device (LVAD)

Left ventricular assist devices (LVADs) are an exceedingly important form of mechanical support for patients with end-stage heart failure. LVADs can be utilized both as a bridge to cardiac transplant and also as a definitive treatment. However, a few complications are associated with LVAD placement, the most common and cumbersome of which is gastrointestinal (GI) bleeding with an incidence of about 30%. These bleeding events often require transfusion therapy, but they are rarely fatal.

The etiologies of GI bleeding following LVAD are multifactorial and include unstable hemodynamics, an acquired von Willebrand factor (vWf) deficiency, impaired platelet aggregation, and activation of fibrinolytic systems. The treatment of choice in LVAD implantation-associated GI bleeding is endoscopy, which plays a vital role in both its diagnosis and management. Even so, its effectiveness in controlling post-LVAD implantation GI bleeding is still poorly ascertained. In this article, we will review the use of medication and alterations in the LVAD setting to prevent the occurrence of GI bleeding, as well as the findings of previously reported literature on LVAD implantation-associated GI bleeding.

Gastrointestinal Bleeding With Left Ventricular Assist Devices (LVAD): Locating the Leak and Identifying Outcomes

BACKGROUND AND GOALS

Gastrointestinal bleeding (GIB) is a significant complication following left ventricular assist device (LVAD) implantation. We evaluated the incidence, predictors, endoscopic findings, and outcomes of GIB in LVAD recipients.

STUDY

Retrospective review of 205 adult patients undergoing HeartMate II LVAD implantation from January 2012 to June 2016. Patients were reviewed and separated into GIB (n=57; 28%) and non-GIB (n=148; 72%) groups.

RESULTS

Median time to GIB was 55 (range, 3 to 730) days. The GIB group patients were older (61±12 vs. 56±13, P=0.0042), more often underwent concomitant tricuspid valve (TV) repair (16% vs. 4%, P=0.007), and a higher percentage were assigned for destination therapy (75% vs. 55%, P=0.01). Angioectasia (33%) was the most common identified cause of GIB. Median time to endoscopic intervention was 1 day. The total number of hospital readmissions after LVAD was higher in the GIB group (median of 5 vs. 3, P=0.001), as was the total number of blood products transfused after LVAD (29 vs. 13, P≤0.0001). GIB was associated with an increased risk of death (hazard ratio, 1.94; 95% confidence interval, 1.16-3.25; P=0.01) and the mortality rate during hospitalization for GIB was 11% (P=0.0004). Receiving a heart transplant was associated with a decreased hazard of death (hazard ratio, 0.40; 95% confidence interval, 0.19-0.85; P=0.016).

CONCLUSIONS

Older age and destination therapy as implant strategy were found to be associated with an increased risk of GIB, consistent with previous studies. A unique finding in our study is the association of TV repair with a higher incidence of GIB. Further studies are needed to investigate possible mechanisms by which TV repair increases the incidence of GIB.

Cardiac Assist Devices: Early Concepts, Current Technologies, and Future Innovations

Congestive heart failure (CHF) is a debilitating condition that afflicts tens of millions of people worldwide and is responsible for more deaths each year than all cancers combined. Because donor hearts for transplantation are in short supply, a safe and durable means of mechanical circulatory support could extend the lives and reduce the suffering of millions. But while the profusion of blood pumps available to clinicians in 2019 tend to work extremely well in the short term (hours to weeks/months), every long-term cardiac assist device on the market today is limited by the same two problems: infections caused by percutaneous drivelines and thrombotic events associated with the use of blood-contacting surfaces. A fundamental change in device design is needed to address both these problems and ultimately make a device that can support the heart indefinitely. Toward that end, several groups are currently developing devices without blood-contacting surfaces and/or extracorporeal power sources with the aim of providing a safe, tether-free means to support the failing heart over extended periods of time.

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.

Acid Suppression to Prevent Gastrointestinal Bleeding in Patients With Ventricular Assist Devices

BACKGROUND

The high incidence of gastrointestinal bleeding (GIB) in patients with ventricular assist devices (VAD) is well known, but there is limited evidence to support the use of proton pump inhibitors (PPIs) or histamine receptor antagonists (H2RA) for preventing GIB in patients with VAD.

MATERIALS AND METHODS

The surgical ICU and VAD databases within a large regional academic cardiac mechanical support and transplant center were queried for patients who underwent VAD implantation between 2010 and 2014. An observational cohort study was conducted to identify which acid suppressing drug regimen was associated with the fewest number of GIB events within 30 d after VAD implantation: PPI, H2RA, or neither. Secondary outcomes included timing, etiology, and location of GIB. Multivariable logistic regression was used to compare treatment cohorts to GIB. Odds ratios, 95% confidence intervals, and P-values were reported from the model.

RESULTS

One hundred thirty-eight patients were included for final analysis, 19 of which had a GIB within 30 days of VAD implantation. Both H2RA and PPI use were associated with reduced GIB compared with the cohort with no acid suppressive therapy. In the multivariate analysis, the PPI cohort showed a statistically significant reduction in GIB (Odds ratio 0.18 [95% confidence interval 0.04-0.79] P = 0.026).

CONCLUSIONS

Using PPI postoperatively in patients with new VAD was associated with a reduced incidence of GIB. Given that GIB is a known complication after VAD placement, clinicians should consider the use of acid suppressive therapy for primary prevention.

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

Introduction:

Suspected small bowel bleeding is frequently encountered in left ventricular assist device recipients and the identification of the culprit lesion may be challenging. Data regarding the safety and yield of small bowel capsule in the investigation of suspected small bowel bleeding are limited. We aimed to evaluate the safety and efficacy of small bowel video capsule endoscopy for the investigation of suspected small bowel bleeding among left ventricular assist device recipients.

Methods:

Patients with left ventricular assist device who underwent video capsule endoscopy for the investigation of suspected small bowel bleeding were identified. Suspected small bowel bleeding was defined as the presence of overt bleeding at least 30 days following left ventricular assist device implantation with no identifiable cause in upper and lower endoscopy.

Results:

A total of 10 patients with left ventricular assist device associated suspected small bowel bleeding performed 12 small bowel capsule endoscopies between January 2008 and December 2015 at our tertiary medical care facility. There were no cases of capsule retention or any other serious adverse events during the exams. A significant finding was identified in 8 out of 10 patients, including 3 cases of small bowel angioectasia, 2 cases of small bowel ulcers, 1 case of cecal polyp, and 2 cases of active bleeding with no apparent bleeding source. Small bowel enteroscopy identified and treated bleeding angioectasia in the latter two cases.

Conclusion:

Small bowel capsule endoscopy is safe and effective in the investigation of left ventricular assist device associated suspected small bowel bleeding.

Endoscopic Management of Nonvariceal, Nonulcer Upper Gastrointestinal Bleeding

Nonvariceal, nonulcer upper gastrointestinal hemorrhage (UGIH) is a less common cause for acute upper gastrointestinal bleeding. However, nonvariceal, nonulcer UGIH is an important entity to identify and treat appropriately to prevent bleeding-related morbidity and mortality. Over the past 40 years, there has been a revolution in gastrointestinal endoscopy and a similar revolution in the management of UGIH. The aim of this article is to focus on the endoscopic management of nonvariceal, nonulcer UGIH, with a focus on the newer diagnostic and treatment modalities currently available.

Acquired coagulopathy in patients with left ventricular assist devices

Chronic heart failure (HF) is a major emerging healthcare problem, associated with a high morbidity and mortality. Left ventricular assist devices (LVADs) have emerged as a successful treatment option for patients with end-stage HF. Despite its great benefit, the use of LVAD is associated with a high risk of complications. Bleeding, pump thrombosis and thromboembolic events are frequently observed complications, with bleeding complications occurring in over a third of the patients. Although the design of the third-generation LVAD has improved greatly, these hemostatic complications still occur. The introduction of an LVAD into the circulatory system results in an altered hematological balance as a consequence of blood-pump interactions, changes in hemodynamics, the rheology, and the concomitant need for anticoagulation while implanted with an LVAD. The majority, if not all, LVAD patients experience a form of platelet dysfunction and impaired von Willebrand factor activity, leading to acquired coagulopathy disorders. Different diagnostic tools and treatment strategies have been reported; however, they require validation in LVAD patients. The present review focuses on acquired coagulopathies, describing the incidence, impact and underlying mechanism of acquired coagulopathy disorders in patients supported by LVADs. In addition, we will discuss diagnostic and management strategies for these acquired coagulopathies.

Tolerability and Biological Effects of Long-Acting Octreotide in Patients With Continuous Flow Left Ventricular Assist Devices

Patients with implanted continuous, nonpulsatile, left ventricular assist devices (LVADs) have increased the occurrence of gastrointestinal bleeding (GIB). Although the pathophysiology is multifactorial, there are few treatments beyond supportive care. Octreotide acetate is a somatostatin analog that reduces GIB in various patient populations. However, there are sparse case series that suggest octreotide acetate may reduce GIB in LVAD patients. This 10 patient, 28 week phase I study evaluated the safety and tolerability of octreotide acetate long-acting release (LAR) 20 mg depot injection every 4 weeks until week 16 after LVAD placement. Secondary aims were occurrence of GIB and measurement of vascular endothelial growth factor, fibrinogen, von Willebrand factor, and platelet aggregation across the study period. Ten patients were enrolled, and eight completed the study. The two study dropouts were not related to octreotide. None of the patients experienced side effects or safety concerns related to octreotide nor did GIB occur in the study population. Vascular endothelial growth factor levels were maintained in the reference range throughout the duration of the study. There did appear to be laboratory evidence of acquired von Willebrand syndrome, with mildly low platelet aggregation studies. In conclusion, octreotide acetate LAR 20 mg depot injection was safe and effective in this population.

Perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery

Aim:

The aim of this study was to describe our institutional experience, primarily with general anesthesiologists consulting with cardiac anesthesiologists, caring for left ventricular assist device (LVAD) patients undergoing noncardiac surgery.

Materials and Methods:

This is a retrospective review of the population of patients with LVADs at a single institution undergoing noncardiac procedures between 2009 and 2014. Demographic, perioperative, and procedural data collected included the type of procedure performed, anesthetic technique, vasopressor requirements, invasive monitors used, anesthesia provider type, blood product management, need for postoperative intubation, postoperative disposition and length of stay, and perioperative complications including mortality.

Statistical Analysis:

Descriptive statistics for categorical variables are presented as frequency distributions and percentages. Continuous variables are expressed as mean ± standard deviation and range when applicable.

Results:

During the study, 31 patients with LVADs underwent a total of 74 procedures. Each patient underwent an average of 2.4 procedures. Of the total number of procedures, 48 (65%) were upper or lower endoscopies. Considering all procedures, 81% were performed under monitored anesthesia care (MAC). Perioperative care was provided by faculty outside of the division of cardiac anesthesia in 62% of procedures. Invasive blood pressure monitoring was used in 27 (36%) procedures, and a central line, peripherally inserted central catheter or midline was in place preoperatively and used intraoperatively for 38 (51%) procedures. Vasopressors were not required in the majority (65; 88%) of procedures. There was one inhospital mortality secondary to multiorgan failure; 97% of patients survived to discharge after their procedure.

Conclusion:

At our institution, LVAD patients undergoing noncardiac procedures most frequently require endoscopy. These procedures can frequently be done safely under MAC, with or without consultation by a cardiac anesthesiologist.

Gastrointestinal Symptoms from Left-Ventricular Assist Device External Compression of the Gastric Lumen

A 74-year-old man with a left-ventricular assist device (LVAD) as destination therapy for end-stage ischemic cardiomyopathy presented with acute upper gastrointestinal bleeding. Other symptoms included chronic early satiety, intermittent nausea, and non-specific abdominal discomfort since LVAD implantation 3 years ago. An actively bleeding duodenal arteriovenous malformation was successfully treated with endoscopic coagulation. There was also evidence of moderate external compression of the anterior gastric wall from the LVAD pump with luminal narrowing in the antrum. While bleeding may be the most commonly encountered gastrointestinal manifestation in LVAD patients, other potential complications, including luminal compression by the device, should be recognized.