Evaluation of GI bleeding after implantation of left ventricular assist device

Patient management important for long-term support beyond 5 years in the BTT: republication of the article published in the Japanese Journal of Artificial Organs

Heart transplantation is considered to be the best treatment for severe heart failure refractory to medical therapy, improving patients' survival and quality of life (QOL). However, the number of donors is smaller than the number of registered applicants for heart transplantation, which increases every year, and the waiting period for heart transplantation has been extended to more than 1700 days by 2022. Since 2011, reimbursement for the implantable left ventricular assist device (iLVAD) was established. The numbers of the iLVAD patients have been increasing year by year. Patients are managed at home with an iLVAD and can live with their families and even return to work, depending on the situation. On the other hand, self-management at home, including caregivers, is important for a safe life. Home management beyond 5 years is becoming more common due to long waiting time for transplant. This article outlines the important aspects of patient management for long-term support. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2023 (Vol. 52, No. 1, pp. 62-66), with some modifications.

Patient-specific severity of von Willebrand factor degradation identifies patients with a left ventricular assist device at high risk for bleeding

BACKGROUND

Continuous-flow left ventricular assist devices (LVADs) cause an acquired von Willebrand factor (VWF) deficiency and bleeding. Models to risk-stratify for bleeding are urgently needed. We developed a model of continuous-flow LVAD bleeding risk from patient-specific severity of VWF degradation.

METHODS

In a prospective, longitudinal cohort study, paired blood samples were obtained from patients (n = 67) with a continuous-flow LVAD before and during support. After 640 ± 395 days, patients were categorized as all-cause bleeders, gastrointestinal (GI) bleeders, or nonbleeders. VWF multimers and VWF clotting function were evaluated to determine bleeding risk.

RESULTS

Of 67 patients, 34 (51%) experienced bleeding, 26 (39%) experienced GI bleeding, and 33 (49%) did not bleed. In all patients, LVAD support significantly reduced high-molecular-weight VWF multimers (P < .001). Bleeders exhibited greater loss of high-molecular-weight VWF multimers (mean ± standard deviation, -10 ± 5% vs -7 ± 4%, P = .008) and reduced VWF clotting function versus nonbleeders (median [interquartile range], -12% [-31% to 4%] vs 0% [-9 to 26%], P = .01). A combined metric of VWF multimers and VWF function generated the All-Cause Bleeding Risk Score, which stratified bleeders versus nonbleeders (86 ± 56% vs 41 ± 48%, P < .001) with a positive predictive value of 86% (95% confidence interval, 66%-95%) and diagnostic odds ratio of 11 (95% confidence interval, 2.9-44). A separate GI Bleeding Risk Score stratified GI bleeders versus nonbleeders (202 ± 114 vs 120 ± 86, P = .003) with a positive predictive value of 88% (64%-97%) and diagnostic odds ratio of 18 (3.1-140).

CONCLUSIONS

The severity of loss of VWF multimers and VWF clotting function generated Bleeding Risk Scores with high predictive value for LVAD-associated bleeding. This model may guide personalized antithrombotic therapy and patient surveillance.

Left Ventricular Assist Device Emergencies: Diagnosis and Management

Durable left ventricular assist devices (LVADs) are a virtually limitless advanced therapy option for an increasingly growing population of patients with end-stage advanced heart failure. As of 2019, 30% to 40% of all patients diagnosed with heart failure were categorized as New York Heart Association class III or IV. In 2018 more than 3.2 million office visits and 1.4 million emergency department visits carried a primary diagnosis of heart failure. Given the rapid growth of the LVAD population, facility in the diagnosis and management of common perioperative and outpatient LVAD emergencies has become of paramount importance in a variety of clinical settings.

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.

Predictors of gastrointestinal bleeding in patients following left ventricular assist device implantation: a systematic review and meta-analysis

Aim: Our study aims to provide a more holistic understanding of the available data and predictive risk factors for gastrointestinal bleed (GIB). Materials & methods: We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Web of Science Core Collection and calculated relative risk and meta-regression was utilized to evaluate for risk factors in order to assess the effect of covariates. Results: Our meta-analysis reported a pooled prevalence rate of GIB of 24.4%. Meta-regression analysis did not yield a statistically significant association between GIB and risk factors, including age, gender, hypertension, chronic kidney disease and diabetes. Conclusion: Studies investigating larger sample sizes are required for conclusive findings.

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.

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.

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.

Preoperative Right Heart Dysfunction and Gastrointestinal Bleeding in Patients with Left Ventricular Assist Devices

Gastrointestinal bleeding (GIB) is a common cause of morbidity among patients supported by left ventricular assist devices (LVADs). The aim of this study was to identify if pre-LVAD right ventricular (RV) dysfunction is associated with risk of GIB after LVAD implantation. Of 398 patients implanted with LVADs between July 2008 and July 2016, 130 (33%) developed GIB at a median of 2.6 months following LVAD implantation. Arteriovenous malformations (AVMs) were found in 42 (34%) GIB patients. Patients with GIB were older and more likely to have hypertension, diabetes, and ischemic cardiomyopathy. On pre-LVAD echocardiography, GIB patients had increased RV diastolic dimension (4.7 ± 0.8 vs. 4.4 ± 0.9 cm, p = 0.02), a higher rate of greater than mild tricuspid valve (TV) regurgitation (73 [60%] vs. 120 [47%], p = 0.006), and underwent TV repair more often (38 [30%] vs. 43 [16%], p = 0.0006) during LVAD implantation. After multivariable adjustment, preoperative greater than mild RV enlargement (hazard ratio [HR] 2.32, 95% CI 1.12-5.03; p = 0.03), TV regurgitation (HR 1.83, CI 1.02-3.44; p = 0.01), and TV repair (HR 3.76, confidence interval [CI] 1.02-4.44; p = 0.01) remained associated with risk of GIB. This finding was driven by the AVM-GIB subgroup. Preoperative RV enlargement and TV regurgitation are associated with post-LVAD AVM-related GIB.

Prothrombin Complex Concentrate for Warfarin Reversal in Patients with Continuous-Flow Left Ventricular Assist Devices: A Narrative Review

Durable left ventricular assist device (LVAD) recipients require long-term anticoagulation to prevent thromboembolic complications. Their management is complicated by the risk of bleeding, which may require rapid anticoagulation reversal. We conducted a narrative review of data published from January 2007 to September 2018, analyzing anticoagulation reversal strategies in patients with durable, continuous-flow LVADs. The aim of this review is to provide guidance for reversal strategies in patients with LVADs experiencing bleeding complications or needing urgent surgical procedures, incorporating four-factor prothrombin complex concentrate (4F-PCC). Most data were from small, retrospective studies. Data for 4F-PCC use were more robust for heart transplant than for other surgical procedures or bleeding management. In patients undergoing heart transplant, 4F-PCC reversed warfarin more rapidly and reduced total blood product use versus other reversal strategies. Most surgical procedures were conducted without excess bleeding when utilizing 4F-PCCs. Time to warfarin reversal was shorter when managing intracranial hemorrhage with 4F-PCC. No differences in thromboembolic rates between 4F-PCC and control groups were observed. Overall, the use of 4F-PCC resulted in more rapid and predictable warfarin reversal in LVAD patients with no apparent risk of thromboembolism. Well-designed, larger prospective trials are required to better define 4F-PCC use in patients with LVADs.

How to Manage Temporary Mechanical Circulatory Support Devices in the Critical Care Setting: Translating Physiology to the Bedside

The incidence of cardiogenic shock and the utilization of mechanical circulatory support devices are increasing in the US. In this review we discuss the pathophysiology of cardiogenic shock through basic hemodynamic and myocardial energetic principles. We also explore the commonly used platforms for temporary mechanical circulatory support, their advantages, disadvantages and practical considerations relating to implementation and management. It is through the translation of underlying physiological principles that we can attempt to maximize the clinical utility of circulatory support devices and improve outcomes in cardiogenic shock.

A population based analysis of trends, risk factors and outcomes associated with gastrointestinal bleeding in patients with left ventricular assist devices

Introduction: Prior to the utilization of continuous flow (CF) devices in 2010, Gastrointestinal (GI) bleeding was a common adverse event related to left ventricular assist device (LVADs) that was found to be even more frequent when CF devices were first introduced. Objective: Given the drastic increase in the use of new CF-LVADs, we sought to determine if CF-LVADs are associated with an increased number of GI bleeds and higher mortality. Methods: We analysed the data from a national inpatient sample database using the ICD-9 procedure code for LVAD use in end-stage heart failure among patients > 18 years. The total sample consisted of 2,359 patients (M _age=55 ± 13.7 years). A majority of the sample was male (77%) and Caucasian (59%). Results: The Incidence of GI bleeding from 2010 to 2014 was 7.46% with no significant change in yearly incidence over five-year period (P=.793). After controlling for age, sex, and length of stay, multivariate logistic regression revealed that significant predictors of GI bleed were acute kidney injury (AOR=1.87, 95% CI=1.26, 2.80), peripheral vascular disease (AOR=1.77, 95% CI=1.02, 2.94), body mass index ≥ 25 (AOR=.46, 95% CI=.22, .87), hemiplegia or paraplegia (AOR=3.01, 95% CI=1.17, 7.05), moderate or severe liver disease (AOR=2.40, 95% CI=.97, 5.34), peptic ulcer disease (AOR=18.13, 95% CI=7.86, 42.38), surgical aortic valve replacement (AOR=2.46, 95% CI=1.12, 5.15), and venous thromboembolism (AOR=2.58, 95% CI=1.57, 4.15). Conclusion: The results of the study show that GI bleeding is highly prevalent in patients with LVADs and there was no improvement in rates of GI bleed over five years since the CF-LVADs were initially introduced and is associated with an increased likelihood of mortality.

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.

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.

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.

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.

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

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

ABO Blood Group and Transfusions In the Intraoperative and Postoperative Period After LVAD Implantation

OBJECTIVES

To assess whether blood group O patients undergoing left ventricular assist device (LVAD) insertion have higher perioperative transfusion requirements, postoperative chest tube output, and postoperative changes in hematocrit.

DESIGN

Retrospective review of 116 LVAD patients from August 2015 to May 2018.

SETTING

Single-institution, urban academic medical center.

PARTICIPANTS

One hundred sixteen LVAD patients analyzed by blood group: group O (n = 49) versus non-O (n = 67).

INTERVENTIONS

Transfusions in the combined intraoperative and postoperative period at 7 days and 90 days after LVAD implantation, chest tube output in the first 24 hours, and hematocrit change in the first 48 hours postoperatively.

RESULTS

There was no difference between group O and non-O within the univariable analysis for both 7-day and 90-day transfusion rates. Adjusting for covariables, blood type O was not associated with packed red blood cells transfusion after accounting for multiple comparisons (odds ratio 1.33 [1.07-1.66], p = 0.01, where p < 0.005 was considered statistically significant as a Bonferroni correction was performed to control the familywise error rate). Additionally, there was no difference in chest tube output over the first 24 hours (1,129 v 1,057 mL, p = 0.47) or hematocrit change in the first 48 hours postoperatively (3.49 v 4.53%, p = 0.15).

CONCLUSION

O blood group is not a significant predictor of transfusion requirements in the combined intraoperative and postoperative period up to 90 days after LVAD implantation.

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.

Facilitating noncardiac surgery for the patient with left ventricular assist device: A guide for the anesthesiologist

The introduction of left ventricular assist device (LVAD) has improved survival rates for patients with end-stage heart failure. Two categories of VADs exist: one generates pulsatile flow and the other produces nonpulsatile continuous flow. Survival is better for patients with continuous-flow LVADs. With improved survival, more of such patients now present for noncardiac surgery (NCS). This review, written for the general anesthesiologists, addresses the perioperative considerations when the patient undergoes NCS. For best outcomes, a multidisciplinary approach is essential in perioperative management of the patient.

Gastrointestinal Bleeding in Left Ventricular Assist Device: Octreotide and Other Treatment Modalities

Left ventricular assist devices (LVADs) offer a therapeutic strategy for patients with end-stage heart failure. Increased device utilization has also increased the incidence of device-related complications including gastrointestinal bleeding (GIB). Multiple mechanisms have been proposed in the pathophysiology of continuous-flow LVAD-associated GIB including physiologic changes associated with high shear and nonpulsatile flow such as gastrointestinal arteriovenous malformations and acquired von Willebrand syndrome. Strategies to minimize the morbidity and mortality of LVAD-associated GIB are needed. Octreotide, a somatostatin analogue, has been described as an adjunct to current therapies and interventions. Factors that contribute to LVAD-associated GIB may be targeted by the pharmacologic effects of octreotide, including improved platelet aggregation, increased vascular resistance, and decreased splanchnic circulation. Octreotide has demonstrated clinical benefit in several case series and clinical trials for the treatment of LVAD-associated GIB. The focus of this article will be to review the pathophysiology of LVAD-associated GIB, discuss pharmacologic and nonpharmacologic treatment modalities, and review available literature on the role of octreotide in the management of LVAD-associated GIB.

Risk Factors of Gastrointestinal Bleeding After Continuous Flow Left Ventricular Assist Device

This study aimed to compare von Willebrand factor (vWF) levels, ristocetin cofactor levels, platelet counts, aortic valve movements, and right heart failure (RHF) as risk factors of gastrointestinal (GI) bleeding in patients with continuous flow left ventricular assist device (cf-LVAD). In a single centre, 90 patients (mean age 52.0 ± 10.5 years), of which 59 were male and 31 were female, had cf-LVAD implantation from October 2010 to November 2012. Seventy-six (84.4%) patients had HeartWare (Medtronic, Mounds View, MN) and 14 (15.5%) had Heartmate II (Thoratec, Pleasanton, CA) implanted. vWF level, ristocetin cofactor level, and platelet count were measured before and after implantation to determine the presence of acquired von Willebrand Syndrome; aortic valve movement and postoperative RHF were evaluated to compare the difference in bleeding and nonbleeding patient groups. Fifteen patients (16.6%) suffered GI bleeding after cf-LVAD implantation. A statistically significant decrease was found in vWF and ristocetin cofactor levels from preoperative period to postoperative period in both bleeding and nonbleeding patient groups (p < 0.05). There was no significant difference in bleeding and nonbleeding groups regarding aortic valve movements (p ≥ 0.05). Postoperative RHF incidence was significantly high in the bleeding patient group compared with the nonbleeding group (p < 0.05). Therefore, depending on the findings of this study, acquired von Willebrand Syndrome was seen in all cf-LVAD patients, and postoperative RHF was an important risk factor for GI bleeding.

Role of imaging in diagnosis and management of left ventricular assist device complications

Heart failure is a clinical condition that is associated with significant morbidity and mortality. With the advent of left ventricular assist device (LVAD), an increasing number of patients have received an artificial heart both as a bridge-to-therapy and as a destination therapy. Clinical trials have shown clear survival benefits of LVAD implantation. However, the increased survival benefits and improved quality of life come at the expense of an increased complication rate. Common complications include perioperative bleeding, infection, device thrombosis, gastrointestinal bleeding, right heart failure, and aortic hemodynamic changes. The LVAD-associated complications have unique pathophysiology. Multiple imaging modalities can be employed to investigate the complications, including computed tomography (CT), positron emission tomography-computed tomography (PET-CT), catheter angiography and echocardiography. Imaging studies not only help ascertain diagnosis and evaluate the severity of disease, but also help direct relevant clinical management and predict prognosis. In this article, we aim to review the common LVAD complications, present the associated imaging features and discuss the role of imaging in their management.

Outcomes in Patients with Left Ventricular Assist Devices, Pacemakers, and Implantable Cardioverter Defibrillators Undergoing Single Balloon Enteroscopy

OBJECTIVES

Obscure overt gastrointestinal bleeding can be challenging to evaluate in patients with electronic cardiac devices such as continuous flow left ventricular assist devices (LVADs), pacemakers (PPMs), and implantable cardioverter defibrillators (ICDs). Limited data exist on the utility and safety of single balloon enteroscopy (SBE) in patients with cardiac devices. We aimed to evaluate the safety, efficacy, diagnostic, and therapeutic outcomes of the aforementioned devices in patients undergoing SBE.

METHODS

A retrospective study was performed using the medical records of 57 patients undergoing SBE at our institution from 2010 to 2014. Patients were divided into two groups: those with cardiac devices and those without. Data on comorbidities, complications, findings, diagnostic, and therapeutic yield were compared. t Test and logistic regression assessed the association between dependent and independent variables. For continuous data, the results were summarized as mean difference and standard deviation. For dichotomous data, the results were summarized as odds ratio and 95% confidence intervals.

RESULTS

The overall age in patients with cardiac devices was 67.89 ± 6.96 versus 66.03 ± 11.95 years in the control. The cardiac device group was composed of 42.1% women; the control comprised 21.1% women. There were 19 patients with cardiac devices; 8 (LVAD + ICD), 1 (LVAD + PPM + ICD), 2 (PPM + ICD), 6 (PPM), 2 (ICD); 38 patients were in the control group. Patients with cardiac devices were hospitalized more often than patients without devices; this finding was not statistically significant (odds ratio 1.826, 95% confidence interval 0.544-6.128, P = 0.389). Procedure times were longer in the cardiac device group, 65.16 ± 49.92 minutes, when compared with the control, 57.40 ± 20.42, but it also did not reach statistical significance (mean difference 7.758, 95% confidence interval -11.360 to 26.876, P = 0.049). There was no statistically significant difference in major or minor events between patients with cardiac devices and the control group. Diagnostic and therapeutic yield and rebleeding rates were similar across both groups.

CONCLUSIONS

Patients in the cardiac device group did not appear to be at any more significant risk than those without cardiac devices. Furthermore, diagnostic and therapeutic yield and rebleeding rates appear to be similar across both groups. Clinicians may perform SBE in these patients safely and effectively, with good overall outcomes.

Timing of Gastrointestinal Bleeding After Implantation of Left Ventricular Assist Devices Associates With Anatomic Location, Presentation, and Management

BACKGROUND & AIMS

Continuous-flow left ventricular assist devices (LVADs) for advanced heart failure have been associated with gastrointestinal bleeding (GIB). We examined the association between time of GIB after LVAD implantation and bleeding location (determined by endoscopy), etiology, and patient outcomes.

METHODS

We performed a retrospective study of consecutive patients who underwent implantation of continuous-flow LVADs from 2008 through 2015. We analyzed data on anatomic location of GIB, etiology, length of hospital stay, transfusion requirement, time to endoscopy, and readmission to the hospital within 30 days (30-day readmission).

RESULTS

GIB developed in 59 of the 271 patients (22%). Higher proportions of patients with GIB during their index hospitalization for LVAD implantation had upper or lower GIB (86.7%) than patients with GIB during a subsequent hospitalization (50.0%; P = .013). Patients with GIB during their index hospitalization also had lower rates of middle GIB (0 vs 20.5%; P = .052), higher rates of overt GIB (100% vs 63.6%; P = .006), longer hospital stays (24 days vs 11 days; P < .001), and more transfusions before endoscopy (7 units vs 4 units; P = .021) than patients with GIB during a subsequent hospitalization. There were no significant differences between groups in time to endoscopy (2 days vs 2.5 days) or 30-day readmission (6.7% vs 9.3%). Angiodysplasias were identified in 100% of patients with middle GIB compared to 48.5% of patients with upper or lower GIB (P < .001) in whom a bleeding lesion was identified.

CONCLUSION

In a retrospective study of patients who underwent implantation of continuous-flow LVADs, we found that timing of GIB associates with the location and severity of bleeding. Although patients with LVADs have an overall increase in risk of middle GIB, patients with GIB during their index LVAD hospitalization should undergo initial evaluation by upper endoscopy and colonoscopy, due to insufficient time for development of small bowel angiodysplasias. Patients who later develop GIB should be evaluated early for middle GI bleeding.

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.

Preoperative Right-Sided Cardiac Congestion Is Associated with Gastrointestinal Bleeding in Patients with Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

Large scale data on preoperative risk stratification for gastrointestinal bleeding (GIB) following continuous-flow left ventricular assist device (CF-LVAD) implantation are scarce.

AIMS

To identify independent predictors for GIB following CF-LVAD implantation.

METHODS

We conducted a retrospective cohort study of consecutive 243 patients who underwent CF-LVAD implantation (HeartMateII) from January 2009 to March 2015 at the University of Chicago Medical Center. GIB was defined as the presence of overt bleeding or occult GIB with ≥ 2 g/dl drop in hemoglobin (Hgb) from recorded baseline values and hemoccult-positive stool. The preoperative and postoperative data were reviewed.

RESULTS

Within a median follow-up duration of 408 (IQR 113-954) days, 83 (34%) patients developed GIB after a median of 149 (IQR 27-615) days after implantation of CF-LVAD. There were no significant differences between the groups of GIB and non-GIB with respect to preoperative demographics and comorbidity except for ethnicity. The source of bleeding was identified in 39 (47%) patients and arteriovenous malformation or submucosal streaming vessel was the most frequent cause of bleeding (18/39, 46%). Multivariate-adjusted analysis demonstrated preoperative central venous pressure (CVP) ≥ 18 mmHg (HR 3.56; 95% CI 1.16-10.9; p = 0.026), mean pulmonary artery pressure (mPA) ≥ 36 mmHg (HR 4.14; 95% CI 1.35-12.7; p = 0.013), and the presence of moderate/severe tricuspid valve disease (HR 1.01; 95% CI 1.01-3.86; p = 0.046) were associated with the risk of GIB.

CONCLUSIONS

In this study, preoperative right-sided cardiac congestion (i.e., increased CVP, mPA and the presence of moderate/severe tricuspid valve disease) was associated with GIB in patients with CF-LVAD.

Clinical Predictors for Repeat Hospitalizations in Left Ventricular Assist Device (LVAD) Patients With Gastrointestinal Bleeding

Background

Patients implanted with left ventricular assist devices (LVAD) carry an increased risk of gastrointestinal bleeding (GIB), estimated at 25% in most studies. Significant efforts are employed in localizing and stopping the source of bleeding, but the rates of repeat hospitalization for GIB remain surprisingly high. Given the increasing incidence of LVAD-dependent end-stage heart failure and the excessive costs associated with repetitive endoscopic investigations, risk factors associated with re-bleeding need to be determined. The aim of our study was to investigate clinical predictors associated with repeat hospitalizations for GIB in patients implanted with a LVAD.

Methods

We conducted a retrospective cohort using the prospectively assembled ventricular assist device database at the University of Alabama at Birmingham. We identified all end-stage heart failure patients who were implanted with a continuous-flow (CF) LVAD between Jan 1, 2009 and Dec 31, 2013. We excluded pulsatile devices, biventricular assist devices (BiVADs), right ventricular assist devices (RVADs), and patients under 19 years of age.

Results

There were 102 patients implanted with a CF-LVAD within the specified time period. With an average follow-up of 127 weeks, 32 (31.4%) patients developed GIB requiring 79 separate hospitalizations. Average time from LVAD implantation to first bleed was 343 days. The re-bleeding rate requiring readmission was 56.3% in those admitted with GIB, with eight (25%) of the patients necessitating multiple readmissions. The average hospital stay for a primary diagnosis of GIB was 9.45 days. Totally, 68 (86%) patients required endoscopic evaluation during their hospitalization, with 35 (44%) necessitating multiple procedures during the same admission. The average time to first endoscopy was 2.5 days with a median of 2 days. Patients receiving early endoscopy (< 48 h from admission) were 57% less likely to require future readmission for GIB compared to patients undergoing late endoscopy (> 48 h) (OR: 0.43, CI: 0.19 - 0.9). Other factors associated with repeat admissions for GIB included indication for LVAD (bridge to transplant had OR: 0.07, CI: 0.02 - 0.27), male gender (OR: 10.4, CI: 1.8 - 59), length of initial hospital stay (OR: 0.83, CI: 0.71 - 0.97), and INR on admission (OR: 3.6, CI: 1.46 - 8.8). Although not statistically significant, patients undergoing subsequent endoscopies during a single admission were 84% less likely to develop re-bleeding in the future (OR: 0.158, CI: 0.025 - 1.02).

Conclusions

GIB in LVAD patients is a significant problem with high rates of readmission despite extensive endoscopic investigations and anticoagulant adjustments. Our experience revealed that early endoscopy, longer initial hospital stay, and better INR control were all associated with decreased rates of readmission for GIB in this population. These modifiable factors should be emphasized and addressed in the future to reduce the burdens associated with repeated hospitalizations.

Prevention and Treatment of Thrombotic and Hemorrhagic Complications in Patients Supported by Continuous-Flow Left Ventricular Assist Devices

PURPOSE OF REVIEW

The purpose of this review is to describe the current knowledge in prevention and treatment of thrombotic (pump thrombosis and ischemic stroke) and bleeding (gastrointestinal and hemorrhagic stroke) complications in patients supported by continuous-flow left ventricular assist devices (CF-LVAD).

RECENT FINDINGS

Left ventricular assist devices (LVADs) are now widely used for the management of end-stage heart failure. Unfortunately, in spite of the indisputable positive impact LVADs have on patients, the frequency and severity of complications are limitations of this therapy. Stroke, pump thrombosis, and gastrointestinal bleeding are among the most serious and frequent complications in these patients. The balance between hemorrhagic and thrombotic complications in patients supported with CF-LVAD is difficult as most patients do not necessarily fit a "bleeder" or a "clotter" profile but rather move from one side to the other of the thrombotic/bleeding spectrum. Further research is necessary to better understand the risk factors and mechanisms involved in the development of these complications.

Reviewing the use of ventricular assist devices in the elderly: where do we stand today?

INTRODUCTION

Implantation of left ventricular assist devices (LVADS) in older patients appears to be an attractive option in the wake of donor shortage and increasing incidence and prevalence of end stage heart failure. Since the inception of the artificial heart program half a century ago tremendous progress in research and development has led to utilization of more sophisticated devices. VADs have therefore emerged as a successful therapy for extending life with meaningful quality. Areas covered: This review will address the use of LVADS as a bridge to transplantation, destination therapy and comparison of LVAD therapy with alternate list heart transplantation in the elderly population. Expert commentary: Age >70 years is an important aspect when assessing LVAD risk, but other characteristics appear to be better predictors of LVAD survival. Elevated pre-operative creatinine, bilirubin and ischemic etiology predispose to a higher risk of mortality. Creatinine has been shown to be a very powerful predictor in post LVAD survival. Based on the existing literature, the authors suggest an algorithm which could be useful when evaluating patients for LVAD implantation.

Continuous-Flow LVAD Support Causes a Distinct Form of Intestinal Angiodysplasia

Rationale:

The objective of this autopsy study was to determine whether gastrointestinal angiodysplasia develops during continuous-flow left ventricular assist device (LVAD) support.

Objective:

LVAD support causes pathologic degradation of von Willebrand factor (vWF) and bleeding from gastrointestinal angiodysplasia at an alarming rate. It has been speculated that LVAD support itself may cause angiodysplasia. The relationship to abnormal vWF metabolism is unknown. We tested the hypothesis that abnormal gastrointestinal vascularity develops during continuous-flow LVAD support.

Methods and Results:

Small bowel was obtained from deceased humans, cows, and sheep supported with a continuous-flow LVAD (n=9 LVAD, n=11 control). Transmural sections of jejunum were stained with fluorescein isothiocyanate–conjugated isolectin-B4 for endothelium to demarcate vascular structures and quantify intestinal vascularity. Paired plasma samples were obtained from humans before LVAD implantation and during LVAD support (n=41). vWF multimers and degradation fragments were quantified with agarose and polyacrylamide gel electrophoresis and immunoblotting. Abnormal vascular architecture was observed in the submucosa of the jejunum of human patients, cows, and sheep supported with a continuous-flow LVAD. Intestinal vascularity was significantly higher after LVAD support versus controls (5.2±1.0% versus 2.1±0.4%, P =0.004). LVAD support caused significant degradation of high–molecular-weight vWF multimers (–9±1%, P <0.0001) and accumulation of low–molecular-weight vWF multimers (+40±5%, P <0.0001) and vWF degradation fragments (+53±6%, P <0.0001).

Conclusions:

Abnormal intestinal vascular architecture and LVAD-associated vWF degradation were consistent findings in multiple species supported with a continuous-flow LVAD. These are the first direct evidence that LVAD support causes gastrointestinal angiodysplasia. Pathologic vWF metabolism may be a mechanistic link between LVAD support, abnormal angiogenesis, gastrointestinal angiodysplasia, and bleeding.

Relationship Between Anticoagulation Intensity and Thrombotic or Bleeding Outcomes Among Outpatients With Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

We evaluated thrombotic and bleeding outcomes in patients with continuous-flow left ventricular assist devices (CF-LVADs), stratified by anticoagulation intensity. Previous studies of outpatients with CF-LVADs have suggested that target international normalized ratio (INR) values <2.5 (range, 2-3) may be used. However, recent studies reported an increase in pump thrombosis among CF-LVADs, especially within the first 6 months of implant.

METHODS AND RESULTS

We retrospectively reviewed 249 outpatients at our center who received a CF-LVAD between January 2005 and August 2013. Using Poisson models, we analyzed their 10 927 INRs to determine INR-specific rates of thrombotic (ischemic stroke and suspected pump thrombosis) and hemorrhagic (gastrointestinal bleeding and hemorrhagic stroke) events occurring outside of the hospital. In multivariate analyses, we adjusted for age, sex, atrial fibrillation, coronary disease, and LVAD type as time-dependent Cox proportional hazard models. During a mean follow-up of 17.6±13.6 months, thrombotic events occurred in 46 outpatients. The highest event rate (0.40 thrombotic events per patient-year) was in the INR range of <1.5, but INR values of 1.5 to 1.99 also had high rates (0.16 thrombotic events per patient-year). INR was inversely associated with thrombotic events (hazard ratio, 0.40; 95% confidence interval, 0.22-0.72; P=0.002). The optimal INR based on weighted mortality of thrombotic and bleeding events was 2.6.

CONCLUSIONS

INR is inversely related to thrombotic events occurring outside of the hospital among patients supported with CF-LVADs. INR values <2.0 increase the rate of thrombotic events occurring outside of the hospital among patients supported with CF-LVADs.

Combined Endoscopic and Surgical Treatment of Severe Gastrointestinal Bleeding in a Patient with Heart Assist Device under Therapeutic Anticoagulation

Gastrointestinal (GI) bleeding is a common complication after heart assist device placement. Reasons for bleeding are multifactorial. Endoscopic therapy is the treatment of choice, whereas invasive procedures are avoided in these critically ill patients. We present the case of a 65-year-old male patient experiencing severe GI bleeding after left ventricular assist device (LVAD) and right ventricular assist device (RVAD) placement with therapeutic anticoagulation. Endoscopically, multiple gastric bleeding sources were found but could not be treated effectively due to a large blood clot. A combined endoscopic and surgical treatment was initiated, including gastrotomy for blood clot removal, surgical transgastric suturing, endoscopic over-the-scope clip (OTSC) placement and hemospray application. Postoperative endoscopic visualization showed effective bleeding control. The patient unfortunately died due to causes unrelated to the treatment. This case shows that a minimal invasive combination of endoscopic and surgical techniques can be an alternative treatment for severe upper GI bleeding in critically ill and anticoagulated patients.

Safety and efficacy of single-balloon enteroscopy in management of gastrointestinal bleeding in patients with a left ventricular assist device

Background and study aims Left ventricular assist devices (LVADs) are currently the standard of care in treatment of patients with end-stage heart failure waiting for heart transplant as well as destination therapy for non-transplant candidates. However, patients with LVADs are at increased risk of gastrointestinal bleeding due to the device's unique effects on hemodynamics. A major source of gastrointestinal bleeding in these patients are gastrointestinal angioectasias located within the small bowel that can only be reached with deep enteroscopy. The goal of our study was to determine the safety and efficacy of single-balloon enteroscopy (SBE) in treating gastrointestinal bleeding in patients with LVADs. Patients and methods We present a retrospective case series performed on patients with LVADs who underwent SBE to treat episodes of gastrointestinal bleeding. All procedures were performed at Emory University Hospital by a single endoscopist. Patient demographics, diagnosis and treatment of gastrointestinal bleeding, episodes of re-bleeding, and procedure-related complications were examined. Results A total of 27 SBE procedures performed in 14 patients were reviewed. SBE was performed in an antegrade approach in 89 % (24/27) of cases. Deep intubation was achieved in all antegrade procedures, with the distal jejunum reached in 79 % (19/24) of cases. The diagnostic yield was 78 %. There were no reported complications associated with the procedures. Conclusions SBE is a safe and effective modality to manage gastrointestinal bleeding in patients with LVADs.

Gastrointestinal Bleeding During the Index Hospitalization for Mechanical Circulatory Support Devices Implantation, a Nationwide Perspective

BACKGROUND

Gastrointestinal bleeding (GIB) is a common adverse event after mechanical circulatory support device implantation. However, the majority of the reported data were obtained from small single-center studies. Our aim was to study the prevalence and predictors of GIB during the index hospitalization of mechanical circulatory support devices implantation using a nationwide database.

METHODS

Nationwide inpatient sample (2009-2011) was used to perform a retrospective cross-sectional study. Adult patients with discharge diagnosis codes of congestive heart failure and procedure codes of left-ventricular assist device (LVAD) or intra-aortic balloon pump (IABP) implantation or orthotopic heart transplant (OHT, reference group) were identified. Our outcome was GIB during the index hospitalization when the device was implanted. Predictors that achieved statistical significance on the univariate analysis were included in a multivariable logistic-regression analysis.

RESULTS

A total of 87,462 patients were included, 87 % of the patients received an IABP, 6 % received LVAD, and 5 % underwent OHT. Prevalence of GIB was 8, 5, and 3 % among those who had LVAD, IABP implantation, and OHT recipients, respectively (p < 0.001). Patients who underwent LVAD implantation had twofold increase in the prevalence of GIB (OR 2.1, 1.7-2.5, p < 0.001) when using IABP or OHT groups as a reference. This increase in the prevalence was not demonstrated among IABP recipients on a multivariate level.

CONCLUSION

Prevalence of GIB was higher among LVAD compared to OHT and IABP recipients and could occur as early as the index admission of the device implantation.

Left Ventricular Assist Devices Impact Hospital Resource Utilization Without Affecting Patient Mortality in Gastrointestinal Bleeding

BACKGROUND

Left ventricular assist devices (LVADs) are being utilized for management of end-stage heart failure and require systemic anticoagulation. Gastrointestinal bleeding (GIB) is one of the most common adverse events following LVAD implantation.

AIM

To investigate the impact of continuous-flow (CF) LVAD implants on outcomes of patients admitted with GIB.

METHODS

This is a cross-sectional study utilizing the Nationwide Inpatient Sample in the CF-LVAD era from 2010 to 2012. All adult admissions with a primary diagnosis of GIB were included. Among hospitalizations with GIB, patients with (cases) and without (controls) CF-LVAD implants were compared using univariate and multivariate analyses. The main outcome measurements were in-hospital mortality, length of stay, and hospitalization costs.

RESULTS

Among 1,002,299 hospitalizations for GIB, 1112 (0.11%) patients had CF-LVADs. Bleeding angiodysplasia accounted for a majority of GIB in CF-LVAD patients (35.4% of 1112). Multivariate analysis adjusting for demographic, hospital and etiological differences, site of GIB, and patient comorbidities revealed that CF-LVADs were not adversely associated with mortality in GIB (OR 0.53, 95% CI 0.07-4.15). However, CF-LVADs independently accounted for prolonged hospitalization (3.5 days, 95% CI 2.6-4.6) and higher hospital charges ($37,032, 95% CI $7991-$66,074).

CONCLUSIONS

In patients admitted with GIB, CF-LVAD implantation accounts for higher healthcare utilization, but is not adversely associated with mortality despite therapeutic anticoagulation, increased comorbidities, and comparatively delayed endoscopy. These findings are relevant as CF-LVADs are the dominant type of LVAD and are associated with increased risk of GIB compared to their predecessors.

Arterial pulsatility under phasic left ventricular assist device support

The aim of this study is to understand whether the phasic Continuous Flow Left Ventricular Assist Device (CF-LVAD) support would increase the arterial pulsatility. A Micromed DeBakey CF-LVAD was used to apply phasic support in an ex-vivo experimental platform. CF-LVAD was operated over a cardiac cycle by phase-shifting the pulsatile pump control with respect to the heart cycle, in 0.05 s increments in each experiment. The pump flow rate was selected as the control variable and a reference model was used to operate the CF-LVAD at a pulsatile speed. Arterial pulse pressure was the highest (9 mmHg) when the peak pump flow is applied at the peak systole under varying speed CF-LVAD support over a cardiac cycle while it was the lowest (2 mmHg) when the peak pump flow was applied in the diastolic phase. The mean arterial pressure and mean CF-LVAD output were the same in each experiment while arterial pulse pressure and pulsatility index varied depending on the phase of reference pump flow rate signal. CF-LVAD speed should be synchronized considering the timing of peak systole over a cardiac cycle to increase the arterial pulsatility. Moreover, it is possible to decrease the arterial pulsatility under counter-pulsating CF-LVAD support.

Early Implementation of Video Capsule Enteroscopy in Patients with Left Ventricular Assist Devices and Obscure Gastrointestinal Bleeding

Gastrointestinal bleeding (GIB) is a frequent challenge encountered in patients implanted with a left ventricular assist device (LVAD), affecting approximately 25% of this population. Many patients have no identifiable source of bleeding after routine esophagogastroduodenoscopy and colonoscopy and are labeled as obscure GIB (OGIB). Significant costs and invasive procedures are required to investigate and stop the source of bleeding in these patients. We performed a retrospective analysis at a single tertiary referral center to investigate the diagnostic yield and overall effectiveness of video capsule enteroscopy (VCE) in this population. Eight patients with LVADs underwent nine VCE studies for OGIB. The diagnostic yield was 100%, with intraluminal blood the most common finding. The jejunum was the most common location for pathology detected on VCE. Sixty-seven percent of the studies directly guided further endoscopy with successful cessation of bleeding in 100% of these patients. Finally, after an average follow-up of 46 weeks, the total number of endoscopic procedures and total units of transfused packed red blood cells (pRBC) were significantly less after the patient underwent the VCE study compared with before. Video capsule enteroscopy is a safe and high-yield investigative procedure in this population and should be implemented earlier to improve patient outcomes and reduce costs of care.