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

Outcomes of treatment for deep left ventricular assist device infection

OBJECTIVE

Among left ventricular assist device patients, the most commonly infected component is the drive line, which can be managed with antibiotics and local debridement. Infection of intrathoracic device components is less common but more difficult to manage. Herein we describe the incidence of deep device infection (DDI) at our center as well as management and outcomes.

METHODS

We retrospectively reviewed 658 patients who underwent implantable left ventricular assist device insertion with HeartMate 2 (Abbott) or HeartMate 3 (Abbott) devices between January 2004 and June 2021. DDI was defined according to radiographic and clinical criteria. Cumulative incidence was calculated using a Fine-Gray subdistribution model; survival analysis was performed using the method of Kaplan and Meier.

RESULTS

There were 32 (4.8%) DDIs during this study period. Drive line infection and re-exploration for bleeding were associated with development of DDI. Cumulative incidence of DDI increased over time, affecting 11% (7%-18%) at 5 years. The dominant microbes involved in DDI were Pseudomonas aeruginosa (19%) and methicillin-resistant Staphylococcus aureus (13%). Nineteen patients (59%) with device infection underwent device exchange, 6 (19%) underwent initial transplant, and 7 (22%) were treated solely with debridement and antibiotics. Of those who underwent device exchange, 12 (63%) developed reinfection of their new device and 6 underwent subsequent heart transplant. Patients who underwent transplantation for management of device infection had improved 5-year survival (80% vs 11%; P = .01) but 3 patients (25%) developed deep sternal wound infection after transplant.

CONCLUSIONS

DDI is a rare but challenging complication in this destination era. Heart transplantation is the preferred management strategy for eligible patients but infectious complication is common.

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.

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

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

The Safety and Efficacy of Phage Therapy for Infections in Cardiac and Peripheral Vascular Surgery: A Systematic Review

New approaches to managing infections in cardiac and peripheral vascular surgery are required to reduce costs to patients and healthcare providers. Bacteriophage (phage) therapy is a promising antimicrobial approach that has been recommended for consideration in antibiotic refractory cases. We systematically reviewed the clinical evidence for phage therapy in vascular surgery to support the unlicensed use of phage therapy and inform future research. Three electronic databases were searched for articles that reported primary data about human phage therapy for infections in cardiac or peripheral vascular surgery. Fourteen reports were eligible for inclusion, representing 40 patients, among which an estimated 70.3% of patients (n = 26/37) achieved clinical resolution. A further 10.8% (n = 4/37) of patients showed improvement and 18.9% (n = 7/37) showed no improvement. Six of the twelve reports that commented on the safety of phage therapy did not report adverse effects. No adverse effects documented in the remaining six reports were directly linked to phages but reflected the presence of manufacturing contaminants or release of bacterial debris following bacterial lysis. The reports identified by this review suggest that appropriately purified phages represent a safe and efficacious treatment option for infections in cardiac and peripheral vascular surgery.

Driveline dressings used in heartmate patients and local complications: A retrospective cohort

BACKGROUND

Patients with long-term ventricular assist devices (VAD) are predisposed to infection, bleeding, and pressure injuries at the insertion of the driveline. There is no consensus on a driveline dressing protocol. Chlorhexidine is often used to clean the driveline exit site and has been associated with lower rates of infection. For driveline coverage, bacteriostatic agents and transparent film have shown good results, but are costly. The same issue was associated with anchorage devices.

OBJECTIVES

The purpose of this study was to evaluate the types of dressings used in the driveline of patients using HeartMate (HM) and to describe the incidence density of local complications (infection, bleeding, and pressure injury) within 30 days postoperatively.

METHODS

A retrospective cohort study was conducted and included 22 patients admitted to the Intensive Care Unit after implantation of HM II and III in a Brazilian private hospital.

RESULTS

Several types of dressings were used in the drivelines. There were 22 different types of dressings. Dressing type 6 (Chlorhexidine, Excilon, Gauze and IV3000) were the most used (45.4%). Subjects using the Flexi-Trak anchoring device had a higher rate of local bleeding (50.0%) and those who used the Hollister device had more infection (61.1%) and pressure injury associated with a medical device (11.1%), compared to others. Infection was the primary complication (45.4%), followed by local bleeding (27.7%).

CONCLUSION

Despite the high variability of products used in the driveline of patients using HeartMate, the dressing made with chlorhexidine, silver-impregnated absorbent foam and transparent film, and the use of anchoring devices was the most frequently used. Infection was the most common complication.

Content Validity of the Left Ventricular Assist Device Bathing Assessment

Many institutions recommend modified bathing techniques for individuals with left ventricular assist devices (LVADs) due to infection risk. Although these techniques may be challenging for patients, there currently is no assessment to evaluate these skills and whether intervention programs have been successful. This article describes the development and content validation of the LVAD Bathing Assessment. The content validity index (CVI) process was used to determine the relevance of assessment items. Modified Kappa indices were calculated to account for the possibility of chance agreement among raters. Eight content validity experts rated each assessment item and provided feedback. The overall assessment and 44 of 47 individual items had excellent content validity (scale-level CVI [S-CVI] = 0.97; item-level CVI [I-CVI] > 0.78). Minor revisions were made based on feedback. Creation of an LVAD bathing assessment may improve care by identifying safety risks that may cause infection. Further studies for construct validation and reliability testing are needed.

Argon Cold Plasma Use and Driveline Infection in Left Ventricular Assist Device Implant Recipients

We conducted a prospective open-labeled, clinical trial, with a two-by-two factorial design, of argon cold plasma (ACP) application and two different types of driveline positioning for the prevention of driveline infection (DLI) in patients with a left ventricular assist device (LVAD) implant. Here, we present the results of ACP application versus no ACP application. Eighty patients were allocated to the control group (no preventive ACP use; n = 40) or ACP group (preventive ACP use for 30 days post-LVAD implantation; n = 40). Patients were followed up for 1 year. The secondary endpoint was survival on device. Preventive ACP use improved 30 day freedom from DLI significantly (100% vs. 85%; p = 0.012); results remained significant at 6 months (92% vs. 69%, p = 0.007) and were 55% and 60%, respectively ( p = 0.65) at 1 year follow-up. With respect to survival on device, results in the control and ACP groups did not differ significantly at 30 days (97.5% vs. 100%, respectively; p = 0.32), but tended to be lower in the control group than in the ACP group at 1 year follow-up (74% vs. 90%, respectively; p = 0.09). In conclusion, preventive ACP use was able to significantly reduce DLI both during the application period and up to 6 months after LVAD implantation.

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.