Left ventricular assist device driveline infections in three contemporary devices

Infections in Patients with Mechanical Circulatory Support

Patients on mechanical circulatory support are at heightened risk for infection given the invasive nature of the devices with internal and external components, the surgical implantation of the devices, and the presence of foreign material susceptible to biofilm formation. This review discusses the new International Society for Heart and Lung Transplantation mechanical circulatory support device infection definitions, inclusive of durable and acute mechanical circulatory support infections, and describes their epidemiology, diagnosis, and management. A multidisciplinary approach is essential for optimal management. Timing of transplantation in the context of active infection is addressed, and areas of future research are highlighted.

Cold atmospheric plasma therapy as a novel treatment for Berlin Heart EXCOR pediatric cannula infections

BACKGROUND

Cold atmospheric plasma (CAP) therapy has been recognized as effective treatment option for reducing bacterial load in chronic wounds, such as adult ventricular assist device (VAD) driveline exit-site infections. Currently, there have been no reports on the safety and efficacy of CAP therapy for pediatric cannula infections and inflammations in paracorporeal pulsatile VADs.

METHODS

The mechanical strength of Berlin Heart EXCOR cannulas were tested both before and after CAP treatment (SteriPlas, Adtec Healthcare Limited, UK) to prove material safety. A ring tensile test of 20 untreated and 20 CAP-treated (5 min) EXCOR cannulas (Ø12mm), assessed the force at the breaking point of the cannulas (Fmax), at 25% (F25%) and 50% (F50%) of the maximum displacement. Additionally, the scanning electron microscope (SEM) micrographs for both groups examined any surface changes. Finally, the case of a 13-year-old male EXCOR patient with cannula infections, treated with CAP over 100 days, is presented.

RESULTS

The in vitro measurements revealed no statistically significant differences in mechanical strength between the control and CAP group for F25% (8.18 ± 0.36 N, vs. 8.02 ± 0.43 N, p = 0.21), F50% (16.87 ± 1.07 N vs. 16.38 ± 1.32 N, p = 0.21), and FMAX (44.55 ± 3.24 N vs. 42.83 ± 4.32 N, p = 0.16). No surface structure alterations were identified in the SEM micrographs. The patient's cannula exit-sites showed a visible improvement in DESTINE wound staging, reduction in bacterial load and inflammatory parameters after CAP treatment without any side effects.

CONCLUSION

Overall, CAP therapy proved to be a safe and effective for treating EXCOR cannula exit-site wound healing disorders in one pediatric patient, but further studies should investigate this therapy in more detail.

Feasibility Testing of the Bionet Sonar Ultrasound Transcutaneous Energy Transmission (UTET) System for Wireless Power and Communication of a LVAD

PURPOSE

To address the clinical need for totally implantable mechanical circulatory support devices, Bionet Sonar is developing a novel Ultrasonic Transcutaneous Energy Transmission (UTET) system that is designed to eliminate external power and/or data communication drivelines.

METHODS

UTET systems were designed, fabricated, and pre-clinically tested using a non-clinical HeartWare HVAD in static and dynamic mock flow loop and acute animal models over a range of pump speeds (1800, 2400, 3000 RPM) and tissue analogue thicknesses (5, 10, 15 mm).

RESULTS

The prototypes demonstrated feasibility as evidenced by meeting/exceeding function, operation, and performance metrics with no system failures, including achieving receiver (harvested) power exceeding HVAD power requirements and data communication rates of 10kB/s and pump speed control (> 95% sensitivity and specificity) for all experimental test conditions, and within healthy tissue temperature range with no acute tissue damage.

CONCLUSION

During early-stage development and testing, engineering challenges for UTET size reduction and stable and safe operation were identified, with solutions and plans to address the limitations in future design iterations also presented.

Heartware ventricular assist device versus HeartMate II versus HeartMate III in advanced heart failure patients: A systematic review and meta-analysis

Objective

Ventricular assist device is one of the treatment options for heart failure patients. Therefore, the purpose of this review is to aid in clinical decision-making of exchanging previous older ventricular assist device models to the newest one, HM3.

Methods

The search was conducted across several databases until February 25, 2023, and was registered with the ID of CRD42023405367. Risk of bias was performed using Cochrane Risk of Bias 2.0 and the Newcastle Ottawa Scale. In order to rank and evaluate the pooled odds ratios and mean differences with 95% confidence intervals, we employed conventional and Bayesian network meta-analysis converted to surface under the cumulative ranking.

Results

A total of 49 studies with 31,105 patients were included in this review. HM3 is the best device exchange choice that causes the lowest risk of mortality (HM3 (99.98) > HM2 (32.43) > HVAD (17.58)), cerebrovascular accidents (HM3 (99.99) > HM2 (42.41) > HVAD (7.60)), other neurologic events beside cerebrovascular accident (HM3 (91.45) > HM2 (54.16) > HVAD (4.39)), pump thrombosis (HM3 (100.00) > HM2 (39.20) > HVAD (10.80)), and bleeding (HM3 (97.12) > HM2 (47.60) > HVAD (5.28)). HM3 is also better than HM2 in hospital admissions (OR: 1.90 (95% CI: 1.15-3.12)). When complications were present, HM2 or Heartware ventricular assist devices exchange to HM3 lowered the mortality rate compared to exchanging it to the same device type.

Conclusion

HM3 is the best device for all six outcomes. Exchange from Heartware ventricular assist devices or HM2 to HM3 rather than the same ventricular assist device type is recommended only if a complication is present.

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.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

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

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.

The History of Durable Left Ventricular Assist Devices and Comparison of Outcomes: HeartWare, HeartMate II, HeartMate 3, and the Future of Mechanical Circulatory Support

The utilization of left ventricular assist devices (LVADs) in end-stage heart failure has doubled in the past ten years and is bound to continue to increase. Since the first of these devices was approved in 1994, the technology has changed tremendously, and so has the medical and surgical management of these patients. In this review, we discuss the history of LVADs, evaluating survival and complications over time. We also aim to discuss practical aspects of the medical and surgical management of LVAD patients and future directions for outcome improvement in this population.

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.

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 (Loadmax) (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 (Torquemax) of the HeartMate II [41.44 (12.61) mNm] and the Carbothane HVAD driveline [46.06 (3.78) mNm] were significantly lower than Torquemax 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 (Torquemax) was found, as the the HeartMate II driveline had the lowest Torquemax and lowest DLI rate, whereas the HeartMate 3 driveline had the highest Torquemax 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.

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.

Comparative assessment of different versions of axial and centrifugal LVADs: A review

Continuous-flow left ventricular assist devices (LVADs) have gained tremendous acceptance for the treatment of end-stage heart failure patients. Among different versions, axial flow and centrifugal flow LVADs have shown remarkable potential for clinical implants. It is also very crucial to know which device serves its purpose better to treat heart failure patients. A thorough comparison of axial and centrifugal LVADs, which may guide doctors in deciding before the implant, still lacks in the literature. In this work, an assessment of axial and centrifugal LVADs has been made to suggest a better device by comparing their engineering, clinical, and technological development of design aspects. Hydrodynamic and hemodynamic aspects for both types of pumps are discussed along with their biocompatibility, bearing types, and sizes. It has been observed numerically that centrifugal LVADs perform better over axial LVADs in every engineering aspect like higher hydraulic efficiency, better characteristics curve, lesser power intake, and also lesser blood damage. However, the clinical outcomes suggest that centrifugal LVADs experience higher events of infections, renal, and respiratory dysfunction. In contrast, axial LVADs encountered higher bleeding and cardiac arrhythmia. Moreover, recent technological developments suggested that magnetic type bearings along with biocompatible coating improve the life of LVADs.

Left ventricular assist device driveline infections in three contemporary devices

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