Absorbable antibiotic beads for treatment of LVAD driveline infections

BACKGOUND

Infections of the left ventricular assist device (LVAD) driveline are a dreaded complication that results in high mortality and morbidity.

METHOD

We retrospectively reviewed five consecutive patients with severe continuous-flow LVAD (HVAD, Heartmate 2, and Heartmate 3) driveline infection. These infections, which developed on an average of 960.4 ± 843.9 days after LVAD placement, were refractory to systemic antibiotics and local wound care. All were treated with extensive surgical debridement, local installation of absorbable antibiotic-loaded calcium sulfate beads (vancomycin and tobramycin), primary wound closure, and 6 weeks of systemic antibiotics after surgery.

RESULTS

Four patients had resolution of DLI, and one had a recurrent infection at another part of the driveline 7 months after the complete resolution of the previous site. This patient was successfully treated with debridement and bead placements. Three patients still have their LVADs, while two received orthotopic heart transplants. At the time of the transplant, there was no evidence of gross infection of the LVAD drivelines or pumps. At the average follow-up time of 425.8 ± 151 days, no patients have an active infection.

CONCLUSION

Treatment of LVAD driveline infection with absorbable antibiotic beads with primary wound closure is a viable option and merits further investigation.

Driveline infection according to driveline positioning in left ventricular assist device implant recipients

We conducted a prospective, open-labeled, clinical trial, with a two-by-two factorial design, of argon cold plasma application and two different types of driveline positioning for the prevention of driveline infection (DLI) in 80 patients with a left ventricular assist device (LVAD) implant. Here, we present the results of intracorporeal loop positioning (n = 40) versus no intracorporeal loop positioning (n = 40). Patients were followed up for 1 year. According to the Driveline Expert STagINg and carE grading (DESTINE) system, a DLI was considered in case of a stage 2 or higher graded infection. During follow-up, 29 (36%) patients experienced a DLI, 16 in the group with intracorporeal loop positioning and 13 in the group with no intracorporeal loop positioning. Kaplan-Meier estimates of freedom from DLI showed no statistically significant difference between study groups during follow-up (p = 0.33). In detail, 30-day freedom from DLI was for the groups with and without intracorporeal loop positioning 92 and 92%, respectively, and 1-year freedom from DLI was 51 and 62%, respectively. In conclusion, this controlled clinical trial was unable to show a statistically significant difference in freedom from DLI during one year of follow-up in groups with or without intracorporeal loop positioning. However, larger trials have to confirm these results.

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.

Experience with dalbavancin for long-term antimicrobial suppression of left ventricular assist device infections

BACKGROUND

Left ventricular assist devices (LVAD) are a common strategy for management of end-stage heart failure. LVADs carry a risk of infection of the implanted device components, and skin flora are commonly implicated. Long-term antibiotics may be needed for management of deep device infection or recurrent superficial infections. In appropriately selected patients, dalbavancin can be a feasible option given its extended dosing interval.

METHODS

This is a retrospective, single-center review of patients presenting with an LVAD infection between January 2011 and November 2022, where management included the use of dalbavancin. Data regarding LVAD placement, details of index infection, dalbavancin use and outcomes was obtained from chart review, and documented in a RedCap database.

RESULTS

The mean time from LVAD placement to index infection was 131.6 weeks (standard deviation 87.2 weeks). The most common targeted organism was Corynebacterium striatum in six of 10 patients. Index infection presented as deep driveline infection in four patients and recurrent superficial driveline infection in three patients. Five patients had a concurrent bloodstream infection. Dalbavancin was discontinued in two patients due to breakthrough infection, with one patient requiring surgical intervention. No drug-related adverse events were noted.

CONCLUSION

Dalbavancin is an attractive option in the management of long-term LVAD infection in patients for whom alternative oral or parenteral antibiotics are not a feasible option. Additional studies are needed to determine the optimal dosing of dalbavancin in this setting, and to study adverse events and long-term outcomes of dalbavancin.

Pump Exchange from a Left Ventricular Assist Device to a Jarvik 2000 with a Postauricular Cable Due to Abdominal Driveline Infection

Driveline infection in patients with implantable left ventricular assist devices (LVAD) remains common and crucial. Once a driveline exit-site infection reaches the LVAD component, radical treatment such as LVAD exchange may become necessary, although the clinical results are unsatisfactory. The Jarvik 2000 device, which utilizes a postauricular cable, allows the driveline to exit the body behind the ear (postauricular) instead of through an abdominal site. Here, we report the case of a patient who had awaited heart transplantation for more than 6 years and had a critical driveline infection that almost reached the LVAD pump. The patient underwent a pump exchange using the Jarvik 2000 with a postauricular cable, with excellent results. It is a useful replacement option for patients with abdominal driveline infections, owing to its small pump pocket and the availability of an alternative pathway for the driveline.

Vitamin D deficiency and driveline infection in patients with a left ventricular assist device implant

Driveline infection is a frequent complication in recipients of durable left ventricular assist devices (LVAD), but its cause is largely unclear. Since vitamin D supplementation can reduce the risk of infections, we aimed at investigating the association of vitamin D deficiency with driveline infection. In 154 patients with continuous flow LVAD implants, we assessed 2-year risk of driveline infection according to vitamin D status (circulating 25-hydroxyvitamin D < 25 nmol/L or ⩾25 nmol/L). Of the study cohort, 34% (n = 53) had 25-hydroxyvitamin D concentrations <25 nmol/L. Kaplan-Meir estimates of 2-year freedom from driveline infection were in the vitamin D deficient and vitamin D non-deficient groups 49.7% and 74.2%, respectively (p = 0.017). Covariate-adjusted hazard ratio of driveline infection for the vitamin D deficient versus non-deficient group was 2.51 [95% CI: 1.11-5.69; p = 0.028). Circulating concentrations of endocrine regulators of calcium and phosphorus metabolism such as parathyroid hormone, 1,25-dihydroxyvitamin D, and fibroblast growth factor-23 were not significantly associated with the risk of driveline infection (p-values > 0.15). In total, our data indicate that in LVAD recipients deficient vitamin D status is a predictor of driveline infection, but future studies are needed to investigate whether these associations are causal.

Prophylactic negative pressure wound therapy is not effective for preventing driveline infection following left ventricular assist device implantation

BACKGROUND

Driveline infection (DLI) following left ventricular assist device (LVAD) implantation remains an unresolved problem. Negative pressure wound therapy (NPWT) promotes wound healing by applying negative pressure on the surface of the wound. Recently, the prophylactic application of NPWT to closed surgical incisions has decreased surgical site infections in various postsurgical settings. Therefore, we evaluated the efficacy and safety of prophylactic NPWT for preventing DLI in patients with LVAD implantation.

METHODS

Prophylactic NPWT was provided to 50 patients who received continuous-flow LVADs as bridge-to-transplant therapy at our institution between May 2018 and October 2020 (NPWT group). The negative pressure dressing was applied immediately after surgery and retained on the driveline exit site for 7 days with a continuous application of -125 mm Hg negative pressure. The primary outcome was DLI within 1 year of LVAD implantation. We compared the rate of DLI incidence in the NPWT group with that in the historical control cohort (50 patients) treated with the standard dressing (SD) who received LVAD implantation between July 2015 and April 2018 (SD group).

RESULTS

No severe complications were associated with the NPWT. During the follow-up period, DLI was diagnosed in 16 participants (32%) in the NPWT group and 21 participants (42%) in the SD group. The rates of DLI incidence and freedom from DLI did not differ between groups (p = 0.30 and p = 0.63).

CONCLUSIONS

Prophylactic NPWT at the driveline exit site was safe following LVAD implantation. However, it did not significantly reduce the risk of DLI.

Impact of an improved driveline management for HeartMate II and HeartMate 3 left ventricular assist devices

BACKGROUND

We evaluated the impact of a standardized driveline care strategy, including a subfascial-tunneling method and dressing protocol, on the incidence of driveline infection (DLI).

METHODS

DLI data from all HeartMate II (HMII) and HeartMate 3 (HM3) patients (including exchange devices) were retrospectively collected between 2013 and 2021. The driveline subfascial-tunneling method was altered in three steps (A: right direct; B: left triple, C: right triple), and the shower protocol was changed in two steps (A: with/without cover, B: with cover). Disinfection was individually tailored after changing the shower protocol. Complications associated with morbidity and mortality were evaluated for each modification.

RESULTS

During the study period, 80 devices were implanted (HMII, n = 54; HM3, n = 26). The 8-year incidence of DLI was 15% (n = 8) in HMII patients and 0% in HM3 patients (p = 0.039). DLI was not associated with hospital mortality. The modified dressing protocol and tunneling method was associated with a significantly better DLI incidence rate in comparison to the previous one: Protocol-A (n = 17), Protocol-B (n = 63), 35% vs 3% (p = 0.0009), Method-A (n = 13), Method-B (n = 42), Method-C (n = 25), 46% vs 5% vs 0% (p = 0.0001). The rete of freedom form DLI at 1, 2, and 3 years had also significant difference between groups: Protocol-A and Protocol-B, 80%, 54%, 54% vs 96%, 96%, 96%, respectively (p < 0.0001), Method-A, Method-B and Method-C, 76%, 44%, 44%, vs 94%, 94%, 94% vs 100%, 100%, respectively (p < 0.0001).

CONCLUSIONS

A standardized triple driveline tunneling strategy and waterproof dressing protocol reduced driveline infection in HM3 patients to 0%.

Driveline Infection in Left Ventricular Assist Device Patients: Effect of Standardized Protocols, Pathogen Type, and Treatment Strategy

Driveline infection (DLI) is common after left ventricular assist device (LVAD). Limited data exist on DLI prevention and management. We investigated the impact of standardized driveline care initiatives, specific pathogens, and chronic antibiotic suppression (CAS) on DLI outcomes. 591 LVAD patients were retrospectively categorized based on driveline care initiatives implemented at our institution (2009-2019). Era (E)1: nonstandardized care; E2: standardized driveline care protocol; E3: addition of marking driveline exit site; E4: addition of "no shower" policy. 87(15%) patients developed DLI at a median (IQR) of 403(520) days. S. aureus and P. aeruginosa were the most common pathogens. 31 (36%) of DLI patients required incision and drainage (I&D) and 5 (5.7%) device exchange. P. aeruginosa significantly increased risk for initial I&D (HR 2.7, 95% CI, 1.1-6.3) and recurrent I&D or death (HR 4.2, 95% CI, 1.4-12.5). Initial I&D was associated with a significant increased risk of death (HR 2.92 (1.33-6.44); P = 0.008) when compared to patients who did not develop DLI. Implementation of standardized driveline care protocol (E2) was associated with increased 2-year freedom from DLI compared to nonstandardized care (HR 0.36, 95% CI, 0.2-0.6, P < 0.01). Additional preventive strategies (E3&E4) showed no further reduction in DLI rates. 57(65%) DLI patients received CAS, 44% of them required escalation to intravenous antibiotics and/or I&D. Presence of P. aeruginosa DLI markedly increased risk for I&D or death. Conditional survival of patients progressing to I&D is diminished. Standardized driveline care protocol was associated with a significant reduction in DLI, while additional preventive strategies require further testing.

New Wound Management of Driveline Infections with Cold Atmospheric Plasma

The use of ventricular assist devices as a bridge to transplant or as destination therapy has increased. Wound complications increase morbidity in this cohort. Cold atmospheric plasma is a source of reactive oxygen and nitrogen species and can reduce the microbial load in skin wounds without negative effects on the surrounding tissue. We evaluated our cold atmospheric plasma treatment for LVAD driveline infections in a retrospective single-center study for peri- and postintervention outcome analysis. Between April 2019 and September 2019, 15 male patients were included (5 HVAD, 10 HeartMate III). The wounds were treated for a mean of 368.5 s with a reduction of bacterial load in treated wounds in 60% of patients, regardless of the pathogen. The most common pathogen was staphylococcus aureus (n = 8 patients). There was a significant reduction of the wound scale (scale 2.80 vs. 1.18; p < 0.001) plus a significant reduction in size (16.08 vs. 1.90 cm3; p = 0.047). Seven patients (46.6%) were free from any signs of local or systemic infection during 1-year follow-up. Five patients (33%) received a heart transplantation. Cold atmospheric plasma treatment is a potent, safe, and painless adjuvant technique for treating driveline infection without the need for repeating surgical interventions.

Surgical repositioning of Jarvik 2000 LVAD power supply pedestal following fall trauma

Advanced heart failure (HF) is one of the leading causes of mortality and morbidity. With an aging population, its prevalence is expected to rise further. Although orthotopic heart transplantation (HTX) remains the gold standard in therapy, there is a significant deficiency in the ratio of donor organs to recipient patients. Left ventricular assist devices (LVAD) could relieve this problem either as a bridge-to-transplant (BTT) or as a destination therapy (DT). Despite the widespread implantation of ventricular assist devices, their efficacy may be limited by some serious adverse events, while infection is a major issue. A longer period of LVAD support significantly increases the risk of driveline infections (DLI). The Jarvik 2000® ventricular assist device (Jarvik Heart, New York, NY, USA) offers prolonged infection-free survival. In our report, we present the case of a 61-year-old female patient with a driveline pedestal that has become fully detached from the skull following a fall trauma. We describe how the traumatized pedestal was surgically replaced by removing the previous, damaged unit and inserting a repositioned new one. The surgical procedure presented in our case has not been performed before and we have not found any similar one in the literature. It requires individual surgical planning and a multidisciplinary surgeon's team to ensure the procedure is safe and feasible.

Non-patient factors associated with infections in LVAD recipients: A scoping review

BACKGROUND

Infections are the most common complication in recipients of durable left ventricular assist devices (LVAD) and are associated with increased morbidity, mortality, and expenditures. The existing literature examining factors associated with infection in LVAD recipients is limited and principally comprises single-center studies. This scoping review synthesizes all available evidence related to identifying modifiable, non-patient factors associated with infections among LVAD recipients.

METHODS

Published studies were identified through searching 5 bibliographic databases: PubMed, Scopus, EMBASE, CINAHL, and Web of Science Core Collection. Inclusion criteria required examination of factors associated with infections among recipients of contemporary, implantable, continuous flow LVADs. Key study characteristics were extracted by 4 independent reviewers and current literature described narratively. The Systems Engineering Initiative for Patient Safety (SEIPS) model was used to develop a taxonomy for non-patient related factors (e.g., tasks, tools, technologies, organization, and environment) associated with infections following LVAD implantation. All analyses took place between February 2019 and May 2021.

FINDINGS

A total of 43 studies met inclusion criteria. The majority of included studies were observational (n = 37), single-center (n = 29), from the U.S. (n = 38), and focused on driveline infections (n = 40). Among the 22 evaluated sub-domains of non-patient related factors, only two: increasing center experience and establishing a silicone-skin interface at the driveline exit site, were identified as consistently being associated with a lower risk of infection.

CONCLUSION

This review identified 43 studies that described non-patient related factors associated with infection in LVAD recipients. Only two factors were consistently associated with lower infection risk in LVAD recipients: increasing experience and establishing a silicone-skin interface at driveline exit site. The large variability in reporting across multiple studied interventions limited the ability to discern their effectiveness.

Mycobacterium abscessus Infection in Left Ventricular Assist Device (LVAD): A Case Series

The limited availability of donor organs worldwide, has provoked a surge in the need for implantable left ventricular assist devices (LVADs) mainly as a bridge to heart transplantation or destination therapy. The rate of complications from LVAD use is also increasing, impacting morbidity, mortality, and costs. LVAD infections due to nontuberculous mycobacteria (NTM) are exceedingly rare, yet very difficult to treat. Here we present three cases of Mycobacterium abscessus LVAD infections. To our knowledge, only two other cases have been documented.

Driveline damage and repair in continuous-flow left ventricular assist devices: A systematic review

With mounting time on continuous-flow left ventricular assist device (CF-LVAD) support, patients occasionally sustain damage to the device driveline. Outcomes associated with external and internal driveline damage and repair are currently not well documented. We sought to evaluate the outcomes of driveline damage and its repair. Electronic search was performed to identify all relevant studies published over the past 20 years. Fifteen studies were selected for analysis comprising of 55 patients with CF-LVAD dysfunction due to driveline damage. Demographic and perioperative variables along with outcomes including survival rates were extracted and pooled for the systematic review. Most patients (53/55) were supported on HeartMate II LVAD (Abbott Laboratories, Abbott Park, IL). Internal damage was more commonly reported than external damage [69.1% (38/55) vs. 30.9% (17/55), P = .01]. Median time to driveline damage was 1.9 years [IQR 1.0, 2.5]. Most patients presented with a CF-LVAD alarm [94.5% (52/55)] and patients with internal driveline damage had a significantly higher rate of alarm activation compared to that observed for those with external damage [38/38 (100%) vs. 14/17 (82.4%), P = .04]. Patients with internal driveline dysfunction were more likely to experience component wear compared to those with external driveline dysfunction [10/38 (26.3%) vs. 0/17 (0%), P = .05]; 14.5% of patients (8/55) underwent external repair of the driveline, 5.5% (3/55) were treated with rescue tape, and 5.5% (3/55) were placed on an ungrounded cable, indicating a short-to-shield event had occurred. A total of 49.1% of patients (27/55) underwent CF-LVAD exchange, 5.5% (3/55) were weaned off the CF-LVAD to explant, and 5.5% (3/55) underwent emergent heart transplantation. The median length of hospital stay was 12 days [IQR 7, 12] and 30-day mortality rate was 14.5% (8/55). Driveline damage was more commonly reported at an internal location and despite being a well-recognized complication, mortality still appears high.

Epidemiology of Left Ventricular Assist Device Infections: Findings From a Large Nonregistry Cohort

BACKGROUND

Infection is a major complication during circulatory support with a left ventricular assist device (VAD). Changes in device characteristics and treatment practices in the last decade can affect the epidemiology of infection. The International Society for Heart and Lung Transplantation (ISHLT) has published recommendations on the prevention and management of VAD infections, but data to support these recommendations remain sparse.

METHODS

We performed a retrospective review of 455 patients who underwent VAD placement from 2009 to 2015. Infection episodes were defined using ISHLT criteria and were also grouped as endovascular or local. Analysis included descriptive statistics.

RESULTS

There were 174 patients (38.6%) with a VAD infection. Infection incidence was 36.9 cases per 100 person-years of VAD support. The driveline was the most common infection site (67.2%). Systemic inflammatory response syndrome (SIRS) criteria were not satisfied in 29.2% of patients with endovascular infections, and computed tomography (CT) examinations were normal in 37.7% of cases. Gram-positive bacteria caused 65.6% of infections in patients with an available culture. Antimicrobial suppression was used in 72.3% of patients who survived treatment. Median survival after infection was 35 months for patients with VAD-related infections versus 14 months for patients with VAD-specific infections.

CONCLUSIONS

VAD infections continue to be a major complication after implantation. Clinical criteria alone were not predictive of serious infections, and many patients with confirmed infection had normal CTs. Patients with VAD-specific infections had lower median survival than patients with VAD-related 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.

Evaluation of a Health Care Performance Improvement Initiative to Facilitate Optimal Clinical Outcomes in Patients Receiving Ventricular Assist Device Support

BACKGROUND

Ventricular assist device (VAD) patients are at high risk for morbidities and mortality. One potentially beneficial component of the Joint Commission VAD Certification process is the requirement that individual VAD programs select 4 performance measures to improve and optimize patients' clinical outcomes.

PROBLEM STATEMENT

Review of patient data after our program's first certification visit in 2008 showed that, compared to national recommendations and published reports, our patients had suboptimal outcomes in 4 areas after device implantation: length of hospital stay, receipt of early (<48 hours) postsurgical physical therapy, driveline infection incidence, and adequacy of nutritional status (prealbumin ≥18 mg/dL).

METHODS

Plan-Do-Study-Act processes were implemented to shorten length of stay, increase patient receipt of early physical therapy, decrease driveline infection incidence, and improve nutritional status. With 2008 as our baseline, we deployed interventions for each outcome area across 2009 to 2017. Performance improvement activities included staff, patient, and family didactic, one-on-one, and hands-on education; procedural changes; and outcomes monitoring with feedback to staff on progress. Descriptive and inferential statistics were examined to document change in the outcomes.

OUTCOMES

Across the performance improvement period, length of stay decreased from 40 to 23 days; physical therapy consults increased from 87% to 100% of patients; 1-year driveline infection incidence went from 38% to 23.5%; and the percentage of patients with prealbumin within the normal range increased from 84% to 90%.

IMPLICATIONS

Performance improvement interventions may enhance ventricular assist device patient outcomes. Interventions' sustainability should be evaluated to ensure that gains are not lost over time.

Absorbable antibiotic beads as an adjuvant therapy in treating ventricular assist devices driveline infection: A case report

BACKGROUND

Ventricular assist devices driveline infections are common, recalcitrant, and carry high morbidity and mortality. Herein, we reported a patient with driveline infection that was successfully treated with a combination of systemic antibiotics, surgical debridement, and instillation of absorbable antibiotic beads to the wound bed.

METHODS AND RESULTS

A 39-year-old man with nonischemic cardiomyopathy underwent insertion of a continuous flow left ventricular assist device. Four years postoperatively, the patient presented with clinical, laboratory, and radiologic signs of driveline tract infection. He underwent extensive surgical debridement, installation of absorbable antibiotic beads that consisted of calcium sulfate, vancomycin, and tobramycin, into the wound bed, and systemic antibiotics. The patient was free of infection 9 month postoperatively.

CONCLUSION

Absorbable calcium sulfate antibiotic beads may serve as a beneficial adjunct to surgical debridement and systemic antibiotics for the treatment of ventricular assist device driveline infection, and merit further investigation.

Efficacy and safety of chronic antimicrobial suppression therapy for left ventricular assist device driveline infections: A single-center descriptive experience

BACKGROUND

Driveline infection (DLI) is the most common left ventricular assist device (LVAD) infectious complication. Short-term antimicrobial therapy and local debridement are the cornerstones of management for these infections, but the use of chronic antimicrobial suppression (CAS) therapy is not well characterized.

METHODS

To better characterize the efficacy of CAS therapy, we performed a retrospective review of all patients (N = 219) receiving care at our tertiary transplant center with continuous-flow LVADs placed between August 2007 and July 2019.

RESULTS

A total of 24 patients were identified as having received CAS therapy as treatment for DLIs. The mean age was 56 years, 50% were female, and chronic kidney disease affected 63% of patients. Staphylococcus aureus accounted for half of all initial DLIs, and the mean length of CAS therapy was 486 days (range 48-2287 days). All patients received per os regimens as suppression therapy. Adverse events impacted 5 of 24 patients (0.43 events per 1000 days). Overall, the use of CAS therapy led to successful outcomes in 50% of patients and 29% experienced treatment failures. The remaining patients experienced stable symptoms. Relapses were the most common cause of treatment failure, and three patients experienced reinfections while on CAS therapy.

CONCLUSIONS

Our study suggests that CAS therapy for DLIs can be well tolerated, and future studies are needed to determine which patients merit suppression.

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

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

New Treatment for Driveline Infection Following Implantation of a Ventricular Assist Device

In patients with an implantable ventricular assist device (VAD), driveline infection (DLI) is a challenging complication. Once DLI occurs, it may lead to pump contamination and/or septicemia, which means that early treatment is essential. We hereby report our initial experiences of a mechanically-powered portable negative pressure wound therapy system (Smart Negative Pressure: SNaPTM) to treat DLI at an outpatient clinic.

Minimum inhibitory concentration changes in relapsed left ventricular assist device driveline infections

Driveline infection is the most common infectious complication in patients with left ventricular assist devices. Minimum inhibitory concentration changes are not well described in relapsed driveline infections. This retrospective descriptive epidemiology study of patients with left ventricular assist device implantation between January 1, 2013, and August 1, 2017, who developed driveline infection with positive cultures aimed to describe minimum inhibitory concentration changes. Of the 330 patients underwent left ventricular assist device implantation, 30 (9%) met criteria for driveline infection. Median duration of follow-up was 26 months (interquartile range 16, 39) and time to first driveline infection was 171 days (interquartile range 83, 403). There were 74 driveline infections: 40 new and 34 relapsed. Staphylococcus aureus was most common in new and relapsed driveline infection. Thirteen patients comprised the 34 relapsed infections, 9 of which experienced a minimum inhibitory concentration change. Median time to first minimum inhibitory concentration change was 56 days (interquartile range 36-88), and type of minimum inhibitory concentration change was an increase in five cases, decrease in two cases, and both increase and decrease in two cases. Minimum inhibitory concentration changes did not result in resistance in S. aureus but did in Pseudomonas aeruginosa and Mycobacterium fortuitum relapsed driveline infection. Time to first relapse from initial infection was longer in those who received suppressive therapy, 60 days versus 83 days, p = 0.047. Relapsed driveline infections were most common with S. aureus. Minimum inhibitory concentration changes were quite variable and may not be the major contributor to relapsed infection in gram-positive driveline infection.

[Driveline Wound Care: Key to the Long-Term Use of Implantable Ventricular Assist Devices]

Heart failure is a complicated chronic disease. Although numerous new medications are used to treat and improve the quality of life of patients with heart failure, the final treatment for terminal heart failure still relies heavily on heart transplants. However, as the number of heart donations is limited, many health institutions implant mechanical assist devices to perform heart functions temporarily. These implanted ventricular assist devices help reduce heart failure symptoms and enhance quality of life. However, driveline infection is one of the more severe complications associated with these devices. If this infection is not controlled, another heart surgery will be necessary to replace the device. Severe driveline infection may even lead to patient death. An approach to care that includes driveline wound care standardization and immobilization of the driveline has been shown to effectively decrease the incidence of driveline infections and to increase the survival rate. As Taiwan still lacks the relevant clinical care standards for implantable ventricular assist device support and driveline wound care, this study introduces the relevant Western literature and the author's clinical experience related to driveline wound management. We hope that this article serves as a useful reference for related nursing care.

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

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

Photographic LVAD Driveline Wound Infection Recognition Using Deep Learning

The steady increase in the number of patients equipped with mechanical heart support implants, such as left ventricular assist devices (LVAD), along with virtually ubiquitous 24/7 internet connectivity coverage is motive to investigate and develop remote patient monitoring. In this study we explore machine learning approaches to infection severity recognition on driveline exit site images. We apply a U-net convolutional neural network (CNN) for driveline tube segmentation, resulting in a Dice score coefficient of 0.95. A classification CNN is trained to predict the membership of one out of three infection classes in photographs. The resulting accuracy of 67% in total is close to the measured expert level performance, which indicates that also for human experts there may not be enough information present in the photographs for accurate assessment. We suggest the inclusion of thermographic image data in order to better resolve mild and severe infections.

Mycobacterium abscessus Left Ventricle Assist Device Driveline Infections: An Emerging Pathogen?

The use of left ventricular assist device is associated with improvement in survival in patients with refractory heart failure. However, driveline infection limits the success of its use as it is associated with significant mortality. We describe the first 2 cases of Mycobacterium abscessus driveline infection. Both patients had persistent infection despite of aggressive antibiotic treatment and local debridement, and only improved after removal of their left ventricular assist devices.

Left ventricular assist device exchange for the treatment of HeartMate II pump thrombosis

Background

Pump thrombosis is the most severe and acute complication of left ventricular assist device (LVAD) therapy and treatment remains challenging. Whilst lysis therapy is often not successful, the exchange of the occluded LVAD is currently the most applied therapeutic treatment for this event. With this study we examine the effects of minimal-invasive LVAD exchange on the rate re-thrombosis and outcomes as well as adverse events in the study group.

Methods

Between February 2004 and December 2015 more than 600 LVADs were implanted at our institution. We retrospectively studied a patient cohort of 41 patients who underwent LVAD exchange because of pump thrombosis at a single institution. Outcomes, rates of re-thrombosis and adverse events were analyzed.

Results

Between February 2004 and December 2015, 87 exchanges of LVADs were performed at a single center. In 41 cases pump thrombosis was the reason for LVAD exchange. A total of 28 patient years (10,276 days) were analyzed. Average ICU stay was 15.8±20.4 days and average in-hospital stay 38.1±37.3 days after LVAD exchange. After thirty days the survival rate was 80.5%, 75.6% after 6 months and 70.7% one year after LVAD exchange. Out of the study cohort, three patients have successfully undergone heart transplantation. Twelve patients suffered a stroke postoperatively (29%). Twelve patients needed postoperative dialysis (29%). No technical complications of the VAD were recorded in the study group. Two patients underwent successful LVAD explantation due to myocardial recovery. One year after LVAD exchange, 14 patients underwent re-exchange due to pump thrombosis (34%). Eight patients suffered from a LVAD related infection out of which two patients were treated by pump exchange. A total of 12 patients died during the complete one year follow up of this study (29%). Four patients died in the second, two in the third and one in the fourth year after LVAD exchange. The remaining 17 patients are still ongoing on the device.Conclusions: It is generally feasible to treat pump thrombosis via LVAD exchange. Yet, the exchange procedure is not without risk and the risk of re-thrombosis (34%), stroke (29%), postoperative dialysis (29%) and perioperative complications remains high.