Perioperative interventions for the prevention of surgical wound infection in adult patients undergoing left ventricular assist devices implantation: A scoping review

BACKGROUND

Surgical wound infection is the most frequent type of care health associated infection. Lack of knowledge about the prevention of surgical wound infection in patients undergoing left ventricular assist device implantation could significantly undermine the potential benefits of surgical intervention.

OBJECTIVES

This study aimed to map the recommendations for adult patients undergoing left ventricular assist device implantation.

DESIGN

This is a scoping review, being registered in the Open Science Framework under DOI https://doi.org/10.17605/OSF.IO/Q76B3 (https://osf.io/q76b3/).

METHOD

Left ventricular assist device coordinators and nurse specialists in dermatology and stomatherapy conducted a scoping review in Scopus, The Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature (CINAHL), limited to the period between 2015 and 2022. The results of this scoping review will be discussed and presented in separate articles. This paper will synthesize research evidence on the perioperative topic.

RESULTS

The initial searches resulted in 771 studies. Sixty nine met the eligibility criteria and were included in the scoping review. Eight articles addressing the perioperative topic that answered the question of this article were included.

CONCLUSION

Although this scoping review included heterogeneous, and scarce studies with left ventricular assist device patients. As such, there are many promising future research directions for this topic.

IMPLICATIONS FOR CLINICAL PRACTICE

Infection surveillance should be an integral part of left ventricular assist device implantation programs in health care institutions. Velvet completely buried in subcutaneous tissues reduces transmission system infection. Triple tunnel method reduces transmission system infection risk.

Numerical methods for hemolysis and thrombus evaluation in the percutaneous ventricular assist device

BACKGROUND

A percutaneous ventricular assist device (pVAD) is an effective method to treat heart failure, but its complications, mainly hemolysis and thrombus formation, cannot be ignored. Accurate evaluation of hemolysis and thrombus formation in pVAD is essential to guide the development of pVAD and reduce the incidence of complications.

METHODS

This study optimized the numerical model to predict hemolysis and thrombus formation in pVAD. The hemolysis model is based on the power law function, and the multi-component thrombus prediction model is improved by introducing the von Willebrand factor.

RESULTS

The error between the numerical simulation and the hydraulic performance experiment is within 5%. The numerical results of hemolysis are in good agreement with those of in vitro experiments. Meanwhile, the thrombus location predicted by the numerical model is the same as that found in the in vivo experiment.

CONCLUSION

The numerical model suggested in this study may therefore accurately assess the possible hemolytic and thrombotic dangers in pVAD, making it an effective tool to support the development of pVAD.

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.

Longitudinal cardiac dimensions in patients undergoing LVAD implantation

BACKGROUND

In conventional left ventricular assist devices (LVAD), a separate outflow graft is sutured to the ascending aorta. Novel device designs may include a transventricular outflow cannula crossing the aortic valve (AV). While transversal ventricular dimensions are well investigated in patients with severe heart failure, little is known about the longitudinal dimensions. These dimensions are, however, particularly critical for the design and development of mechanical circulatory support (MCS) devices with transaortic outflow cannula.

METHODS

In an explorative retrospective cohort study at the University Medical Center Freiburg, Germany, the longitudinal cardiac dimensions of patients undergoing computed tomography angiography (CTA) before and, if available, after LVAD implantation were analyzed. Among others, the following dimensions were assessed: (a) apex to AV, (b) apex to mitral valve, (c) AV to sinotubular junction (STJ), (d) apex to STJ, (e) apex to brachiocephalic artery (BCA), and (f) AV to BCA.

RESULTS

In total, 44 LVAD patients (36 male, age 55.8 years, height 1.75 m) were included. The longitudinal cardiac dimensions were (a) 114.5 ± 12.1 mm, (b) 108.0 ± 12.4 mm, (c) 20.9 ± 2.9, (d) 135.4 ± 13.4 mm, (e) 206.0 ± 18.3, and (f) 91.5 ± 9.8 mm. Postoperatively, (a) and (b) decreased by 31.5% and 39.5%, respectively (N = 14).

CONCLUSIONS

Longitudinal cardiac dimensions may be reduced by up to 40% after LVAD implantation. A better knowledge of these dimensions and their postoperative alterations in LVAD patients may improve surgical planning and help to design MCS devices with transventricular outflow cannula.

Modifiable risk factor reduction for pediatric ventricular assist devices and the influence of persistent modifiable risk factors at transplant

OBJECTIVES

Ventricular assist devices (VADs) are associated with a mortality benefit in children. Database-driven analyses have associated VADs with reduction of modifiable risk factors (MRFs), but validation with institutional data is required. The authors studied MRF reduction on VAD and the influence of persistent MRFs on survival after heart transplant.

METHODS

All patients at the authors' institution requiring a VAD at transplant (2011-2022) were retrospectively identified. MRFs included renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2), hepatic dysfunction (total bilirubin ≥1.2 mg/dL), total parenteral nutrition dependence, sedatives, paralytics, inotropes, and mechanical ventilation.

RESULTS

Thirty-nine patients were identified. At time of VAD implantation, 18 patients had ≥3 MRFs, 21 had 1 to 2 MRFs, and 0 had 0 MRFs. At time of transplant, 6 patients had ≥3 MRFs, 17 had 1 to 2 MRFs, and 16 had 0 MRFs. Hospital mortality occurred in 50% (3 out of 6) patients with ≥3 MRFs at transplant vs 0% of patients with 1 to 2 and 0 MRFs (P = .01 for ≥3 vs 1-2 and 0 MRFs). MRFs independently associated with hospital mortality included paralytics (1.76 [range, 1.32-2.30]), ventilator (1.59 [range, 1.28-1.97]), total parenteral nutrition dependence (1.49 [range, 1.07-2.07]), and renal dysfunction (1.31 [range, 1.02-1.67]). Two late mortalities occurred (3.6 and 5.7 y), both in patients with 1 to 2 MRFs at transplant. Overall posttransplant survival was significantly worse for ≥3 versus 0 MRFs (P = .006) but comparable between other cohorts (P > .1).

CONCLUSIONS

VADs are associated with MRF reduction in children, yet those with persistent MRFs at transplant experience a high burden of mortality. Transplanting VAD patients with ≥3 MRFs may not be prudent. Time should be given on VAD support to achieve aggressive pre-transplant optimization of MRFs.

Absorbable antibiotic beads for treatment of LVAD driveline infections

BACKGOUND

Infections of the left ventricular assist device (LVAD) driveline are a dreaded complication that results in high mortality and morbidity.

METHOD

We retrospectively reviewed five consecutive patients with severe continuous-flow LVAD (HVAD, Heartmate 2, and Heartmate 3) driveline infection. These infections, which developed on an average of 960.4 ± 843.9 days after LVAD placement, were refractory to systemic antibiotics and local wound care. All were treated with extensive surgical debridement, local installation of absorbable antibiotic-loaded calcium sulfate beads (vancomycin and tobramycin), primary wound closure, and 6 weeks of systemic antibiotics after surgery.

RESULTS

Four patients had resolution of DLI, and one had a recurrent infection at another part of the driveline 7 months after the complete resolution of the previous site. This patient was successfully treated with debridement and bead placements. Three patients still have their LVADs, while two received orthotopic heart transplants. At the time of the transplant, there was no evidence of gross infection of the LVAD drivelines or pumps. At the average follow-up time of 425.8 ± 151 days, no patients have an active infection.

CONCLUSION

Treatment of LVAD driveline infection with absorbable antibiotic beads with primary wound closure is a viable option and merits further investigation.

Surgical Treatment of Tricuspid Valve Regurgitation in Patients Undergoing Left Ventricular Assist Device Implantation: Interim analysis of the TVVAD trial

OBJECTIVES

Right heart failure remains a serious complication of left ventricular assist device therapy. Many patients presenting for left ventricular assist device implantation have significant tricuspid regurgitation. It remains unknown whether concurrent tricuspid valve surgery reduces postoperative right heart failure. The primary aim was to identify whether concurrent tricuspid valve surgery reduced the incidence of moderate or severe right heart failure within the first 6 months after left ventricular assist device implantation.

METHODS

Patients with moderate or severe tricuspid regurgitation on preoperative echocardiography were randomized to left ventricular assist device implantation alone (no tricuspid valve surgery) or with concurrent tricuspid valve surgery. Randomization was stratified by preoperative right ventricular dysfunction. The primary end point was the frequency of moderate or severe right heart failure within 6 months after surgery.

RESULTS

This report describes a planned interim analysis of the first 60 randomized patients. The tricuspid valve surgery group (n = 32) had mild or no tricuspid regurgitation more frequently on follow-up echocardiography studies compared with the no tricuspid valve surgery group (n = 28). However, at 6 months, the incidence of moderate and severe right heart failure was similar in each group (tricuspid valve surgery: 46.9% vs no tricuspid valve surgery: 50%, P = .81). There was no significant difference in postoperative mortality or requirement for right ventricular assist device between the groups. There were also no significant differences in secondary end points of functional status and adverse events.

CONCLUSIONS

The presence of significant tricuspid regurgitation before left ventricular assist device is associated with a high incidence of right heart failure within the first 6 months after surgery. Tricuspid valve surgery was successful in reducing postimplant tricuspid regurgitation compared with no tricuspid valve surgery but was not associated with a lower incidence of right heart failure.

Real-world data of patients affected by advanced heart failure treated with implantable cardioverter defibrillator and left ventricular assist device: Results of a multicenter observational study

BACKGROUND

Left ventricular assist device (L-VAD) implantation is increasingly used in patients with heart failure (HF) and most patients also have an implantable cardioverter defibrillator (ICD). Limited data are available on the incidence of ICD therapies and complications in this special setting. The aim of this study was to analyze the real-world incidence and predictors of ICD therapies, complications and interactions between ICD and L-VAD.

METHODS

We conducted a multicenter retrospective observational study in patients with advanced HF implanted with ICD and a continuous-flow L-VAD, followed-up in five advanced HF centers in Northern Italy.

RESULTS

A total of 234 patients (89.7% male, median age 59, 48.3% with ischemic etiology) were enrolled. After a median follow-up of 21 months, 66 patients (28.2%) experienced an appropriate ICD therapy, 22 patients (9.4%) an inappropriate ICD therapy, and 17 patients (7.3%) suffered from an interaction between ICD and L-VAD. The composite outcome of all ICD-related complications was reported in 41 patients (17.5%), and 121 (51.7%) experienced an L-VAD-related complication. At multivariable analysis, an active ventricular tachycardia (VT) zone and a prior ICD generator replacement were independent predictors of ICD therapies and of total ICD-related complications, respectively.

CONCLUSIONS

Real-world patients with both L-VAD and ICD experience a high rate of ICD therapies and complications. Our findings suggest the importance of tailoring device programming in order to minimize the incidence of unnecessary ICD therapies, thus sparing the need for ICD generator replacement, a procedure associated to a high risk of complications.

Experimental validation of the power law hemolysis model using a Couette shearing device

BACKGROUND

The study of blood trauma, such as hemolysis in blood-carrying devices, is crucial due to the high incidence of adverse events like alteration of blood function, bleeding, and multi-organ failure. The extent of flow-induced hemolysis, predominantly influenced by stress duration and intensity, is described by established model parameters based on the power law approach. In recent years, various parameters were determined using different Couette shearing devices and donor species. However, they have not been validated due to limited experimental data.

METHODS

This study provides hemolysis measurements in a Couette shearing device and evaluates the suitability of different power law parameters. The revised Couette shearing device generates well-defined dynamic stress loads that are repeatedly applied to blood samples at a defined temperature. Human blood samples with an adjusted hematocrit of 30%, were tested with varying repetitions (20 to 80 times). The half-sinusoidal stress loads had amplitudes of 73 to 140 Pa and exposure times of 24 msec per repetition. The parameters of five common power law hemolysis approaches were then compared with the experimental data.

RESULTS

The prediction with the power law model parameters C = 3.458 × 10-6, α = 0.2777 and β = 2.0639 showed a good agreement with the experimental results.

CONCLUSION

The effect of multiple short-time stresses on hemolysis was investigated to validate the power law hemolysis model with the Couette shearing device of this study.

Repeat left ventricular-assisted device exchange and upgrade from second- to third-generation devices in a high-volume single center

BACKGROUND

Pump exchange is an established strategy to treat LVAD-related complications such as thrombosis, infection, and driveline failure. Pump upgrades with an exchange to newer generation devices are being performed to the advantage of the patient on long-term support. The safety and efficacy of a repeat LVAD exchange with a concomitant upgrade to a third-generation pump have not been reported.

METHODS

We performed a retrospective analysis of all consecutive patients who underwent a repeat LVAD device exchange and upgrade to HeartMate III (HMIII) at Houston Methodist Hospital between December 2018 and December 2020.

RESULTS

Five patients underwent exchange and upgrade to HMIII within the specified timeframe. Four patients had already had two prior exchanges (all HMII to HMII), and one patient had one prior exchange (HVAD to HVAD). In all cases, implantation was performed as destination therapy. The surgical exchange was performed via redo median sternotomy on full cardiopulmonary bypass. No unplanned redo surgery of the device component was required. In-hospital mortality was 20% in this very high-risk population. At 1-, 3-, and 6-month follow-up, all discharged patients were on HMIII support, with no major LVAD-related adverse events reported.

CONCLUSION

We report the feasibility and safety of a repeat pump exchange with an upgrade to HMIII in a high-volume center. The decision for medical therapy versus surgical exchange has to be tailored to individual cases based on risk factors and clinical stability but in expert hands, even a re-redo surgical approach grants options for good medium-term outcomes.

Microaxial Flow Pump or Standard Care in Infarct-Related Cardiogenic Shock

BACKGROUND

The effects of temporary mechanical circulatory support with a microaxial flow pump on mortality among patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock remains unclear.

METHODS

In an international, multicenter, randomized trial, we assigned patients with STEMI and cardiogenic shock to receive a microaxial flow pump (Impella CP) plus standard care or standard care alone. The primary end point was death from any cause at 180 days. A composite safety end point was severe bleeding, limb ischemia, hemolysis, device failure, or worsening aortic regurgitation.

RESULTS

A total of 360 patients underwent randomization, of whom 355 were included in the final analysis (179 in the microaxial-flow-pump group and 176 in the standard-care group). The median age of the patients was 67 years, and 79.2% were men. Death from any cause occurred in 82 of 179 patients (45.8%) in the microaxial-flow-pump group and in 103 of 176 patients (58.5%) in the standard-care group (hazard ratio, 0.74; 95% confidence interval [CI], 0.55 to 0.99; P = 0.04). A composite safety end-point event occurred in 43 patients (24.0%) in the microaxial-flow-pump group and in 11 (6.2%) in the standard-care group (relative risk, 4.74; 95% CI, 2.36 to 9.55). Renal-replacement therapy was administered to 75 patients (41.9%) in the microaxial-flow-pump group and to 47 patients (26.7%) in the standard-care group (relative risk, 1.98; 95% CI, 1.27 to 3.09).

CONCLUSIONS

The routine use of a microaxial flow pump with standard care in the treatment of patients with STEMI-related cardiogenic shock led to a lower risk of death from any cause at 180 days than standard care alone. The incidence of a composite of adverse events was higher with the use of the microaxial flow pump. (Funded by the Danish Heart Foundation and Abiomed; DanGer Shock ClinicalTrials.gov number, NCT01633502.).

Impact of Age, Gender, and Body Mass Index on Short-Term Outcomes of Patients With Cardiogenic Shock on Mechanical Circulatory Support

This single-center, observational study assessed the impact of age, gender, and body mass index (BMI) in patients with cardiogenic shock (CS) on temporary mechanical circulatory support. All adult patients admitted to the Cleveland Clinic main campus Cardiac Intensive Care Unit (CICU) between December 1, 2015, to December 31, 2019, CICU with CS necessitating mechanical circulatory support (MCS) with intra-aortic balloon pump, Impella, or venous arterial-extra corporeal membrane oxygenation were retrospectively analyzed for this study. Baseline characteristics and 30-day outcomes were collected through physician-directed chart review. The impact of age, gender, and BMI on 30-day mortality was assessed using multivariable logistic regression. Kaplan-Meier survival curves were used to analyze the survival difference in specific subsets. A total of 393 patients with CS on temporary MCS were admitted to our CICU during the study period. The median age of our cohort was 63 years (interquartile range 54 to 70 years), median BMI was 28.50 kg/m2 (interquartile range 24.62 to 29.72) and 70% (n = 276) were men. In total, 22 patients >80 years had received MCS compared with 372 patients <80 years. Patients >80 years on MCS had significantly higher 30-day mortality compared with those <80 years (81.8% vs 49.3%, p = 0.006). Upon stratifying patients by BMI, 161 (41%) patients were found to have BMI ≥30 kg/m2 whereas 232 (59%) patients had BMI <30 kg/m2. Comparison of 30-day mortality revealed that patients with BMI ≥30 did significantly worse than patients with BMI <30 (59.6% vs 45.3%, p = 0.007). There was no difference in 30-day mortality between men and women. On multivariable logistic regression, both age and BMI had a positive linear relation with adjusted 30-day mortality whereas gender did not have a major effect. Advanced age and higher BMI are independently associated with worse outcomes in patients with CS on MCS. Utilizing a strict selection criterion for patients in CS is pertinent to derive the maximum benefit from advanced mechanical support.

Circulating biomarkers of the CS4P and CLIP scores are not altered in a pig model of acute cardiogenic shock and additional short-term circulatory support

BACKGROUND

Cardiogenic shock (CS) is the leading cause of death in patients with myocardial infarction with a mortality rate greater than 50%. Recently, the CS 4 Proteins (CS4P) and CLIP scores have been developed to predict survival in CS patients. However, their impact in acute CS and additional short-term left ventricular (LV) circulatory support as prognostic markers is currently not known.

METHODS AND RESULTS

CS was induced in a porcine model by injecting microsphere particles into the left main coronary artery. Mechanical circulatory support was performed by additional percutaneous LV unloading using an Impella microaxial flow-pump for 30 minutes. Serum samples were collected at baseline, following the onset of CS, and additional LV unloading. Serum levels of biomarkers of the CS4P (beta-2-microglobulin, ALDOB, L-FABP, SerpinG1) and the CLIP scores (Cystatin C, Lactate, Interleukin-6, NT-proBNP) were neither different at any time point investigated nor did they correlate with cardiac output.

CONCLUSION

The CS4P and CLIP scores do not reflect immediate whole-body dysregulation in acute CS and have not been able to predict the potential reversal following additional short-term mechanical support by LV unloading in our experimental model. The impact of both scores as prognostic markers after the immediate onset of CS and following additional short-term LV unloading to identify patients at greatest risk remains to be determined.

Pseudomonas aeruginosa ventricular assist device infections: findings from ineffective phage therapies in five cases

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular Pseudomonas aeruginosa LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14-51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in P. aeruginosa endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.

Long-term kidney outcomes in pediatric continuous-flow ventricular assist device patients

BACKGROUND

Continuous-flow ventricular assist devices (CF-VADs) are used increasingly in pediatric end-stage heart failure (ESHF) patients. Alongside common risk factors like oxidant injury from hemolysis, non-pulsatile flow constitutes a unique circulatory stress on kidneys. Post-implantation recovery after acute kidney injury (AKI) is commonly reported, but long-term kidney outcomes or factors implicated in the evolution of chronic kidney disease (CKD) with prolonged CF-VAD support are unknown.

METHODS

We studied ESHF patients supported > 90 days on CF-VAD from 2008 to 2018. The primary outcome was CKD (per Kidney Disease Improving Global Outcomes (KDIGO) criteria). Secondary outcomes included AKI incidence post-implantation and CKD evolution in the 6-12 months of CF-VAD support.

RESULTS

We enrolled 134 patients; 84/134 (63%) were male, median age was 13 [IQR 9.9, 15.9] years, 72/134 (54%) had preexisting CKD at implantation, and 85/134 (63%) had AKI. At 3 months, of the 91/134 (68%) still on a CF-VAD, 34/91 (37%) never had CKD, 13/91 (14%) developed de novo CKD, while CKD persisted or worsened in 49% (44/91). Etiology of heart failure, extracorporeal membrane oxygenation use, duration of CF-VAD, AKI history, and kidney replacement therapy were not associated with different CKD outcomes. Mortality was higher in those with AKI or preexisting CKD.

CONCLUSIONS

In the first multicenter study to focus on kidney outcomes for pediatric long-term CF-VAD patients, preimplantation CKD and peri-implantation AKI were common. Both de novo CKD and worsening CKD can happen on prolonged CF-VAD support. Proactive kidney function monitoring and targeted follow-up are important to optimize outcomes.

Associations Between Preimplant Cancer Type and Left Ventricular Assist Device Outcomes: An INTERMACS Registry Analysis

We used the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to examine whether history of a solid versus hematologic malignancy impacts outcomes after left ventricular assist device (LVAD) implantation. We included LVAD recipients (2007-2017) with cancer history reported (N = 14,799, 21% female, 24% Black). Multivariate models examined the association between cancer type and post-LVAD mortality and adverse events. Competing risk analyses compared death and heart transplantation between cancer types and those without cancer in bridge-to-transplant (BTT) patients. A total of 909 (6.1%) patients had a history of cancer (4.9% solid tumor, 1.3% hematologic malignancy). Solid tumors were associated with higher mortality (adjusted hazard ratio [aHR] = 1.31, 95% confidence interval [CI] = 1.09-1.57), major bleeding (aHR = 1.15, 95% CI = 1.00-1.32), and pump thrombosis (aHR = 1.52, 95% CI = 1.09-2.13), whereas hematologic malignancies were associated with increased major infection (aHR = 1.43, 95% CI = 1.14-1.80). Compared to BTT patients without a history of cancer, solid tumor patients were less likely to undergo transplantation (adjusted subdistribution HR [aSHR] = 0.63, 95% CI = 0.45-0.89) and hematologic malignancy patients were as likely to experience death (aSHR = 1.16, 95% CI = 0.63-2.14) and transplantation (aSHR = 0.69, 95% CI = 0.44-1.08). Cancer history and type impact post-LVAD outcomes. As LVAD utilization in cancer survivors increases, we need strategies to improve post-LVAD outcomes in these patients.

Evaluation of enoxaparin for bridging of warfarin in outpatients with left ventricular assist devices (LVADs)

BACKGROUND

Patients with left ventricular assist devices (LVADs) require systemic anticoagulation. The use of enoxaparin for bridging to warfarin remains understudied in this population.

METHODS

This single-center retrospective study was performed to characterize enoxaparin use and associated thrombotic and bleeding outcomes in adult outpatients with LVADs from January 2018 to July 2021.

RESULTS

Fifty-four enoxaparin bridging events were evaluated in 49 patients. Most patients with HeartMate II (HM2) and HeartWare (HVAD) devices received enoxaparin dosed 1 mg/kg every 12 h. In patients with HeartMate 3 (HM3) devices, an equal number of patients received 0.5 mg/kg every 12 h and 1 mg/kg every 12 h, with a smaller subset receiving intermediate doses. The median duration of bridging was 6 days (4-8 [IQR]). One major bleeding event required discontinuation of enoxaparin and hospitalization in a patient with an HM3 device. Thrombotic events occurred in four patients with two incidents of pump thrombosis requiring pump exchange and two ischemic strokes. All thrombotic events occurred in patients with HVAD or HM2 devices.

CONCLUSION

These results suggest that enoxaparin bridging in LVAD patients was well-tolerated with low bleeding and thrombotic rates, particularly with the HM3 device.

Intracorporeal LVAD implantation in pediatric patients: A single-center 10 years' experience

BACKGROUND

Mechanical cardiac support is currently an effective strategy to reduce morbidity and mortality in pediatric patients. However, solid evidence regarding the feasibility of intracorporeal devices in children still needs to be provided. We report our 10-year experience with intracorporeal left ventricular assist devices (LVAD) in children.

MATERIALS AND METHODS

We included all patients undergoing intracorporeal, continuous-flow LVAD implantation between 2012 and 2022. Baseline and postoperative data were collected from the institutional database.

RESULTS

Seven HeartWare and 4 HeartMate3 were implanted in 11 patients (median age 13.9 years, median body surface area - BSA - 1.42 m2, IQR 1.06-1.68). The most frequent indication to LVAD implant was dilated cardiomyopathy (72.7%). All candidates underwent a thorough preoperative advanced imaging. Three-dimensional reconstructions and implant fit simulation were performed when BSA was <1.2 m2, weight <30 kg, or internal transverse thoracic diameter <20 cm. There was no operative death. The most common postoperative complication was surgical re-exploration due to bleeding (27.3%). One patient died of severe neurological complications after about 3 months of hospitalization. No late deaths or unplanned re-hospitalizations occurred in the remaining 10, 6 of whom were discharged home. There were no major complications at the follow-up. All survivors underwent successful heart transplantation.

CONCLUSIONS

Intracorporeal LVAD implantation proved to be a potentially feasible and safe option in young teenagers and children whose BSA was >1.0 m2. In borderline cases, the 3D reconstruction with implant fit simulation can effectively help to identify those patients who can safely undergo intrathoracic LVAD implantation.

Treatment Strategies and Outcomes of Right Ventricular Failure Post Left Ventricular Assist Device Implantation: An INTERMACS Analysis

Right heart failure (RHF) management after left ventricular assist device (LVAD) implantation includes inotropes, right ventricular mechanical support, and heart transplantation. The purpose of this study is to compare different RHF treatment strategies in patients with a magnetically levitated centrifugal LVAD. A total of 6,632 Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) patients from 2013 to 2020 were included. Of which, 769 (69.6%) patients (group 1) were supported with inotropes (≥14 days post-LVAD implantation), 233 (21.1%) patients (group 2) were supported with temporary right ventricular assist device (RVAD) that was implanted during LVAD implant, 77 (7.0%) patients (group 3) with durable centrifugal RVAD implanted during the LVAD implant, and 26 (2.4%) patients (group 4) were supported with RVAD (temporary or permanent), which was implanted at a later stage. Groups 1 and 4 had higher survival rates in comparison with group 2 (hazard ratio [HR] = 0.513, 95% confidence intervals [CIs] = 0.402-0.655, p < 0.001, versus group 1) and group 3 (HR = 0.461, 95% CIs = 0.320-0.666, p < 0.001, versus group 1). Patients in group 3 showed higher heart transplantation rates at 12 and 36 months as compared with group 1 (40.4% and 46.6% vs. 21.9% and 37.4%, respectively), group 2 (40.4% and 46.6% vs. 25.8% and 39.3%, respectively), and group 4 (40.4% and 46.6% vs. 3.8% and 12.0%, respectively). Severe RHF post-LVAD is associated with poor survival. Patients with LVAD who during the perioperative period are in need of right ventricular temporary or durable mechanical circulatory support constitute a group at particular risk. Improvement of devices tailored for right ventricular support is mandatory for further evolution of the field.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Special Considerations for Mechanical Circulatory Support or Device Therapy in Adult Congenital Heart Disease Heart Failure

Heart failure has become the leading cause of mortality in adult congenital heart disease (ACHD) patients after the fifth decade of life. There is scanty evidence supporting the use of guideline-directed medical therapy in ACHD, especially in systemic right ventricle or single ventricle physiology. In complex patients, diagnosing heart failure and timely referral for advanced therapies are challenging. Mechanical circulatory support has been significantly developed over the past decade and has recently emerged as a feasible therapeutic option for these patients. This review summarizes current evidence of mechanical circulatory support in this population, its potential uses, and challenges.

Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database

BACKGROUND

Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) on the basis of relative and absolute contraindications to transplantation. Multiple factors may lead to changes in the strategy of support after LVAD implantation.

METHODS

Based on INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020 data, 11,262 patients survived to 3 months on continuous-flow LVADs with intent of BTT or DT. Preimplant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months.

RESULTS

Among 3216 BTT patients at 3 months, later transplant delisting or death without transplant occurred in 536 (16.7%) and was more common with age, profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51; P = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure as defined by inotropic therapy, predicted delisting and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33; P = 0.0024). Of 8046 patients surviving to 3 months with the intent of destination therapy, 750 (9.3%) subsequently underwent listing or transplantation, often with initial histories of acute HF (HR 1.70, 95% CI 1.27-2.27; P = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63; P = 0.0099). Multiple gastrointestinal bleeding events (≥ 4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275; P = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9; P = 0.0011).

CONCLUSIONS

Implant strategies change over time in relation to preimplant characteristics and adverse events post implant. Preimplant recognition of factors predicting later change in implant strategy will refine initial triage, whereas further reduction of post-LVAD complications will expand options, including eventual consideration of heart transplantation.

A multicenter evaluation of the HeartMate 3 risk score

BACKGROUND

The Heartmate 3 (HM3) risk score (HM3RS) was derived and validated internally from within the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) trial population and provides 1- and 2-year mortality risk prediction for patients in those before HM3 left ventricular assist device (LVAD) implantation. We aimed to evaluate the HM3RS in nontrial unselected patients, including those not meeting inclusion criteria for MOMENTUM 3 trial enrollment.

METHODS

Patients who underwent HM3 LVAD implant at 1 of 7 US centers between 2017 and 2021, with at least 1-year follow-up, were included in this analysis. Patients were retrospectively assessed for their eligibility for the MOMENTUM 3 trial based on study inclusion and exclusion criteria. HM3RS risk discrimination was evaluated using time-dependent receiver operating characteristic curve analysis for 1-year mortality for all patients and further stratified by MOMENTUM 3 trial eligibility. Kaplan-Meier curves were constructed using the HM3RS-based risk categories.

RESULTS

Of 521 patients included in the analysis, 266 (51.1%) would have met enrollment criteria for MOMENTUM 3. The 1- and 2-year survival for the total cohort was 85% and 81%, respectively. There was no statistically significant difference in survival between those who met and did not meet enrollment criteria at 1 (87% vs 83%; p = 0.21) and 2 years postimplant (80% vs 78%; p = 0.39). For the total cohort, HM3RS predicted 1-year survival with an area under the curve (AUC) of 0.63 (95% confidence interval [CI]: 0.57-0.69, p < 0.001). HM3RS performed better in the subset of patients meeting enrollment criteria: AUC 0.69 (95% CI:0.61-0.77, p < 0.001) compared to the subset that did not: AUC 0.58 (95% CI: 0.49-0.66, p = 0.078).

CONCLUSIONS

In this real-world evidence, multicenter cohort, 1- and 2-year survival after commercial HM3 LVAD implant was excellent, regardless of trial eligibility. The HM3RS provided adequate risk discrimination in "trial-like" patients, but predictive value was reduced in patients who did not meet trial criteria.

Computational investigation of outflow graft variation impact on hemocompatibility profile in LVADs

BACKGROUND

Hemocompatibility-related adverse events (HRAE) occur commonly in patients with left ventricular assist devices (LVADs) and add to morbidity and mortality. It is unclear whether the outflow graft orientation can impact flow conditions leading to HRAE. This study presents a simulation-based approach using exact patient anatomy from medical images to investigate the influence of outflow cannula orientation in modulating flow conditions leading to HRAEs.

METHODS

A 3D model of a proximal aorta and outflow graft was reconstructed from a computed tomography (CT) scan of an LVAD patient and virtually modified to model multiple cannula orientations (n = 10) by varying polar (cranio-caudal) (n = 5) and off-set (anterior-posterior) (n = 2) angles. Time-dependent computational flow simulations were then performed for each anatomical orientation. Qualitative and quantitative hemodynamics metrics of thrombogenicity including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell platelet activation potential (ECAP), particle residence time (PRT), and platelet activation potential (PLAP) were analyzed.

RESULTS

Within the simulations performed, endothelial cell activation potential (ECAP) and particle residence time (PRT) were found to be lowest with a polar angle of 85°, regardless of offset angle. However, polar angles that produced parameters at levels least associated with thrombosis varied when the offset angle was changed from 0° to 12°. For offset angles of 0° and 12° respectively, flow shear was lowest at 65° and 75°, time averaged wall shear stress (TAWSS) was highest at 85° and 35°, and platelet activation potential (PLAP) was lowest at 65° and 45°.

CONCLUSION

This study suggests that computational fluid dynamic modeling based on patient-specific anatomy can be a powerful analytical tool when identifying optimal positioning of an LVAD. Contrary to previous work, our findings suggest that there may be an "ideal" outflow cannula for each individual patient based on a CFD-based hemocompatibility profile.

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.

18F-FDG PET/CT in left ventricular assist device infections: In-depth characterization and clinical implications

BACKGROUND

Previous retrospective studies suggest a good diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/computed tomography (CT) in left ventricular assist device (LVAD) infections. Our aim was to prospectively evaluate the role of PET/CT in the characterization and impact on clinical management of LVAD infections.

METHODS

A total of 40 patients (aged 58 [53-62] years) with suspected LVAD infection and 5 controls (aged 69 [64-71] years) underwent 18F-FDG-PET/CT. Four LVAD components were evaluated: exit site and subcutaneous driveline (peripheral), pump pocket, and outflow graft. The location with maximal uptake was considered the presumed site of infection. Infection was confirmed by positive culture (exit site or blood) and/or surgical findings.

RESULTS

Visual uptake was present in 40 patients (100%) in the infection group vs 4 (80%) control subjects. For each individual component, the presence of uptake was more frequent in the infection than in the control group. The location of maximal uptake was most frequently the pump pocket (48%) in the infection group and the peripheral components (75%) in the control group. Maximum standard uptake values (SUVmax) were higher in the infection than in the control group: SUVmax (average all components): 6.9 (5.1-8.5) vs 3.8 (3.7-4.3), p = 0.002; SUVmax (location of maximal uptake): 10.6 ± 4.0 vs 5.4 ± 1.9, p = 0.01. Pump pocket infections were more frequent in patients with bacteremia than without bacteremia (79% vs 31%, p = 0.011). Pseudomonas (32%) and methicillin-susceptible Staphylococcus aureus (29%) were the most frequent pathogens and were associated with pump pocket infections, while Staphylococcus epidermis (11%) was associated with peripheral infections. PET/CT affected the clinical management of 83% of patients with infection, resulting in surgical debridement (8%), pump exchange (13%), and upgrade in the transplant listing status (10%), leading to 8% of urgent transplants.

CONCLUSIONS

18F-FDG-PET/CT enables the diagnosis and characterization of the extent of LVAD infections, which can significantly affect the clinical management of these patients.

Gastrointestinal bleeding following Heartmate 3 left ventricular assist device implantation: The Michigan Bleeding Risk Model

BACKGROUND

Gastrointestinal bleeding (GIB) results in frequent hospitalizations and impairs quality of life in durable left ventricular assist device (LVAD) recipients. Anticipation of these events before implantation could have important implications for patient selection and management.

METHODS

The study population included all adult HeartMate 3 (HM3) primary LVAD recipients enrolled in the STS Intermacs registry from January 2017 to December 2020. Using multivariable modeling methodologies, we investigated the relationships between preimplantation characteristics and postimplant bleeding, bleeding and death, and additional bleeding episodes on subsequent bleeding episodes and created a risk score to predict the likelihood of post-LVAD GIB based solely on preimplantation factors.

RESULTS

Of 6,425 patients who received an HM3 LVAD, 1,010 (15.7%) patients experienced GIB. Thirteen preimplantation factors were independent predictors of post-LVAD GIB. A risk score was created from these factors and calculated for each patient. By 3 years postimplant, GIB occurred in 11%, 26%, and 43% of low-, medium- and high-risk patients, respectively. Experiencing 1 post-LVAD GIB event was associated with an increased risk for further GIB events, with 33.9% of patients experiencing at least 1 recurrence. While post-LVAD GIB was associated with mortality, there was no relationship between number of GIB events and death.

CONCLUSIONS

The Michigan Bleeding Risk Model is a simple tool, which facilitates the prediction of post-LVAD GIB in HM3 recipients using 13 preimplant variables. The implementation of this tool may help in the risk stratification process and may have therapeutic and clinical implications in HM3 LVAD recipients.

A multicenter evaluation of external outflow graft obstruction with a fully magnetically levitated left ventricular assist device

BACKGROUND

The HeartMate 3 (HM 3; Abbott) left ventricular assist device (LVAD) has improved hemocompatibility-related adverse outcomes. In sporadic cases, external compression of the outflow graft causing obstruction (eOGO) can result from substance accumulation between the outflow graft and its bend relief. We sought to evaluate the prevalence, course, and clinical implications of eOGO in an international study.

METHODS

A multicenter retrospective analysis of HM 3 LVADs implanted between November 2014 and April 2021 (n = 2108) was conducted across 17 cardiac centers in 8 countries. We defined eOGO as obstruction >25% in the cross-sectional area in imaging (percutaneous angiography, computed tomography, or intravascular ultrasound). The prevalence and annual incidence were calculated. Serious adverse events and outcomes (death, transplantation, or device exchange) were analyzed for eOGO cases.

RESULTS

Of 2108 patients, 62 were diagnosed with eOGO at a median LVAD support duration of 953 (interquartile range, 600-1267) days. The prevalence of eOGO was 3.0% and the incidence at 1, 2, 3, 4, and 5 years of support was 0.6%, 2.8%, 4.0%, 5.2%, and 9.1%, respectively. Of 62 patients, 9 were observed, 27 underwent surgical revision, 15 underwent percutaneous stent implantation, 8 received a heart transplant, and 2 died before intervention. One patient underwent surgical revision and later stent implantation. The mortality with therapeutic intervention was 9/53 (17.0%).

CONCLUSIONS

Although uncommon, HM 3 LVAD-supported patients might develop eOGO with an increasing incidence after 1 year of support. Although engineering efforts to reduce this complication are under way, clinicians must maintain a focus on early detection and remain vigilant.

Management of incessant ventricular arrhythmias in a patient with left ventricular assist device: a case report

BACKGROUND

The implantation of left ventricular assist devices (LVADs) as a bridge to transplantation or as destination therapy in end-stage heart failure patients is frequently complicated by the emergence of ventricular arrhythmias (VAs). These arrhythmias have been implicated in precipitating deleterious clinical outcomes, increased mortality rates and augmented healthcare expenditures.

CASE PRESENTATION

We present a challenging case of a 49-year-old male with a history of dilated cardiomyopathy who received an LVAD. Post-implantation, the patient suffered from intractable VAs, leading to multiple rehospitalizations and hemodynamic deterioration. Despite exhaustive medical management and electrical cardioversion attempts, the patient's VAs persisted, ultimately necessitating prioritization for cardiac transplantation.

DISCUSSION

This case highlights the challenges in managing VAs in LVAD patients and the importance of multidisciplinary collaboration. While pharmacological intervention is the initial strategy, catheter ablation may be considered in selected cases when medication is insufficient. In instances of intractable VAs, expeditious listing for heart transplantation as a high-priority candidate is advisable when feasible.

Intraoperative prophylactic right ventricular assist device in prevention of postcardiotomy failure

OBJECTIVES

In patients at risk of developing right ventricular failure after cardiac surgery, right ventricular support with a ventricular assist device may be a promising strategy to reduce mortality. We present our experience with intraoperative right ventricular assist device implantation as a prevention strategy of right ventricular failure after cardiac surgery.

METHODS

Between 2016 and 2022, we implanted four right ventricular assist devices prophylactically in a series of patients with surgical indication for valvular heart disease and high risk of postoperative right ventricular failure. Indications for the right ventricular assist device were suprasystemic pulmonary hypertension or severe right ventricular dysfunction.

RESULTS

Externalization of the device cannulas through intercostal spaces was performed in three patients, allowing early mobilization and withdrawal without resternotomy. Removal of the device ocurred on the eighth postoperative day. ICU and hospital length of stay was 12 (±1.6) and 23 days (±4.2) respectively. Hospital mortality was null. No patient died during follow-up, mean follow-up was 32.5 months [1-72]. Patients improved their NYHA functional class up to grade II during follow-up.

CONCLUSIONS

Acute right ventricular failure after cardiac surgery remains a significant cause of morbidity and mortality. Prophylactic strategies to prevent postoperative right ventricular dysfunction may decrease the incidence of refractory postoperative right ventricular failure. We propose a novel approach to prevent right failure after cardiac surgery with prophylactic intraoperative ventricular assist device implantation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Discussion of hemodynamic optimization strategies and the canonical understanding of hemodynamics during biventricular mechanical support in cardiogenic shock: does the flow balance make the difference?

BACKGROUND

Mechanical circulatory support (MCS) devices may stabilize patients with severe cardiogenic shock (CS) following myocardial infarction (MI). However, the canonical understanding of hemodynamics related to the determination of the native cardiac output (CO) does not explain or support the understanding of combined left and right MCS. To ensure the most optimal therapy control, the current principles of hemodynamic measurements during biventricular support should be re-evaluated.

METHODS

Here we report a protocol of hemodynamic optimization strategy during biventricular MCS (VA-ECMO and left ventricular Impella) in a case series of 10 consecutive patients with severe cardiogenic shock complicating myocardial infarction. During the protocol, the flow rates of both devices were switched in opposing directions (+ / - 0.7 l/min) for specified times. To address the limitations of existing hemodynamic measurement strategies during biventricular support, different measurement techniques (thermodilution, Fick principle, mixed venous oxygen saturation) were performed by pulmonary artery catheterization. Additionally, Doppler ultrasound was performed to determine the renal resistive index (RRI) as an indicator of renal perfusion.

RESULTS

The comparison between condition 1 (ECMO flow > Impella flow) and condition 2 (Impella flow > VA-ECMO flow) revealed significant changes in hemodynamics. In detail, compared to condition 1, condition 2 results in a significant increase in cardiac output (3.86 ± 1.11 vs. 5.44 ± 1.13 l/min, p = 0.005) and cardiac index (2.04 ± 0.64 vs. 2.85 ± 0.69, p = 0.013), and mixed venous oxygen saturation (56.44 ± 6.97% vs. 62.02 ± 5.64% p = 0.049), whereas systemic vascular resistance decreased from 1618 ± 337 to 1086 ± 306 s*cm-5 (p = 0.002). Similarly, RRI decreased in condition 2 (0.662 ± 0.05 vs. 0.578 ± 0.06, p = 0.003).

CONCLUSIONS

To monitor and optimize MCS in CS, PA catheterization for hemodynamic measurement is applicable. Higher Impella flow is superior to higher VA-ECMO flow resulting in a more profound increase in CO with subsequent improvement of organ perfusion.

A multi-constituent model for assessing the effect of impeller shroud on the thrombosis potential of a centrifugal blood pump

Centrifugal blood pumps can be used for treating heart failure patients. However, pump thrombosis has remained one of the complications that trouble clinical treatment. This study analyzed the effect of impeller shroud on the thrombosis risk of the blood pump, and predicted areas prone to thrombosis. Multi-constituent transport equations were presented, considering mechanical activation and biochemical activation. It was found that activated platelets concentration can increase with shear stress and adenosine diphosphate(ADP) concentration increasing, and the highest risk of thrombosis inside the blood pump was under extracorporeal membrane oxygenation (ECMO) mode. Under the same condition, ADP concentration and thrombosis index of semi-shroud impeller can increase by 7.3% and 7.2% compared to the closed-shroud impeller. The main reason for the increase in thrombosis risk was owing to elevated scalar shear stress and more coagulation promoting factor-ADP released. The regions with higher thrombosis potential were in the center hole, top and bottom clearance. As a novelty, the findings revealed that impeller shroud can influence mechanical and biochemical activation factors. It is useful for identifying potential risk regions of thrombus formation based on relative comparisons.

Long-term implantable ventricular assist device support in children

BACKGROUND

In pediatrics, implantable continuous-flow ventricular assist devices (IC-VAD) are often used as a "temporary" support, bridging children to cardiac transplantation during the same hospital admission.

METHODS

We conducted a retrospective review of our consecutive patients undergoing IC-VAD support at a tertiary pediatric heart center between 2008 and 2022.

RESULTS

We identified 100 IC-VAD implant encounters: HeartWare HVAD (67; 67%), HeartMate II (17; 17%), and HeartMate 3 (16; 16%). The median (range) age, weight, and body surface area at implantation were 14.1 (3.0-56.5) years, 54.8 (13.3-140) kg, and 1.6 (0.6-2.6) m2, respectively. Cardiomyopathy (58; 58%) was the most common etiology, followed by congenital heart disease (37; 37%, including 13 single ventricle). At 6 months of IC-VAD support, 94 (94%) encounters achieved positive outcomes: ongoing support (59; 59%), transplant (33; 33%), and cardiac recovery (2; 2%). Eighty-two encounters (82%) resulted in home discharge with ongoing VAD support, including 38 (46%, out of 82) requiring readmission and 7 (9%, out of 82) resulting in death. There was a clinically significant decrease in morbidity rates before versus after home discharge: bleeding (1.55 vs 0.06), infection (0.84 vs 0.37), and stroke (0.84 vs 0.15 event per patient-year). Overall, 86 encounters (86%) reached positive end points at the latest follow-up (64 transplant, 15 ongoing support, and 7 recovery). Infection (29%; 4 of 14) was the most common cause of negative outcomes, followed by cerebrovascular accident (21%; 3), and unresolved frailty (21%; 3). The estimated overall survival at 1, 2, and 5 years was 90%, 86%, and 77%, respectively.

CONCLUSIONS

This study suggests the feasibility of outpatient management of pediatric IC-VAD support. The ability to offer true long-term support maximizes the potential of IC-VAD support, not limited to a temporary bridging tool for heart transplantation.

Impella - Current issues and future expectations for the percutaneous, microaxial flow left ventricular assist device

The importance of temporary mechanical circulatory support for treating acute heart failure with cardiogenic shock is increasingly recognized, and Impella (Abiomed, Danvers, MA, USA) has received particular attention in this regard. Impella is an axial flow left ventricular assist device (LVAD) built into the tip of a catheter. It is inserted via a peripheral artery and implanted into the left ventricle. Although the morphology of Impella is different from a typical LVAD, it has similar actions and effects as an LVAD in terms of left ventricular drainage and aortic blood delivery. Impella increases mean arterial pressure (MAP) and systemic blood flow, thereby improving peripheral organ perfusion and promoting recovery from multiple organ failure. In addition, left ventricular unloading with increased MAP increases coronary perfusion and decreases myocardial oxygen demand, thereby promoting myocardial recovery. Impella is also useful as a mechanical vent of the left ventricle in patients supported with veno-arterial extracorporeal membrane oxygenation. Indications for Impella include emergency use for cardiogenic shock and non-emergent use during high-risk percutaneous coronary intervention and ventricular tachycardia ablation. Its intended uses for cardiogenic shock include bridge to recovery, durable device, heart transplantation, and heart surgery. Prophylactic use of Impella in high-risk patients undergoing open heart surgery to prevent postcardiotomy cardiogenic shock is also gaining attention. While there have been many case reports and retrospective studies on the benefits of Impella, there is little evidence based on sufficiently large randomized controlled trials (RCTs). Currently, several RCTs are now ongoing, which are critical to determine when, for whom, and how these devices should be used. In this review, we summarize the principles, physiology, indications, and complications of the Impella support and discuss current issues and future expectations for the device.

Durable left ventricular assist device explantation following recovery in paediatric patients: Determinants and outcome after explantation

OBJECTIVES

Myocardial recovery in children supported by a durable left ventricular assist device is a rare, but highly desirable outcome because it could potentially eliminate the need for a cardiac transplant and the lifelong need for immunosuppressant therapy and the risk of complications. However, experience with this specific outcome is extremely limited.

METHODS

All patients < 19 years old supported by a durable left ventricular assist device from the European Registry for Patients with Mechanical Circulatory Support database were included. Participating centres were approached for additional follow-up data after explantation. Associated factors for explantation due to myocardial recovery were explored using Cox proportional hazard models.

RESULTS

The incidence of recovery in children supported by a durable left ventricular assist device was 11.7% (52/445; median duration of support, 122.0 days). Multivariable analyses showed body surface area (hazard ratio 0.229; confidence interval 0.093-0.565; P = 0.001) and a primary diagnosis of myocarditis (hazard ratio 4.597; confidence interval 2.545-8.303; P < 0.001) to be associated with recovery. Left ventricular end-diastolic diameter in children with myocarditis was not associated with recovery. Follow-up after recovery was obtained for 46 patients (88.5%). Sustained myocardial recovery was reported in 33/46 (71.7%) at the end of the follow-up period (28/33; >2 year). Transplants were performed in 6/46 (11.4%) (in 5 after a ventricular assist device was reimplanted). Death occurred in 7/46 (15.2%).

CONCLUSIONS

Myocardial recovery occurs in a substantial portion of paediatric patients supported with durable left ventricular assist devices, and sustainable recovery is seen in around three-quarters of them. Even children with severely dilated ventricles due to myocarditis can show recovery. Clinicians should be attentive to (developing) myocardial recovery. These results can be used to develop internationally approved paediatric weaning guidelines.

The Effects of Exercise on Cardiogenic Shock with an Intra-Aortic Balloon Pump: A Case Report

This case report describes the exercise program on a hospitalized 54-year-old male patient with cardiogenic shock waiting for a heart transplant assisted by an intra-aortic balloon pump, a temporary mechanical circulatory support device. The temporary mechanical circulatory support device, an intra-aortic balloon pump, was placed in the left subclavian artery, enabling the exercise protocol. Measurements and values from Swan-Ganz catheter, blood sample, brain natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hs-CRP), as well as the six-minute walk test (6MWT) and venous oxygen saturation (SvO2) were obtained before and after an exercise protocol. The exercise training protocol involved the use of an unloaded bed cycle ergometer once a day, for a maximum of 30 minutes, to the tolerance limit. No adverse events or events related to the dislocation of the intra-aortic balloon pump were observed during the exercise protocol. The exercise program resulted in higher SvO2 levels, with an increased 6MWT with lower Borg dyspnea scores (312 meters vs. 488 meters and five points vs. three points, respectively). After completing the ten-day exercise protocol, the patient underwent a non-complicated heart transplant surgery and a full recovery in the ICU. This study showed that exercise is a feasible option for patients with cardiogenic shock who are using an intra-aortic balloon pump and that it is well-tolerated with no reported adverse events.

Impella device in fulminant myocarditis: Japanese Registry for Percutaneous Ventricular Assist Device (J-PVAD) registry analysis on outcomes and adverse events

AIMS

Given that fulminant myocarditis, characterized by unstable haemodynamics, is a significant clinical challenge and that traditional pharmacological treatments have limitations, evaluating alternatives such as the Impella device is a crucial focus of this study. Further, this study presents pioneering large-scale registry data on its use in managing fulminant myocarditis.

METHODS AND RESULTS

Data from the Japanese Registry for Percutaneous Ventricular Assist Devices (J-PVAD) were analysed to assess Impella's role in managing fulminant myocarditis from February 2020 to December 2021. The primary outcome was 30-day mortality for those treated with Impella. Of the 269 patients treated with Impella, 107 used Impella standalone, and 162 used ECPELLA (Impella combined with extracorporeal membrane oxygenation). The average age was 54 years, with 42.8% females. Overall, 74.3% survived at 30 days. Specifically, the success rate was 68.5% for the ECPELLA group and 83.2% for the Impella standalone group. Cox regression highlighted that lower estimated glomerular filtration rate and pre-Impella systolic blood pressure increased adverse event risk, while Swan-Ganz catheterization use reduced it. Adverse events were noted in 48.7% of patients, such as bleeding (32.0%) and deteriorating renal function (8.6%).

CONCLUSION

Impella's use in fulminant myocarditis demonstrates encouraging short-term outcomes, albeit with significant adverse events. These findings align with previous mechanical circulatory support studies, emphasizing caution regarding haemorrhagic issues. Further studies are essential to enhance patient selection and treatment approaches.

Kidney Function Trajectories and Right Heart Failure Following LVAD Implantation

BACKGROUND

Preoperative kidney dysfunction is a risk factor for right heart failure (RHF) after implantation of a left ventricular assist device (LVAD). However, characteristic kidney function trajectories before and after post-LVAD RHF are uncertain, so we investigated this.

METHODS AND RESULTS

We identified individuals who received primary continuous-flow LVAD implantation from July 1, 2014 to December 31, 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data set. Incident RHF was ascertained using the INTERMACS definition at 1 and 3 months and classified as transient or persistent. Kidney function trajectories before and after RHF onset, and relationships of baseline kidney function with RHF risk at the different time points, were assessed. We identified 8076 LVAD recipients who met inclusion criteria. Incident RHF was present at 1 month in 26.4%. There were 4850 individuals with follow-up at 3 months, with incident RHF in 4.2%. Kidney function trajectories differed from pre-LVAD implantation to 1-month follow-up by RHF category, with those developing persistent RHF having no improvement in baseline kidney function. For trajectories before the 3-month RHF ascertainment time, the shape was similar for those with and without RHF, with lower estimated glomerular filtration rate levels among those who developed RHF. Baseline estimated glomerular filtration rate levels below the normal range were associated with higher risk of RHF at 1 and 3 months.

CONCLUSIONS

In LVAD recipients, preimplantation kidney function and subsequent kidney function trajectories differed substantially by RHF at 1 and 3 months postimplantation, even after adjustment for several confounders. This may demonstrate bidirectional associations between kidney function and right ventricular function in LVAD recipients.

Transcatheter management of pure native aortic valve regurgitation in patients with left ventricular assist device

OBJECTIVES

Aortic valve regurgitation (AR) frequently complicates the clinical course after left ventricular assist device (LVAD) implantation. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement (SAVR) in this cohort with a mostly high surgical risk profile. The unique challenges in LVAD patients, such as presence of non-calcified aortic valves and annular dilatation, raise concerns about device migration and paravalvular leakage (PVL) leading to missing device success. This study evaluates procedural outcomes and survival rates in LVAD patients who underwent TAVI, emphasizing strategies to enhance device success.

METHODS

Between January 2017 and April 2023, 27 LVAD patients with clinically significant AR underwent elective or urgent TAVI at our centre. Primary end-points were procedural success rates, without the need for a second transcatheter heart valve (THV) and postprocedural AR/PVL. Secondary outcomes included survival rates and adverse events.

RESULTS

Among the cohort, 14.8% received AR-dedicated TAVI devices, with none requiring a second THV. There was no intraprocedural AR, and 1 patient (25%) had AR > 'trace' at discharge. Additionally, 25.9% underwent device landing zone (DLZ) pre-stenting with a standard TAVI device, all without needing a second THV. There was no intraprocedural AR, and none to trace AR at discharge. Among the 59.3% receiving standard TAVI devices, 37.5% required a second THV. In this subgroup, intraprocedural AR > 'trace' occurred in 12.5%, decreasing to 6.25% at discharge. In-hospital mortality was 3.7%, and median follow-up survival was 388 days (interquartile range 208-1167 days).

CONCLUSIONS

TAVI yields promising procedural outcomes and early survival rates in LVAD patients with AR. Tailored TAVI devices and pre-stenting techniques enhance procedural success. Continued research into these strategies is essential to optimize outcomes in this complex patient cohort.

Right ventricular dysfunction in left ventricular assist device candidates: is it time to change our prospective?

The use of left ventricular assist devices (LVAD) has significantly increased in the last years, trying to offer a therapeutic alternative to heart transplantation, in light also to the significant heart donor shortage compared to the growing advanced heart failure population. Despite technological improvements in the devices, LVAD-related mortality is still fairly high, with right heart failure being one of the predominant predictors. Therefore, many efforts have been made toward a thorough right ventricular (RV) evaluation prior to LVAD implant, considering clinical, laboratory, echocardiographic, and invasive hemodynamic parameters. However, there is high heterogeneity regarding both which predictor is the strongest as well as the relative cut-off values, and a consensus has not been reached yet, increasing the risk of facing patients in which the distinction between good or poor RV function cannot be surely reached. In parallel, due to technological development and availability of mechanical circulatory support of the RV, LVADs are being considered even in patients with suboptimal RV function. The aim of our review is to analyze the current evidence regarding the role of RV function prior to LVAD and its evaluation, pointing out the extreme variability in parameters that are currently assessed and future prospective regarding new diagnostic tools. Finally, we attempt to gather the available information on the therapeutic strategies to use in the peri-operative phase, in order to reduce the incidence of RV failure, especially in patients in which the preoperative evaluation highlighted some conflicting results with regard to ventricular function.

Evaluation of cardiac arrhythmia in pediatric patients with Left Ventricular Assist Device (L-VAD)

OBJECTIVE

Pediatric heart failure is an important cause of morbidity and mortality in childhood. Left ventricular assist devices (L-VAD) are used for bridging to transplantation in patients with indications for heart transplantation.

PATIENTS AND METHODS

The children included in the study were patients who underwent implantation of an L-VAD due to advanced heart failure at Ege University Faculty of Medicine Hospital between January 2009 and January 2023.

RESULTS

Of the 33 patients who underwent L-VAD implantation, 16 (48.5%) were female and 17 (51.5%) were male. The median age at surgery was 13 years (IQR, 9.5-15). The median weight was 44 kg (IQR, 25.65-52), the median height was 158 cm (IQR, 134.5-168.5), and the median body surface area was 1.37 m2 (IQR, 0.95-1.51). All patients who underwent L-VAD implantation had an echocardiographic diagnosis of dilated cardiomyopathy. The patients underwent a median of 16 (IQR, 9-21) ECGs, and the median number of 24-hour Holter ECGs obtained was 3 (IQR, 2-5). Arrhythmias that occurred after L-VAD implantation were classified as atrial and ventricular. Ventricular arrhythmia included ventricular tachycardia (VT) lasting for more than 30 seconds (sustained VT), VT lasting for less than 30 seconds (nonsustained VT), and ventricular fibrillation. Atrial arrhythmias included atrial flutter, atrial fibrillation, supraventricular tachycardia, and atrial ectopic tachycardia. During the follow-up, atrial or ventricular arrhythmias were observed in 11 (33%) patients. The most common rhythm disturbances before L-VAD implantation were ventricular arrhythmias, while after the surgery, atrial arrhythmias were found to be the most frequent. A total of 5 patients underwent cardioversion (n=2) or defibrillation (n=3) due to arrhythmia.

CONCLUSIONS

In patients undergoing L-VAD implantation, rhythm disorders that could normally lead to hemodynamic instability are frequently encountered. In these rhythm disorders, medical therapy should be attempted before resorting to cardioversion or defibrillation, and subsequently, more aggressive treatment methods should be considered.