Continuous-flow devices and percutaneous site infections: clinical outcomes

Current status and future directions in pediatric ventricular assist device

A ventricular assist device (VAD) is a form of mechanical circulatory support that uses a mechanical pump to partially or fully take over the function of a failed heart. In recent decades, the VAD has become a crucial option in the treatment of end-stage heart failure in adult patients. However, due to the lack of suitable devices and more complicated patient profiles, this therapeutic approach is still not widely used for pediatric populations. This article reviews the clinically available devices, adverse events, and future directions of design and implementation in pediatric VADs.

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.

Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: Data from a multicenter experience

BACKGROUND

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF). Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs with a lower risk of short- and long-term of device-related complications and infections.The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation.

METHODS

The study population included patients with a preexisting S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy.

RESULTS

The study population included 30 patients (25 male; median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population. Electromagnetic interference (EMI) occurred in 21 (70%) patients. The primary sensing vector was the one most significantly involved in determining EMI. Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector. The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks (IS) due to EMI. Six patients (20%) experienced appropriate shocks. No S-ICD extraction because of need for antitachycardia pacing, ineffective therapy or infection was reported.

CONCLUSIONS

Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS and undersensing in the post-operative period following LVAD implantation should be considered. Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.

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.

Transdermal wires for improved integration in vivo

Alternative engineering approaches have led the design of implants with controlled physical features to minimize adverse effects in biological tissues. Similar efforts have focused on optimizing the design features of percutaneous VAD drivelines with the aim to prevent infection, omitting however a thorough look on the implant-skin interactions that govern local tissue reactions. Here, we utilized an integrated approach for the biophysical modification of transdermal implants and their evaluation by chronic sheep implantation in comparison to the standard of care VAD drivelines. We developed a novel method for the transfer of breath topographical features on thin wires with modular size. We examined the impact of implant's diameter, surface topography, and chemistry on macroscopic, histological, and physical markers of inflammation, fibrosis, and mechanical adhesion. All implants demonstrated infection-free performance. The fibrotic response was enhanced by the increasing diameter of implants but not influenced by their surface properties. The implants of small diameter promoted mild inflammatory responses with improved mechanical adhesion and restricted epidermal downgrowth, in both silicone and polyurethane coated transdermal wires. On the contrary, the VAD drivelines with larger diameter triggered severe inflammatory reactions with frequent epidermal downgrowth. We validated these effects by quantifying the infiltration of macrophages and the level of vascularization in the fibrotic zone, highlighting the critical role of size reduction for the benign integration of transdermal implants with skin. This insight on how the biophysical properties of implants impact local tissue reactions could enable new solutions on the transdermal transmission of power, signal, and mass in a broad range of medical devices.

Infections in Patients With Left Ventricular Assist Devices: Current State and Future Perspectives

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment.

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%.

Outcomes of modular cable exchange in HeartMate 3 patients versus conventional driveline repair in HeartMate II patients

BACKGROUND

Driveline (DL) damages are a common difficulty among ventricular assist devices (VAD). Repairing the electrical fibers inside the DL on a running pump is hazardous and requires technical expertise, which is not easily available on site. A new feature of the HeartMate3 (Abbott, U.S.A.) LVAD is a modular driveline that allows an easy exchange of the DL cord. In this report we analyze our experiences with this feature.

METHODS

We performed a retrospective analysis of 302 patients who underwent either HeartMate II or HeartMate 3 implantation between February 2004 and September 2021. Patients were screened for driveline faults and need for exchange or repair of driveline or VAD exchange. Documented were baseline characteristics, reasons for DL or VAD exchange, and complications. Follow-up was three months after the procedure.

RESULTS

We present a cohort of 302 patients who underwent either HMII (n = 107;35.4%) or HM 3 (n = 195; 64.5%) implantation. Out of those, 40 patients (40/302; 13.2%) required driveline repair (DLRe) or exchange (DLEx). Out of 107 HMII patients, 9 showed severe DL damages (9/107; 8.4%). Six patients (6/9; 66.6%) underwent DLRe, two patients (2/6; 33.3%) required VAD exchange after DLRe, one patient (1/2;50%) experienced emergency VAD exchange after pump stop. The DLRe procedure in the other four patients (4/6; 66.6%) was successful. Due to damage to the internal driveline two patients (2/9; 22.2%) underwent emergency device exchange and one patient (1/9;11.1%) was listed for transplantation. 31 out 195 HM3 patients underwent exchange of the modular DL. In none of the cases, damages of the internal fibers were the reasons for the exchange. In 100% of the cases, damages of the external coating were the reason for DL exchange. In none of the cases, complications occurred after the exchange procedure.

CONCLUSIONS

Driveline damages are a habitual, recurrent complication in VAD patients. The exchange of the modular driveline cable of the HM3 is feasible and safe compared to the conventional DL repair in HMII patients. Risky repair attempts and surgical LVAD exchange due to major damages of the electrical fibers can be avoided successfully by the new feature of HM3 driveline.

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.

Nontuberculous Mycobacterial Infections Associated With Left Ventricular Assist Devices in 3 Patients

Durable left ventricular assist devices (LVADs) provide circulatory support in patients with end-stage heart failure; however, complications include infection of the driveline exit site. Nontuberculous mycobacterial infections are rare in patients with LVADs, but they should be considered in those who have undergone device exchanges and have bacterial infections with driveline exit-site discharge but no fever or leukocytosis. We reviewed the charts of patients who had an LVAD implanted at our institution from January 2009 through December 2019, to identify those with a device-related nontuberculous mycobacterial infection. Collected data included patient demographics, premorbid conditions, infection type, previous device complications, treatment, and outcomes. We identified infections in 3 patients (mean age, 41 yr): Mycobacterium abscessus in 2 and M. chimaera in 1. All had a HeartMate II device and had undergone device exchanges for pump thrombosis or for driveline fault or infections. All presented with driveline exit-site discharge without fever or leukocytosis. The mean time between initial device implantation and diagnosis of a nontuberculous mycobacterial infection was 55 months. All 3 patients were treated with antibiotics and underwent localized surgical débridement; one underwent an additional device exchange. The M. abscessus infections disseminated, and both patients died; the patient with M. chimaera infection continued to take suppressive antibiotics. Nontuberculous mycobacterial infections are associated with high morbidity and mortality rates, warranting prompt diagnosis and treatment.

Decreasing driveline infections in patients supported on ventricular assist devices: a care pathway approach

Background

Driveline infections (DLIs) are a common adverse event in patients on ventricular assist devices (VADs) with incidence ranging from 14% to 59%. DLIs have an impact on patients and the healthcare system with efforts to prevent DLIs being essential. Prior to our intervention, our program had no standard driveline management presurgery and postsurgery. The purpose of this Quality Improvement (QI) initiative was to reduce DLIs and related admissions among patients with VAD within the first year post implant.

Methods

In anticipation of the QI project, we undertook a review of the programs’ current driveline management procedures and completed a survey with patients with VAD to identify current barriers to proper driveline management. Retrospective data were collected for a pre-QI intervention baseline comparison group, which included adult patients implanted with a durable VAD between 1 January 2017 and 31 July 2018. A three-pronged care pathway (CP) was initiated among patients implanted during August 2018 to July 2019. The CP included standardised intraoperative, postoperative and predischarge teaching initiatives and tracking. Using statistical process control methods, DLIs and readmissions in the first year post implant were compared between patients in the CP group and non-CP patients. P-charts were used to detect special cause variation.

Results

A higher proportion of CP group patients developed a DLI in the first year after implant (52% vs 32%). None developed a DLI during the index admission, which differed from the non-CP group and met criteria for special cause variation. There was a downward trend in cumulative DLI-related readmissions among CP group patients (55% vs 67%). There was no association between CP compliance and development of DLIs within 1 year post implant.

Conclusion

The CP did not lead to a reduction in the incidence of DLIs but there was a decrease in the proportion of patients with DLIs during their index admission and those readmitted for DLIs within 1 year post implant. This suggests that the CP played a role in decreasing the impact of DLIs in this patient population. However, given the short time period of follow-up longer follow-up will be required to look for sustained effects.

Does infection predispose to thrombosis during long term ventricular assist device support?

BACKGROUND

Infections and thrombotic events remain life-threatening complications in patients with ventricular assist devices (VAD).

METHODS

We describe the relationship between both events in our cohort of patients (n=220) supported with the HeartWare VAD (HVAD). This is a retrospective analysis of patients undergoing HVAD implantation between July 2009 and March 2019 at the Freeman Hospital, Newcastle upon Tyne, United Kingdom.

RESULTS

Infection was the most common adverse event in HVAD patients, with 125 patients (56.8%) experiencing ≥ one infection (n=168, 0.33 event-per-person-year-EPPY), followed by pump thrombosis (PT) in 61 patients (27.7%, 0.16 EPPY). VAD-specific infections were the largest group of infections. Of the 125 patients who had an infection, 66 (53%) had a thrombotic event. Both thrombotic events and infections were related to the duration of support, though there was only limited evidence that infections predispose to thrombosis. Those with higher than median levels of CRP during the infection were more likely to have an ischaemic stroke (IS) (34.5% vs 16.7%, p=0.03), though not PT or a combined thrombotic event (CTE: first PT or IS). However, in multivariate analysis there was no significant effect of infection predisposing to CTE.

CONCLUSIONS

Infection and thrombotic events are significant adverse events related to the duration of support in patients receiving HVADs. Infections do not clearly predispose to thrombotic events.

Effect of Ventricular Assist Device Self-care Simulation-Based Mastery Learning on Driveline Exit Site Infections: A Pilot Study

BACKGROUND

Ventricular assist device simulation-based mastery learning (SBML) results in better patient and caregiver self-care skills compared with usual training.

OBJECTIVE

The aim of this study was to evaluate the effect of SBML on driveline exit site infections.

METHODS

We compared the probability of remaining infection free at 3 and 12 months between patients randomized to SBML or usual training.

RESULTS

The SBML-training group had no infections at 3 months and 2 infections at 12 months, yielding a Kaplan-Meier estimate of the probability of remaining infection free of 0.857 (95% confidence interval [CI], 0.692-1.00) at 12 months. The usual-training group had 6 infections at 3 months with no additional infections by 12 months. Kaplan-Meier estimates of remaining infection free at 3 and 12 months were 0.878 (95% CI, 0.758-1.00) and 0.748 (95% CI, 0.591-0.946), respectively. Time-to-infection distributions for SBML versus usual training showed a difference in 12-month infection rates of 0.109 (P = .07).

CONCLUSIONS

Ventricular assist device self-care SBML resulted in fewer 12-month infections.

Driveline Features as Risk Factor for Infection in Left Ventricular Assist Devices: Meta-Analysis and Experimental Tests

Background: Risk factors for driveline infection (DLI) in patients with left ventricular assist devices are multifactorial. The aim of this study was to analyze the correlation between mechanical driveline features and DLI occurrence.

Methods: A meta-analysis was conducted that included studies reporting DLI rates at 6 months after implantation of any of three contemporary devices (HVAD with Pellethane or Carbothane driveline, HeartMate II, and HeartMate 3). Further, outer driveline diameter measurements and ex-vivo experimental three-point bending and torsion tests were performed to compare the stiffness of the four different driveline types.

Results: 21 studies with 5,393 patients were included in the meta-analysis. The mean weighted DLI rates ranged from 7.2% (HeartMate II) to 11.9% (HeartMate 3). The HeartMate II driveline had a significantly lower maximal bending force (Load_max) (4.52 ± 0.19 N) compared to the Carbothane HVAD (8.50 ± 0.08 N), the HeartMate 3 (11.08 ± 0.3 N), and the Pellethane HVAD driveline (15.55 ± 0.14 N) (p < 0.001). The maximal torque (Torque_max) of the HeartMate II [41.44 (12.61) mNm] and the Carbothane HVAD driveline [46.06 (3.78) mNm] were significantly lower than Torque_max of the Pellethane HVAD [46.06 (3.78) mNm] and the HeartMate 3 [95.63 (26.60) mNm] driveline (p < 0.001). The driveline of the HeartMate 3 had the largest outer diameter [6.60 (0.58) mm]. A relationship between the mean weighted DLI rate and mechanical driveline features (Torque_max) was found, as the the HeartMate II driveline had the lowest Torque_max and lowest DLI rate, whereas the HeartMate 3 driveline had the highest Torque_max and highest DLI rate.

Conclusions: Device-specific mechanical driveline features are an additional modifiable risk factor for DLI and may influence clinical outcomes of LVAD patients.

Competing Risks to Transplant in Bridging with Continuous Flow Left Ventricular Assist Devices

BACKGROUND

Continuous flow left ventricular assist device(CF-LVAD) support is a mainstay in the hemodynamic management of patients with end-stage heart failure refractory to optimal medical therapy. In this report, we evaluated waitlist complications and competing outcomes for CF-LVAD patients compared to primary transplant candidates listed for orthotopic heart transplantation(OHT) at a single center.

METHODS

All patients listed for OHT between 2006-2020 at our institution were retrospectively reviewed(n=300 CF-LVAD; n=244 primary transplant). Kaplan-Meier methodology with log-rank testing was used to evaluate survival outcomes. Terminal outcomes of death, delisting, and transplant were assessed as competing risks and compared between groups using Gray's test. Multivariable Fine-Gray regression was used to identify predictors of transplantation.

RESULTS

One-year rates of transplant, delisting, and death were 48%, 8%, and 2%, respectively for CF-LVAD patients and 45%, 15%, and 9% for primary transplant(all P<0.001). Waitlist mortality at 5 years was 4% among CF-LVAD patients and 13% for primary transplants. All-cause mortality after listing was lower for CF-LVAD patients(P=0.017). There was no difference in post-transplant survival between groups(P=0.250). On multivariable Fine-Gray regression, stroke(P=0.017), respiratory failure(P=0.032), right ventricular failure(P=0.019), and driveline infection(P=0.050) were associated with decreased probability of transplantation. Post-transplant survival was not significantly worse for CF-LVAD patients who experienced device-related complications(P=0.901).

CONCLUSIONS

While device related-complications were significantly associated with decreased rates of transplant, CF-LVAD patients had excellent waitlist outcomes overall. In light of the 2018 allocation score change, the risk of complications should be taken into account when deciding whether to offer CF-LVAD as a bridge to transplant.

Ventricular Assist Device Driveline Infection and Development of Intracranial Hemorrhage: A Case Series

Durable left ventricular assist devices (LVAD) are frequently complicated by driveline infection. The objective of this case series was to examine whether an association exists between driveline infection and intracranial hemorrhage. This retrospective case series included patients at a single tertiary care hospital on durable LVAD support who developed intracranial hemorrhage. Physical examination data, vital signs, and laboratory markers of sepsis including blood cultures and imaging of driveline sites were reviewed. A total of nine patients were included in the case series. At the time of hemorrhagic event, five patients had active driveline infection, and five patients were found to be bacteremic. All bacteremic patients were found to have supratherapeutic INR at the time of presentation. Although five patients experienced subarachnoid hemorrhage, only one patient was found to have a cerebral aneurysm. This case series highlights a possible association between LVAD driveline infection and intracranial hemorrhage, and the need for further research to better understand the pathophysiology driving this association.

On the function of biosynthesized cellulose as barrier against bacterial colonization of VAD drivelines

Bacterial colonization of drivelines represents a major adverse event in the implantation of left ventricular assist devices (L-VADs) for the treatment of congestive heart failure. From the external driveline interface and through the skin breach, pathogens can ascend to the pump pocket, endangering the device function and the patient’s life. Surface Micro-Engineered Biosynthesized cellulose (BC) is an implantable biomaterial, which minimizes fibrotic tissue deposition and promotes healthy tissue regeneration. The topographic arrangement of cellulose fibers and the typical material porosity support its potential protective function against bacterial permeation; however, this application has not been tested in clinically relevant animal models. Here, a goat model was adopted to evaluate the barrier function of BC membranes. The external silicone mantle of commercial L-VAD drivelines was implanted percutaneously with an intervening layer of BC to separate them from the surrounding soft tissue. End-point evaluation at 6 and 12 weeks of two separate animal groups revealed the local bacterial colonization at the different interfaces in comparison with unprotected driveline mantle controls. The results demonstrate that the BC membranes established an effective barrier against the bacterial colonization of the outer driveline interface. The containment of pathogen infiltration, in combination with the known anti-fibrotic effect of BC, may promote a more efficient immune clearance upon driveline implantation and support the efficacy of local antibiotic treatments, therefore mitigating the risk connected to their percutaneous deployment.

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.

Systems of conductive skin for power transfer in clinical applications

The primary aim of this article is to review the clinical challenges related to the supply of power in implanted left ventricular assist devices (LVADs) by means of transcutaneous drivelines. In effect of that, we present the preventive measures and post-operative protocols that are regularly employed to address the leading problem of driveline infections. Due to the lack of reliable wireless solutions for power transfer in LVADs, the development of new driveline configurations remains at the forefront of different strategies that aim to power LVADs in a less destructive manner. To this end, skin damage and breach formation around transcutaneous LVAD drivelines represent key challenges before improving the current standard of care. For this reason, we assess recent strategies on the surface functionalization of LVAD drivelines, which aim to limit the incidence of driveline infection by directing the responses of the skin tissue. Moreover, we propose a class of power transfer systems that could leverage the ability of skin tissue to effectively heal short diameter wounds. In this direction, we employed a novel method to generate thin conductive wires of controllable surface topography with the potential to minimize skin disruption and eliminate the problem of driveline infections. Our initial results suggest the viability of the small diameter wires for the investigation of new power transfer systems for LVADs. Overall, this review uniquely compiles a diverse number of topics with the aim to instigate new research ventures on the design of power transfer systems for IMDs, and specifically LVADs.

The role of chronic suppressive antibiotics therapy in superficial drive line infection relapse of left ventricular assist devices: A retrospective cohort from a tertiary care center

INTRODUCTION

Drive line infections (DLIs) are common complications of left ventricular assist devices (LVADs). Data on use of suppression antibiotic therapy are limited.

METHODS

We performed a retrospective review of 451 patients who underwent LVAD placement from January 2009 to May 2015. First superficial DLIs were included for analysis. We examined factors associated with the use of chronic suppressive antibiotics (CSAs) therapy. Cox proportional hazards models were performed to identify factors associated with DLI relapse with the same organism as the initial DLI.

RESULTS

A total of 69 patients developed a superficial DLI within a median of 195 (interquartile range [IQR] 98-348) days of LVAD insertion. The median age was 57 years, 87% were males, and 74% were White. Gram positive bacteria caused 61% of infections, with Staphylococcus aureus being the most common (35%). Forty-three (62%) patients received suppressive antibiotic therapy. Relapse DLI occurred in 29 (42%) patients. Independent risk factors for relapse infection in multivariable analysis were sepsis (aHR 5.94 [CI 1.42-24.92]), and MRSA DLI (aHR 4.19 [CI 1.37-12.79]). There was no difference in the proportion of patients with relapse among those who were treated with antibiotic suppression therapy versus not (44% vs. 38%, p = 0.64), although relapse occurred at a later time in those who received suppression (185 vs. 69 days, p < 0.01).

CONCLUSION

CSA therapy was associated with delayed time to DLI relapse but no significant difference in the proportion of patients with relapse. A prospective study is needed to examine the effect of suppression on relapse rates.

The Predictive Value of Changes in Body Mass Index for the Incidence of Device-Specific Infections in Patients With Implantable Left Ventricular Assist Devices

BACKGROUND

Implantable left ventricular assist devices (LVAD) have improved quality of life and survival in patients with advanced heart failure. However, LVAD-specific infections and predicting which patients will develop infections remain challenging. This study investigated whether changes in body mass index (BMI) during hospitalization following LVAD implantation are associated with LVAD-specific infections within 1 year of implantation.Methods and Results:Patients (n=135) undergoing LVAD implantation were retrospectively divided into 2 groups based on changes in BMI from LVAD implantation to discharge: those with and without decreases in BMI. Each group was further subdivided according to baseline albumin concentrations (high [>3.7 g/dL] and low [≤3.7 g/dL]). Twenty patients developed LVAD-specific infections within 1 year. Receiver operating characteristic curve analysis resulted in a ∆BMI cut-off of less than -0.128 kg/m². In multivariate analysis, younger patients and those with decreases in BMI had significantly higher rates of LVAD-specific infection (P=0.010 and P=0.035, respectively). LVAD-specific infection rates were significantly higher for patients with low albumin and decreases in BMI than for patients with low albumin but no decrease in BMI.

CONCLUSIONS

Decreases in BMI during hospitalization after LVAD implantation and younger age were independently associated with LVAD-specific infection within 1 year. Strict patient management may be needed to avoid decreases in BMI during hospitalization after LVAD implantation, particularly in patients with low baseline albumin concentrations.

Driveline exit-site care protocols in patients with left ventricular assist devices: a systematic review

 

OBJECTIVES

Driveline infections continue to be a significant complication following left ventricular assist device (LVAD) implantation. Driveline exit-site care is crucial for the prevention of infections; however, there are no uniform guidelines. The goal of this study was to provide an overview of the currently published driveline exit-site care protocols in patients with LVAD.

METHODS

A systematic literature review was performed. Studies before 15 December 2020 were included if the number of driveline infections was a primary outcome and the driveline exit-site care protocol was explained.

RESULTS

Eleven articles were included in the systematic review, including 1602 patients with LVADs. The median of the frequency of driveline infections in the articles was 13.8% with a range of 0–52.6%. There was a marked variability in the methods of care of driveline exit sites, without a standardized driveline dressing technique in patients with LVADs. The frequency of driveline infections was 6–7.5% in studies using a dressing kit that included chlorhexidine, a silver-based dressing and an anchoring device. Furthermore, there was variability in the anchoring devices and the frequency of dressing changes, which varied from daily to weekly. No specific anchoring device or change frequency was found to be superior.

CONCLUSIONS

Based on this systematic review, driveline exit care protocols that included chlorhexidine, a silver-based dressing, the use of an anchoring device and dressing kits might be best in reducing driveline infection rates. However, prospective studies with larger cohorts are needed to establish the optimal protocol for driveline exit-site care.

The outcome of patients with peripartum cardiomyopathy and consecutive implantation of a left ventricular assist device

OBJECTIVES

Peripartum cardiomyopathy (PPCM) is a form of systolic heart failure occurring toward the end of pregnancy or in the period after delivery. Lack of myocardial recovery or therapy-refractory cardiogenic shock are rare complications and left ventricular assist device (LVAD) systems might be used as a life-saving option. The aim of this study was to investigate outcomes of PPCM patients supported with LVAD, registered in the European Registry for Patients with Mechanical Circulatory Support (EUROMACS).

METHODS

All patients registered in EUROMACS with a primary diagnosis of PPCM were included in this study. Demographic, preoperative, intraoperative, postoperative, and follow-up data were collected and patients analysed concerning their outcome after initiation of LVAD therapy.

RESULTS

Between May 2011 and September 2018, 16 patients with PPCM and consecutive LVAD implantation were enrolled into EUROMACS. The median age of the patient population was 31 (26;41) years with a mean left ventricular ejection fraction (LV-EF) of 15% ± 6%. In-hospital mortality after LVAD implantation was 6% (n = 1). One-year mortality accounted for 13% (n = 2). Six patients (40%) were transplanted with a median support time of 769 (193;1529) days. Weaning of LVAD support due to ventricular recovery was feasible in 3 (20%) patients.

CONCLUSION

In patients with severe PPCM, LVAD therapy is associated with considerably low in-hospital mortality, potentially allowing bridging to heart transplantation, or left ventricular recovery. Therefore, durable mechanical support should be considered as a treatment option in this, by nature, young and often otherwise healthy patient population.

Contemporary Management Strategies in VAD Infection

PURPOSE OF REVIEW

The use of durable ventricular assist devices (VAD) to manage end-stage heart failure is increasing, but infection remains a leading cause of morbidity and mortality among patients with VAD. In this review, we synthesize recent data pertaining to the epidemiology, diagnosis, management, and prevention of VAD infections, discuss transplant considerations in patients with VAD infections, and highlight remaining knowledge gaps. We also present a conceptual framework for treating clinicians to approach these infections that draws on the same principles that guide the treatment of analogous infections that occur in patients without VAD.

RECENT FINDINGS

Despite advances in device design, surgical techniques, and preventative interventions, more than a third of VAD recipients still experience infection as an adverse outcome. Positron emission tomography has emerged as a promising modality for identifying and characterizing VAD infections. High-quality data to support many of the routine therapeutic strategies currently used for VAD infections-including suppressive antibiotic therapy, surgical debridement/device exchange, and novel antimicrobials for emerging multidrug-resistant organisms-remain limited. Although pre-transplant VAD infection may impact some early transplant outcomes, transplantation remains a viable option for patients with most types of VAD infection. Standardized definitions of VAD infection applied to large registry datasets have yielded key insights into the epidemiology of infectious complications among VAD recipients, but more prospective studies are needed to evaluate the effectiveness of existing and novel diagnostic and therapeutic strategies.

Short-term Retention of Patient and Caregiver Ventricular Assist Device Self-care Skills after Simulation-based Mastery Learning

Background

We developed a simulation-based mastery learning (SBML) curriculum that boosted self-care skills for patients with a ventricular assist device (VAD). In this study, we evaluated short-term skills retention.

Methods

We assessed skill retention among patients and caregivers who participated in VAD self-care SBML at a tertiary care center. We compared discharge skills tests (immediately after completing SBML) to 1- and 3-month follow-up tests to assess skill retention.

Results

Fifteen patients and 15 caregivers completed discharge and follow-up testing. Skills were largely retained at 1- and 3-months.

Conclusions

SBML results in short-term retention of VAD self-care skills.

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.

The Joint Association of Septicemia and Cerebrovascular Diseases with In-Hospital MortalityAmong Patients with Left Ventricular Assist Device in the United States

OBJECTIVES

Left ventricular assist device (LVAD) is associated with complications such as cerebrovascular diseases (CEVD) as well as septicemia which is often preventable. With their use increasing in the U.S., identifying patients with LVAD who are at high risk for short-term mortality is essential for targeted effective patient management strategies to prevent adverse outcomes. We investigated the individual and joint association of CEVD and septicemia with the risk of in-hospital mortality in patients with LVAD in the U.S.

MATERIALS AND METHODS

We used data from the National Inpatient Sample from 2004 to 2015 to identify patients ≥18 years of age who underwent LVAD implantation by means of International Classification of Disease, 9th Revision, codes. Multivariable hierarchical negative binomial regression models were used to estimate risk ratios (RR) and 95% confidence intervals (CI) for in-hospital mortality by CEVD-septicemia status.

RESULTS

The mean age of the 4638 patients was 56 years, and 23% of them were women. Approximately 13% of patients had septicemia; 7% had CEVD and 2% had both conditions. In models adjusted for demographic, lifestyle/behavior factors and comorbid conditions, the risk of in-hospital mortality was almost threefold higher among patients with septicemia alone (RR=2.84, CI:2.24-3.60); two-and-half fold higher among patients with CEVD alone (RR=2.53, CI:1.85-3.48); and almost fourfold among patients with both septicemia and CEVD (RR=3.76, CI: 2.38-5.94, P_interaction = <0.001) CONCLUSION: The presence of both septicemia and CEVD was associated with a substantially higher risk of in-hospital mortality among LVAD patients when compared to septicemia or CEVD alone.

Association of cigarette smoking and adverse events in left ventricular assist device patients

INTRODUCTION

Adverse events (AEs) associated with left ventricular assist devices (LVADs) cause significant morbidity and mortality. Little is known about patient-specific factors that contribute to rates of AEs. The purpose of this study was to assess the association of cigarette smoking history and AEs following LVAD implantation.

METHODS

This study was a single-center, observational examination of 355 consecutive patients who underwent continuous-flow LVAD implantation from May 1, 2008 to July 1, 2018. Based on self-report, 348 patients with available data were categorized as never, former, or current smokers. Pre-LVAD implantation baseline characteristics were obtained, and summary characteristics were calculated. Hospitalizations for gastrointestinal bleeds, driveline infections, strokes, pump thromboses, and acute heart failure were evaluated. The Cox proportional hazard model was used to estimate the association of smoking and AE-related hospital admissions. The cumulative incidence competing risk method was used for survival analysis.

RESULTS

Current (8.22%, p 0.006) and former (4.75%, p 0.026) smokers had a greater proportion of admissions for pump thrombosis compared to never smokers (2.22%). Former smoking was associated with admission for driveline infection (HR 2.43, CI 1.08-5.46, p 0.03) on multivariate analysis. There were no significant associations between smoking and the other AEs of interest. There was no difference in survival among the three groups.

CONCLUSIONS

Smokers had a higher proportion of admissions for pump thrombosis compared to never smokers, and former smoking was associated with admission for driveline infections in patients with LVADs.

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.

Anticoagulant treatment and bleeding complications in patients with left ventricular assist devices

INTRODUCTION

The treatment options for advanced heart failure patients drastically changed with the introduction of left ventricular assist devices (LVADs), either as bridge to transplant or as destination therapy for patients ineligible for transplant. Despite major benefits in terms of survival, functional status and quality of life, managing patients with LVADs comes with several challenges. The most significant challenge is balancing between the risks of thrombotic and bleeding complications.

AREAS COVERED

The present review describes the pathophysiological mechanisms explaining the alterations in the hemostatic profile of LVAD patients, and summarizes current evidence to guide clinical decision making with regard to anticoagulant treatment and management of bleeding complications.

EXPERT OPINION

LVAD patients require life-long anticoagulant therapy to reduce the risk of pump thrombosis. However, exposing LVAD patients to anticoagulant therapy, in combination with common acquired coagulopathies after LVAD implantation such as acquired von Willebrand syndrome, comes with high risks of bleeding. There is a need for randomized controlled trials in LVAD patients to determine the optimal antithrombotic regimen and find the most effective balance between thrombotic and bleeding complications. In addition, strategies to specifically target the acquired von Willebrand syndrome and its associated angiodysplasias need to be evaluated in the LVAD population.

Left ventricular assist device-associated infections: incidence and risk factors

Background

Left ventricular assist device (LVAD)-associated infections are major complications that can lead to critical outcomes. The aims of this study were to assess the incidence of and to determine the risk factors for LVAD-associated infections.

Methods

We included all consecutive patients undergoing LVAD implantation between January 1, 2010, and January 1, 2019, in a single institution. Infection-related data were retrospectively collected by review of patient's medical files. LVAD-associated infections were classified into three categories: percutaneous driveline infections, pocket infections and pump and/or cannula infections.

Results

We enrolled 72 patients. Twenty-one (29.2%) patients presented a total of 32 LVAD-associated infections. Eight (38.1%) patients had more than one infection. Five (62.5%) pocket infections and one (50.0%) pump and/or cannula infection were preceded by a driveline infection. The median delay between the operation and LVAD-associated infection was 6.5 (1.4-12.4) months. The probability of having a LVAD-associated infection at one year after receiving an implant was 26.6% (95% CI: 17.5-40.5%). Percutaneous driveline infections represented 68.7% of all LVAD-associated infections. Staphylococcus aureus and coagulase-negative staphylococci were the predominant bacteria in LVAD-associated infections (53.1% and 15.6%, respectively). Hospital length of stay (sdHR =1.22 per 10 days; P=0.001) and postoperative hemodialysis (sdHR =0.17; P=0.004) were statistically associated with infection. Colonization with multidrug-resistant bacteria was more frequent in patients with LVAD-associated infections than in others patients (42.9% vs. 15.7%; P=0.013).

Conclusions

LVAD-associated infections remain an important complication and are mostly represented by percutaneous driveline infections. Gram-positive cocci are the main pathogens isolated in microbiological samples. Patients with LVAD-associated infections are more frequently colonized with multidrug-resistant bacteria.

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.

Preliminary Results of a New Treatment Strategy for Relapsed Left Ventricular Assist Device-Specific Infections

BACKGROUND

Relapsed ventricular assist device-specific infections are associated with high morbidity, mortality, and hospital costs. A new combination of cold atmospheric plasma and special dressing technique with negative pressure wound therapy with an additional underlay of carbon cloth and hypochlorite rinsing solutions has been developed and reported in this study.

METHODS

Between January 2016 and January 2018, 9 patients with relapsed infected driveline or pump pocket infection were treated with this new combined strategy. The primary endpoint was complete wound healing without recurrence of infection, defined as the presence at the same site within the first year after treatment. The secondary endpoint was control of infection, defined as a marked reduction of the infected area.

RESULTS

After a median treatment time of 3 weeks, an immediate response was observed in all patients, and complete healing was achieved in 6 patients. Five patients met the primary endpoint, and infection did not recur after a median follow-up of 17.5 (range, 12.1 to 21.8) months. One patient underwent heart transplantation 6 months after successful wound treatment (complete wound healing). The remaining 3 patients were discharged with controlled infection. After a median follow-up of 5.7 months, 1 destination therapy patient died at home, and 2 patients underwent urgent heart transplantation because of recurrence of infection caused by Pseudomonas aeruginosa. Side effects were not observed.

CONCLUSIONS

The new combination treatment offers a promising option for patients with ventricular assist device-relapsed infection. Despite this, further studies are warranted to confirm those encouraging preliminary results.

Driveline Sepsis Presenting As Gout

In patients with a history of gout, there could be a delay in diagnosis of a septic joint, which increases morbidity and mortality. The literature reports rare instances of coexistent gout and septic arthritis. We present a 64-year-old male with non-ischemic cardiomyopathy, supported by a HeartWare ventricular assist device, who developed a methicillin-resistant Staphylococcus aureus (MRSA) driveline infection four months after device implant. He achieved suppression with minocycline 100 mg by mouth twice a day for five months before presenting to the emergency room with symptoms of gout. Joint aspirate was consistent with a diagnosis of MRSA as well as gout. The patient presented with typical symptoms of a percutaneous driveline infection: soreness at the exit site, erythema, and thick, purulent drainage. Wound culture of the driveline confirmed MRSA and guided antibiotic treatment. His presentation was unusual in that sepsis was identified only after he presented with septic arthritis, which led to the collection of blood cultures. He had no fever, chills, nausea, vomiting, or hypotension. This case illustrates that unresolving gout symptoms after one treatment, in a patient with a known driveline infection, should be further evaluated for possible sepsis and septic arthritis. The patient’s unusual presentation of sepsis caused difficulties in diagnosis and management. To our knowledge, this is the first reported case of a driveline infection seeding a joint and causing septic arthritis.

Causes and predictors of early mortality in patients treated with left ventricular assist device implantation in the European Registry of Mechanical Circulatory Support (EUROMACS)

PURPOSE

The aim of the study was to analyze early mortality after continuous-flow left ventricular assist device (LVAD) implantation which remains high.

METHODS

We analyzed consecutive (n = 2689) patients from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) undergoing continuous-flow LVAD implantation. The primary outcome was early (< 90 days) mortality. Secondary outcomes were differential causes of early post-operative death following LVAD implantation.

RESULTS

Univariable and multivariable analysis as well as regression analysis were used to examine determinants and differential causes of early (< 90 days) mortality after LVAD implantation. During the first 90 days, 2160 (80%) patients were alive with ongoing LVAD support, 40(2%) patients underwent heart transplantation, and 487(18%) deceased. The main causes of early death were MOF (36%), sepsis (28%), cardiopulmonary failure (CPF; 10%), CVA (9%), and right-sided heart failure (RHF, 8%). Furthermore, MOF and sepsis are 70% of causes of death in the first week. Independent clinical predictors of early death were age, female sex, INTERMACS profile 1 to 3, and ECMO. Laboratory predictors included elevated serum creatinine, total bilirubin, lactate, and low hemoglobin. Furthermore, hemodynamic predictors included elevated RA-to-PCWP ratio, pulmonary vascular resistance, and low systemic vascular resistance. Longer total implantation time was also independent predictor of early mortality. A simple model of 12 variables predicts early mortality following LVAD implantation with a good discriminative power with area under the curve of 0.75.

CONCLUSIONS

In the EUROMACS registry, approximately one out of five patients die within 90 days after LVAD implantation. Early mortality is primarily dominated by multiorgan failure followed by sepsis. A simple model identifies important parameters which are associated with early mortality following LVAD implantation.

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.

Patient, Caregiver, and Clinician Perceptions of Ventricular Assist Device Self-care Education Inform the Development of a Simulation-based Mastery Learning Curriculum

BACKGROUND

Patients who undergo ventricular assist device (VAD) implantation and their caregivers must rapidly learn a significant amount of self-care skills and knowledge.

OBJECTIVE

The aim of this study was to explore patient, caregiver, VAD coordinator, and physician perspectives and perceptions of existing VAD self-care training to inform development of a simulation-based mastery learning (SBML) curriculum to teach patients and caregivers VAD self-care skills and knowledge.

METHODS

We conducted semistructured, in-person interviews with patients with a VAD, their caregivers, VAD coordinators, and physicians (cardiac surgeons, an infectious disease physician, and advanced heart failure cardiologists). We used a 2-cycle team-based iterative inductive approach to coding and analysis.

RESULTS

We interviewed 16 patients, 12 caregivers, 7 VAD coordinators, and 11 physicians. Seven major themes were derived from the interviews including (1) identification of critical curricular content, (2) need for standardization and assessment, (3) training modalities, (4) benefits of repetition, (5) piercing it all together, (6) need for refresher training, and (7) provision of training before implant.

CONCLUSIONS

Findings from this study suggest that SBML is a natural fit for the high-risk tasks needed to save VAD self-care. The 7 unique training-related themes derived from the qualitative data informed the design and development of a VAD SBML self-care curriculum.

Sequential Pattern Mining of Longitudinal Adverse Events After Left Ventricular Assist Device Implant

Left ventricular assist devices (LVADs) are an increasingly common therapy for patients with advanced heart failure. However, implantation of the LVAD increases the risk of stroke, infection, bleeding, and other serious adverse events (AEs). Most post-LVAD AEs studies have focused on individual AEs in isolation, neglecting the possible interrelation, or causality between AEs. This study is the first to conduct an exploratory analysis to discover common sequential chains of AEs following LVAD implantation that are correlated with important clinical outcomes. This analysis was derived from 58,575 recorded AEs for 13,192 patients in International Registry for Mechanical Circulatory Support (INTERMACS) who received a continuous-flow LVAD between 2006 and 2015. The pattern mining procedure involved three main steps: (1) creating a bank of AE sequences by converting the AEs for each patient into a single, chronologically sequenced record, (2) grouping patients with similar AE sequences using hierarchical clustering, and (3) extracting temporal chains of AEs for each group of patients using Markov modeling. The mined results indicate the existence of seven groups of sequential chains of AEs, characterized by common types of AEs that occurred in a unique order. The groups were identified as: GRP1: Recurrent bleeding, GRP2: Trajectory of device malfunction & explant, GRP3: Infection, GRP4: Trajectories to transplant, GRP5: Cardiac arrhythmia, GRP6: Trajectory of neurological dysfunction & death, and GRP7: Trajectory of respiratory failure, renal dysfunction & death. These patterns of sequential post-LVAD AEs disclose potential interdependence between AEs and may aid prediction, and prevention, of subsequent AEs in future studies.

18F-FDG PET/CT in Left-Ventricular Assist Device Infection: Initial Results Supporting the Usefulness of Image-Guided Therapy

Accurate definition of the extent and severity of left-ventricular assist device (LVAD) infection may facilitate therapeutic decision making and targeted surgical intervention. Here, we explore the value of ¹⁸F-FDG PET/CT for guidance of patient management. Methods: Fifty-seven LVAD-carrying patients received 85 whole-body ¹⁸F-FDG PET/CT scans for the work-up of device infection. Clinical follow-up was obtained for up to 2 y. Results: PET/CT showed various patterns of infectious involvement of the 4 LVAD components: driveline entry point (77% of patients), subcutaneous driveline path (87%), pump pocket (49%), and outflow tract (58%). Driveline smears revealed Staphylococcus or Pseudomonas strains as the underlying pathogen in most cases (48 and 34%, respectively). At receiver-operating-characteristic analysis, an ¹⁸F-FDG SUV of more than 2.5 was most accurate to identify smear-positive driveline infection. Infection of 3 or all 4 LVAD components showed a trend toward lower survival than did infection of 2 or fewer components (P = 0.089), whereas involvement of thoracic lymph nodes was significantly associated with an adverse outcome (P = 0.001 for nodal SUV above vs. below median). Finally, patients who underwent early surgical revision within 3 mo after PET/CT (n = 21) required significantly less inpatient hospital care during follow-up than did those receiving delayed surgical revision (n = 11; P < 0.05). Conclusion: Whole-body ¹⁸F-FDG PET/CT identifies the extent of LVAD infection and predicts adverse outcome. Initial experience suggests that early image-guided surgical intervention may facilitate a less complicated subsequent course.

Left Ventricular Assist Devices 101: Shared Care for General Cardiologists and Primary Care

Ambulatory patients with a left ventricular assist device (LVAD) are increasing in number, and so is their life expectancy. Thus, there is an increasing need for care of these patients by non-LVAD specialists, such as providers in the emergency department, urgent care centers, community-based hospitals, outpatient clinics, etc. Non-LVAD specialists will increasingly come across LVAD patients and should be equipped with the knowledge and skills to provide initial assessment and management for these complex patients. These encounters may be for LVAD-related or unrelated issues. However, there are limited data and guidelines to assist non-LVAD specialists in caring for these complex patients. The aim of our review, targeting primary care providers (both inpatient and outpatient), general cardiologists, and other providers is to describe the current status of durable LVAD therapy in adults, patient selection, management strategies, complications and to summarize current outcome data.