Left ventricular assist device-related infections: past, present and future

Antibody Response to SARS-CoV-2 Vaccination in Heart Failure Patients: Retrospective Single-Center Cohort Study

We sought to investigate the impact of heart failure on anti-spike antibody positivity following SARS-CoV-2 vaccination. Our study included 103 heart failure (HF) patients, including those with and without left ventricular assist devices (LVAD) selected from our institutional transplant waiting list as well as 104 non-heart failure (NHF) patients who underwent open heart surgery at our institution from 2021 to 2022. All the patients received either heterologous or homologous doses of BNT162b2 and CoronaVac. The median age of the HF group was 56.0 (interquartile range (IQR): 48.0-62.5) and the NHF group was 63.0 (IQR: 56.0-70.2) years, and the majority were males in both groups (n = 78; 75.7% and n = 80; 76.9%, respectively). The majority of the patients in both the HF and NHF groups received heterologous vaccinations (n = 43; 41.7% and n = 52; 50.3%, respectively; p = 0.002). There was no difference in the anti-spike antibody positivity between the patients with and without heart failure (p = 0.725). Vaccination with BNT162b2 led to significantly higher antibody levels compared to CoronaVac alone (OR: 11.0; 95% CI: 3.8-31.5). With each passing day after the last vaccine dose, there was a significant decrease in anti-spike antibody positivity, with an OR of 0.9 (95% CI: 0.9-0.9). Furthermore, hyperlipidemia was associated with increased antibody positivity (p = 0.004).

No Association between Clinical Periodontal Conditions and Microbiological Findings on Driveline of Patients with Left-Ventricular Assist Devices (LVAD)

The aim of this retrospective study was to investigate whether there would be an association between periodontal disease parameters and positive bacterial findings at the driveline of patients with a left ventricular assist device (LVAD). Patients with an LVAD, who underwent a full oral and microbiological examination between 2016 and 2018, were included. During oral examination, periodontitis severity (stage and grade) and the periodontal inflamed surface area (PISA) were evaluated. A microbiological analysis was performed from swabs of the driveline, whereby different bacterial species were cultivated and analyzed. A total of 73 patients were included in the current study. The majority of participants (80.8%) had at least one positive bacterial finding during the study period. Most patients had a periodontitis stage of III-IV (80.9%). The determined PISA of the total group was 284.78 ± 352.29 mm². No associations were found between the periodontal disease parameters and the bacterial findings in general, the bacterial findings on the day of oral examination or the bacterial findings 12 months prior to/after the oral examination (p > 0.05). Periodontitis is not associated with cultivated microbiological findings at the driveline of patients with an LVAD and thus appears not to be a risk indicator for driveline colonization. Nevertheless, the high periodontal burden in LVAD patients underlines the need for their improved periodontal care.

Does minimally invasive approach reduce risk of infection after ventricular assist device implantation?

BACKGROUND

We analyzed patients with left ventricular assist device (LVAD) related and specific infection, and aimed to determine whether surgical technique implantation affect the frequency of infection.

METHODS

We retrospectively analyzed the data of 99 patients who received LVAD at our department between June 2013 and June 2019. Patients were divided into two groups according to the surgical technique. Group A (n = 58) was conventional sternotomy (CS) and group B (n = 41) was on-pump minimally invasive left thoracotomy (MILT). Demographics, preoperative risk factors, LVAD infections, surgical incision site, driveline site, and outcomes were compared between these two groups.

RESULTS

Mean follow up time was 589 ± 480 (31-2171) days. Infection was detected in 34% (41/99) of LVAD patients. Admission to emergency department and intensive care unit (ICU) in last 6 months were significantly higher in MILT group. There was no difference between the two groups in terms of driveline exit site infection (CS: 28%, MILT: 27%) (p > 0.05). Seven (17%) patients had infection in the thoracotomy incision site area in the MILT group. The rate of ICU hospitalization in the last 6 months was seen as the only independent risk factor increasing the frequency of infection (R = 0.30; p = 0.016). Survival analysis at 60 days, 1 year and 2 years showed no difference between the two groups (p = 0.09).

CONCLUSIONS

Despite advances in pump technology and surgical technique, infection is still an important cause of mortality and morbidity.

Reduction of Postoperative Infections Through Routine Preoperative Universal Decolonization of Advanced Heart Failure Patients With Chlorhexidine and Mupirocin Before Left Ventricular Assist Device Implantation: A Single-Center Observational Study

BACKGROUND

Left ventricular assist devices (LVADs) are increasingly being used in patients with advanced heart failure as bridge to transplant, bridge to decision, or destination therapy. Infections are a major complication associated with LVADs. Staphylococcus aureus is one of the common causative organisms associated with LVAD infections. Methicillin resistant staphylococcus aureus (MRSA)-colonized patients are at an increased risk for developing MRSA-associated infections. Various studies have demonstrated decolonization of skin with topical chlorhexidine and nares with 2% intranasal mupirocin ointment is effective in reducing MRSA-associated infections.

OBJECTIVE

The objective of this observational study was to examine the impact of a universal decolonization protocol using topical chlorhexidine and intranasal mupirocin ointment for 5 days before LVAD implantation on postoperative infections (30, 60, and 90 days) and 30-day infection-related rehospitalization.

METHODS

A preoperative universal decolonization with 4% chlorhexidine daily whole-body bath and 2% intranasal mupirocin ointment twice a day for 5 days was implemented for patients undergoing elective LVAD implantation. Using an observational study design, we included a convenience sample of 84 subjects who were established patients in an accredited advanced heart failure program. Thirty-seven patients served in the standard protocol group, and 47 in the universal decolonization protocol group participated in the observational study.

RESULTS

In the standard protocol group, there were 4 MRSA infections with none in the universal decolonization group (χ = 5.34, P = .03). In total, there were 8 surgical site infections in the standard protocol group and 1 in the universal decolonization group (χ = 5.95, P = .01).

CONCLUSION

A 5-day universal decolonization protocol before LVAD implantation was effective in reducing total infections as well as MRSA-specific infections.

The Impact of Left Ventricular Assist Device Infections on Postcardiac Transplant Outcomes: A Systematic Review and Meta-Analysis

Left ventricular assist devices (LVADs) are associated with numerous short- and long-term complications, including infection. The impact LVAD infections have on clinical outcomes after transplantation is not well established. We sought to determine whether the presence of infection while on LVAD support negatively influences outcomes after cardiac transplantation. We searched electronic databases and bibliographies for full text studies that identified LVAD infections during support and also reported on posttransplant outcomes. A meta-analysis of posttransplant survival was conducted using a random effects model. Of 2,373 records, 13 bridge to transplant (BTT) cohort studies were selected (n = 6,631, 82% male, mean age 50.7 ± 2.7 years). A total of 6,067 records (91.5%) received transplant. There were 3,718 (56.1%) continuous-flow LVADs (CF-LVADs), 1,752 (26.4%) pulsatile LVADs, and 1,161 (17.5%) unknown type records. A total of 2,586 records (39.0%) developed LVAD infections. Patients with LVAD infections were younger (50.5 ± 1.5 vs. 51.3 ± 1.5, p = 0.02), had higher body mass indeices (BMIs) (28.4 ± 0.7 vs. 26.8 ± 0.4, p < 0.01), and longer LVAD support times (347.0 ± 157.6 days vs. 180.2 ± 106.0 days, p < 0.01). Meta-analysis demonstrated increased posttransplant mortality in those patients who had an LVAD infection (hazard ratio [HR] 1.30, 95% CI: 1.16-1.46, p < 0.001). Subgroup meta-analyses by continuous-flow and pulsatile device type demonstrated significant increased risk of death for both types of devices (HR 1.47, 95% CI: 1.22-1.76, p < 0.001 and 1.71, 95% CI: 1.19-2.45, p = 0.004, respectively). Patients who develop LVAD infections are younger, have higher BMIs and longer LVAD support times. Our data suggests that LVAD-related infections result in a 30% increase in postcardiac transplantation mortality. Strategies to prevent LVAD infections should be implemented to improve posttransplant outcomes in this high-risk population.

Bloodstream Infections in Continuous Flow Left Ventricular Assist Device Recipients: Diagnostic and Clinical Implications

Bloodstream infection (BSI) is a common complication of left ventricular assist device (LVAD) support and particularly difficult to treat. The presentation is often variable because of altered physiology and augmentation of cardiac output by the device. We studied LVAD recipients at a single institution. Multivariate logistic and Cox (with time-varying parameters) regression were implemented. Of 212 patients, 58% experienced infections. Driveline infection (DLI) affected 31%, with 60% of them having deep-tissue involvement. Sixty-six patients (31%) suffered from 135 BSIs. Systemic inflammatory response syndrome (SIRS) was present in 47% of BSIs at presentation and associated with increased mortality. Right heart failure, destination therapy, Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile, morbid obesity, and deep-DLI were independent risk factors for BSI. The BSI was independently associated with mortality. Bridge-to-transplantation (BTT) patients were more likely to receive transplant if they did not have BSIs. Among 104 BTT patients who received heart transplantation, development of BSI was associated with shorter time-to-transplantation. Diagnosis of BSI poses diagnostic and prognostic challenges because of the hemodynamic profile of LVAD patients who may not mount the expected physiologic response to sepsis. Although SIRS criteria lack sensitivity in the LVAD population, SIRS signifies increased risk for death. Deep DLI was the strongest predictor of BSI. Despite the upgrade in listing status of BTT-LVADs with BSIs and shorter time-to-transplantation, BSI remain a major cause of mortality. BSIs are associated with significant mortality and should be regarded as a serious complication, similar to pump thrombosis and stroke.

Infection profile in neonatal patients during extracorporeal membrane oxygenation

OBJECTIVES

To describe risk factors for acquired infection during neonatal extracorporeal membrane oxygenation and to examine the predictive value of inflammatory markers in the diagnosis of infection.

METHODS

A retrospective study was conducted with data for patients under 30 days supported with extracorporeal membrane oxygenation from 2003 to April 2016, in a neonatal intensive care unit.

RESULTS

Our study included 160 neonatal patients, the average age of connection was 8.5 days and the duration of extracorporeal membrane oxygenation support was 9.7 days. The incidence of confirmed infection was 23%. Patients with confirmed infection present more frequently: vaginal delivery, lower birth weight, female sex, diagnosis of congenital diaphragmatic hernia, and longer duration of extracorporeal membrane oxygenation. When comparing the group of patients with confirmed infection and suspicion of infection, there were no significant differences in the inflammatory markers. When calculating the slope for each one, the difference in white blood cell count slope 72 h before the infection is significant; in patients with confirmed infection, the count of white blood cell increases (slope: 0.25), versus the group of patients with suspected infection in whom the count decreases (slope: -0.39). No differences were found in other variables.

CONCLUSION

Our study describes that the factors that increase the risk of infection are lower birth weight, vaginal birth, duration of extracorporeal membrane oxygenation, and a positive trend of white blood cell 72 h prior to infection/suspicion. Further studies are necessary to include or definitively rule out the use of these factors and the biomarkers as predictors of infection in neonatal patients supported with extracorporeal membrane oxygenation.

Outcomes of patients with infection related to a ventricular assist device after heart transplantation

BACKGROUND

Despite significant advances in durable mechanical support survival, infectious complications remain the most common adverse event after ventricular assist device (VAD) implantation and the leading cause of early death after transplantation. In this study, we aim to describe our local infectious epidemiology and review short-term survival and infectious incidence rates in the post-transplantation period and assess risk factors for infectious episodes after transplantation.

METHODS

Retrospective single-center study of all consecutive adult heart transplant patients from 2008 to 2017. Survival data were estimated and summarized using the Kaplan-Meier method. We quantified and evaluated the difference in the incidence rate between patients with and without infection using a Fine-Gray model. The outcome of interest is the time to first infection diagnosis with post-transplant death as the competing event.

RESULTS

Among 278 heart transplant patients, 74 (26.5%) underwent LVAD implantation. Twenty-one patients (28.3%) developed an infection while supported by an LVAD. When compared to patients supported by an LVAD without a preceding infection, BMI was significantly greater (31.2 vs 27.8 kg/m² , P = .03). Median follow-up post-transplantation was 3.01 years. Significant risk factors for the competing risk regression for infection after heart transplantation include LVAD infection (HR 1.94, [95% CI] 1.11-3.39, P = .020) and recipient COPD (HR 2.14, [95% CI] 1.39-3.32, P = .001) when adjusted for recipient age, gender, hypertension, diabetes mellitus, and body mass index.

CONCLUSIONS

Patients with LVAD-related infection had a significantly increased risk of infectious complications after heart transplantation. Further research on the avoidance of induction agents and reduced maintenance immunosuppression in this patient population is warranted.

A Rising Hope of an Artificial Heart: Left Ventricular Assisted Device - Outcome, Convenience, and Quality of Life

With the introduction of mechanical circulatory support, mainly continuous-flow left ventricular assisted devices (CF-LVAD), prolonging survival in end-stage heart failure patients can be seen in a new light. We also anticipate its use as a definitive therapy to overcome the limited donor organ resources for cardiac transplant. However, LVADs also have undesirable device-related complications and questionable improvement in the quality of life. In this review, we searched published articles using PubMed and Google Scholar to identify the complications and outcome of post-LVAD patients from 2014 to 2019. The studies we used included all study design types and a wide range of demographic variables focusing on age, sex, choice of LVAD as a bridge to cardiac transplant, or definitive therapy. For patients with New York Heart Association (NYHA) Class III B or IV or heart failure with reduced ejection fraction (HFrEF) with maximal medication therapy, there is a significant increase in mean ejection fraction from 4% to 6%. For patients with drug-induced cardiac toxicity or other causes of cardiac toxicity, with no significant risk factors, the ejection fraction increased to nearly 50% within 10-25 days of LVAD usage. There is also a substantial improvement in the quality of life in this literature review comparing to the pre-LVAD stage, as long as complications are taken into account. Data is limited for making an accurate judgment on the quality of life and functional capacity of LVADs. We found that the use of LVADs is not fully cost-effective, but still less financially burdening than a cardiac transplant. Although data from worldwide is limited and restricted to studies having a range of one to two years of follow-up, we conclude that LVADs are promising in improving cardiac function and the best bridging therapy available for patients waiting on a transplant.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Left ventricular assist devices and their complications: A review for emergency clinicians

INTRODUCTION

End stage heart failure is associated with high mortality. However, recent developments such as the ventricular assist device (VAD) have improved patient outcomes, with left ventricular assist devices (LVAD) most commonly implanted.

OBJECTIVE

This narrative review evaluates LVAD epidemiology, indications, normal function and components, and the assessment and management of complications in the emergency department (ED).

DISCUSSION

The LVAD is a life-saving device in patients with severe heart failure. While first generation devices provided pulsatile flow, current LVAD devices produce continuous flow. Normal components include the pump, inflow and outflow cannulas, driveline, and external controller. Complications related to the LVAD can be divided into those that are LVAD-specific and LVAD-associated, and many of these complications can result in severe patient morbidity and mortality. LVAD-specific complications include device malfunction/failure, pump thrombosis, and suction event, while LVAD-associated complications include bleeding, cerebrovascular event, infection, right ventricular failure, dysrhythmia, and aortic regurgitation. Assessment of LVAD function, patient perfusion, and mean arterial pressure is needed upon presentation. Electrocardiogram and bedside ultrasound are key evaluations in the ED. LVAD evaluation and management require a team-based approach, and consultation with the LVAD specialist is recommended.

CONCLUSION

Emergency clinician knowledge of LVAD function, components, and complications is integral in optimizing care of these patients.

Staphylococcal driveline infections are the predominant type of left ventricular assist device associated infections in Singapore

BACKGROUND

Left ventricular assist device (LVAD) associated infections (LVADIs) have substantial morbidity and mortality. We aim to describe the incidence and epidemiology of LVADIs in an Asian cohort. This is currently not well studied.

METHODS

We conducted a retrospective review of 52 patients who underwent LVAD implantation from 1 May 2009-31 December 2014 in National Heart Centre Singapore. LVADIs were defined based on definitions proposed by the International Society for Heart and Lung Transplantation.

RESULTS

There were 39 males and 13 females. Seventy-three percent had Heartmate II LVAD implant while 27% received Heartware HVAD. Eighty-one percent were implanted as bridge to heart transplantation, 19% as destination therapy. Forty-five episodes of LVADIs occurred in 25 patients. Overall LVADI incidence was 47.5 cases per 100 patient-years. Driveline infections (58%) were the commonest type of LVADI. The commonest causative organisms were coagulase-negative staphylococci (33%), Staphylococcus aureus (31%) and Corynebacterium species (19%). Twelve percent of patients with LVADI required surgical debridement and one patient required pump exchange due to pump pocket infection. All-cause mortality was 13%.

CONCLUSIONS

The findings of our study add to the understanding and epidemiology of LVADIs, particularly in the Asian setting. This can contribute to the development of evidence based strategies to prevent and manage LVADIs.

Hyperpyrexia in a patient with a left ventricular assist device: a diagnosis beyond the obvious

As the number of patients receiving a left ventricular assist device increases, physicians must always keep in mind that several conditions can present with non-specific symptoms, such as fever, tachypnoea and confusion. We herein report the case of a left ventricular assist device patient who developed a life-threatening condition with acute hyperthermia, confusion and extremities' clonus and muscle spasms. The patient was diagnosed with serotonin syndrome, attributed to the coadministration of 2 commonly prescribed medications (citalopram and omeprazole). This case highlights that a significant proportion of left ventricular assist device patients is treated with serotonergic agents that may predispose them to the appearance of serotonin syndrome, a potentially life-threatening condition.

Delayed febrile response with bloodstream infections in patients with continuous-flow left ventricular assist devices

Bloodstream infections (BSIs) are common in patients with continuous-flow left ventricular assist devices (CF-LVADs). Whether CF-LVADs modulate the febrile response to BSIs is unknown. We retrospectively compared the febrile response to BSIs in patients with heart failure (HF) with CF-LVADs versus a control population of patients with HF receiving inotropic infusions. BSIs were adjudicated using the Centers for Disease Control and Prevention and the National Healthcare Safety Network criteria. Febrile status (temperature ≥38°C, 100.4 °F), temperature at presentation with BSI, and the highest temperature within 72 hours (Tmax) were collected. We observed 59 BSIs in LVAD patients and 45 BSIs in controls. LVAD patients were more likely to be afebrile and to have a lower temperature at presentation than control (88% vs 58%, p=0.002, and 37°C ±0.7 vs 37.7°C ±1.0, p=0.0009, respectively). By 72 hours, the difference in afebrile status diminished (53% vs 44%, p=0.42), and the Tmax was similar between the LVAD and control groups (37.9°C±0.9 vs 38.2°C±0.8, respectively, p=0.10). In conclusion, at presentation with a BSI, the vast majority of CF-LVAD patients were afebrile, an event which occurred at a higher frequency when compared with patients with advanced HF on chronic inotropes via an indwelling venous catheter. These data alert clinicians to have a very low threshold to obtain blood cultures in CF-LVAD patients even in the absence of fever. Further study is needed to determine whether a delayed or diminished febrile response represents another pathophysiological consequence of CF-LVADs.

Left Ventricular Assist Devices: How Do We Define Success?

Despite the growing acceptance of left ventricular assist device (LVAD) therapy to improve survival and quality of life in heart failure (HF) patients, uncertainties persist regarding the definition of a successful implant. We sought to define an innovative approach to assess success and subsequently compare preoperative variables affecting outcomes. From January 2007 to 2015, 278 patients underwent LVAD implantation. Median age at implant was 62 years and 81% patients were males. Indication for support was bridge-to-transplantation in 36% patients and the etiology of HF was ischemic in 49% patients. Based on clinically relevant and accepted standards, we defined successful LVAD implant as someone who was alive or transplanted at 2 years, had two or less readmissions in the first year, had no major adverse events in the first year, and had a New York Heart Association class of ≤ II at 6 months. Follow-up was obtained for a median of 1.7 years for a total of 605 patient-years-of-support. Based on our criteria, 81/278 (29%) patients were defined as having a successful implant. Univariate predictors of LVAD failure included destination therapy indication (hazard ratio [HR] = 2.11 [1.24, 3.58]), ischemic cardiomyopathy (HR = 1.73 [1.02, 2.94]), and a higher left ventricular ejection fraction (HR = 1.54 [1.07, 2.22]). After multivariable analysis, only destination therapy indication (HR = 2.2 [1.28, 3.78]) was found to be independently predictive of success failure. Despite an overall trend toward improved outcomes on device therapy, our criteria classified only one-third of patients as successful. Continued improvements in adverse event profiles, appropriate patient selection, and optimal time of implantation, together hold the key to improve outcomes after LVAD therapy.

The impact of infection among left ventricular assist device recipients on post-transplantation outcomes: A retrospective review

INTRODUCTION

Left ventricular assist device (LVAD) infections are common, and the consequences of LVAD infections on orthotopic heart transplantation (OHT) outcomes are not well described.

AIMS

The aim of this study was to describe clinical characteristics and evaluate risk factors for developing LVAD infections, and examine outcomes of LVAD-specific infections (VSI) after OHT.

METHODS

We retrospectively investigated the records of 74 consecutive patients at two institutions who had undergone LVAD placement and subsequent OHT between January 2007 and December 2012.

RESULTS

Forty-six of 74 (62%) LVAD recipients who underwent OHT had pre-transplant infections, and 18 (24%) had LVAD-specific infection (VSI), of which 71% were caused by gram-negative organisms. Of pre-transplant non-LVAD infections, Clostridium difficile infection (CDI) was the most common (26%) followed by urinary tract infection (UTI, 16%) and pneumonia (PNA 15%). Univariate analysis comparing subjects with VSI to those without VSI showed a significant association with time spent outside the hospital prior to transplantation (median 231.8 days vs 142.2 days, P < 0.03) and total time between VAD placement and OHT (244.0 days and 150.5 days, P < 0.002). Logistic regression was performed and significant predictors for VAD-related infection were age and the presence of diabetes, with type of device as an effect modifier. Six months post-OHT survival was not significantly affected by the presence of VSI prior to transplant. There was a trend toward an association between the presence of any infection and post-transplant rejection (P < 0.09). There were 10 post-transplant deaths by 6 months. Of these deaths, 4/10 (40%) were cardiopulmonary and 6/10 (60%) were related to infections.

CONCLUSIONS

Advanced age and presence of diabetes were predictors of VSI, as well as type of VAD device, although device choice is likely affected by many clinical factors including age and comorbidities, as well as institution-specific preferences. VSI was not associated with a decrease in 6-month post-OHT survival. However, infections remain the major causes of death by 6 months post-transplant. Certain infections are associated with an increased risk of rejection, which merits further investigation.

Perioperative Prophylaxis for Total Artificial Heart Transplantation

BACKGROUND

Practice variation regarding perioperative antimicrobial prophylaxis in total artificial heart transplantations (TAH-t) across institutions is unknown. The aim of our survey was to assess the current practices for prevention of infection in TAH-t recipients among different programs.

METHODS

An electronic survey was sent to programs that implant Syncardia TAH (Syncardia Systems, Tuscon, Ariz, USA). Proportions were analyzed for categorical variables; means and SDs were analyzed for continuous variables.

RESULTS

The majority of centers (80.8%) had a formal surgical infection prophylaxis protocol. For non-penicillin-allergic patients, five (20.1%) institutions reported using a 4-drug regimen, seven (29.2%) used a 3-drug regimen, five (20.1%) used a 2-drug regimen, and seven (29.2%) used a cephalosporin alone. Similar data was seen in the penicillin-allergic patients. Infections were reported to occur postoperatively in 52.2% centers. During the first month after TAH-t, bacteremia represented 27.3%, driveline infections 27.2%, pulmonary infections 9%, and mediastinal infections 18.2%. The most common organisms seen within the first month were Candida spp., Escherichia coli, and Pseudomonas aeruginosa (21.4%). In 65% of centers, the mean rate of death post-TAH-t due to infection was 14.5% (SD, 22.3%). The mean rate of patients surviving until orthotopic heart transplantation was 58.6% (SD, 27.7%).

CONCLUSIONS

Preventing infections post-TAH-t is key to decreasing morbidity and mortality. All institutions administered perioperative prophylaxis for TAH-t with significant variation among the centers. The majority of the centers have a formal perioperative prophylactic protocol.

Wound care of the driveline exit site in patients with a ventricular assist device: A systematic review

BACKGROUND

This study aims to systematically define and analyze the studies on driveline exit site care methods for patients with a ventricular assist device.

METHODS

The studies related to driveline exit site care of the patients with a ventricular assist device published in English and Turkish between 2008 and 2017 were reviewed from the international Science Direct, PubMed, Web of Science, Scopus, and the national databases. Of a total of 83 articles, a total of seven research articles which met the inclusion criteria were included in the study.

RESULTS

Findings related to the agents used in the cleaning of the driveline exit site, dressing closures, dressing change frequency, and use of driveline anchoring devices were obtained from studies included in the research. It was found that chlorhexidine solution for skin cleaning and sterile gauze sheets and transparent covering for dressing closure were the most preferred methods for the driveline exit site care. Dressing change frequency varied considerably from center to center and anchoring devices were used in all studies.

CONCLUSION

There is no gold standard method for the driveline exit site care of patients with a ventricular assist device and researches on the driveline exit site care seem to be limited. It is recommended that large-scale, randomized-controlled studies should be conducted which would provide a stronger proof of the driveline exit site care.

CT Imaging of Complications Associated with Continuous-Flow Left Ventricular Assist Devices (LVADs)

Heart failure is becoming increasingly prevalent, and more patients are being treated with left ventricular assist devices (LVADs), either as a bridge to transplant or as destination therapy. The use of continuous-flow LVADs is on the rise. LVAD therapy is associated with several classes of complications, including bleeding, thrombosis, and infection. CT imaging can be used effectively to diagnose LVAD complications, including mediastinal hematomas and pericardial, abdominal wall, and retroperitoneal hemorrhage, inflow and outflow graft and aortic thrombi, and driveline and pump pocket infections. CT can also be helpful in cases of device malfunction and can detect outflow graft kinking and inflow cannula misalignment. When interpreting CT scans in patients with LVADs, accessory materials implanted with the device should not be mistaken for hemorrhage or calcification. With training in recognizing LVAD complications, radiologists can play an important role in the evaluation of patients with heart failure.

The Risk of Cardiac Device-Related Infection in Bacteremic Patients Is Species Specific: Results of a 12-Year Prospective Cohort

BACKGROUND

The species-specific risk of cardiac device-related infection (CDRI) among bacteremic patients is incompletely understood.

METHODS

We conducted a prospective cohort study of hospitalized patients from October 2002 to December 2014 with a cardiac device (CD) and either Staphylococcus aureus bacteremia (SAB) or Gram-negative bacteremia (GNB). Cardiac devices were defined as either prosthetic heart valves (PHVs), including valvular support rings, permanent pacemakers (PPMs)/automatic implantable cardioverter defibrillators (AICDs), or left ventricular assist devices (LVADs).

RESULTS

During the study period, a total of 284 patients with ≥1 CD developed either SAB (n = 152 patients) or GNB (n = 132 patients). Among the 284 patients, 150 (52.8%) had PPMs/AICDs, 72 (25.4%) had PHVs, 4 (1.4%) had LVADs, and 58 (20.4%) had >1 device present. Overall, 54.6% of patients with SAB and 16.7% of patients with GNB met criteria for definite CDRI (P < .0001). Multivariable logistic regression analysis revealed that 3 bacterial species were associated with an increased risk for CDRI: Staphylococcus aureus (odds ratio [OR] = 5.57; 95% confidence interval [CI], 2.16-14.36), Pseudomonas aeruginosa (OR = 50.28; 95% CI, 4.16-606.93), and Serratia marcescens (OR = 7.75; 95% CI, 1.48-40.48).

CONCLUSIONS

Risk of CDRI among patients with bacteremia varies by species. Cardiac device-related infection risk is highest in patients with bacteremia due to S aureus, P aeruginosa, or S marcescens. By contrast, it is lower in patients with bacteremia due to other species of Gram-negative bacilli. Patients with a CD who develop bacteremia due to either P aeruginosa or S marcescens should be considered for diagnostic imaging to evaluate for the presence of CDRI.

Left ventricular assist pump pocket infection: conservative treatment strategy for destination therapy candidates

BACKGROUND

Heart failure is a major cause of mortality and morbidity, particularly among patients with advanced disease and no access to cardiac transplantation. LVAD implantation is not only a bridge-to-transplantation option for patients awaiting a heart donor, but is often used as bridge-to-destination therapy in patients unsuited for transplantation for various reasons. LVAD infection is considered the second-most common cause of death in patients who survive the initial 6 months on LVAD support. Few reports describe the indications for chronic suppressing antibiotic therapy, device exchange, methods for exchanging infected devices, post-exchange antimicrobial management status, and the outcomes of such patients.

CASE PRESENTATION

This is the case of a 74-year-old male patient with numerous comorbidities who received urgent surgical management for severe heart failure with a HeartMate II. Six months later he developed an LVAD pump infection with methicillin-resistant Staphylococcus epidermidis, which was diagnosed with leucocyte scintigraphy. The patient received an omental graft over the LVAD and a chronic suppressive antibiotic regime. A marked leukocyte scintigraphy showed the infection's regression 6 months after the initiation of antibiotic treatment.

DISCUSSION

We concisely reviewed the driveline infections and the main aspects of the LVAD pump infection. We reviewed options for conservative and nonconservative management and showed that conservative management of the LVAD pump infection is possible.

CONCLUSIONS

There are no defined recommendations for the management of LVAD pump infection. This case is among the few in the literature showing that conservative treatment of an LVAD pump infection is possible.

Do Prior Driveline Infections Increase the Risk of Infection in Heart Transplant Patients Treated With Rabbit Antithymocyte Globulin Induction Therapy?

BACKGROUND

The use of mechanical circulatory support devices (MCSDs) has been increasing over the past several years. Driveline infections (DLIs) are one of the most common complications seen in these patients; reportedly, up to 50% of patients with MCSDs can develop this complication. It is believed that the removal of the driveline results in treatment of the localized infection area. MCSD patients are also known to develop circulating antibodies. These circulating antibodies have been associated with poor outcomes after heart transplantation. The use of rabbit antithymocyte globulin (ATG) as induction therapy reportedly decreases the development of circulating antibodies; it is now commonly used in sensitized patients undergoing heart transplantation. It is unknown whether ATG induction therapy immediate posttransplant will increase the risk of infection of those MCSD patients with DLIs.

METHODS

Between 2003 and 2013, we evaluated 57 MCSD patients who subsequently underwent heart transplantation and received ATG induction therapy. Patients were divided into those with previous MCSD DLI and those without, and they were assessed for 1-year freedom from infection (specifically, sternal wound infections). One-year survival and freedom from treated rejection, both cellular and antibody mediated, were also assessed.

RESULTS

MCSD patients with DLIs who received ATG induction did not have a lower freedom from any treated infection and from sternal wound infection posttransplant compared with those MCSD patients without DLIs and not treated with ATG induction. There were also no significant differences between the 2 groups in terms of 1-year posttransplant survival and freedom from treated rejection.

CONCLUSIONS

The use of ATG induction in patients with prior DLIs did not seem to increase the risk for posttransplant infection (eg, sternal wound infection). ATG induction can therefore be safely used in this population.

The Role of Computed Tomography in Predicting Left Ventricular Assist Device Infectious Complications

Objective:

The purpose of this study is to identify early computed tomography findings around the driveline which would predict mediastinal or left ventricular assist device (LVAD) pocket abscess formation.

Materials and Methods:

A retrospective analysis was performed on 128 LVAD recipients between January 2007 and December 2011. Infectious complications were subdivided into those affecting the driveline and those resulting in abscess formation either around the LVAD pump or mediastinum. The size and location of infiltrative changes surrounding the driveline were used to predict infection propagation resulting in abscess.

Results:

Of the 128 patients, 49 (38.3%) patients developed driveline infections and 24 (18.8%) patients developed abscess. 87.5% patients who developed abscess had a preceding driveline infection. The mean time from driveline infection to the development of pump pocket abscess was approximately 7 months. In addition, patients with abscess in the pump pocket or mediastinum had preceding infiltrative changes surrounding the driveline ≥14 mm (P = 0.0001). A preperitoneal location and size of infiltrative changes ≥14 mm were correlated with a higher likelihood of abscess formation (P = 0.0002).

Conclusion:

Our study demonstrates the predictive value of infection/infiltrative changes around the driveline, which increases the risk for abscess formation in the LVAD pump pocket and/or in the mediastinum.

Ventricular assist devices and sleep-disordered breathing

Congestive heart failure is one of the leading causes of morbidity and mortality in the United States, and left ventricular assist devices have revolutionized treatment of end-stage heart failure. Given that sleep apnea results in significant morbidity in these patients with advanced heart failure, practicing sleep physicians need to have an understanding of left ventricular assist devices. In this review, we summarize what is known about ventricular assist devices as they relate to sleep medicine.

Endocarditis in left ventricular assist device

Heart failure is one of the leading causes of death in developed nations. End stage heart failure often requires cardiac transplantation for survival. The left ventricular assist device (LVAD) has been one of the biggest evolvements in heart failure management often serving as bridge to transplant or destination therapy in advanced heart failure. Like any other medical device, LVAD is associated with complications with infections being reported in many patients. Endocarditis developing secondary to the placement of LVAD is not a frequent, serious and difficult to treat condition with high morbidity and mortality. Currently, there are few retrospective studies and case reports reporting the same. In our review, we found the most common cause of endocarditis in LVAD was due to bacteria. Both bacterial and fungal endocarditis were associated with high morbidity and mortality. In this review we will be discussing the risk factors, organisms involved, diagnostic tests, management strategies, complications, and outcomes in patients who developed endocarditis secondary to LVAD placement.

A Case of Leukocytoclastic Vasculitis Caused by Listeria monocytogenes Bacteremia

Importance. Infections can cause leukocytoclastic vasculitis. Observations. We report the case of a patient with a left ventricular assist device who presented with acute kidney injury and biopsy proven leukocytoclastic vasculitis. Blood cultures grew Listeria monocytogenes. The patient's rash improved with treatment of the underlying Listeria infection. Conclusion. Clinicians should be aware that there are a number of broad categories of disease associated with the histologic finding of vasculitis, including infection. It is important to keep in mind the risk factors of a particular patient when formulating a differential diagnosis. This is the first reported case of Listeria bacteremia causing leukocytoclastic vasculitis.

Durable Mechanical Circulatory Support versus Organ Transplantation: Past, Present, and Future

For more than 30 years, heart transplantation has been a successful therapy for patients with terminal heart failure. Mechanical circulatory support (MCS) was developed as a therapy for end-stage heart failure at a time when cardiac transplantation was not yet a useful treatment modality. With the more successful outcomes of cardiac transplantation in the 1980s, MCS was applied as a bridge to transplantation. Because of donor scarcity and limited long-term survival, heart transplantation has had a trivial impact on the epidemiology of heart failure. Surgical implementation of MCS, both for short- and long-term treatment, affords physicians an opportunity for dramatic expansion of a meaningful therapy for these otherwise mortally ill patients. This review explores the evolution of mechanical circulatory support and its potential for providing long-term therapy, which may address the limitations of cardiac transplantation.

Left Ventricular Assist Devices: The Adolescence of a Disruptive Technology

Clinical outcomes for patients with advanced heart failure receiving left ventricular assist devices are driven by appropriate patient selection, refined surgical technique, and coordinated medical care. Perhaps even more important is innovative pump design. The introduction and widespread adoption of continuous-flow ventricular assist devices has led to a paradigm shift within the field of mechanical circulatory support, making the promise of lifetime device therapy closer to reality. The disruption caused by this new technology, on the one hand, produced meaningful improvements in patient survival and quality of life, but also introduced new clinical challenges, such as bleeding, pump thrombosis, and acquired valvular heart disease. Further evolution within this field will require financial investment to sustain innovation leading to a fully implantable, durable, and cost-effective pump for a larger segment of patients with advanced heart failure.

Necrotizing pulmonary aspergillosis and ventricular assist device infection: case report and review of literature

Necrotizing pulmonary aspergillosis and Aspergillus device infection are rare and have potentially fatal complications after left ventricular assist device (LVAD) implantation. To date, few cases of patients surviving Aspergillus device infection have been published, with survival reported only after device removal. We present a patient implanted with an LVAD in whom necrotizing pulmonary aspergillosis with device involvement was successfully treated by segmentectomy and prolonged antifungal treatment without device exchange or removal. Similar cases in the literature were searched for and are discussed in view of the severity of this complication.

Suspected involvement of EPTFE membrane in sterile intrathoracic abscess and pericardial empyema in a multi-allergic LVAD recipient: a case report

Device-related infections in recipients of left ventricular assist devices (LVAD) have been recognized as a major source of morbidity and mortality. They require a high level of diagnostic effort as part of the overall burden resulting from infectious complications in LVAD recipients. We present a multi-allergic patient who was treated for persistent sterile intrathoracic abscess formation and pericardial empyema following minimally invasive LVAD implantation including use of a sheet of e-polytetrafluoroethylene (ePTFE) membrane to restore pericardial integrity. Sterile abscess formation and pericardial empyema recurred after surgical removal until the ePTFE membrane was removed, suggesting that in disposed patients, ePTFE may be related to sterile abscess formation or sterile empyema.

Disseminated Streptococcus pneumoniae infection involving a ventricular assist device

We describe the first reported case, to our knowledge, of disseminated pneumococcal infection involving a left ventricular assist device (LVAD). The management of this infection was extremely challenging, requiring multiple surgical debridements, LVAD removal, and prolonged courses of antibiotics. The Streptococcus pneumoniae isolate was found to be serotype 19F, which is included in both the pneumococcal polysaccharide and conjugate vaccines. This report highlights the importance of routine screening for up-to-date vaccination in patients who undergo LVAD implantation.

Role of gallium SPECT-CT in the diagnosis of left ventricular assist device infections

Infection remains a well-established complication after the placement of left ventricular assist devices (LVADs). Defining the extent of infection is a challenging task as there are few effective imaging modalities and no standardized guidelines regarding imaging in the diagnosis of device-related infections (DRIs). The use of gallium with single photon emission tomography-computed tomography (Ga-SPECT-CT) has not been previously reported in localizing DRIs. We reviewed the charts and images of five patients with LVADs who underwent Ga-SPECT-CT for the diagnosis of various types of DRIs. Gallium SPECT-CT further clarified the extent of infections among LVAD patients, allowing for patient-specific tailored treatments including surgical debridement. Gallium SPECT-CT is a useful tool when diagnosing LVAD infections and could potentially be the imaging modality of choice in the near future. With improved imaging studies, such as Ga-SPECT-CT, allowing for earlier and more accurate diagnoses of DRIs, the outcome of such infections is likely to improve.

Case report: atypical fungal obstruction of the left ventricular assist device outflow cannula

We describe a very rare case of outflow cannula obstruction with fungal infectious thrombus formation. Discussion includes the etiology, diagnosis, and management of fungal infection complications related with long-term mechanical circulatory support. Left ventricular assist devices (LVADs) are increasingly used as bridge to transplant and permanent long-term therapy in the population with end-stage heart failure. Even though better clinical outcomes have been achieved with the newer-generation continuous-flow devices, infection complications are still a major risk for patients with continuous-flow LVAD implantation in long-term follow-up [Ann Thorac Surg 90:1270-1277, 2010]. Device-related infections can be categorized as driveline infections, pump-pocket infections, and LVAD-associated endocarditis [Expert Rev Med Devices 8: 627-634, 2011]. The microbiological profile is very heterogeneous; the most common pathogens are Staphylococcus, Pseudomonas, Streptococcus species, and Candida. Severe fungal infection may lead to dysfunction of the LVAD due to obstructive mass formation within the device. Due to the only anecdotal reports in the current literature, we present a very rare case of outflow fungal infectious thrombus formation leading to outflow cannula obstruction in patient with LVAD.

General surgical complications associated with the use of long-term mechanical circulatory support devices: are we 'under-reporting' problems?

Multiple complications are associated with use of ventricular assist devices (VADs). Cardiac-related complications and infections are most frequently reported. VADs, however, can also lead to a number of general surgical complications equally significant in terms of morbidity and mortality. The authors performed a systematic literature search to review current data that specifically relate general surgical complications to patients who undergo left VAD implantation. The review provides a relatively clear understanding of the spectrum of general surgical complications and shows that they contribute significantly to morbidity and mortality in these patients.

Management of patients with implanted ventricular assist devices for noncardiac surgery: a clinical review

While originally primarily used as bridge to cardiac transplantation and bridge to recovery, more commonly ventricular assist devices (VADs) are being inserted as destination therapy. These patients are being discharged from transplant and mechanical assist centers, living as outpatients, and thus the pool of community-dwelling patients with VADs continues to expand. Not infrequently they present for surgical procedures either directly related to the device itself or more often incidental to the fact that they have a VAD. This scenario may be more common in patients with VADs placed for destination therapy because these patients tend to be older and have more comorbidities and are living longer with their device. Thus, it is important for all anesthesiologists to be aware of the special anesthesia needs of patients with VADs requiring noncardiac surgery.

Impact of adverse events on ventricular assist device outcomes

Left ventricular assist devices have been proven to be superior to medical therapy for advanced heart failure patients awaiting heart transplantation and viable alternatives to transplantation for destination therapy patients. Improvements in the design of ventricular assist devices have been rewarded by a decrease in adverse events and an increase in survival. Despite significant progress, even the latest generation left ventricular assist devices are burdened by a significant long-term adverse events profile that will increasingly challenge physicians as patients survive longer on implantable mechanical circulatory support. In this review, we analyze the impact of long-term adverse events on clinical outcomes in the major trials of continuous flow left ventricular assist devices. We discuss several of the more pertinent and interesting adverse events, examine their potential causes, and explore their future implications.

Exercise guidelines for inpatients following ventricular assist device placement: a systematic review of the literature

BACKGROUND

For patients with end-stage heart failure awaiting transplantation, lack of donor organs has created an increased need for alternatives such as left ventricular assist device (LVAD) implantation. The purpose of this study is to determine safe and effective exercise parameters for physical therapy in the acute care setting.

METHODS

A systematic literature review was conducted according to PRISMA guidelines using Sackett's Levels of Evidence to rate the evidence. Multiple databases were searched with inclusion criteria of: available in English, inpatient care up to 6 months postoperatively, description of intervention type and exercise parameters.

EXCLUSION CRITERIA

no defined exercise parameters, outpatient treatment, infection post VAD, or palliative or hospice care post VAD.

RESULTS

Six studies out of 1,291 articles met inclusion criteria. Common exercise parameters used were the Borg Rating of Perceived Exertion scale 11-13 (6-20 scale) or > 4 (0-10 scale), Dyspnea scale > 2 (0-4 scale) and > 5 (0-10 scale), mean arterial pressure (MAP) 70-95 mmHg, and LVAD flow > 3L/min. Levels of evidence ranged from case controlled to expert opinion.

CONCLUSION

Current evidence on inpatient exercise parameters for patient's status post LVAD implantation is not sufficient to suggest definitive guidelines; however, these exercise parameters provide a reference for patient care.

Advances and future directions for mechanical circulatory support

Although cardiac transplant remains the gold standard for the treatment of end-stage heart failure, limited donor organ availability and growing numbers of eligible recipients have increased the demand for alternative therapies. Limitations of first-generation left ventricular assist devices for long-term support of patients with end-stage disease have led to the development of newer second-generation and third-generation pumps, which are smaller, have fewer moving parts, and have shown improved durability, allowing for extended support. The HeartMate II (second generation) and HeartWare (third generation) are 2 devices that have shown great promise as potential alternatives to transplantation in select patients.