Clinical management for complications related to implantable LVAD use

Driveline infections in left ventricular assist devices-Incidence, epidemiology, and staging proposal

BACKGROUND

Driveline infections (DLI) are a serious complication in patients with left ventricular assist devices (LVAD). Apart from the differentiation between superficial and deep DLI, there is no consensus on the classification of the severity of DLI. Little is known about risk factors and typical bacteria causing DLI in centrifugal-flow LVADs.

METHODS

In this single-center study with 245 patients, DLI were classified by their local appearance using a modification of a score suggested by the Sharp Memorial group. The driveline exit site was inspected routinely every 6 months.

RESULTS

Severe DLI were detected in 34 patients (15%) after 6 months and in 24 patients (22%) after 24 months. The proportion of patients with DLI increased significantly during the follow-up (p = 0.0096). The most common bacteria in local smears were Corynebacterium, coagulase-negative Staphylococcus, and Staphylococcus aureus. Fifty-nine patients were hospitalized more than once for DLI. In these patients, S. aureus was the most common bacterium. It was also the most common bacterium in blood cultures. Higher BMI, no partnership, and a HeartMate 3 device were identified as risk factors for DLI in a multivariable cause-specific Cox regression.

CONCLUSION

This study is a standardized analysis of DLI in a large cohort with centrifugal-flow LVADs.

Insights into the daily life of ventricular assist device coordinators: Outcome of an international questionnaire

BACKGROUND

As the incidence of heart failure in developed countries is on the rise, mechanical circulatory support (MCS) often remains the only treatment option for patients with end-stage heart failure and is well established worldwide. Even though VAD coordinators play a key role in VAD programs, their responsibilities and daily duties are not clearly defined and characterized. Recently published data from the first 5-year multicenter clinical trial assessing experience with the HeartMate 3 left ventricular system (Abbott, Abbott Park, IL) show an overall survival of 61% at 5 years. When it comes to possible improvements to these systems, it is necessary for developers not only to know the status quo but also to determine and consider the visions and wishes of those individuals who take care of patients, provide education and deal with possible complications. This would be helpful a meaningful effort towards implementing a standard of care.

METHODS

To fill this knowledge gap, we conducted an online survey using the SurveyMonkey tool, addressing representatives of programs implanting VADs worldwide. Representatives answered a standardized block of 14 questions and were asked to provide responses within 3 months.

RESULTS

A total of 91 VAD coordinators from centers of various regions of the world completed the survey. The majority came from European countries. The numbers of patients followed up by the centers ranged from <20 to 390 patients. The majority of VAD coordinators had a nursing background (68%). Seventy-seven percent of the centers operate a 24-h hotline and 3-monthly visits to the outpatient department are most common. Fifty-nine percent of the centers do not use an infection scoring system for driveline wound care. The majority of the centers indicated that an optimized follow-up concept including wound care, medication, and social care is crucial and the key issue for an improved outcome. Smaller components and intensified psychosocial support ranked highest in questions about how to improve quality of life. Surprisingly, the future prospects of telemetric monitoring were not rated high in significance.

CONCLUSIONS

There is a wide variability in the composition and tasks of VAD programs worldwide. Implementing a standard of care and improving psychosocial care as well as equipment is regarded most important to improve outcomes and quality of life. From the point of view of those responsible, the significance of telemetric monitoring seemed overrated.

Mechanical circulatory support for adults in Japan: A 10-year perspective

Globalization in Asia and consequent strengthening of healthcare economic factors in tandem with an increasing heart failure (HF) population have enhanced potential for development and progress in the fields of HF medicine and mechanical circulatory support (MCS). In Japan, there are unique opportunities to investigate the outcome of acute and chronic MCS and a national registry for percutaneous and implantable left ventricular assist device (LVAD) including Impella pumps has been established. A Peripheral extracorporeal membrane oxygenation (ECMO) for acute MCS has been used in more than 7000 patients annually and Impella usage in more than 4000 patients over the past 4 years was noted. Recently, a novel centrifugal pump with hydrodynamically levitated impeller was developed and approved for mid-term extracorporeal circulatory support. In terms of chronic MCS more than 1200 continuous flow LVADs have been implanted during the past decade, and 2-year survival rate after primary LVAD implantation is 91%. Because of donor organ shortage, more than 70% of heart transplant recipients required LVAD support for more than 3 years and prevention and treatment of complications during long-term LVAD support have become important. Five important topics including hemocompatibility-related complications, LVAD infections, aortic valve insufficiency, right ventricular failure and cardiac recovery during LVAD support are discussed in this review for improving clinical outcomes. Findings from Japan will continue to provide useful information regarding MCS for the Asia-Pacific region and beyond.

Staged left ventricular assist device reimplantation via the left anterior wall approach for a patient with severe pump pocket infection

Pump pocket infection (PPI) is a refractory condition that can cause lethal complications in patients with a left ventricular assist device (LVAD). We report a case of PPI after LVAD implantation for ischemic cardiomyopathy that was successfully treated with staged pump reimplantation into the left ventricular anterior wall with the pedicled omental transfer. Major modification of the pump implantation site might be a useful strategy for local infection control of severe PPI.

Risk factors of gynecological bleeding in female patients with left-ventricular assist device

Women with implantable left-ventricular assist devices (LVADs) experience gynecological bleeding (GYN-bleeding). However, a few studies have investigated female-specific problems. Therefore, this study aimed to identify the risk factors for adverse GYN-bleeding after LVAD implantation. We retrospectively analyzed 59 women (mean age: 41 ± 15 years) with long-term implantable LVAD support (≥ 6 months) at our institution between 2005 and 2018. The history of GYN-bleeding before implantation was defined as abnormal utero-ovarian bleeding, excessive menstruation, uterine fibroids, and endometrial lesions. GYN-bleeding after implantation was defined as a requirement of emergency outpatient visits and/or hospitalization, blood transfusions, hormonal therapy, and/or surgery. Additionally, risk factors for GYN-bleeding were identified using the Cox regression model. Twenty-four GYN-bleeding cases were seen in 15 patients (two times: five patients, three times: two patients, 0.18 events per patient-year). The 1- and 2-year GYN-bleeding-free rates were 84% and 73%, respectively. Twelve patients (17 events) required RBC ≥ 4 units, and five patients (7 events) required FFP ≥ 4 units. Seven patients required pseudomenopausal treatment after blood transfusion, and four patients required surgical treatment. Fifteen patients with GYN-bleeding after implantation were significantly younger than the remaining 44 patients without GYN-bleeding (34 ± 12 years vs. 43 ± 16 years, P = 0.02). Multivariable risk analysis showed a history of GYN-bleeding before implantation was a significant risk factor (hazard ratio 3.7 [1.2-10.6], P = 0.004). Patients with a history of GYN-bleeding before LVAD implantation have a high risk of developing GYN-bleeding after implantation. We should identify the high-risk population and prepare for the management of GYN-bleeding.

Ventricular Assist Device Driveline Infections: A Systematic Review

Infection is the most common complication in patients undergoing ventricular assist device (VAD) implantation. Driveline exit site (DLES) infection is the most frequent VAD infection and is a significant cause of adverse events in VAD patients, contributing to morbidity, even mortality, and repetitive hospital readmissions. There are many risk factors for driveline infection (DLI) including younger age, smaller constitution of patients, obesity, exposed velour at the DLES, longer duration of device support, lower cardiac index, higher heart failure score, DLES trauma, and comorbidities such as diabetes mellitus, chronic kidney disease, and depression. The incidence of DLI depends also on the device type. Numerous measures to prevent DLI currently exist. Some of them are proven, whereas the others remain controversial. Current recommendations on DLES care and DLI management are predominantly based on expert consensus and clinical experience of the certain centers. However, careful and uniform DLES care including obligatory driveline immobilization, previously prepared sterile dressing change kits, and continuous patient education are probably crucial for prevention of DLI. Diagnosis and treatment of DLI are often challenging because of certain immunological alterations in VAD patients and microbial biofilm formation on the driveline surface areas. Although there are many conservative and surgical methods described in the DLI treatment, the only possible permanent solution for DLI resolution in VAD patients is heart transplantation. This systematic review brings a comprehensive synthesis of recent data on the prevention, diagnostic workup, and conservative and surgical management of DLI in VAD patients.

Four-quadrant visualization of systemic circulatory equilibrium: right ventricular failure after left ventricular assist device implantation

Right ventricular failure (RVF) is a serious adverse event after left ventricular assist device (LVAD) implantation but difficult to be characterized. This study aimed to visualize the dynamic circulatory equilibrium of acute RVF after LVAD implantation using a new four-quadrant diagram constructed by 1) cardiac function with central venous pressure (CVP) and cardiac index (CI) axes, 2) arterial vascular resistance with CI and mean blood pressure (mBP) axes, 3) pressure-diuretic function with mBP and net urinary sodium output (net U-Na) axes, and 4) venous compliance with net U-Na and CVP axes. Twenty LVAD patients were stratified into two groups, group S (≤10 days) and group L (>10 days), according to duration of postoperative inotropic support. The preoperative equilibrium loops were small in both groups. In the early postoperative phase, the loop in group S became dramatically enlarged to the left and upward, indicating increased CVP and CI by LVAD support. In group L, however, augmentation of CI was smaller despite similarly increased CVP, and net U-Na was decreased despite increased mBP. In the late postoperative phase, the equilibrium loop in group L recovered as similar to that seen in group S. Thus, acute RVF, as shown in group L, was characterized by the shape of the loop constructed by marked increased CVP, a relatively small increase in CI, and concomitant impairment of pressure natriuresis. In conclusion, the novel four-quadrant presentation of systemic circulatory equilibrium provides clear visualization of RVF after LVAD implantation, thus serving as a useful guide for prompt and optimal management.NEW & NOTEWORTHY Systemic circulatory dynamics are regulated by various negative feedback systems, including cardiac, arterial, venous, and renal functions, as well as autonomic nervous systems. The present novel four-quadrant presentation of their functions allows clear visualization of dynamic organ-to-organ interactions that can lead to a new circulatory equilibrium after therapeutic intervention. This new system physiological framework can serve as a useful guide for prompt and optimal management of circulatory malfunction.

Evaluation of real-time thrombus detection method in a magnetically levitated centrifugal blood pump using a porcine left ventricular assist circulation model

Pump thrombosis induces significant complications and requires timely detection. We proposed real-time monitoring of pump thrombus in a magnetically levitated centrifugal blood pump (mag-lev pump) without using additional sensors, by focusing on the changes in the displacement of the pump impeller. The phase difference between the current and displacement of the impeller increases with pump thrombus. This thrombus detection method was previously evaluated through simulated circuit experiments using porcine blood. Evaluation of real-time thrombus detection in a mag-lev blood pump was performed using a porcine left ventricular assist circulation model in this study. Acute animal experiments were performed five times using five Japanese domestic pigs. To create thrombogenic conditions, fibrinogen coating that induces thrombus formation in a short time was applied to the inner surfaces of the pump. An inflow and an outflow cannula were inserted into the apex of the left ventricle and the carotid artery, respectively, by a minimally invasive surgical procedure that allowed minimal bleeding and hypothermia. Pump flow was maintained at 1 L/min without anticoagulation. The vibrational frequency of the impeller (70 Hz) and its vibrational amplitude (30 μm) were kept constant. The thrombus was detected based on the fact that the phase difference between the impeller displacement and input current to the magnetic bearing increases when a thrombus is formed inside a pump. The experiment was terminated when the phase difference increased by over 1° from the lowest value or when the phase difference was at the lowest value 12 hours after commencing measurements. The phase difference increased by over 1° in three cases. The pump was stopped after 12 hours in two cases. Pump thrombi were found in the pump in three cases in which the phase difference increased by over 1°. No pump thrombus was found in the other two cases in which the phase difference did not increase. We succeeded in real-time thrombus monitoring of a mag-lev pump in acute animal experiments.

Ventricular Assist Device-Specific Infections

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

Left ventricular assist device driveline infections in three contemporary devices

Driveline infections (DLI) are common adverse events in left ventricular assist devices (LVADs), leading to severe complications and readmissions. The study aims to characterize risk factors for DLI readmission 2 years postimplant. This single‐center study included 183 LVAD patients (43 HeartMate II [HMII], 29 HeartMate 3 [HM3], 111 HVAD) following hospital discharge between 2013 and 2017. Demographics, clinical parameters, and outcomes were retrospectively analyzed and 12.6% of patients were readmitted for DLI, 14.8% experienced DLI but were treated in the outpatient setting, and 72.7% had no DLI. Mean C‐reactive protein (CRP), leukocytes and fibrinogen were higher in patients with DLI readmission (P < .02) than in outpatient DLI and patients without DLI, as early as 60 days before readmission. Freedom from DLI readmission was comparable for HMII and HVAD (98% vs. 87%; HR, 4.52; 95% CI, 0.58‐35.02; P = .15) but significantly lower for HM3 (72%; HR, 10.82; 95% CI, 1.26‐92.68; P = .03). DLI (HR, 1.001; 95% CI, 0.999‐1.002; P = .16) or device type had no effect on mortality. DLI readmission remains a serious problem following LVAD implantation, where CRP, leukocytes, and fibrinogen might serve as risk factors already 60 days before. HM3 patients had a higher risk for DLI readmissions compared to HVAD or HMII, possibly because of device‐specific driveline differences.

Benchtop von Willebrand Factor Testing: Comparison of Commercially Available Ventricular Assist Devices and Evaluation of Variables for a Standardized Test Method

Gastrointestinal bleeding occurs in 20-30% of patients receiving ventricular assist devices (VADs) due, in part, to acquired von Willebrand syndrome. We examined factors to optimize a benchtop method to quantify changes in von Willebrand Factor (VWF) multimer distribution and function in VADs, then applied them to evaluate commercially available devices. Human plasma was circulated through flow loops with VADs. Several experimental conditions were examined, including temperature, viscosity, and enzyme inhibition. Samples were analyzed for VWF collagen-binding activity (VWF:CB) and VWF antigen level. von Willebrand Factor multimer profiles were quantified using gel electrophoresis, near-infrared in-gel visualization, and densitometric analysis. The VWF:CB/antigen ratio in the HeartMate II, CentriMag, and HVAD exhibited average decreases of 46%, 44%, and 36% from baseline after 360 minutes of operation. High molecular weight (hVWF) multimer loss occurred within 30 minutes, although the Levacor and control loop profiles were unchanged. Varying temperature and viscosity altered hVWF degradation rate, but not the final results. Inhibition of a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13 (ADAMTS13) can potentially distinguish mechanoenzymatic cleavage of VWF from mechanical degradation. We developed a repeatable benchtop method to evaluate VWF compatibility of VADs similar to hemolysis testing that can be adopted for preclinical VAD evaluation.

Endoscopic Algorithm for Management of Gastrointestinal Bleeding in Patients With Continuous Flow LVADs: A Prospective Validation Study

BACKGROUND

Gastrointestinal bleeding (GIB) is a common complication of left ventricular assist device (LVAD) therapy accounting for frequent hospitalizations and high resource utilization.

METHODS

We previously developed an endoscopic algorithm emphasizing upfront evaluation of the small bowel and minimizing low-yield procedures in LVAD recipients with GIB. We compared the diagnostic and therapeutic yield of endoscopy, health-care costs, and re-bleeding rates between conventional GIB management and our algorithm using chi-square, Fisher's exact test, Wilcoxon-Mann-Whitney, and Kaplan-Meier analysis.

RESULTS

We identified 33 LVAD patients with GIB. Presentation was consistent with upper GIB in 20 (61%), lower GIB in 5 (15%), and occult GIB in 8 (24%) patients. Forty-one endoscopies localized a source in 23 (56%), resulting in 14 (34%) interventions. Algorithm implementation compared with our conventional cohort was associated with a 68% increase in endoscopic diagnostic yield (P< .01), a 113% increase in therapeutic yield (P= .01), a 27% reduction in the number of procedures per patient (P < .01), a 33% decrease in length of stay (P < .01), and an 18% reduction in estimated costs (P < .01). The same median number of red blood cell transfusions were used in the 2 cohorts, with no increase in re-bleeding events in the algorithm cohort (33.3%) compared with our conventional cohort (43.7%).

CONCLUSIONS

Our endoscopic management algorithm for GIB in LVAD patients proved effective in reducing low-yield procedures, improving the diagnostic and therapeutic yield of endoscopy, and decreasing health-care resource utilization and costs, while not increasing the risk of a re-bleeding event.

Early outcomes with durable left ventricular assist device replacement using the HeartMate 3

BACKGROUND

The HeartMate 3 (HM3) left ventricular assist device (LVAD) (Abbott, Inc, Chicago, Ill) is a fully magnetically levitated centrifugal implantable pump used to treat patients with chronic heart failure. The MOMENTUM (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) trial demonstrated that patients treated with the HM3 experienced reduced need for reoperation for LVAD replacement compared with a control group receiving an axial flow design, Heartmate II (Abbott, Inc). However, there are few reports of using HM3 as the replacement pump in patients who already are supported by a durable LVAD and experience a device-related complication necessitating replacement.

METHODS

An institutional LVAD database was used to identify 19 consecutive patients who underwent pump replacement to HM3 (group 1) versus 85 consecutive control patients who underwent pump replacement to either Heartmate II or HeartWare Ventricular Assist Device (Medtronic Inc, Minneapolis, Minn) (group 2), at a single institution from January 2010 to August 2018. Patient baseline characteristic and outcomes were obtained from a prospectively maintained database. The primary endpoint was a composite of freedom from death or need for another replacement surgery.

RESULTS

There was no difference between the groups in heart failure etiology, indication for replacement, as well as the average days on the previous pump or the type of previous pump. The HM3 group did have a significantly greater body mass index (37 vs 31.6 P = .01), a greater number of previous LVAD implants (36.8% vs 5.9%, had 2 previous LVADs, P < .001), and a greater number of previous sternotomies (31.6% vs 7.1%, had 3 previous sternotomies, P = .001). No difference was found between the groups in terms of postoperative adverse event rates. With regards to the primary endpoint, the patients with HM3 replacements (group 1) versus group 2 experienced significantly greater freedom from either death or need for another replacement during the follow-up period (P = .039). During follow-up, there were no thrombosis events for the patients who received replacement with HM3.

CONCLUSIONS

LVAD replacement with HM3 can be performed safely and may be considered as the pump of choice in patients requiring LVAD replacement.

Low Incidence of Pump-Related Infections in Jarvik 2000 Ventricular Assist Device Recipients with a Subcostal Driveline Exit Site

Driveline infection has been a persistent problem with mechanical cardiac assist devices. The reported incidence of infection has been low in patients who receive a Jarvik 2000 continuous-flow left ventricular assist device when a skull-pedestal driveline exit site is used. We evaluated whether this is also true when a subcostal driveline exit site is used. We reviewed baseline demographic variables, postimplantation vital signs, laboratory values, and culture results in patients who underwent Jarvik 2000 implantation at our center from April 2000 through October 2009, including follow-up through June 2014. All patients had a subcostal driveline exit site. We defined device-related infection as a positive blood or wound culture associated with a medical or surgical device intervention. Event and time-to-event rates were calculated. Eighty-one patients received 89 Jarvik 2000 devices, all as bridges to transplantation. The median support duration was 69 days (interquartile range, 27-153 d; range, 2-2,249 d). Five superficial driveline infections and one incision-site infection occurred (0.002 events per patient-year of support). The median time from pump implantation to onset of driveline infection was 30 days; the incision-related infection occurred at 44 days. The Jarvik 2000 has a low incidence of infection when implanted with use of a subcostal driveline exit site. The incidence of pump infections is particularly low. Using a subcostal driveline exit site may be as effective in preventing infections as using a skull-pedestal driveline exit site. We detail our findings in this report.

Outcomes and Predictors of Readmissions with GI Bleeding in Patients with Left Ventricular Assist Devices

OBJECTIVES

Gastrointestinal (GI) bleeding is a major comorbidity in patients with left ventricular assist devices (LVADs). The study aim was to estimate the rate of hospital readmissions for GI bleeding in patients with LVADs using a nationally representative database. Additionally, we evaluated the etiologies, costs, endoscopy utilization, mortality, and predictors of GI bleeding readmissions in these patients.

METHODS

We analyzed data from the National Readmissions Database (NRD) from 2010 through 2014. We compared hospitalized adult patients with congestive heart failure (CHF) who underwent LVAD implantation (cases) with CHF patients without LVAD or heart transplant (controls). Three age- and sex-matched controls were randomly selected per single case. A multivariate Cox regression model was used to compare the hazards of 60-day all-cause and GI bleeding readmission between the groups, controlling for significant confounders.

RESULTS

A total of 3293 hospitalized patients with CHF who had LVAD placement (cases) and 9879 who did not have LVADs (controls) were included in the study. At 60 days, patients with LVAD had a significantly higher readmission rate with GI bleeding (8.7% vs 2.3%, adjusted hazard ratio [aHR] 4.45, 95% confidence interval 3.71-5.33, P < 0.0001). The all-cause readmission rate also was higher (43.3% vs 35.7%, aHR 1.23, 95% confidence interval 1.12-1.34, P < 0.0001). The most common etiologies of bleeding in patients with LVADs were gastroduodenal and small intestinal arteriovenous malformations (28.6%). During bleeding readmissions, patients with LVAD were more likely to undergo endoscopy (72.1% vs 33.5%, P < 0.0001) and receive packed red blood cell transfusions (62% vs 36.6%, P< 0.0001) compared with controls. GI bleeding readmissions were more costly ($40,936 vs $35,313, P< 0.0001), and longer (12 vs 10.9 days, P< 0.0001) in patients with LVADs compared with controls. Independent risk factors for 60-day GI bleeding readmission were increasing age (aHR 1.04, P< 0.0001) and GI bleeding during index admission (aHR 2.68, P< 0.0001). In those without bleeding during index admission, increasing age and chronic anemia were associated with 60-day GI bleeding readmission. Mortality during bleeding readmission was similarly low in patients with LVADs compared with CHF controls (0.2% vs 0.3%, P = 0.14).

CONCLUSIONS

After LVAD implantation, there is a fivefold increased risk of readmission with GI bleeding within 60 days. Gastroduodenal and small intestinal arteriovenous malformations are the most common culprit lesions. These findings suggest that small bowel enteroscopy should be considered as the initial test of choice in patients with suspected upper gastroduodenal bleeding. Readmissions with bleeding in patients with LVADs increase morbidity and cost of care but not mortality. Older patients and those with a history of bleeding during LVAD implantation are at higher risk of bleeding readmission and may benefit from close monitoring and cautious anticoagulation to prevent rebleeding.

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.

Omental and deep inferior epigastric artery perforator flap coverage after heart transplantation to manage wide left ventricular assist device exposure with pocket infection

Infection is a serious potential complication after left ventricular assist device (LVAD) implantation. In general, infection of the device pocket, with device exposure, should be managed by early device removal and heart transplantation. However, because of the small number of donors in Japan, accelerating access to heart transplantation is often difficult and the LVAD can be widely exposed during the waiting period. We report our experience of successful heart transplantation in a patient with a widely exposed LVAD with pocket infection. A 48-year-old man suffered from heart failure due to idiopathic dilated cardiomyopathy. An LVAD was implanted, but postoperative infection led to blood pump exposure. Heart transplantation was performed 4 months after LVAD exposure, at which time the epigastric skin defect measured 14 × 8 cm. The skin defect could not be closed after heart transplantation, so it was covered by an omental flap with split-thickness skin grafts. 7 days postoperatively, the peritoneal suture broke and the intestinal tract prolapsed outside the body. Reintroduction of the prolapsed intestinal tract and deep inferior epigastric artery perforator (DIEP) flap coverage of the omental flap were performed. The postoperative course was uneventful. There have been no reports of the management of wide skin defects in the presence of infection when heart transplantation is performed. Omental flap placement was useful for controlling long-lasting infection. An omental flap placed in a patient with a wide epigastric skin defect should be covered by durable skin flap, such as a DIEP flap, to avoid intestinal prolapse.

Risk of stroke early after implantation of a left ventricular assist device

OBJECTIVE

Stroke is one of the major adverse events after left ventricular assist device implantation. Risk of stroke is the highest immediately after left ventricular assist device implantation and then increases again in chronic periods. There is no study that has analyzed risk factors for stroke in acute phase. We investigated the risk factors for stroke in the acute phase after left ventricular assist device implantation in the present study.

METHODS

Between October 2005 and December 2016, 158 consecutive patients (mean age, 43 ± 14 years; 34% were women) underwent continuous-flow left ventricular assist device (50 HeartMate II [Abbott Medical, Abbott Park, Ill], 38 DuraHeart [Terumo Heart, Ann Arbor, Mich], 33 Jarvik2000 [Jarvik Heart, New York, NY], 23 EVAHEART [Sun Medical, Moriyama City, Japan], 14 HeartWare [Framingham, Mass]) implantation in our institution. We analyzed the risk factors for a symptomatic stroke within 90 days after left ventricular assist device implantation.

RESULTS

Stroke occurred in 28 patients in the acute phase after left ventricular assist device implantation. Multivariate analysis revealed that low cardiac output (odds ratio, 0.25; 0.07-0.92; P = .024) during postoperative 12 to 24 hours was the only independent risk factor for stroke in the acute phase. Patients with stroke in the acute phase had higher serum lactate dehydrogenase levels at any point until postoperative 14 days. Patients with the HeartMate II device particularly showed a statistically significant negative relationship between cardiac output during postoperative 12 to 24 hours and serum lactate dehydrogenase levels at postoperative 14 days (r = -0.313, P = .03).

CONCLUSIONS

Our study demonstrated that patients with perioperative lower cardiac output and higher lactate dehydrogenase level developed stroke in the acute phase after left ventricular assist device implantation. These results suggested that maintenance of sufficient left ventricular assist device flow is important in prevention of stroke, which may be related to subclinical pump thrombosis.

Limited usefulness of endoscopic evaluation in patients with continuous-flow left ventricular assist devices and gastrointestinal bleeding

BACKGROUND

Gastrointestinal bleeding (GIB) is a frequent cause of re-admission in patients with continuous-flow left ventricular assist devices (CF-LVADs) and is associated with multiple endoscopic procedures and high resource utilization. Our aim was to determine the diagnostic and therapeutic yield of endoscopy and to develop a more cost-effective approach for the management of GIB in CF-LVAD recipients.

METHODS

We retrospectively reviewed 428 patients implanted with a CF-LVAD between 2009 and 2016 at the Columbia University Medical Center and identified those hospitalized for GIB. Patients were categorized into upper GIB (UGIB), lower GIB (LGIB) and occult GIB (OGIB), based on clinical presentation.

RESULTS

Eighty-seven CF-LVAD patients underwent a total of 164 GIBs, resulting in 239 endoscopies. Index presentation was consistent with UGIB in 30 (34.5%), LGIB in 19 (21.8%) and OGIB in 38 (43.7%) patients. On the first GIB, 147 endoscopies localized a bleeding source in 49 (30%), resulting in 24 (16.3%) endoscopic interventions. Of 45 lesions identified, arteriovenous malformations (AVMs) were the most common (22, 48.9%). A gastric or small bowel source (HR 2.8, p = 0.003) and an endoscopic intervention (HR 1.9, p = 0.04) predicted recurrent GIB. The proposed algorithm may reduce the number of endoscopic procedures by 45% and costs by 35%.

CONCLUSIONS

Occult GIB is the most common presentation in CF-LVAD patients and carries the lowest diagnostic and therapeutic yield of endoscopy. Performing an intervention was among the strongest predictors of recurrent GIB. Our proposed algorithm may decrease the number of low-yield procedures and improve resource utilization.

Driveline Infection in Ventricular Assist Devices and Its Implication in the Present Era of Destination Therapy

Advances in mechanical circulatory support devices provided the technology to develop long-term, implantable left ventricular assist devices as bridge to transplant, destination therapy, and in a lesser group of patients, as bridge to recovery. Despite the benefits from this innovative therapy, with their increased use, many complications have been encountered, one of the most common being infections. With the driveline acting as a portal to the exterior environment, an infection involving this structure is the most frequent one. Because patients with destination therapy are expected to receive circulatory support for a longer period of time, we will focus this review on the risk factors, prevention, and treatment options for driveline infections.

Evaluation of right ventricular function using liver stiffness in patients with left ventricular assist device

Objectives

Although right ventricular failure (RVF) is a major concern after left ventricular assist device (LVAD) implantation, methodologies to evaluate RV function remain limited. Liver stiffness (LS), which is closely related to right-sided filling pressure and may indicate RVF severity, could be non-invasively and repeatedly assessed using transient elastography. Here we investigated the suitability of LS as a parameter of RV function in pre- and post-LVAD periods.

Methods

The study included 55 patients with LVAD implantation as a bridge to transplantation between 2011 and 2015 whose LS was assessed using transient elastography.

Results

Seventeen patients presented with RVF, defined as requiring inotropic support for ≥30 days, nitric oxygen inhalation for ≥5 days, and/or mechanical RV support following LVAD implantation. Survival of patients with RVF was significantly worse compared with that of patients without RVF. Multivariate logistic regression analysis identified preoperative LS, LV diastolic dimension, RV stroke work index, and dilated phase of hypertrophic cardiomyopathy aetiology as significant risk factors; the combination of these parameters could improve predictive power of post-LVAD RVF with areas under the curve of 0.89. Furthermore, LS was significantly decreased by LV unloading and significantly correlated with right-sided filling pressure.

Conclusions

In addition to dilated hypertrophic cardiomyopathy aetiology, reduced RV stroke work index and small LV dimension, we demonstrated that non-invasively measured LS was a predictor of post-LVAD RVF and can be used as a parameter for the evaluation and optimization of RV function in the perioperative period.

Correlation between driveline features and driveline infection in left ventricular assist device selection

Although the survival rate for left ventricular assist device (LVAD) therapy has improved, device-related complications are an unpredictable threat to the patient's quality of life. We focused on driveline infection, and aimed to determine whether specific features of drivelines affect the frequency of infection. We enrolled patients who underwent LVAD implantation and were followed-up at our institute between 2007 and 2015. We counted the occurrences of driveline infection requiring any antibiotic therapy over a 2-year study period. Furthermore, we experimentally measured and compared the outer diameters and stiffness of three devices. Of all, 72 patients received an LVAD during the enrollment period. LVADs were HeartMate II (n = 32), EVAHEART (n = 22), and DuraHeart (n = 18). The outer diameters and stiffness were measured in five of each device. HeartMate II group had the highest driveline infection-free rate among all three devices during the study period (p = 0.042). The driveline of the HeartMate II LVAD had a significantly smaller outer diameter and lower stiffness than that of the other two devices (p < 0.05 for both). In conclusion, device-specific driveline features may affect the development of driveline infection during LVAD therapy.

Risk Factors and Outcomes of Gastrointestinal Bleeding in Left Ventricular Assist Device Recipients

Increasing use of left ventricular assist devices (LVADs) has been accompanied by rising incidence of gastrointestinal bleeding (GIB). Objectives of this study were to determine the yearly incidence of GIB in LVAD recipients, compare outcomes of continuous-flow (CF) and pulsatile-flow LVAD eras, and investigate for risk factors. The Healthcare Cost and Utilization Project-Nationwide Inpatient Sample database from 2005 to 2010 was analyzed. Primary outcome of interest was incidence of GIB in LVAD recipients. Multivariate logistic regression model was used to examine independent associations of GIB with risk factors and outcomes. An estimated 8,879 LVAD index admissions and 8,722 readmissions in LVAD recipients over 6 years were analyzed. The yearly incidence of GIB after LVAD implantation increased from 5% in 2005 to 10% in 2010. On multivariate regression analysis, the odds of GIB was 3.24 times greater (95% confidence interval 1.53 to 6.89) in the era of CF LVADs than in the era of pulsatile-flow LVADs. Compared to their younger counterparts, in LVAD recipients aged >65 years, the adjusted odds of GIB was 20.5 times greater (95% confidence interval 2.24 to 188). GIB did not significantly increase the inhospital mortality but increased the inpatient length of stay. In conclusion, the incidence of GIB in LVAD recipients has increased since the use of CF LVADs has increased, leading to greater inpatient lengths of stay and hospital charges. Older recipients of CF LVADs appear to be at a greater risk of GIB.

Left Ventricular Assist Device Driveline Infections

Heart failure is a chronic progressive disease that affects millions of people in the United States. Although medical management of heart failure has helped improve quality of life and survival, end-stage heart failure ultimately requires a heart transplant or long-term left ventricular assist device (LVAD) support. With more patients awaiting transplant, the demand for hearts outweighs the supply of donor hearts. The use of LVADs is increasing in patients with advanced heart failure as a treatment option for those awaiting a heart transplant or as a long-term solution if they are ineligible for a transplant. Although the LVAD is a marvel of modern medicine, infection is a cause of concern because today’s LVADs are powered externally through a percutaneous driveline that can be a major source of infection.