Left Ventricular Assist Device Infections: A Systematic Review

Clinical and cost-effectiveness of left ventricular assist devices as destination therapy for advanced heart failure: systematic review and economic evaluation

Background

Selected patients with advanced heart failure ineligible for heart transplantation could benefit from left ventricular assist device therapy as 'destination therapy'. There is evidence of the efficacy of destination therapy; however, it is not currently commissioned within the United Kingdom National Health Service due to the lack of economic evidence.

Objective

What is the clinical and cost-effectiveness of a left ventricular assist device compared to medical management for patients with advanced heart failure ineligible for heart transplantation (destination therapy)?

Methods

A systematic review of evidence on the clinical and cost-effectiveness of left ventricular assist devices as destination therapy was undertaken including, where feasible, a network meta-analysis to provide an indirect estimate of the relative effectiveness of currently available left ventricular assist devices compared to medical management. For the systematic reviews, data sources searched (up to 11 January 2022) were Cochrane CENTRAL, MEDLINE and EMBASE via Ovid for primary studies, and Epistemonikos and Cochrane Database of Systematic Reviews for relevant systematic reviews. Trial registers were also searched, along with data and reports from intervention-specific registries. Economic studies were identified in EconLit, CEA registry and the NHS Economic Evaluation Database (NHS EED). The searches were supplemented by checking reference lists of included studies. An economic model (Markov) was developed to estimate the cost-effectiveness of left ventricular assist devices compared to medical management from the United Kingdom National Health Service/personal social service perspective. Deterministic and probabilistic sensitivity analyses were conducted to explore uncertainties. Where possible, all analyses focused on the only currently available left ventricular assist device (HeartMate 3TM, Abbott, Chicago, IL, USA) in the United Kingdom.

Results

The clinical effectiveness review included 134 studies (240 articles). There were no studies directly comparing HeartMate 3 and medical management (a randomised trial is ongoing). The currently available left ventricular assist device improves patient survival and reduces stroke rates and complications compared to earlier devices and relative to medical management. For example, survival at 24 months is 77% with the HeartMate 3 device compared to 59% with the HeartMate II (MOMENTUM 3 trial). An indirect comparison demonstrated a reduction in mortality compared to medical management [relative risk of death 0.25 (95% confidence interval 0.13 to 0.47); 24 months; this study]. The cost-effectiveness review included 5 cost analyses and 14 economic evaluations covering different generations of devices and with different perspectives. The reported incremental costs per quality-adjusted life-year gained compared to medical management were lower for later generations of devices [as low as £46,207 (2019 prices; United Kingdom perspective; time horizon at least 5 years)]. The economic evaluation used different approaches to obtain the relative effects of current left ventricular assist devices compared to medical management from the United Kingdom National Health Service/personal social service perspective. All gave similar incremental cost-effectiveness ratios of £53,496-58,244 per quality-adjusted life-year gained - lifetime horizon. Model outputs were sensitive to parameter estimates relating to medical management. The findings did not materially differ on exploratory subgroup analyses based on the severity of heart failure.

Limitations

There was no direct evidence comparing the clinical effectiveness of HeartMate 3 to medical management. Indirect comparisons made were based on limited data from heterogeneous studies regarding the severity of heart failure (Interagency Registry for Mechanically Assisted Circulatory Support score distribution) and possible for survival only. Furthermore, the cost of medical management of advanced heart failure in the United Kingdom is not clear.

Conclusions

Using cost-effectiveness criteria applied in the United Kingdom, left ventricular assist devices compared to medical management for patients with advanced heart failure ineligible for heart transplant may not be cost-effective. When available, data from the ongoing evaluation of HeartMate 3 compared to medical management can be used to update cost-effectiveness estimates. An audit of the costs of medical management in the United Kingdom is required to further decrease uncertainty in the economic evaluation.

Study registration

This study is registered as PROSPERO CRD42020158987.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR128996) and is published in full in Health Technology Assessment; Vol. 28, No. 38. See the NIHR Funding and Awards website for further award information.

Mechanical Characterization of Anchoring Devices for the Prevention of Driveline Infection in Left Ventricular Assist Device Patients

Driveline infection (DLI) is associated with increased mortality and morbidity in left ventricular assist device (LVAD) patients. Because trauma to the driveline exit-site (DLES) is a risk factor for DLI, adhesive anchoring devices are used to immobilize the DL. In this study, commonly used products (identified through literature review and contact with nine international VAD implantation centers) were mechanically characterized to evaluate their effectiveness in preventing DLES trauma. Eight devices were tested in an in vitro abdominal model of the DLES, where a tensile force (10 N) was applied to a HeartMate 3 DL, whereas the resulting force ( FTotal ) on the DLES was recorded using a three-axis load cell. Four devices (CathGrip: FTotal = 2.1 ± 0.4 N, Secutape: FTotal = 2.6 ± 0.3 N, Hollister: FTotal = 2.7 ± 0.5 N, Tubimed: FTotal = 2.9 ± 0.2 N) were significantly ( p < 0.05) better at preventing tensile forces at the DLES compared to the other four devices (Main-Lock: FTotal = 3.7 [0.7] N, Secutape sensitive: FTotal = 3.9 ± 0.4 N, Foley Anchor: FTotal = 4.3 ± 0.5 N, Grip-Lok: FTotal = 5.4 ± 0.8 N). Immobilization of the DL with each anchoring device resulted in lower tensile force on the DLES than without an anchor ( FTotal = 8.2 ± 0.3 N). In conclusion, the appropriate selection of anchoring devices plays a critical role in reducing the risk of DLI, whereas the CathGrip, Secutape, Hollister, or Tubimed were superior in preventing trauma to the DLES in this study.

Plastic Surgery Involvement With Surgical Management of Infected Ventricular Assist Devices Decreased Lifetime Return to Operating Room and 90-Day Infectious Complications

BACKGROUND

The use of left ventricular assist devices (LVADs) for patients with end-stage cardiac failure awaiting heart transplantation has become increasingly common. However, ventricular assist device-related infections remain a major problem complicating their long-term use. Retrospective review has previously shown a decrease in lifetime return to operating room (RTOR) with no change in 90-day complications when a muscle or omental flap is used for coverage after washout for infection. We wished to determine if early plastic surgery intervention led to a decreased length of stay for these patients.

METHODS

Patients with LVAD readmitted for LVAD infection at a single institution from 2008 to 2021 were identified using a preexisting database. Patients were followed retrospectively for an average of 3.2 years. Patient demographics, preoperative diagnosis/disease state, type of ventricular assist device inserted, postoperative day of ventricular assist device infection onset, definitive device coverage, timing of coverage procedure after the initial washout for infection, type of flap used for coverage, 90-day complications after definitive coverage, and lifetime return to operating room for infection were reviewed. Comparison analysis with χ2 and analysis of variance testing was used to analyze outcomes.

RESULTS

Of 568 patients admitted with an LVAD infection, 104 underwent operative debridement and closure by plastic and reconstructive surgery (PRS) or cardiothoracic surgery (CTS). Fifty-three underwent PRS closure, and 51 underwent CTS closure. There was an increased incidence of diabetes among the PRS group (P < 0.001); otherwise, there was no difference in baseline characteristics. There was increased RTOR over a lifetime with CTS closure compared with PRS (P = 0.03) and increased 90-day risk of infection (P = 0.007). Patients with PRS closure had an increased risk of postoperative hematoma (P = 046). Plastic and reconstructive surgery was typically consulted on hospital day 10. Both PRS and CTS closure patients were discharged on postoperative day 7, on average (P = 0.542).

CONCLUSIONS

Plastic surgery involvement with surgical decision making and closure of infected LVAD devices has a decrease in lifetime RTOR and decreased 90-day complications related to infections. There may be a benefit to earlier PRS consultation for coverage assessment.

Left ventricular assist device-associated driveline infections as a specific form of complicated skin and soft tissue infection/acute bacterial skin and skin structure infection - issues and therapeutic options

PURPOSE OF REVIEW

This review comments on the current guidelines for the treatment of wound infections under definition of acute bacterial skin and skin structure infections (ABSSSI). However, wound infections around a catheter, such as driveline infections of a left ventricular assist device (LVAD) are not specifically listed under this definition in any of the existing guidelines.

RECENT FINDINGS

Definitions and classification of LVAD infections may vary across countries, and the existing guidelines and recommendations may not be equally interpreted among physicians, making it unclear if these infections can be considered as ABSSSI. Consequently, the use of certain antibiotics that are approved for ABSSSI may be considered as 'off-label' for LVAD infections, leading to rejection of reimbursement applications in some countries, affecting treatment strategies, and hence, patients' outcomes. However, we believe driveline exit site infections related to LVAD can be included within the ABSSSI definition.

SUMMARY

We argue that driveline infections meet the criteria for ABSSSI which would enlarge the 'on-label' antibiotic armamentarium for treating these severe infections, thereby improving the patients' quality of life.

Artificial intelligence-based analysis of body composition predicts outcome in patients receiving long-term mechanical circulatory support

BACKGROUND

Obesity is a known cardiovascular risk factor and associated with higher postoperative complication rates in patients undergoing cardiac surgery. In heart failure (HF), conflicting evidence in terms of survival has been reported, whereas sarcopenia is associated with poor prognosis. An increasing number of HF patients require left ventricular assist device (LVAD) implantations. The postoperative mortality has improved in recent years but is still relatively high. The impact of body composition on outcome in this population remains unclear. The aim of this investigation was to examine the preoperative computed tomography (CT) body composition as a predictor of the postoperative outcome in advanced HF patients, who receive LVAD implantations.

METHODS

Preoperative CT scans of 137 patients who received LVADs between 2015 and 2020 were retrospectively analysed using an artificial intelligence (AI)-powered automated software tool based on a convolutional neural network, U-net, developed for image segmentation (Visage Version 7.1, Visage Imaging GmbH, Berlin, Germany). Assessment of body composition included visceral and subcutaneous adipose tissue areas (VAT and SAT), psoas and total abdominal muscle areas and sarcopenia (defined by lumbar skeletal muscle indexes). The body composition parameters were correlated with postoperative major complication rates, survival and postoperative 6-min walk distance (6MWD) and quality of life (QoL).

RESULTS

The mean age of patients was 58.21 ± 11.9 years; 122 (89.1%) were male. Most patients had severe HF requiring inotropes (Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS] profile I-III, 71.9%) secondary to coronary artery diseases or dilated cardiomyopathy (96.4%). Forty-four (32.1%) patients were obese (body mass index ≥ 30 kg/m2 ), 96 (70.1%) were sarcopene and 19 (13.9%) were sarcopene obese. Adipose tissue was associated with a significantly higher risk of postoperative infections (VAT 172.23 cm2 [54.96, 288.32 cm2 ] vs. 124.04 cm2 [56.57, 186.25 cm2 ], P = 0.022) and in-hospital mortality (VAT 168.11 cm2 [134.19, 285.27 cm2 ] vs. 135.42 cm2 [49.44, 227.91 cm2 ], P = 0.033; SAT 227.28 cm2 [139.38, 304.35 cm2 ] vs. 173.81 cm2 [97.65, 254.16 cm2 ], P = 0.009). Obese patients showed no improvement of 6MWD and QoL within 6 months postoperatively (obese: +0.94 ± 161.44 months, P = 0.982; non-obese: +166.90 ± 139.00 months, P < 0.000; obese: +0.088 ± 0.421, P = 0.376; non-obese: +0.199 ± 0.324, P = 0.002, respectively). Sarcopenia did not influence the postoperative outcome and survival within 1 year after LVAD implantation.

CONCLUSIONS

Preoperative AI-based CT body composition identifies patients with poor outcome after LVAD implantation. Greater adipose tissue areas are associated with an increased risk for postoperative infections, in-hospital mortality and impaired 6MWD and QoL within 6 months postoperatively.

Pre-Implant Immune Status is Associated with Infection Risk After Left Ventricular Assist Device Implantation

Purpose

Infection is the most common complication after left ventricular assist device (LVAD) implantation. The immune status of LVAD patients is relevant for the incidence and severity of infection, but it is unknown if there is a predisposing immune status prior to LVAD implantation that contributes to an increased risk for infection in the post-implant period. We analyzed the pre-LVAD immune status in patients with infection within 3 months after LVAD implantation in comparison to infection-free patients.

Patients and Methods

Fifty-four consecutive LVAD patients were included in this study. According to their infectious history in the first 3 months after LVAD implantation, these patients were grouped into an infection (n=23) and an infection-free group (n=31). Pre-LVAD blood samples were obtained for flow cytometric analysis of immunological parameters including B cells, subsets of T, dendritic and natural killer cells. Patient-specific, clinical and laboratory data were recorded.

Results

Blood count analysis prior to LVAD implantation showed comparable counts of erythrocytes (p=0.19), platelets (p=0.33) and leukocytes (p=0.50) between patients with infection and infection-free patients in the post-implant period. Patients with infection in the first 3 months after LVAD implantation had lower concentrations of lymphocytes (p=0.02). Forty percent of the patients with infection showed more often pre-LVAD neutrophil-to-lymphocyte ratios (NLR) >7 than patients without infection in the first 3 months after LVAD implantation (14%, p=0.05). Patients with infection already had lower percentages of CD3+ T cells (p=0.03), CD19+ B cells (p<0.01), BDCA2+ pDCs (p=0.03) and BDCA4+ plasmacytoid DCs (pDCs) (p=0.05) prior to LVAD implantation than infection-free patients.

Conclusion

Our results demonstrated that patients with infection in the early post-implant period showed lower concentrations of lymphocytes, especially of CD3+ T cells and CD19+ B cells, decreased percentages of BDCA2+ and BDCA4+ pDCs, and had more often NLRs >7 indicating moderate-to-severe inflammation. Thus, we identified specific immunological changes pre-LVAD that could help to identify patients at risk for infection in the early post-implant period.

Left Ventricular Assist Device and the Current State of the Art: HeartMate 3 at 5 Years

Left ventricular assist devices (LVADs) or cardiac transplantation are the two prevailing methods of treating patients with end-stage heart failure. The availability of donor hearts is insufficient to meet the needs of patients with advanced heart failure. LVADs offer a potential alternative to transplantation for those patients who cannot wait or are otherwise unsuited for cardiac transplantation. The field has made tremendous progress in the past 20 years. In this review, the current state of the art is summarized with respect to current generation LVADs.

Clinical and economic impact of ventricular assist device infections: a real-world claims analysis

BACKGROUND

VAD therapy has revolutionized the treatment of end-stage heart failure, but infections remain an important complication. The objective of this study was to characterize the clinical and economic impacts of VAD-specific infections.

METHODS

A retrospective analysis of a United States claims database identified members ≥ 18 years with a claim for a VAD implant procedure, at least 6 months of pre-implant baseline data, and 12 months of follow-up between 1 June 2016 and 31 December 2019. Cumulative incidence of infection was calculated. Infection and non-infection cohorts were compared regarding mortality, healthcare utilization, and total cost. Regression models were used to identify risk factors associated with infections and mortality.

RESULTS

A total of 2,259 patients with a VAD implant were included, with 369 experiencing infection (12-month cumulative incidence 16.1%). Patients with infection were 2.1 times more likely to die (p < 0.001, 95% CI [1.5-2.9]). The mean 12-month total cost per US patient was $354,339 for the non-infection cohort and $397,546 for the infection cohort, a difference of $43,207 (p < 0.0001).

CONCLUSIONS

VAD infections were associated with higher mortality, more healthcare utilization, and higher total cost. Strategies to minimize VAD-specific infections could lead to improved clinical and economic outcomes.

Clinical Outcomes of Left Ventricular Assist Device Pump Infection

Few studies have focused on the clinical outcomes and risk factors of left ventricular assist device (LVAD) pump infection, and no standard treatment for LVAD pump infection has been established. Therefore, we used a therapeutic flowchart to manage LVAD pump infections. We retrospectively evaluated 220 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2021 at Osaka University, Japan. First, we performed wound debridement, negative-pressure wound therapy, antibiotic treatment, and omental flap transposition. Subsequently, we administered conservative treatment, scheduled implantable LVAD exchange, or emergent removal of the implantable LVAD and exchange for extracorporeal LVAD or percutaneous LVAD (IMPELLA). Pump infections occurred in 32 patients. The survival rates of patients with pump infections during LVAD support were 93%, 74%, and 61% at 180 days, 1 year, and 2 years after LVAD pump infection, respectively. Fifteen patients underwent successful heart transplantation. Bridge-to-bridge surgery, preoperative use of venoarterial extracorporeal membrane oxygenation or percutaneous LVAD, high lactate dehydrogenase levels, and driveline infection were significantly associated with pump infection. Our study reveals that poor preoperative condition and driveline infection were significant risk factors for LVAD pump infection.

Long-term Dalbavancin for Suppression of Gram-Positive Chronic Left Ventricular Assist Device Infections

Background

Infection is the leading cause of morbidity and mortality in patients with left ventricular assist devices (LVADs). Prolonged suppressive therapy should be strongly considered and is often used in patients with recurrent infections when source control cannot be achieved. Dalbavancin is a promising option in patients with LVADs requiring prolonged durations of antibiotic therapy, especially when no oral alternatives are available.

Methods

This case series included 8 patients receiving dalbavancin for the long-term suppression of gram-positive infections at Emory University Hospital and Emory St Joseph's Hospital.

Results

The overall incidence of breakthrough infections occurred in 5 of the 8 patients included in the study. One patient experienced an early breakthrough infection within 1 month of dalbavancin initiation. Another experienced a breakthrough infection within 3 and 6 months of dalbavancin initiation, and the final 3 patients experienced a breakthrough infection within 6 and 12 months. The average duration of dalbavancin suppression therapy among all patients was 229 days, and no adverse effects were reported.

Conclusions

Dalbavancin is a promising option in patients who require long-term suppression for chronic gram-positive LVAD infections, given its unique pharmacokinetic profile and excellent tissue penetration. The use of biweekly dalbavancin infusions in our 8 patients prevented infection for an extended period of time despite some of the patients not being able to consistently receive infusions. Larger studies are needed to determine the efficacy and safety of using dalbavancin for long-term suppression of gram-positive LVAD infections.

Clinical Characteristics and Outcomes of Clostridioides difficile Infection in Patients With Left Ventricular Assist Device

The literature regarding Clostridioides difficile infection (CDI) in left ventricular assist devices (LVADs) patients is limited. Therefore, we aimed to characterize the clinical course, risk factors, management, and outcomes of LVAD patients who developed CDI. Adult patients who underwent LVAD placement during 2010-2022 and developed CDI were included. To determine risk factors and outcomes, we matched CDI patients with LVAD patients who did not develop CDI. Each CDI case was matched with up to two control subjects by age, sex, and time from LVAD implantation. Forty-seven of 393 LVAD patients (12.0%) developed CDI. The median time from LVAD implantation to CDI was 147 days (interquartile range 22.5-647.0). The most common CDI treatment was oral vancomycin (n = 26, 55.3%). Thirteen patients (27.7%) required treatment extension because of a lack of clinical response. Three patients (6.4%) developed recurrent CDI. When 42 cases were matched to 79 control subjects, antibiotic exposure within 90 days was significantly associated with CDI (adjusted odds ratio 5.77; 95% confidence interval, 1.87-17.74; p = 0.002). Moreover, CDI was associated with 1 year mortality (adjusted hazard ratio 2.62; 95% confidence interval, 1.18-5.82; p = 0.018). This infection occurs most often within the first year after LVAD implantation and was associated with 1 year mortality. Antibiotic exposure is an important risk for CDI.

Dynamics of bacterial pathogens at the driveline exit site in patients with ventricular assist devices: A prospective, observational, single-center cohort study

BACKGROUND

Driveline infections (DLIs) at the exit site are frequent in patients with left ventricular assist devices (LVADs). The dynamics from colonization to infection are yet to be investigated. We combined systematic swabbing at the driveline exit site and genomic analyses to study the dynamics of bacterial pathogens and get insights into DLIs pathogenesis.

METHODS

A prospective, observational, single-center cohort study at the University Hospital of Bern, Switzerland was performed. Patients with LVAD were systematically swabbed at the driveline exit site between June 2019 and December 2021, irrespective of signs and symptoms of DLI. Bacterial isolates were identified and a subset was whole-genome sequenced.

RESULTS

Fifty-three patients were screened, of which 45 (84.9%) were included in the final population. Bacterial colonization at the driveline exit site without manifestation of DLI was frequent and observed in 17 patients (37.8%). Twenty-two patients (48.9%) developed at least one DLI episode over the study period. Incidence of DLIs reached 2.3 cases per 1000 LVAD days. The majority of the organisms cultivated from exit sites were Staphylococcus species. Genome analysis revealed that bacteria persisted at the driveline exit site over time. In four patients, transition from colonization to clinical DLI was observed.

CONCLUSIONS

Our study is the first to address bacterial colonization in the LVAD-DLI setting. We observed that bacterial colonization at the driveline exit site was a frequent phenomenon, and in a few cases, it preceded clinically relevant infections. We also provided acquisition of hospital-acquired multidrug-resistant bacteria and the transmission of pathogens between patients.

Review of Implantable Left Ventricular Assist Devices

Mechanical circulatory support has been an indispensable treatment for severe heart failure. While the development of a total artificial heart has failed, left ventricular assist devices (LVAD) have evolved from extracorporeal to implantable types. The first generation implantable LVAD (pulsatile device) was used as a bridge to transplantation, and demonstrated improvement in survival rate and activity of daily living. The evolution from the first-generation (pulsatile device) to the second-generation (continuous flow device: axial flow pump and centrifugal pump) has resulted in many clinical benefits by reducing mechanical failures and minimizing device size. Furthermore, third-generation devices, which use a moving impeller suspended by magnetic and/or hydrodynamic forces, have improved overall device reliability and durability. Unfortunately, there are still many device-related complications, and further device development and improvement of patient management methods are required. However, we expect to see further development of implantable VADs, including for destination therapy, in future.

Multiple cerebral septic emboli sourcing from a ventricular assist device: a case report

Background

Patients carrying portable cardiac devices are at high risk of serious infections, such as endocarditis and sepsis. The event of a neurological complication should be taken into account, despite the fact that this group of patients is as a rule, strictly anticoagulated and monitored duly.

Case Description

We present the case of a patient of middle age with heart failure awaiting for organ transplantation, and meanwhile having a ventricular assist device (VAD) implanted. The suspicion of an infection was raised following a purulent drainage from the external lead of the device, as well as the clinical picture of malaise, fever and sweating. A right hemiparesis complicated the condition and the brain computerized tomography (CT) scan demonstrated the presence of several hemorrhagic lesions. The suspicion of septic emboli was proven following the result of hemoculture yielding Staphylococcus epidermidis.

Conclusions

The patient was treated with antibiotics, anti-seizure drugs and with supportive therapy, with good recovery of the clinical picture. He was transferred to a cardiac surgery facility for a revision, or eventually for a replacement of the VAD. There is clearly a need for an increased awareness of probable neurological events among patients holding external heart devices. Available guidelines for their follow-up and monitoring should be strictly respected, in order to avoid complications, and eventually install a prompt and adequate treatment.

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.

Clinical Outcomes in Patients With Bacteremia and Concomitant Left Ventricular Assist Devices and Cardiac Implantable Electronic Devices

Infection remains a common cause of morbidity and mortality in patients with both left ventricular assist devices (LVADs) and cardiac implanted electronic devices (CIEDs) with limited data describing outcomes in patients who have both devices implanted. We performed a single-center, retrospective, observational cohort study of patients with both a transvenous CIED and LVAD who developed bacteremia. Ninety-one patients were evaluated. Eighty-one patients (89.0%) were treated medically and nine patients (9.9%) underwent surgical management. A multivariable logistic regression showed that blood culture positivity for >72 hours was associated with inpatient death, when controlled for age and management strategy (odds ratio [OR] = 3.73 [95% confidence interval {CI} = 1.34-10.4], p = 0.012). In patients who survived the initial hospitalization, the use of long-term suppressive antibiotics was not associated with the composite outcome of death or infection recurrence within 1 year, when controlled for age and management strategy (OR = 2.31 [95% CI = 0.88-2.62], p = 0.09). A Cox proportional hazards model showed that blood culture positivity for >72 hours was associated with a trend toward increased mortality in the first year, when controlled for age, management strategy, and staphylococcal infection (hazard ratio = 1.72 [95% CI = 0.88-3.37], p = 0.11). Surgical management was associated with a trend toward decreased mortality (hazard ratio = 0.23 [95% CI = 0.05-1.00], p = 0.05).

Efficacy of catheter cleaning methods using intravenous indwelling catheter, 10% silver nitrate solution and a monofilament nylon thread for deeply progressed superficial driveline infections: case series

Driveline infection (DLI) is treated by local irrigation via driveline exit site (DLES) and surgical debridement is considered in patients with deep DLI. We describe three cases of deeply progressed superficial DLI that were considered to require surgical debridement but could be treated with a unique catheter cleaning method using intravenous indwelling catheter, a cotton swab with 10% silver nitrate solution and a monofilament nylon thread. Case 1 was a 60-y-old man with ischemic cardiomyopathy with left ventricular assist device implantation 2 y before. Daily bedside debridement with 10% silver nitrate solution was performed via the DLES. Case 2 was a 43-y-old man with ischemic cardiomyopathy who had recurrent DLI with methicillin-resistant Staphylococcus aureus, and case 3 was a 49-y-old woman with hypertrophic cardiomyopathy, who also showed improvement in their DLI with Pseudomonas aeruginosa. These cleaning methods may be useful for the deeply progressed superficial DLI.

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.

Successful Bacteriophage-Antibiotic Combination Therapy against Multidrug-Resistant Pseudomonas aeruginosa Left Ventricular Assist Device Driveline Infection

There is considerable interest in the use of bacteriophages (phages) to treat Pseudomonas aeruginosa infections associated with left ventricular assist devices (LVADs). These infections are often challenging to manage due to high rates of multidrug resistance and biofilm formation, which could potentially be overcome with the use of phages. We report a case of a 54-year-old man with relapsing multidrug-resistant P. aeruginosa LVAD driveline infection, who was treated with a combination of two lytic antipseudomonal phages administered intravenously and locally. Treatment was combined with LVAD driveline repositioning and systemic antibiotic administration, resulting in a successful outcome with clinical cure and eradication of the targeted bacteria. However, laboratory in vitro models showed that phages alone could not eradicate biofilms but could prevent biofilm formation. Phage-resistant bacterial strains evolved in biofilm models and showed decreased susceptibility to the phages used. Further studies are needed to understand the complexity of phage resistance and the interaction of phages and antibiotics. Our results indicate that the combination of phages, antibiotics, and surgical intervention can have great potential in treating LVAD-associated infections. More than 21 months post-treatment, our patient remains cured of the infection.

Daptomycin Pharmacokinetics in Blood and Wound Fluid in Critical Ill Patients with Left Ventricle Assist Devices

Daptomycin is a cyclic lipopeptide antibiotic with bactericidal effects against multidrug-resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). For critically ill patients, especially in the presence of implants, daptomycin is an important therapeutic option. Left ventricle assist devices (LVADs) can be utilized for intensive care patients with end-stage heart failure as a bridge to transplant. We conducted a single-center prospective trial with critically ill adults with LVAD who received prophylactic anti-infective therapy with daptomycin. Our study aimed to evaluate the pharmacokinetics of daptomycin in the blood serum and wound fluids after LVAD implantation. Daptomycin concentration were assessed over three days using high-performance liquid chromatography (HPLC). We detected a high correlation between blood serum and wound fluid daptomycin concentration at 12 h (IC95%: 0.64 to 0.95; r = 0.86; p < 0.001) and 24 h (IC95%: -0.38 to 0.92; r = 0.76; p < 0.001) after antibiotic administration. Our pilot clinical study provides new insights into the pharmacokinetics of daptomycin from the blood into wound fluids of critically ill patients with LVADs.

Management of pregnancy in left ventricular assist device and heart transplant recipients: a concise review

PURPOSE OF REVIEW

Women of reproductive age are increasingly undergoing heart transplantation (HT) or left ventricular assist device (LVAD) implantation for advanced heart failure. This review is intended to give an overview of the current state of the art management of pregnancy in patients with LVAD or HT recipients.

RECENT FINDINGS

Heart transplant recipients are at increased risk for graft rejection, renal dysfunction, preeclampsia and worsening of comorbidities (hypertension and diabetes). Patients with LVAD are at higher risk of thromboembolic events, infections, right ventricular failure and require close surveillance during pregnancy. Preconception counseling must be offered to all women of reproductive age group with HT or LVAD to avoid unplanned pregnancies.

SUMMARY

A multidisciplinary approach with close antepartum and postpartum surveillance is recommended.

Update on Mechanical Circulatory Support

Mechanical circulatory support (MCS) devices provide temporary or intermediate- to long-term support for acute cardiopulmonary support. In the last 20 to 30 years, tremendous growth in MCS device usage has been seen. These devices offer support for isolated respiratory failure, isolated cardiac failure, or both. Initiation of MCS devices requires the input from multidisciplinary teams using patient factors and institutional resources to guide decision making, along with a planned "exit strategy" for bridge to decision, bridge to transplant, bridge to recovery, or as destination therapy. Important considerations for MCS use include patient selection, cannulation/insertion strategies, and complications of each device.

Clinical Characteristics and Outcomes of Persistent Staphylococcal Bacteremia in a Tertiary Care Hospital

Clinical outcomes of persistent staphylococcal bacteremia vary depending on the causative organism. This secondary data analysis study compared the clinical characteristics of persistent Staphylococcus aureus (S. aureus)- and coagulase-negative staphylococci (CoNS)-caused bacteremia, focusing on the methicillin-resistant status. This study used data collected from patients who underwent blood cultures between January 2012 and December 2021 at Tohoku University Hospital, Japan. Patients with persistent staphylococcal bacteremia were divided into groups based on the pathogen and methicillin-resistant status, and their characteristics were analyzed. The primary outcomes were early (30-day), late (30–90 days), and 90-day mortality rates. The early, late, and 90-day mortality rates were similar between the persistent CoNS and S. aureus bacteremia groups. Patients with persistent methicillin-resistant S. aureus (MRSA) bacteremia tended to have higher early, late, and 90-day mortality rates than those with persistent methicillin-susceptible S. aureus bacteremia (not statistically significant). No differences were observed between the methicillin-resistant and-susceptible CoNS groups. In patients with persistent CoNS bacteremia, mortality tended to increase, especially in debilitated or immunocompromised patients with distant metastases, underscoring the importance of infection source control. Mortality tended to be high in patients with persistent MRSA bacteremia, especially when persistent bacteremia clearance was not confirmed, illustrating the need for careful therapeutic management.

CoronaVac, BNT162b2 and heterologous COVID-19 vaccine outcomes in patients with ventricular assist device

BACKGROUND

A consensus has not yet been reached regarding which COVID-19 vaccine program should be applied in patients with ventricular assist device (VAD). Our aim was to assess the clinical outcome of inactivated, mRNA and heterologous vaccine program in patient with VAD.

METHODS

In this retrospective and cross-sectional study; adult patients who underwent VAD implantation between January 2012 and September 2021 and received any vaccine that were used in Republic of Türkiye for COVID-19, were included. The patients were divided into three groups according to the type of vaccine; "inactivated," "mRNA" and "heterologous." Clinical outcomes were analyzed.

RESULTS

Eighteen patients were in each group in the "inactivated," "mRNA" and "heterologous" groups. Mean age was 51.6 ± 12 years in "inactivated" group, 42.5 ± 15.5 years in "mRNA" group and 41.1 ± 15.4 years in "heterologous" group. There was no significant difference between the groups in age, gender, body surface area, body mass index and etiology (p > 0.05). After last dose of vaccines, the number of patients had COVID-19 positive test were three (16.7%), one (5.6%), and two (11.1%) in "inactivated," "mRNA" and "heterologous" groups, respectively. Pump thrombosis was seen in two patients in "mRNA" group and one patient in "heterologous" group. No pump thrombosis was seen in "inactivated" group. COVID-19-related death or intubation was not observed.

CONCLUSION

All vaccine that used for COVID-19 are safe and effective in patients with VAD. In countries that give priority to inactivated vaccines, mRNA vaccines may then be made as boosters.

Flap Coverage of Infected Ventricular Assist Devices Influences Patient Outcomes

BACKGROUND

The use of left ventricular assist devices (LVADs) for patients with end-stage cardiac failure awaiting heart transplantation has become increasingly common. However, ventricular assist device-related infections remain a major problem complicating their long-term use. Poor data exist to determine how to manage these infections after operative debridement.

METHODS

Patients who underwent insertion of a ventricular assist device and had a subsequent readmission for LVAD infection at the University of Rochester Medical Center from 2012 to 2022 were identified through accessing the medical records archives of the hospital. Patients were followed retrospectively for an average of 3.2 years. Patient demographics, preoperative diagnosis/disease state, type of ventricular assist device inserted, postoperative day of ventricular assist device infection onset, infectious organism identified at initial washout, infectious organism identified at time of definitive device coverage, timing of coverage procedure after the initial washout for infection, type of flap used for coverage, 90-day complications after definitive coverage, and lifetime return to operating room for infection were reviewed. Comparison analysis with a χ2 test was used to analyze outcomes.

RESULTS

Of 568 patients admitted with an LVAD-related infection 117 underwent operative debridement. Of these, 34 underwent primary closure, 31 underwent closure with secondary intention (negative pressure wound therapy with split thickness skin grafting), and 52 were closed with a flap (pectoralis, omental, latissimus, or vertical rectus abdominus musculocutaneous flap). There was a statistically significant higher incidence of return to the operating room (RTOR) for infection over a lifetime with primary closure compared with secondary intention and flap reconstruction (P = 0.01, 0.02), but no difference in 90-day complications (P = 0.76, P = 0.58). Eighty-three patients had a positive culture upon definitive coverage with 24 having a postsurgical complication, 15 of which required lifetime RTOR for infection. Thirty four were closed with negative cultures with 9 having a complication and 4 requiring RTOR for infection. This was not statistically significant for complications or RTOR (P = 0.79, 0.40). Culture data were further substratified into bacterial cultures (n = 73) versus fungal cultures (n = 10), and there was no statistically significant difference between these compared with complications or RTOR (P = 0.40, 0.39).

CONCLUSIONS

Coverage of infected LVADs with locoregional flaps or allowing to granulate using wound vac therapy has a decreased lifetime RTOR for future infections for these patients without increase in 90-day complications. Timing of RTOR should not be impacted by positive cultures provided there is healthy granulation tissue in the wound.

Dalbavancin as chronic antibiotic suppression therapy for left ventricular assist device driveline infection due to methicillin-resistant Staphylococcus aureus: a case report

Left Ventricular Assist Devices (LVADs) represent an important therapeutic option in the management of advanced heart failure. We report a case of 74 years-old male with a Jarvik 2000® (Jarvik Heart, New York, USA) LVAD who presented with an infection of the LVAD driveline due to methicillin-resistant Staphylococcus aureus (MRSA) that was treated with dalbavancin as chronic antimicrobial suppression therapy without adverse events and maintaining a good quality of life for more than 37 weeks. Dalbavancin could represent a valid option for the treatment of LVAD infections because of its efficacy, pharmacokinetic/pharmacodynamic proprieties, safety and tolerability.

Threatened Ventricular Assist Devices: Meta-analysis of Negative Pressure Therapy and Flap Reconstruction Outcomes

Infected Ventricular Assist Device (VAD)-associated wounds are common and associated with significant morbidity and mortality. The efficacy of hardware salvage utilizing flaps and negative pressure wound therapy (NPWT) remains understudied. We hypothesized that patients treated with flaps and/or NPWT would have higher hardware salvage rates compared with other surgical management strategies.

METHODS

A meta-analysis study evaluating VAD-associated wounds was performed following PRISMA guidelines. Primary predictor variables were flap-reconstruction (FR), NPWT, no FR, and infection location (mediastinum versus driveline). Primary outcomes were hardware retention (salvage) versus explantation, infection recurrence, or death. Twenty-nine studies were included. Standard statistical methods included logistic regression analysis.

RESULTS

Seventy-four subjects with nonsignificant demographic differences between cohorts were identified. Overall salvage was 59.5% in both driveline and mediastinum cohorts. Overall, NPWT significantly improved salvage compared with no NPWT [77.4% versus 46.5% respectively (P = 0.009)], and FR significantly improved salvage compared with no FR [68.6% versus 39.1% respectively (P = 0.022)]. Logistic regression analysis predicting odds of salvage by FR (area under curve = 0.631) was significantly three times higher (95% CI: 1.2-9.5) and predicting the odds for salvage by NPWT (area under curve = 0.656) was significantly four times higher (95% CI: 1.4-11.1) compared with other treatment.

CONCLUSIONS

NPWT or flap reconstruction for treatment of threatened VAD hardware was associated with a significantly improved device salvage compared with other surgical strategies. Further study should focus on subgroup analysis of flaps utilized and synergistic treatment benefits.

Left Ventricular Assist Device in Patients With Alcohol Abuse or Illicit Drug Use

The impact of substance abuse, including alcohol abuse or illicit drug use, on outcomes after left ventricular assist device (LVAD) implantation, has not been fully elucidated. Accordingly, to test the hypothesis that such a history would be associated with worse outcomes, we analyzed the Interagency Registry for Mechanically Assisted Circulatory Support registry. All patients from the Interagency Registry for Mechanically Assisted Circulatory Support registry who received a continuous-flow LVAD from June 2006 to December 2017 were included. The median follow-up duration was 12.9 months (interquartile range, 5.3 to 17.5). The final study group consisted of 15,069 patients, of which 1,184 (7.9%) had a history of alcohol abuse and 1,139 (7.6%) had a history of illicit drug use. The overall mortality rates in the alcohol, illicit drug, and control groups were 25%, 21%, and 29%, respectively. Cox regression analysis showed that having a history of alcohol abuse (hazard ratio, 0.97, 95% confidence interval, 0.84 to 1.13, p = 0.72) or illicit drug use (hazard ratio, 1.02, 95% confidence interval, 0.86 to 1.21, p = 0.81) was not significantly associated with increased risk of all-cause mortality when compared with general LVAD population. On the contrary, after adjusting for other covariates, a history of alcohol abuse or illicit drug use was significantly associated with increased device malfunction/pump thrombosis, device-related infection, or all-cause hospitalization (all p <0.05). Furthermore, After LVAD implantation, these patients had a lower quality of life assessed by the Kansas City Cardiomyopathy Questionnaire compared with those who did not. In conclusion, our findings suggest that patients with a history of alcohol abuse or illicit drug use are at risk for adverse device-related events with a lower quality of life after continuous-flow LVAD implantation compared with the general LVAD population.

IgM-enriched immunoglobulin as adjuvant therapy for heart transplant after infection of left ventricular assist devices

Patients undergoing heart transplantation (HTx) with active infection of left ventricular assist devices (LVAD) are at high risk for postoperative infections. Between 2021 and 2022, five (P1-P5) of a total of n = 44 patients underwent HTx in our department while suffering from LVAD infection. Postoperatively, patients received adjuvant IgM-enriched human intravenous immunoglobulin (IGM-IVIG), consisting of 76% IgG, 12% IgM, and 12% IgA as a novel approach to prevent infective complications. While in P1, P2, and P4, LVAD driveline infection was known before HTx; in P3 and P5, abscess of device pocket was found incidentally during HTx. After a single dose of IGM-IVIG, all patients showed adequate rise in serum immunoglobulins. In the postoperative course, no patient developed infective complications. All patients were successfully discharged and in good condition at the last follow-up. Therefore, IGM-IVIG seems to be an effective adjuvant treatment for patients undergoing HTx with LVAD infections.

Sleeping prone with a left ventricular assist device: Dream or reality?

BACKGROUND

Among many other factors, restrictions on sleeping positions decrease quality of life after durable left ventricular assist device implantation. Specifically, device manufacturers and clinicians typically advise against sleeping in the prone position owing to concerns for driveline disruption, exit site infection, and hemodynamic compromise. Yet, no data exist to inform these recommendations and to the best of our knowledge no studies have examined sleep position in people with left ventricular assist devices. We report the first case of a person with a left ventricular assist device who slept prone, every night, for over one year.

CASE

This is a 38-year-old man with a HeartWare™ left ventricular assist device who had previously not disclosed that he was sleeping in the prone position for the 16 months following device implantation. The patient did not suffer any episodes of device-related malfunction, infection, neurologic insult, or hemodynamic compromise. We performed a non-invasive assessment in both supine and prone positions to better understand the hemodynamic effects of the prone position.

CONCLUSION

In select recipients of left ventricular assist devices, sleeping in the prone position may be safely tolerated.

Implications of Causes of Intracranial Hemorrhage During Left Ventricular Assist Device Support

BACKGROUND

Intracranial hemorrhage (ICH) is a frequent complication in patients with an implanted left ventricular assist device (LVAD) for advanced heart failure. Bloodstream infection is known to be associated with ICH in patients with LVAD, but its effects on ICH-associated mortality are unknown. We compared characteristics and mortality of infection-associated, traumatic, and spontaneous hemorrhages.

METHODS

Patients in an LVAD registry at a tertiary care center were reviewed for this cohort study. ICH included intraparenchymal hemorrhage, subarachnoid hemorrhage, and subdural hemorrhage. Hemorrhages were categorized into infectious, traumatic, and spontaneous by the presence or absence of concurrent device-associated infection or antecedent trauma.

RESULTS

Of 683 patients with an LVAD, 73 experienced ICH (10.7%). Intraparenchymal hemorrhage was the most prevalent (72%), followed by subarachnoid hemorrhage (27%) and subdural hemorrhage (23%), with multiple concurrent hemorrhage subtypes in 16 patients (22%). Median time from implantation to ICH was shorter in spontaneous ICH than in infection-associated ICH (100 days vs. 252 days, p = 0.048). The prevalence of the different subtypes of ICH were similar between spontaneous and infection-associated ICH, and no differences were seen in mortality between the different causes of ICH.

CONCLUSIONS

Although spontaneous ICH occurred earlier after LVAD implantation than infection-associated ICH, no difference in mortality was seen between the different causes of ICH.

Patient factors associated with left ventricular assist device infections: A scoping review

Infections are widely prevalent in left ventricular assist device (LVAD) recipients and associated with adverse events including mortality and rehospitalizations. Current evidence examining factors associated with infections in this setting predominantly comprises single-center observational data. We performed a scoping review to systematically summarize all existing studies examining patient-related factors associated with infections after LVAD implantation. Studies published between 01/06 and 02/19 were identified through searching 5 bibliographic databases: PubMed, Scopus, EMBASE, CINAHL, and Web of Science Core Collection. Inclusion criteria required examination of patient-related factors associated with infections among recipients of contemporary implantable, continuous flow LVADs. Key study characteristics were extracted by four independent reviewers and current literature described narratively. All analyses took place between February 2019 and May 2021. A total of 31 studies met inclusion criteria. All included studies were observational, and most commonly focused on driveline infections (n = 17). Factors studied most commonly included body composition (n = 8), diabetes and other comorbidities (n = 8), and psychosocial/socio-economic factors (n = 6). Studies were frequently single-center with heterogeneity in definition of infectious outcomes as well as exposure variables. Patient race and sex did not correlate with infection risk. There was no consistent association noted between obesity, diabetes, or psychosocial/socio-economic factors and infections in LVAD recipients. Two studies reported a significant association between malnutrition and hypoalbuminemia and post implant infections. This review summarizes 31 studies that described patient-related factors associated with infection after LVAD implantation. Patient related comorbidities, especially body composition and diabetes, were most commonly evaluated, but were not consistently associated with infections after LVAD implantation.

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.

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.

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.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

Relation of Left Ventricular Assist Device Infections With Cardiac Transplant Outcomes

Left ventricular assist device (LVAD)-specific infections (LSIs) are common in patients on LVAD support awaiting heart transplant (HT), yet their impact on post-HT outcomes is not completely understood. We hypothesized that LSIs would result in vasoplegia and negatively affect post-HT 30-day and 1-year outcomes. LSI was defined as driveline, pump, or pocket infection. The short-term outcome was a composite of acute renal failure, allograft rejection, and mortality at 30 days after HT. The long-term outcome was a composite of allograft rejection and death within 1 year after HT. We performed a retrospective analysis of 111 HT recipients bridged with durable LVAD support at our institution from May 2012 to August 2019. Of these, 63 patients had LSIs, with 94% of the infections being driveline infections. Vasoplegia was more prevalent in the LSI group but not significantly (7 vs 2 persons, p = 0.3). There was no difference in the composite end point of acute renal failure, rejection, or death at 30 days (30% vs 25%, p = 0.55) or 1-year end point of rejection and death (38% vs 40%, p = 0.87) in patients with LSI versus those without LSI. In conclusion, LSIs were common in patients on LVAD who underwent HT in our single-center contemporary cohort. However, LSI was not associated with adverse outcomes at 30 days or at 1 year after HT.

Identifying Causative Microorganisms in Left Ventricular Assist Device Infections as a Guide for Developing Bacteriophage Therapy

BACKGROUND

As more left ventricular-assist devices (LVADs) are implanted, multidrug-resistant LVAD infections are becoming increasingly common, partly due to bacterial biofilm production. To aid in developing bacteriophage therapy for LVAD infections, we have identified the most common bacterial pathogens that cause LVAD driveline infections (DLIs) in our heart transplant referral center.

MATERIALS AND METHODS

We studied a retrospective cohort of patients who received LVADs from November 2003 to August 2017 to identify the common causative organisms of LVAD infection. We also studied a prospective cohort of patients diagnosed with DLIs from October 2018 to May 2019 to collect bacterial strains from DLIs for developing bacteriophages to lyse causative pathogens. LVAD infections were classified as DLI, bacteremia, and pump/device infections in the retrospective cohort.

RESULTS

In the retrospective cohort of 582 patients, 186 (32.0%) developed an LVAD infection, with 372 microbial isolates identified. In the prospective cohort, 96 bacterial strains were isolated from 54 DLIs. The microorganisms causing DLIs were similar in the two cohorts; the most common isolate was Staphylococcus aureus. We identified 6 prospective S. aureus strains capable of biofilm formation. We developed 3 bacteriophages that were able to lyse 5 of 6 of the biofilm-forming S. aureus strains.

CONCLUSIONS

Similar pathogens caused LVAD DLIs in our retrospective and prospective cohorts, indicating our bacterial strain bank will be representative of future DLIs. Our banked bacterial strains will be useful in developing phage cocktails that can lyse ≥80% of the bacteria causing LVAD infections at our institution.

Bacteriophages for the Treatment of Graft Infections in Cardiovascular Medicine

Bacterial infections of vascular grafts represent a major burden in cardiovascular medicine, which is related to an increase in morbidity and mortality. Different factors that are associated with this medical field such as patient frailty, biofilm formation, or immunosuppression negatively influence antibiotic treatment, inhibiting therapy success. Thus, further treatment strategies are required. Bacteriophage antibacterial properties were discovered 100 years ago, but the focus on antibiotics in Western medicine since the mid-20th century slowed the further development of bacteriophage therapy. Therefore, the experience and knowledge gained until then in bacteriophage mechanisms of action, handling, clinical uses, and limitations were largely lost. However, the parallel emergence of antimicrobial resistance and individualized medicine has provoked a radical reassessment of this approach and cardiovascular surgery is one area in which phages may play an important role to cope with this new scenario. In this context, bacteriophages might be applicable for both prophylactic and therapeutic use, serving as a stand-alone therapy or in combination with antibiotics. From another perspective, standardization of phage application is also required. The ideal surgical bacteriophage application method should be less invasive, enabling highly localized concentrations, and limiting bacteriophage distribution to the infection site during a prolonged time lapse. This review describes the latest reports of phage therapy in cardiovascular surgery and discusses options for their use in implant and vascular graft infections.

Association between continuous-flow left ventricular assist device infections requiring long-term antibiotic use and post-heart transplant morbidity and mortality

BACKGROUND AND AIM OF STUDY

There exists controversy regarding the impact of infection in patients with a left ventricular assist device (LVAD) on post-heart transplant outcomes. This study evaluated the association between infections during LVAD support and the risk of early and late post-heart transplant infection, rejection, and mortality in transplant recipients bridged with an LVAD.

METHODS

This is a single-center retrospective observational cohort study of consecutive adults supported with a continuous flow LVAD undergoing heart transplant between 2006 and 2019 at the Toronto General Hospital. The grade of LVAD infection was classified as per International Society of Heart and Lung Transplantation guidelines. Patients were divided into three groups: (1) patients with LVAD-specific infection confirmed with positive cultures requiring long-term antibiotic use until the time of transplant; (2) patients with any type of infection in whom antibiotics were stopped at least 1 month before transplant; (3) patients without any infections between LVAD implant and transplant. Logistic regression and Cox proportional hazard models were used to evaluate early- and late-post transplant outcomes, respectively.

RESULTS

We included 75 LVAD recipients: 16 (21%) patients had a chronic LVAD-related infection on suppressive antibiotics, 30 (40%) had a resolved infection, and 29 (39%) had no infections. During a median post-transplant follow-up time of 4 (2 to 7) years, 65 (87%) patients developed infections, 43 (64%) rejections, and 17 (23%) deaths. Both short- and long-term risks of infection, rejection, and mortality did not differ significantly among the groups.

CONCLUSION

LVAD patients with infections did not have a significantly higher risk of infection, rejection, or mortality at any time point after transplant.

Cefazolin plus ertapenem and heart transplantation as salvage therapy for refractory LVAD infection due to methicillin-susceptible Staphylococcus aureus: A case series

The use of left ventricular assist devices (LVADs) is increasingly more common as the availability of donor organs in relation to failing hearts is outstandingly limited. Infections are the most common complications in LVAD recipients, particularly those caused by Staphylococcus spp. Refractory LVAD-related infections are not uncommon as achieving adequate source control is often not feasible before heart transplantation. Evidence suggest that cefazolin plus ertapenem is effective in refractory methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, but this approach has not been described in LVAD recipients. In this article, we report two cases of refractory MSSA bacteremia in LVAD recipients that were successfully treated with salvage therapy with cefazolin plus ertapenem and subsequent heart transplantation. This treatment strategy should be considered in patients with refractory LVAD-associated infection due to MSSA that are not responding to standard treatment.

Treatment of HeartMate III-LVAD driveline infection by negative pressure wound therapy: Result of our case series

Driveline infection is one of the most frequent complications following left ventricular assist device (LVAD) treatment and there is no consensus for its management. The standard approach to treat foreign-body infection is complete device ablation, which is not always feasible and therefore not an elected method for LVAD driveline infections. Here we share the results from a series of cases successfully treated for driveline infection by negative pressure wound therapy (NPWT) therapy. Between 2016 and 2020, five male patients were hospitalized in our unit with a driveline infection of HeartMate III-LVAD^®. Ultrasonography and/or thoraco-abdominal CT confirmed the diagnosis, infection localization, and abscess formation. Following an antibiotic treatment, an urgent surgical abscess drainage and debridement of the infected tissues were performed. At the end of the procedure, NPWT was applied. NPWT re-dressing and debridement of wound was performed every 3-4 days. The wound was closed surgically after obtaining negative culture results and good healing. The patients were discharged in good condition, without signs of infection. Two patients underwent successful heart transplantation after 1 and 13 months. Other patients did not show any residual or recurrent infection during the follow-up within 25 months. Driveline infection following LVAD implantation is a significant complication and a challenging in terms of management for both; the surgical team and the patient. These results from our case series report a successful and less invasive approach by using NPWT for the treatment of LVAD driveline infections.

Sternectomy for Candida albicans sternal osteomyelitis after left ventricular assist device implantation

Fungal osteomyelitis is an uncommon complication after cardiac surgery and associated with high mortality. A case of Candida albicans and Staphylococcus epidermidis osteomyelitis with device infection after implantation of a left ventricular assist device in a 60-year-old male patient is presented here. After clinical identification and confirmation with microbiological examinations and fluorodeoxyglucose positron emission tomography (FDG-PET) scan, debridement was performed. Surgical specimens grew C. albicans and S. epidermidis. Fluconazole, daptomycin, and negative pressure wound therapy were initiated, but failed to achieve healing. Total sternectomy and pectoralis flap reconstruction were performed. There was no recurrent infection for C. albicans on a prolonged antifungal regime. The combination of antifungal therapy and aggressive surgical debridement may be useful to control fungal osteomyelitis.

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.

Prevalence and management of driveline infections in mechanical circulatory support - a single center analysis

Background

Driveline infections in continuous-flow left ventricular assist devices (cf-LVAD) remain the most common adverse event. This single-center retrospective study investigated the risk factors, prevalence and management of driveline infections.

Methods

Patients treated after cf-LVAD implantation from December 2014 to January 2020 were enrolled. Baseline data were collected and potential risk factors were elaborated. The multi-modal treatment was based on antibiotic therapy, daily wound care, surgical driveline reposition, and heart transplantation. Time of infection development, freedom of reinfection, freedom of heart transplantation, and death in the follow-up time were investigated.

Results

Of 75 observed patients, 26 (34.7%) developed a driveline infection. The mean time from implantation to infection diagnosis was 463 (±399; range, 35–1400) days. The most common pathogen was Staphylococcus aureus (n = 15, 60%). First-line therapy was based on antibiotics, with a primary success rate of 27%. The majority of patients (n = 19; 73.1%) were treated with surgical reposition after initial antibiotic therapy. During the follow-up time of 569 (±506; range 32–2093) days, the reinfection freedom after surgical transposition was 57.9%. Heart transplantation was performed in eight patients due to resistant infection. The overall mortality for driveline infection was 11.5%.

Conclusions

Driveline infections are frequent in patients with implanted cf-LVAD, and treatment does not efficiently avoid reinfection, leading to moderate mortality rates. Only about a quarter of the infected patients were cured with antibiotics alone. Surgical driveline reposition is a reasonable treatment option and does not preclude subsequent heart transplantation due to limited reinfection freedom.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01589-6.

Nosocomial Infection

OBJECTIVE

The first 70 years of critical care can be considered a period of "industrial revolution-like" advancement in terms of progressing the understanding and care of critical illness. Unfortunately, like the industrial revolution's impact on the environment, advancing ICU care of increasingly elderly, immunosuppressed, and debilitated individuals has resulted in a greater overall burden and complexity of nosocomial infections within modern ICUs. Given the rapid evolution of nosocomial infections, the authors provide an updated review.

DATA SOURCES AND STUDY SELECTION

We searched PubMed and OVID for peer-reviewed literature dealing with nosocomial infections in the critically ill, as well as the websites of government agencies involved with the reporting and prevention of nosocomial infections. Search terms included nosocomial infection, antibiotic resistance, microbiome, antibiotics, and intensive care.

DATA EXTRACTION AND DATA SYNTHESIS

Nosocomial infections in the ICU setting are evolving in multiple domains including etiologic pathogens plus novel or emerging pathogens, prevalence, host risk factors, antimicrobial resistance, interactions of the host microbiome with nosocomial infection occurrence, and understanding of pathogenesis and prevention strategies. Increasing virulence and antimicrobial resistance of nosocomial infections mandate increasing efforts toward their prevention.

CONCLUSIONS

Nosocomial infections are an important determinant of outcome for patients in the ICU setting. Systematic research aimed at improving the prevention and treatment of nosocomial infections is still needed.