Thalidomide for treatment of gastrointestinal angiodysplasia in patients with left ventricular assist devices: case series and treatment protocol

Inhibition of angiogenesis in the management of refractory gastrointestinal bleeding in patients with LVAD support

BACKGROUND

Gastrointestinal bleeding (GIB) in patients with continuous flow left ventricular assist devices (CF-LVADs) is often related to GI angiodysplasia (GIAD). We previously reported data on VEGF inhibition with IV bevacizumab in the treatment of LVAD-associated GIAD bleeding, and now present follow-up data on patients treated with IV bevacizumab and/or low-dose oral pazopanib.

METHODS

All consecutive adult patients with LVAD-associated GIB from GIAD treated with bevacizumab or pazopanib, from July 20, 2017 to June 22, 2022, were included in the analysis. Data on hospitalizations, GI endoscopic procedures, and blood transfusions were obtained from first admission for GIB up to a median of 35.7 months following treatment initiation (range 1.3-59.8 months).

RESULTS

Eleven patients (91% male, mean 69.5 ± 8.9 years) were included. Eight patients (73%) received IV bevacizumab, two patients (18%) received oral pazopanib, and one patient (9%) received bevacizumab followed by pazopanib therapy. We observed a significantly decreased number of annualized hospitalizations for GIB (median difference - 2.87, p = 0.002), blood transfusions (median difference - 20.9, p = 0.01), and endoscopies (median difference - 6.95, p = 0.007) in patients pre- and post-anti-angiogenic therapy (bevacizumab and/or pazopanib). Similarly, a significant improvement in these clinical outcomes was noted in the bevacizumab group with decreased annualized hospitalizations (median difference - 2.75, p = 0.014), blood transfusions (median difference - 24.5, p = 0.047), and number of endoscopies (median differences -6.88, p = 0.006).

CONCLUSION

Anti-angiogenic therapy with IV bevacizumab and/or low-dose oral pazopanib appears to provide benefits in patients with LVAD-associated GIB with reduced hospitalizations, blood transfusions, and need for GI endoscopic procedures.

Gastrointestinal bleeding following Heartmate 3 left ventricular assist device implantation: The Michigan Bleeding Risk Model

BACKGROUND

Gastrointestinal bleeding (GIB) results in frequent hospitalizations and impairs quality of life in durable left ventricular assist device (LVAD) recipients. Anticipation of these events before implantation could have important implications for patient selection and management.

METHODS

The study population included all adult HeartMate 3 (HM3) primary LVAD recipients enrolled in the STS Intermacs registry from January 2017 to December 2020. Using multivariable modeling methodologies, we investigated the relationships between preimplantation characteristics and postimplant bleeding, bleeding and death, and additional bleeding episodes on subsequent bleeding episodes and created a risk score to predict the likelihood of post-LVAD GIB based solely on preimplantation factors.

RESULTS

Of 6,425 patients who received an HM3 LVAD, 1,010 (15.7%) patients experienced GIB. Thirteen preimplantation factors were independent predictors of post-LVAD GIB. A risk score was created from these factors and calculated for each patient. By 3 years postimplant, GIB occurred in 11%, 26%, and 43% of low-, medium- and high-risk patients, respectively. Experiencing 1 post-LVAD GIB event was associated with an increased risk for further GIB events, with 33.9% of patients experiencing at least 1 recurrence. While post-LVAD GIB was associated with mortality, there was no relationship between number of GIB events and death.

CONCLUSIONS

The Michigan Bleeding Risk Model is a simple tool, which facilitates the prediction of post-LVAD GIB in HM3 recipients using 13 preimplant variables. The implementation of this tool may help in the risk stratification process and may have therapeutic and clinical implications in HM3 LVAD recipients.

Shear-induced acquired von Willebrand syndrome: an accomplice of bleeding events in adults on extracorporeal membrane oxygenation support

Extracorporeal membrane oxygenation (ECMO) is an increasingly acceptable life-saving mechanical assistance system that provides cardiac and/or respiratory support for several reversible or treatable diseases. Despite important advances in technology and clinical management, bleeding remains a significant and common complication associated with increased morbidity and mortality. Some studies suggest that acquired von Willebrand syndrome (AVWS) is one of the etiologies of bleeding. It is caused by shear-induced deficiency of von Willebrand factor (VWF). VWF is an important glycoprotein for hemostasis that acts as a linker at sites of vascular injury for platelet adhesion and aggregation under high shear stress. AVWS can usually be diagnosed within 24 h after initiation of ECMO and is always reversible after explantation. Nonetheless, the main mechanism for the defect in the VWF multimers under ECMO support and the association between AVWS and bleeding complications remains unknown. In this review, we specifically discuss the loss of VWF caused by shear induction in the context of ECMO support as well as the current diagnostic and management strategies for AVWS.

Vascular Function in Continuous Flow LVADs: Implications for Clinical Practice

Left ventricular assist devices (LVADs) have been increasingly used in patients with advanced heart failure, either as a destination therapy or as a bridge to heart transplant. Continuous flow (CF) LVADs have revolutionized advanced heart failure treatment. However, significant vascular pathology and complications have been linked to their use. While the newer CF-LVAD generations have led to a reduction in some vascular complications such as stroke, no major improvement was noticed in the rate of other vascular complications such as gastrointestinal bleeding. This review attempts to provide a comprehensive summary of the effects of CF-LVAD on vasculature, including pathophysiology, clinical implications, and future directions.

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.

Gastrointestinal Bleeding Rates in Left Ventricular Assist Device Population Reduced with Octreotide Utilization

Patients with continuous-flow left ventricular assist devices have a high risk of gastrointestinal bleeding (GIB) and recurrent bleeding. Studies have shown octreotide can reduce the risk of GIB. This retrospective, case-crossover study, evaluated the efficacy of octreotide for the prevention of recurrent GIB in patients with left ventricular assist devices between August 2008 and October 2018. A total of 32 patients received octreotide and were included in the study. Hospital admission for GIB was evaluated before and after the initiation of octreotide. Each case served as his/her own control. Most patients were on a reduced aspirin dose (56.2%) and had a reduced international normalized ratio goal (59.4%) before starting monthly octreotide. The most common dose of long-acting octreotide was 30 mg every 28 days. Overall, octreotide decreased the frequency of GIB (4.3 vs. 0.9 events/year, p < 0.001). Nineteen (59.4%) patients did not have a subsequent gastrointestinal bleed. Of the 13 patients who rebled after initiation of octreotide, the frequency of events decreased by 2.6 bleeds per patient per year (4.8 vs. 2.2; p = 0.043). In high-risk patients who have failed conventional therapy, octreotide can be useful for the prevention of recurrent GIB.

Acquired von Willebrand Syndrome

Acquired von Willebrand syndrome can occur in the setting of myeloproliferative neoplasms; plasma cell dyscrasias and other lymphoproliferative disorders; autoimmune conditions; and causes of increased shear forces, such as aortic stenosis or other structural heart disease and mechanical circulatory support. The depletion of von Willebrand factor, especially high-molecular-weight multimers, can lead to mucocutaneous bleeding and the formation of arteriovenous malformations, particularly in the gastrointestinal tract. Management focuses on correction of the underlying cause when possible, but may include intravenous immunoglobulins, von Willebrand factor concentrate, rituximab, or antiangiogenic therapy depending on the clinical context.

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.

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.

Ventricular Assist Devices and Chronic Kidney Replacement Therapy: Technology and Outcomes

Heart failure and kidney failure are very common conditions, precipitating and exacerbating each other. Left ventricular assist devices (LVADs) represent a relatively new technology for treatment of advanced heart failure. Kidney dysfunction, if present, makes candidate selection for LVADs challenging and contributes to multiple complications while the patients are on an LVAD support. Although kidney function generally improves after LVAD implantation, some patients develop acute and then chronic kidney disease sometimes requiring kidney replacement therapies (KRTs). Overall, chronic KRT in LVAD recipients is feasible and well tolerated, but routine technique of blood pressure monitoring should be adjusted to the continuous blood flow. Both hemodialysis and peritoneal dialysis can be used. Unique challenges for chronic KRT posed by the presence of LVAD are discussed in this review.

HFSA/SAEM/ISHLT clinical expert consensus document on the emergency management of patients with ventricular assist devices

Mechanical circulatory support is now widely accepted as a viable long-term treatment option for patients with end-stage heart failure (HF). As the range of indications for the implantation of ventricular assist devices grows, so does the number of patients living in the community with durable support. Because of their underlying disease and comorbidities, in addition to the presence of mechanical support, these patients are at a high risk for medical urgencies and emergencies (Table 1). Thus, it is the responsibility of clinicians to understand the basics of their emergency care. This consensus document represents a collaborative effort by the Heart Failure Society of America, the Society for Academic Emergency Medicine, and the International Society for Heart and Lung Transplantation (ISHLT) to educate practicing clinicians about the emergency management of patients with ventricular assist devices. The target audience includes HF specialists and emergency medicine physicians, as well as general cardiologists and community-based providers.

A reappraisal of the pharmacologic management of gastrointestinal bleeding in patients with continuous flow left ventricular assist devices

Advancements in the design and functionality of continuous flow left ventricular assist devices (CF-LVADs), as well as a limited number of donor hearts, have resulted in an increased utilization of this therapy among advanced heart failure (HF) patients. Despite these advancements, gastrointestinal bleeding (GIB) remains a common complication after CF-LVAD implantation. The mechanism of GIB in these patients is complex and includes a combination of angiodysplasia, platelet dysfunction, acquired von Willebrand disease, and a variety of patient-specific factors including advanced age and history of GIB. Several pharmacotherapy options have been reported in the literature, though studies supporting the use of these agents are often small, retrospective reports. Within this review, we discuss the various pharmacologic agents, their proposed mechanisms of action, and the available literature pertaining to their effectiveness and tolerability. Additionally, we propose an evidence-based treatment algorithm, encompassing the updated literature, cost of therapy, medication side effects, and ease of administration.

Thalidomide for refractory gastrointestinal bleeding from vascular malformations in patients with significant comorbidities

BACKGROUND

Refractory gastrointestinal bleeding (GIB) secondary to gastrointestinal vascular malformations (GIVM) such as gastrointestinal angiodysplasia (GIAD) and gastric antral vascular ectasia (GAVE) remains challenging to treat when endoscopic therapy fails. Recently thalidomide has been suggested as a treatment option for refractory GIB.

AIM

To determine the outcome of patients treated with thalidomide for refractory GIB due to GIVM.

METHODS

IRB approved, single center, retrospective review of electronic medical records from January 2012 to November 2018. Patients age > 18 years old, who had > 3 episodes of GIB refractory to medical or endoscopic therapy, and who had been treated with thalidomide for at least 3 mo were included. The primary endpoint was recurrence of GIB 6 mo after initiation of thalidomide.

RESULTS

Fifteen patients were included in the study, all with significant cardiac, hepatic, or renal comorbidities. The cause of GIB was GIAD in 10 patients and GAVE in 5 patients. Two patients were lost to follow up. Of the 13 patients followed, 38.5% (n = 5) had no recurrent GIB or transfusion requirement after treatment with thalidomide. Furthermore, 84.6% (n = 11) of patients had a reduction in transfusion requirements and hospitalizations for GIB. Thalidomide was discontinued in 2 patients due to cost (n = 1) and medication interaction (n = 1). Reported adverse reactions included fatigue (n = 3), neuropathy (n = 2), dizziness (n = 1), and constipation (n = 1). Six patients died during follow up due to unknown cause (n = 4) and sepsis (n = 2).

CONCLUSION

Thalidomide appears to be an effective treatment for refractory GIB due to GIAD or GAVE in a Western population with significant comorbidities.

An Emergency Medicine-focused Summary of the HFSA/SAEM/ISHLT Clinical Consensus Document on the Emergency Management of Patients With Ventricular Assist Devices

Mechanical circulatory support is increasingly used as a long-term treatment option for patients with end-stage heart failure. Patients with implanted ventricular assist devices are at high risk for a range of diverse medical urgencies and emergencies. Given the increasing prevalence of mechanical circulatory support devices, this expert clinical consensus document seeks to help inform emergency medicine and prehospital providers regarding the approach to acute medical and surgical conditions encountered in these complex patients.

Effect of Angiotensin II Inhibitors on Gastrointestinal Bleeding in Patients With Left Ventricular Assist Devices

BACKGROUND

Angiotensin II receptor activation may result in angiogenesis, and ultimately arteriovenous malformations (AVM), through transforming growth factor (TGF)-β and angiopoietin-2 pathway activation.

OBJECTIVES

The goal of this study was to determine whether angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB) were associated with lower risk of major gastrointestinal bleeds (GIB) and AVM-related GIBs in continuous-flow left ventricular assist device (CF-LVAD) patients.

METHODS

The authors reviewed HeartMate II CF-LVAD recipients between January 2009 and July 2016. Major GIBs were endoscopically confirmed requiring ≥2 U of packed red blood cells or resulting in death. ACE inhibitor/ARB dose was abstracted from medical records. ACE inhibitor/ARB exposure status was landmarked at 30 days post-operatively to avoid immortal time bias. Fine and Gray hazard models assessed the impact of ACE inhibitor/ARB therapy on major GIB and AVM-related GIB, whereas standard Cox regression assessed the impact on mortality, adjusting for baseline variables.

RESULTS

One-hundred and eleven patients were included with a mean 2.1 ± 1.4 years follow-up. Patients who received an ACE inhibitor/ARB within 30 days post-operatively had a 57% reduction in the risk of major GIB (adjusted hazard ratio [aHR]: 0.43; 95% confidence interval [CI]: 0.19 to 0.97; p = 0.042) and a 63% reduction in the risk of AVM-related GIB (aHR: 0.37; 95% CI: 0.16 to 0.84; p = 0.017). When the mean daily post-operative lisinopril-equivalent ACE inhibitor/ARB dose was >5 mg, the risk of major GIB decreased in a dose-threshold manner (aHR: 0.28; 95% CI: 0.09 to 0.85; p = 0.025).

CONCLUSIONS

ACE inhibitor/ARB therapy is associated with a protective effect of developing GIBs in CF-LVAD patients, with a dose threshold of >5 mg of daily lisinopril equivalence, possibly due to prevention of AVM formation.

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.

Acquired Von Willebrand Syndrome (AVWS) in cardiovascular disease: a state of the art review for clinicians

Von Willebrand Factor (vWF) is a large glycoprotein with a broad range of physiological and pathological functions in health and disease. While vWF is critical for normal hemostasis, vascular integrity and repair, quantitative and qualitative abnormalities in the molecule can predispose to serious bleeding and thrombosis. The heritable form of von Willebrand Disease was first described nearly a century ago, but more recently, recognition of an acquired condition known as acquired von Willebrand Syndrome (AVWF) has emerged in persons with hematological, endocrine and cardiovascular diseases, disorders and conditions. An in-depth understanding of the causes, diagnostic approach and management of AVWS is important for practicing clinicians.

Clinical and In Vitro Evidence That Left Ventricular Assist Device-Induced von Willebrand Factor Degradation Alters Angiogenesis

Background Gastrointestinal bleeding from angiodysplasia is a major problem in continuous-flow left ventricular assist device (LVAD) patients. LVAD shear stress causes pathologic degradation of VWF (von Willebrand factor). A mechanistic relationship between VWF degradation and angiodysplasia has not been explored. We tested 2 novel hypotheses: (1) clinical hypothesis: VWF fragments are elevated in LVAD patients that develop angiodysplasia and (2) in vitro hypothesis: VWF fragments generated during LVAD support alter angiogenesis, which may contribute to angiodysplasia. Methods and Results Clinical study: Paired blood samples were collected from continuous-flow LVAD patients (n=35). VWF was quantified with immunoblotting. In vitro experiments: (1) To investigate whether LVAD support alters angiogenesis, human endothelial cells were cultured with LVAD patient plasma (n=11). To investigate mechanism, endothelial cells were cultured with VWF fragments produced by exposing human VWF and ADAMTS-13 (VWF protease) to LVAD-like shear stress (175 dyne/cm², n=8). Clinical study results: in all patients (n=35, mean support 666±430 days), LVAD support degraded high-molecular-weight VWF multimers ( P<0.0001) into low-molecular-weight VWF multimers ( P<0.0001) and VWF fragments ( P<0.0001). In patients with gastrointestinal bleeding from angiodysplasia (n=7), VWF fragments were elevated ( P=0.02) versus nonbleeders. In contrast, in patients with gastrointestinal bleeding without angiodysplasia, VWF fragments were not elevated versus nonbleeders ( P=0.96). In vitro experiments results: LVAD patient plasma caused abnormal angiogenesis with reduced tubule length ( P=0.04) and migration ( P=0.05). Similarly, endothelial cells grown with VWF degradation fragments exhibited reduced tubule length ( P<0.001) and migration ( P=0.01). Conclusions LVAD patients who bled from angiodysplasia had higher levels of VWF fragments than nonbleeders and gastrointestinal bleeders without angiodysplasia. VWF fragments caused abnormal angiogenesis in vitro. These findings suggest that VWF fragments may be a mechanistic link between LVAD support, abnormal angiogenesis, angiodysplasia, and gastrointestinal bleeding.

Omega-3 Therapy Is Associated With Reduced Gastrointestinal Bleeding in Patients With Continuous-Flow Left Ventricular Assist Device

Background Gastrointestinal bleeding (GIB) is a common complication seen in patients supported with left ventricular assist devices (LVADs) and is related to increased inflammation and angiogenesis. Omega-3 is an unsaturated fatty acid that possesses anti-inflammatory and antiangiogenic properties. This study aims to assess the prophylactic efficacy of treatment with omega-3 on the incidence of GIB in LVAD patients. Methods and Results Among consecutive 166 LVAD patients enrolled in this analysis, 30 patients (49 years old and 26 male) received 4 mg/d of omega-3 therapy for 310±87 days and 136 patients in the control group (58 years old and 98 male) were observed for 302±102 days. One-year GIB-free rate was significantly higher in the omega-3 group as compared with the control group (97% versus 73%; P=0.02). Omega-3 therapy was associated with the occurrence of GIB in both the univariate (hazard ratio, 0.12; 95% CI, 0.02-0.91; P=0.040) and multivariate Cox proportional hazard ratio analyses (hazard ratio, 0.13; 95% CI, 0.02-0.98; P=0.047). The frequency of GIB was significantly lower in the omega-3 group (0.08±0.42 versus 0.37±0.93 events/y; P=0.01), accompanied by significantly lower blood product transfusion and shorter days in the hospital. The frequency of GIB remained lower among the omega-3 group after matching for patient background characteristics (96% versus 73%, P=0.028). Conclusions LVAD patients treated with omega-3 had a significant increase in freedom from GIB. A randomized controlled study is warranted to evaluate the use of omega-3 in LVAD patients.

Arteriovenous malformations respond poorly to argon plasma coagulation in patients with continuous flow left ventricular assist devices

BACKGROUND

Gastrointestinal bleeding in patients with continuous flow left ventricular assist devices (LVADs) causes significant morbidity. Arteriovenous malformations (AVMs) cause 30-60% of bleeds, yet the efficacy of endoscopic interventions and risk factors for rebleeding have not been studied.

PATIENTS AND METHODS

The charts of all LVAD patients undergoing endoscopy for gastrointestinal bleeding at Stanford between January 2010 and December 2017 were reviewed. Cox proportional hazard modeling was used to evaluate risk factors for rebleeding, including the type of endoscopic treatment, patient characteristics, and endoscopic findings.

RESULTS

Of 54 total LVAD patients presenting with gastrointestinal bleeding, 23 (42.6%) had AVMs documented on endoscopy. Treatment with argon plasma coagulation (APC) alone was associated with a higher risk of rebleeding compared to no treatment [hazard ratio (HR)=4.77, P=0.012], and compared with clip±APC (HR=7.47, P=0.012). The 90-day bleed-free rate was 10.9% with APC, 100% with clipping±APC, and 83.3% with no endoscopic treatment. Additional risk factors for rebleeding included the presence of gastric AVMs (HR=3.64, P=0.024), and presence of hematochezia (HR=5.15, P=0.05). In a multiple Cox regression model, only the presence of gastric AVMs (HR=5.50, P=0.029) and APC use (HR=14.3, P=0.008) remained significant predictors of rebleeding.

CONCLUSION

The use of APC alone for the treatment of AVMs in LVAD patients had a high failure rate. The presence of gastric AVMs was a significant risk factor for rebleeding in LVAD patients. Management decisions should take these factors into account.

Acquired von Willebrand Syndrome in Patients With Ventricular Assist Device

During the last decade the use of ventricular assist devices (VADs) for patients with severe heart failure has increased tremendously. However, flow disturbances, mainly high shear induced by the device is associated with bleeding complications. Shear stress-induced changes in VWF conformation are associated with a loss of high molecular weight multimers (HMW) of VWF and an increased risk of bleeding. This phenomenon and its cause will be elaborated and reviewed in the following.

Resource utilization and hospital readmission associated with gastrointestinal bleeding in patients with continuous-flow left ventricular assist devices

Gastrointestinal bleeding (GIB) occurs in up to 40% of patients with continuous-flow (CF) left ventricular assist devices (LVADs). We sought to identify targets to improve hospital resource utilization and decrease readmissions after GIB. We performed a single-center, retrospective analysis of LVAD-associated GIB resulting in hospital admission between July 2011 and April 2014. Follow-up data were collected through March 2015. We analyzed 57 admissions for GIB in 23 patients. One or more diagnostic imaging study was performed in 47% of admissions, with a definite or probable source of GIB identified in 23%. A total of 76 endoscopies were performed (≥ 1 endoscopy in 79% of admissions, ≥ 2 in 42%). Definite or probable bleeding sources were identified in 25% and 12% of endoscopies, respectively. Patients who underwent multiple endoscopies were no more likely to have a bleeding source identified (OR 1.48; 95% CI 0.50-4.32; p = 0.59) and had longer hospital stays (11.1 vs. 7.8 days, p < 0.02). Readmission rates for GIB at 30 and 90 days were 33% and 53%, respectively. A decrease in antiplatelet regimen at discharge was associated with lower rate of readmission for GIB (OR 0.16; 95% CI 0.03-0.82; p = 0.03) or any cause (OR 0.21; 95% CI 0.05-0.85; p = 0.04) at 30 and 90 days. GIB in patients with CF-LVADs is associated with significant in-hospital resource utilization and high rates of readmission. Imaging and endoscopy are common, but have low diagnostic yield and infrequently result in successful intervention. Strategies to reduce resource utilization and prevent readmission are warranted.

Omega-3 Therapy Is Associated With Reduced Gastrointestinal Bleeding in Patients With Continuous-Flow Left Ventricular Assist Device

Background Gastrointestinal bleeding (GIB) is a common complication seen in patients supported with left ventricular assist devices (LVADs) and is related to increased inflammation and angiogenesis. Omega-3 is an unsaturated fatty acid that possesses anti-inflammatory and antiangiogenic properties. This study aims to assess the prophylactic efficacy of treatment with omega-3 on the incidence of GIB in LVAD patients. Methods and Results Among consecutive 166 LVAD patients enrolled in this analysis, 30 patients (49 years old and 26 male) received 4 mg/d of omega-3 therapy for 310±87 days and 136 patients in the control group (58 years old and 98 male) were observed for 302±102 days. One-year GIB-free rate was significantly higher in the omega-3 group as compared with the control group (97% versus 73%; P=0.02). Omega-3 therapy was associated with the occurrence of GIB in both the univariate (hazard ratio, 0.12; 95% CI, 0.02-0.91; P=0.040) and multivariate Cox proportional hazard ratio analyses (hazard ratio, 0.13; 95% CI, 0.02-0.98; P=0.047). The frequency of GIB was significantly lower in the omega-3 group (0.08±0.42 versus 0.37±0.93 events/y; P=0.01), accompanied by significantly lower blood product transfusion and shorter days in the hospital. The frequency of GIB remained lower among the omega-3 group after matching for patient background characteristics (96% versus 73%, P=0.028). Conclusions LVAD patients treated with omega-3 had a significant increase in freedom from GIB. A randomized controlled study is warranted to evaluate the use of omega-3 in LVAD patients.

Controversies and Challenges of Ventricular Assist Device Therapy

Left ventricular assist device (LVAD) therapy has emerged as an increasingly vital facet of the treatment algorithm for advanced heart failure. Growing experience with LVAD support has led to substantial improvements in outcomes, with 1-year survival rates approaching that of cardiac transplantation. These therapeutic refinements have engendered growing interests in the potential for expanding the clinical indications for LVAD therapy to patients with less advanced heart failure. The primary obstacles to this evolution of care center largely on the prevention and/or management of the adverse events associated with LVAD therapy along with patient preference. Many programs also face the mounting difficulty of balancing quality outcomes with the increased volume of implants. During the recently assembled Users Meeting organized by St. Jude Medical, heart failure clinicians from nearly 50 LVAD implanting centers discussed these and other challenges and controversies impacting the field. The present review summarizes the key insights gleaned from this meeting.

Emerging role of thalidomide in the treatment of gastrointestinal bleeding

Thalidomide was initially synthesised in 1954 and marketed as a sedative and antiemetic for morning sickness. It was withdrawn in 1961 due to the realisation that it was teratogenic with over 10 000 children born with congenital abnormalities. Since then it has been used for treatment of dermatological and oncological conditions, including myeloma. In 1994, it was found to have a potent antiangiogenic effect via downregulation of vascular endothelial growth factor (VEGF). This has led to its use in gastrointestinal bleeding, as vascular abnormalities such as angiodysplasia have been found to have elevated VEGF levels. This article will review the current evidence of the use of thalidomide in bleeding associated with gastrointestinal vascular malformations, including angiodysplasia, gastric cancer and radiation-induced proctitis.

Long-Acting Octreotide Reduces the Recurrence of Gastrointestinal Bleeding in Patients With a Continuous-Flow Left Ventricular Assist Device

BACKGROUND

Recurrent gastrointestinal bleeding is one of the most significant adverse events in patients with left ventricular assist devices (LVADs).

METHODS

We enrolled LVAD patients who had received an intramuscular injection of 20 mg octreotide every 4 weeks as secondary prevention for recurrent gastrointestinal bleeding despite conventional medical therapies and repeated transfusions. The frequency of gastrointestinal bleeding and other associated clinical outcomes before and during octreotide therapy were compared.

RESULTS

Thirty LVAD patients (66.4 ± 8.8 years old, 16 men [53%]) received octreotide therapy for 498.8 ± 356.0 days without any octreotide-associated adverse events. The frequency of gastrointestinal bleeding was decreased significantly during octreotide therapy (from 3.4 ± 3.1 to 0.7 ± 1.3 events/year; P < .001), accompanied by significant reductions in red blood cell and flesh frozen plasma transfusions, days in hospital, and need for endoscopic procedures (P < .05 for all).

CONCLUSIONS

Octreotide therapy reduced the frequency of recurrent gastrointestinal bleeding and may be considered for secondary prevention.

Efficacy of Video Capsule Endoscopy in the Management of Suspected Small Bowel Bleeding in Patients With Continuous Flow Left Ventricular Assist Devices

Background

Continuous flow left ventricular assist device (CF-LVAD) patients have a high prevalence of gastrointestinal bleeding from the small bowel. Video capsule endoscopy (VCE) is often used for diagnosis in these patients, but efficacy has yet to be determined. In this study, we evaluated the efficacy of VCE in the management of CF-LVAD patients with suspected small bowel bleeding by comparing to a non-VCE CF-LVAD control group.

Methods

We retrospectively reviewed the charts of all patients with CF-LVADs implanted at Stanford Hospital from January 2010 to October 2015. Patients were included in the study if there was a clinical suspicion of small bowel bleeding and either a negative upper endoscopy or colonoscopy.

Results

A total of 26 patients met inclusion criteria for a total of 15 encounters where VCE was done, and 25 where VCE was not done. There were no statistical differences when comparing these groups in terms of medical therapy use (thalidomide or octreotide), enteroscopy use (double-balloon or push), intervention on lesions, or any 30-day outcomes. There was no advantage to VCE with regard to the composite endpoint time to re-bleed or death related to re-bleeding (median 114 vs. 161 days, P = 0.15) after removing patients who did not get a VCE due to death or critical illness.

Conclusions

We did not find VCE changed management or outcomes in CF-LVAD patients with suspected small bowel bleeding at our institution when compared to a non-VCE control group. Our experience is small and single center, and larger, multi-center studies could further elucidate the utility of VCE in this patient population.

Left Ventricular Assist Devices for Lifelong Support

Continuous-flow left ventricular assist devices (LVADs) have revolutionized advanced heart failure care. These compact, fully implantable heart pumps are capable of providing meaningful increases in survival, functional capacity, and quality of life. Implantation volumes continue to grow, but several challenges remain to be overcome before LVADs will be considered as the therapy of choice for all patients with advanced heart failure. They must be able to consistently extend survival for the long term (7 to 10 years), rather than the midterm (3 to 5 years) more typical of contemporary devices; they must incorporate design elements that reduce shear stress and avoid stasis to reduce the frequent adverse events of bleeding, stroke, and pump thrombosis; and they must become more cost-effective. The advancements in engineering, implantation technique, and medical management detailed in this review will highlight the progress made toward achieving lifelong LVAD support and the challenges that remain.

Novel use of low-dose thalidomide in refractory gastrointestinal bleeding in left ventricular assist device patients

BACKGROUND

Gastrointestinal bleeding (GIB) is a complication reported in patients post left ventricular assist device (LVAD) implantation that is associated with high mortality rates. Thalidomide is an anti-angiogenic compound that may offer a potential option for management of refractory LVAD-related GIB.

METHODS

A single-center, retrospective review was conducted from January 2009 to October 2016 at a tertiary cardiology center. It included LVAD patients initiated on thalidomide for refractory GIB.

RESULTS

All patients (n = 11) were started on thalidomide 50 mg nocte and there was resolution of GIB in all patients except one (90.9%) during initial thalidomide treatment.The median duration of thalidomide therapy was 98 days (interquartile range: 34-215). The dose of thalidomide was reduced for 2 patients due to adverse effects. Thalidomide therapy was discontinued in 6 patients due to cessation of GIB (n = 4) and adverse effects (n = 2). Reported adverse effects included LVAD thrombosis (n = 2), somnolence (n = 1), neuropathy (n = 1), constipation (n = 1), and transaminitis (n = 1).Recurrent GIB occurred in 4 patients (45.4%) post-discontinuation of thalidomide therapy, which led to the re-initiation of therapy.

CONCLUSIONS

Thalidomide appears to be a safe and effective option for management of refractory LVAD-related GIB. Monitoring for recurrent GIB should be performed closely following cessation of thalidomide therapy.

Tumor necrosis factor-α levels and non-surgical bleeding in continuous-flow left ventricular assist devices

BACKGROUND

Non-surgical bleeding (NSB) due to angiodysplasia is common in left ventricular assist device (LVAD) patients. Thrombin-induced angiopoietin-2 (Ang-2) expression in LVAD patients leads to altered angiogenesis and is associated with lower angiopoietin-1 (Ang-1) and increased NSB. However, the mechanism for decreased Ang-1, made by pericytes, is unknown and the origin of thrombin in LVAD patients is unclear. We hypothesized that high tumor necrosis factor-α (TNF-α) levels in LVAD patients induce pericyte apoptosis, tissue factor (TF) expression and vascular instability.

METHODS

We incubated cultured pericytes with serum from patients with heart failure (HF), LVAD or orthotopic heart transplantation (OHT), with or without TNF-α blockade. We performed several measurements: Ang-1 expression was assessed by reverse transcript-polymerase chain reaction (RT-PCR) and pericyte death fluorescently; TF expression was assessed by RT-PCR in cultured endothelial cells incubated with patient plasma with or without TNF-α blockade; and TF expression was assessed in endothelial biopsy samples from these patients by immunofluorescence. We incubated cultured endothelial cells on Matrigel with patient serum with or without TNF-α blockade and determined tube formation by microscopy.

RESULTS

Serum from LVAD patients had higher levels of TNF-α, suppressed Ang-1 expression in pericytes, and induced pericyte death, and there was accelerated endothelial tube formation compared with serum from patients without LVADs. TF was higher in both plasma and endothelial cells from LVAD patients, and plasma from LVAD patients induced more endothelial TF expression. All of these effects were reversed or reduced with TNF-α blockade. High levels of TNF-α were associated with increased risk of NSB.

CONCLUSIONS

Elevated TNF-α in LVAD patients is a central regulator of altered angiogenesis, pericyte apoptosis and expression of TF and Ang-1.

Von Willebrand factor and angiogenesis: basic and applied issues

The recent discovery that von Willebrand factor (VWF) regulates blood vessel formation has opened a novel perspective on the function of this complex protein. VWF was discovered as a key component of hemostasis, capturing platelets at sites of endothelial damage and synthesized in megakaryocytes and endothelial cells (EC). In recent years, novel functions and binding partners have been identified for VWF. The finding that loss of VWF in EC results in enhanced, possibly dysfunctional, angiogenesis is consistent with the clinical observations that in some patients with von Willebrand disease (VWD), vascular malformations can cause severe gastrointestinal (GI) bleeding. In vitro and in vivo studies indicate that VWF can regulate angiogenesis through multiple pathways, both intracellular and extracellular, although their relative importance is still unclear. Investigation of these pathways has been greatly facilitated by the ability to isolate EC from progenitors circulating in the peripheral blood of normal controls and patients with VWD. In the next few years, these will yield further evidence on the molecular pathways controlled by VWF and shed light on this novel and fascinating area of vascular biology. In this article, we will review the evidence supporting a role for VWF in blood vessel formation, the link between VWF dysfunction and vascular malformations causing GI bleeding and how they may be causally related. Finally, we will discuss how these findings point to novel therapeutic approaches to bleeding refractory to VWF replacement therapy in VWD.

Angiotensin II antagonism is associated with reduced risk for gastrointestinal bleeding caused by arteriovenous malformations in patients with left ventricular assist devices

BACKGROUND

Angiogenesis is implicated in formation of gastrointestinal arteriovenous malformations (AVMs). Angiotensin II signaling is involved in angiogenesis through the vascular endothelial growth factor (VEGF) and angiopoietin-2 pathways. We hypothesized that angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) therapy would be associated with a reduced risk of all-cause gastrointestinal bleeding (GIB) and AVM-associated GIB in patients with left ventricular assist devices (LVADs).

METHODS

We reviewed records of all adult patients receiving a continuous-flow LVAD (HeartMate II or HeartWare HVAD) at Johns Hopkins Hospital between January 2004 and December 2014. Of 192 patients, 131 were included for final analyses. Logistic regression analysis adjusting for demographic, cardiovascular, and laboratory variables was used to assess the association of ACEI or ARB therapy with GIB.

RESULTS

Of 131 patients, 100 received ACEI or ARB therapy during LVAD support. Of the 31 patients who did not receive ACEI or ARB, 15 experienced GIB (48%), with 9 caused by AVMs (29%). Of 100 patients who received ACEI or ARB therapy, 24 experienced GIB (24%), with 9 caused by AVMs (9%). Logistic regression hazards model demonstrated that ACEI or ARB therapy was independently associated with a reduced risk for all-cause GIB (odds ratio 0.29, 95% confidence interval 0.12-0.72) and AVM-related GIB (odds ratio 0.23, 95% confidence interval 0.07-0.71).

CONCLUSIONS

Angiotensin II antagonism is associated with a reduced risk of AVM-related GIB in patients with LVADs. This association is independent of age, sex, blood pressure, renal function, international normalized ratio, LVAD type, and cardiomyopathy etiology.

Novel Use of Thalidomide in Recurrent Gastrointestinal Tract Bleeding in Patients with Left Ventricular Assist Devices: A Case Series

BACKGROUND

Bleeding is an important and common complication of left ventricular assist devices (LVADs). One of the common causes of gastrointestinal bleeding is arteriovenous malformations. However, the source of bleeding is often hard to identify. Thalidomide is efficacious in treatment of gastrointestinal (GI) bleeding in non-LVAD patients. We report our experience of the use of thalidomide in the treatment of GI bleeding in four patients with LVAD.

METHOD AND RESULTS

Four patients who had recurrent GI bleeding from May 2009 to December 2014 were started on thalidomide. All of them responded to treatment and had no further gastrointestinal bleeding while on thalidomide. One patient developed constipation, requiring thalidomide to be stopped. Another patient developed symptomatic neuropathy, that resolved with reduction of dosage.

CONCLUSION

Thalidomide appears safe and efficacious in LVAD patients with recurrent gastrointestinal bleeding.

Bleeding recurrence in patients with gastrointestinal vascular malformation after thalidomide

Thalidomide may be used for the treatment of gastrointestinal vascular malformation (GIVM), but the long-term response and adverse effects are unknown. Aim to study the recurrence rate of GIVM bleeding after thalidomide treatment, the response to treatment, and the adverse effects.This was a retrospective study of 80 patients with GIVM treated with thalidomide between November 2003 and November 2013. Patients received a course of 100 mg/day of thalidomide for 4 months and were followed up for at least 1 year. The response rate during follow-up, the recurrence rate after the 1st course of treatment, and the rate of retreatment were assessed. Comorbidities, the need for blood transfusion, yearly bleeding episodes, hemoglobin levels, hospitalization after thalidomide treatment, and the rate of adverse effects were also examined.The overall response rate during follow-up was 79.5% (62/78). The recurrence rate was 21.0% after the 1st course of thalidomide. The response rate of retreatment was 100%. After thalidomide treatment, yearly blood transfusion amounts, yearly bleeding episodes, and yearly hospitalization numbers were significantly decreased, while hemoglobin levels were significantly increased (P < 0.001). Adverse effects were observed in 60.0% (48/80) of the patients. Serious adverse effects were reported in 31.3% (25/80). The overall response rate was 76.7% (23/30) in 30 patients with comorbidities, while the rate was 78.0% (39/50) in patients without comorbidities (P = 0.55). The rate of serious adverse effects was similar between the comorbidities (33.3%) and no-comorbidities groups (30.0%) (P = 0.76).Thalidomide showed a good response rate and low adverse effect rate in patients with recurrent gastrointestinal bleeding due to GIVM.

Gastrointestinal Bleeding Following LVAD Placement from Top to Bottom

BACKGROUND

Left ventricular assist devices (LVADs) are an increasingly prevalent form of mechanical support for patients with end-stage heart failure. These devices can be implanted both as a bridge to transplant and as definitive/destination therapy. Gastrointestinal (GI) bleeding is one of the most common and recalcitrant long-term complications following LVAD implantation, with an incidence approaching 30 %.

AIMS

This review will discuss what is known about the pathophysiology of GI bleeding in LVADs and the currently available options for medical and/or endoscopic management.

RESULTS

The pathophysiology of bleeding is multifactorial, with hemodynamic alterations, acquired von Willebrand factor deficiency, and coagulopathy being most often implicated. The majority of bleeding events in this population result from angioectasias and gastroduodenal erosive disease. While these bleeding events are significant and often require transfusion therapy, they are rarely life threatening. Endoscopy remains the standard of care with upper endoscopy offering the highest diagnostic yield in these patients. However, the effectiveness of endoscopic hemostasis in this population is not well established. A small number of studies have evaluated medical therapy and alterations in LVAD settings as a means of preventing or treating bleeding with variable results.

CONCLUSIONS

In summary, GI bleeding with LVADs is a common occurrence and will continue to be as more LVADs are being performed for destination therapy.

Video capsule endoscopy in left ventricular assist device recipients with obscure gastrointestinal bleeding

AIM: To assess whether video capsule endoscopy (VCE) affects the outcomes of left ventricular assist devices (LVADs) recipients with gastrointestinal bleeding.

METHODS: This is a retrospective study of LVAD recipients with obscure gastrointestinal bleeding (OGIB) who underwent VCE at a tertiary medical center between 2005 and 2013. All patients were admitted and monitored with telemetry and all VCE and subsequent endoscopic procedures were performed as inpatients. A VCE study was considered positive only when P2 lesions were found and was regarded as negative if P1 or P0 were identified. All patients were followed until heart transplant, death, or the end of the study.

RESULTS: Between 2005 and 2013, 30 patients with LVAD underwent VCE. Completion rate of VCE was 93.3% and there was no capsule retention. No interference of VCE recording or the function of LVAD was found. VCE was positive in 40% of patients (n = 12). The most common finding was active small intestinal bleeding (50%) and small intestinal angiodysplasia (33.3%). There was no difference in the rate of recurrent bleeding between patients with positive and negative VCE study (50.0% vs 55.6%, P = 1.00) during an average of 11.6 ± 9.6 mo follow up. Among patients with positive VCE, the recurrent bleeding rate did not differ whether subsequent endoscopy was performed (50% vs 50%, P = 1.00).

CONCLUSION: VCE can be safely performed in LVAD recipients with a diagnostic yield of 40%. VCE does not affect recurrent bleeding in LVAD patients regardless of findings.

Acquired von Willebrand syndrome associated with left ventricular assist device

Left ventricular assist devices (LVAD) provide cardiac support for patients with end-stage heart disease as either bridge or destination therapy, and have significantly improved the survival of these patients. Whereas earlier models were designed to mimic the human heart by producing a pulsatile flow in parallel with the patient's heart, newer devices, which are smaller and more durable, provide continuous blood flow along an axial path using an internal rotor in the blood. However, device-related hemostatic complications remain common and have negatively affected patients' recovery and quality of life. In most patients, the von Willebrand factor (VWF) rapidly loses large multimers and binds poorly to platelets and subendothelial collagen upon LVAD implantation, leading to the term acquired von Willebrand syndrome (AVWS). These changes in VWF structure and adhesive activity recover quickly upon LVAD explantation and are not observed in patients with heart transplant. The VWF defects are believed to be caused by excessive cleavage of large VWF multimers by the metalloprotease ADAMTS-13 in an LVAD-driven circulation. However, evidence that this mechanism could be the primary cause for the loss of large VWF multimers and LVAD-associated bleeding remains circumstantial. This review discusses changes in VWF reactivity found in patients on LVAD support. It specifically focuses on impacts of LVAD-related mechanical stress on VWF structural stability and adhesive reactivity in exploring multiple causes of AVWS and LVAD-associated hemostatic complications.

Bowel Angiodysplasia and Myocardial Infarction secondary to an ischaemic imbalance: a case report

Angiodysplasia, defined as a vascular ectasia or arteriovenous malformation, is the most frequent cause of occult bleeding in patients older than 60 years and a significant association with several cardiac condition is described. Patients with anemia and negative findings on upper endoscopy and colonoscopy should be referred for further investigation of the small bowel. The investigation of choice, when available, is wireless capsule endoscopy. Several therapeutic options are available in this cases, as we reviewed in this report. We report a case of 78-year old man admitted to our Intensive Coronary Unit for dyspnea and chest pain. A diagnosis of non-ST-segment elevation acute coronary syndrome was made and a concomintant, significant anemia was found (hemoglobin 8.2 g/dl).

No cororary disease was found by an angiography though the past medical history revealed systemic hypertension, chronic kidney disease (KDOQY stage III), and diabetes mellitus type II on insuline therapy. A Wireless Video capsule examination was positive for jejunum angiodysplasia and an argon plasma coagulation was chosen as terapeutic option. No subsequent supportive therapy and interventions were required in subsequent one year of follow-up.