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.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Body mass index-dependent immunological profile changes after left ventricular assist device implantation

Purpose

Infection is a common complication following left ventricular assist device (LVAD) implantation. Patients with obesity are particularly at risk due to their high percentage of adipose tissue and the resulting chronic inflammatory state and resulting immunological changes. This study investigated changes of immunological parameters in relation to body mass index (BMI) during the first year after LVAD implantation.

Methods

Blood samples were obtained prior to LVAD implantation and at 3 (1st FU), 6 (2nd FU) and 12 mo (3rd FU) after LVAD implantation. Patients were divided into three groups (normal weight: BMI of 18.5-24.9 kg/m2; n=12; pre-obesity: 25.0-29.9 kg/m2; n=15; obesity: ≥ 30.0 kg/m2; n=17) based on their BMI at the time of LVAD implantation. Flow cytometric analyses for CD4+ and CD8+ T cells, regulatory T cells (Tregs), B cells as well as dendritic cells (DCs) were performed.

Results

After LVAD implantation, obese patients (0.51 ± 0.20%) showed a higher proportion of overall DCs than normal-weight (0.28 ± 0.10%) and pre-obese patients (0.32 ± 0.11%, p<0.01) at 3rd FU. The proportion of BDCA3+ myeloid DCs was lower in obese patients (64.3 ± 26.5%) compared to normal-weight patients (82.7 ± 10.0%, pnormal-weight vs. obesity=0.05) at 2nd FU after LVAD implantation. The analysis of BDCA4+ plasmacytoid DCs revealed a reduced proportion in pre-obese (21.1 ± 9.8%, pnormal-weight vs. pre-obesity=0.01) and obese patients (23.7 ± 10.6%, pnormal-weight vs. obesity=0.05) compared to normal-weight patients (33.1 ± 8.2%) in the 1st FU. T cell analysis showed that CD4+ T cells of obese patients (62.4 ± 9.0%) significantly increased in comparison to pre-obese patients (52.7 ± 10.0%, ppre-obesity vs. obesity=0.05) and CD8+ T cells were lower in obese patients (31.8 ± 8.5%) than in normal-weight patients (42.4 ± 14.2%; pnormal-weight vs. obesity=0.04) at the 3rd FU. Furthermore, we observed significantly reduced proportions of Tregs in pre-obese patients compared to normal-weight and obese patients at 2nd FU (p=0.02) and 3rd FU (p=0.01) after LVAD implantation.

Conclusion

This study reported changes of the innate and adaptive immune system of pre-obese and obese compared to normal-weight patients one year after LVAD implantation. DCs and their subsets, CD8+ T cells and Tregs were affected immune cell populations that indicate immunological changes which might increase the incidence of postoperative infection.

Outcome of patients supported with the HeartMate 3 after extracorporeal life support: On behalf of the Durable Mechanical Circulatory Support After Extracorporeal Life Support Study Group

OBJECTIVES

The Durable Mechanical Circulatory Support System After Extracorporeal Life Support registry is a multicenter registry of patients who were bridged from extracorporeal life support to a durable mechanical circulatory support system. Although numerous studies have highlighted the favorable outcomes after implantation of the HeartMate 3 (Abbott), the objective of our study is to examine the outcomes of patients who received HeartMate 3 support after extracorporeal life support.

METHODS

Data of patients undergoing HeartMate 3 implantation from January 2016 to April 2022 at 14 centers were collected and evaluated. Inclusion criteria were patients with extracorporeal life support before HeartMate 3 implantation. The outcome was reported and compared with patients receiving other types of pumps.

RESULTS

A total of 337 patients were bridged to durable mechanical circulatory support system after extracorporeal life support in the study period. Of those patients, 140 were supported with the HeartMate 3. The other types of pumps included 170 HeartWare HVADs (Medtronic) (86%), 14 HeartMate II devices (7%), and 13 (7%) other pumps (7%). Major postoperative complications included right heart failure requiring temporary right ventricular assist device in 60 patients (47%). Significantly lower postoperative stroke (16% vs 28%, P = .01) and pump thrombosis (3% vs 8%, P = .02) rates were observed in the patients receiving the HeartMate 3. The 30-day, 1-year, and 3-year survivals in patients receiving the HeartMate 3 were 87%, 73%, and 65%, respectively.

CONCLUSIONS

In this critically ill patient population, the survivals of patients who were transitioned to the HeartMate 3 are deemed acceptable and superior to those observed when extracorporeal life support was bridged to other types of durable mechanical circulatory support systems.

Health status analysis is comparable in HM3 patients with different preoperative grades of mitral regurgitation

BACKGROUND

The guidelines for mechanical circulatory support of the International Society for Heart and Lung Transplantation do not recommend the routine replacement or repair of the mitral valve at the time point of left ventricular assist device (LVAD) implantation. We investigated different parameters of health status including exercise capacity, anxiety and depression after LVAD implantation in patients with different preoperative grades of mitral regurgitation (MR).

METHODS

A single-center analysis of health status was performed including 45 patients with HeartMate 3 (HM 3) implantation using the 12-items Short Form Health Survey (SF-12) and the Hospital Anxiety and Depression Score (HADS) questionnaires. The study groups were classified according to echocardiographically defined preoperative grade of MR. The group without severe MR comprised 33 patients; the group with severe MR comprised 12 patients.

RESULTS

Demographic and preclinical characteristics as well as LVAD complications such as thrombosis and bleeding events were comparable between LVAD patients with severe and not severe MR (p > 0.05). Severe MR resolved in all patients after LVAD implantation and improved to moderate, mild or no MR in both groups in a period ranging from 6 months until 2 years. The analyses of SF-12 questionnaire revealed that the physical (p = 0.44) and mental health (p = 0.64) was comparable. The grade of anxiety (p = 0.34) and depression (p = 0.44) was comparable between the groups. Exercise capacity measured by the 6 min walk test correlated positively with the SF-12-determined physical health (p < 0.01, r = 0.518) and negatively with the HADS anxiety (p = 0.01, r = -0.399) and depression (p < 0.01, r = -0.570) scores.

CONCLUSIONS

Our data showed that the health status is comparable in HM 3 patients with different preoperative MR severities in the post-LVAD period. Preoperative severe MR resolves in the majority of patients early after LVAD implantation and is not associated with concomitant mitral valve repair or replacement at the time of LVAD implantation.

Heterogeneity in Clinical Practices for Post-Cardiotomy Extracorporeal Life Support: a Pilot Survey from the PELS-1 Multicenter Study

BACKGROUND

High-quality evidence for post-cardiotomy extracorporeal life support (PC-ECLS) management is lacking. This study investigated the real-world PC-ECLS clinical practices.

METHODS

This cross-sectional, multi-institutional, international pilot survey explored center organization, anticoagulation management, left ventricular unloading, distal limb perfusion, PC-ECLS monitoring and transfusions practices. Twenty-nine questions were distributed among 34 hospitals participating in the Post-cardiotomy Extra-Corporeal Life Support Study.

RESULTS

Of the 32 centers [16 low-volume (50%); 16 high-volume (50%)] that responded, 16 (50%) had dedicated ECLS specialists. Twenty-six centers (81.3%) reported using additional mechanical circulatory supports. Anticoagulation practices were highly heterogeneous: 24 hospitals (75%) reported using patient's bleeding status as a guide, without a specific threshold in 54.2% of cases. Transfusion targets ranged 7-10 g/dL. Most centers used cardiac venting on a case-by-case basis (78.1%) and regular distal limb perfusion (84.4%). Nineteen (54.9%) centers reported dedicated monitoring protocols including daily echocardiography (87.5%), Swan-Ganz catheterization (40.6%), cerebral near-infrared spectroscopy (53.1%) and multimodal assessment of limb ischemia. Inspection of the circuit (71.9%), oxygenator pressure drop (68.8%), plasma free hemoglobin (75%), d-dimer (59.4%), lactate dehydrogenase (56.3%) and fibrinogen (46.9%) are used to diagnose hemolysis and thrombosis.

CONCLUSIONS

This study shows remarkable heterogeneity in clinical practices for PC-ECLS management. More standardized protocols and better implementation of available evidence are recommended.

Stroke and pump thrombosis following left ventricular assist device implantation: The impact of the implantation technique

Objectives

Several studies have shown the potential advantage of less-invasive surgery (LIS) for left ventricular assist device (LVAD) implantation. This study aims to determine the impact of LIS on stroke and pump thrombosis events after LVAD implantation.

Methods

Between January 2015 and March 2021, 335 consecutive patients underwent LVAD implantation using either conventional sternotomy (CS) or the LIS technique. Patient characteristics was prospectively collected. All patients were followed up until October 2021. Logistic multivariate regression and propensity-matched analyses were performed to account for confounding factors.

Results

A total of 242 patients (F = 32; 13.0%) underwent LVAD implantation with CS and 93 patients (F = 8; 8.6%) with the LIS approach. Propensity matching generated two groups, including 98 patients in the CS group and 67 in the LIS group. Intensive care unit stay for the LIS group patients was significantly shorter than that for the CS group patients [2 (IQR: 2-5) days vs. 4 (IQR: 2-12) days, p < 0.01]. There were no significant differences in the incidence of stroke events (14% in CS vs. 16% in the LIS group; p = 0.6) or in pump thrombosis (6.1% in CS vs. 7.5% in the LIS group; p = 0.8) between the groups. The hospital mortality rate in the matched cohort was significantly lower in the LIS group (7.5% vs. 19%; p = 0.03). However, the 1-year mortality rate showed no significant difference between both groups (24.5% in CS and 17.9% in LIS; p = 0.35).

Conclusions

The LIS approach for LVAD implantation is a safe procedure with potential advantage in the early postoperative period. However, the LIS approach remains comparable to the sternotomy approach in terms of postoperative stroke, pump thrombosis, and outcome.

The Impact of Obesity on T and NK Cells after LVAD Implantation

INTRODUCTION

Infections are a major problem after left ventricular assist device (LVAD) implantation that affects morbidity, mortality, and the quality of life. Obesity often increases the risk for infection. In the cohort of LVAD patients, it is unknown if obesity affects the immunological parameters involved in viral defense. Therefore, this study investigated whether overweight or obesity affects immunological parameters such as CD8+ T cells and natural killer (NK) cells.

METHODS

Immune cell subsets of CD8+ T cells and NK cells were compared between normal-weight (BMI 18.5-24.9 kg/m2, n = 17), pre-obese (BMI 25.0-29.9 kg/m2, n = 24), and obese (BMI ≥30 kg/m2, n = 27) patients. Cell subsets and cytokine serum levels were quantified prior to LVAD implantation and at 3, 6, and 12 months after LVAD implantation.

RESULTS

At the end of the first postoperative year, obese patients (31.8% ± 2.1%) had a lower proportion of CD8+ T cells than normal-weight patients (42.4% ± 4.1%; p = 0.04), and the percentage of CD8+ T cells was negatively correlated with BMI (p = 0.03; r = -0.329). The proportion of circulating NK cells increased after LVAD implantation patients in normal-weight (p = 0.01) and obese patients (p < 0.01). Patients with pre-obesity showed a delayed increase (p < 0.01) 12 months after LVAD implantation. Further, obese patients showed an increase in the percentage of CD57+ NK cells after 6 and 12 months (p = 0.01) of treatment, higher proportions of CD56bright NK cells (p = 0.01), and lower proportions of CD56dim/neg NK cells (p = 0.03) 3 months after LVAD implantation than normal-weight patients. The proportion of CD56bright NK cells positively correlated with BMI (p < 0.01, r = 0.403) 1 year after LVAD implantation.

CONCLUSIONS

This study documented that obesity affects CD8+ T cells and subsets of NK cells in patients with LVAD in the first year after LVAD implantation. Lower proportions of CD8+ T cells and CD56dim/neg NK cells and higher proportion of CD56bright NK cells were detected in obese but not in pre-obese and normal-weight LVAD patients during the first year after LVAD implantation. The induced immunological imbalance and phenotypic changes of T and NK cells may influence viral and bacterial immunoreactivity.

Extracorporeal Membrane Oxygenation for Graft Dysfunction Early After Heart Transplantation: A Systematic Review and Meta-analysis

INTRODUCTION

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a prevailing option for the management of severe early graft dysfunction. This systematic review and individual patient data (IPD) meta-analysis aims to evaluate (1) mortality, (2) rates of major complications, (3) prognostic factors, and (4) the effect of different VA-ECMO strategies on outcomes in adult heart transplant (HT) recipients supported with VA-ECMO.

METHODS AND RESULTS

We conducted a systematic search and included studies of adults (≥18 years) who received VA-ECMO during their index hospitalization after HT and reported on mortality at any timepoint. We pooled data using random effects models. To identify prognostic factors, we analysed IPD using mixed effects logistic regression. We assessed the certainty in the evidence using the GRADE framework. We included 49 observational studies of 1477 patients who received VA-ECMO after HT, of which 15 studies provided IPD for 448 patients. There were no differences in mortality estimates between IPD and non-IPD studies. The short-term (30-day/in-hospital) mortality estimate was 33% (moderate certainty, 95% confidence interval [CI] 28%-39%) and 1-year mortality estimate 50% (moderate certainty, 95% CI 43%-57%). Recipient age (odds ratio 1.02, 95% CI 1.01-1.04) and prior sternotomy (OR 1.57, 95% CI 0.99-2.49) are associated with increased short-term mortality. There is low certainty evidence that early intraoperative cannulation and peripheral cannulation reduce the risk of short-term death.

CONCLUSIONS

One-third of patients who receive VA-ECMO for early graft dysfunction do not survive 30 days or to hospital discharge, and one-half do not survive to 1 year after HT. Improving outcomes will require ongoing research focused on optimizing VA-ECMO strategies and care in the first year after HT.

Early and mid-term outcomes after aortic valve intervention in patients with previous stentless or stented bioprostheses

BACKGROUND

Limited data are available concerning comparative outcomes of redo aortic valve interventions, including surgery after aortic valve replacement (AVR) with either stented or stentless bioprostheses. We investigated the comparative outcomes of redo aortic valve interventions, including surgery after AVR with either stented or stentless bioprostheses.

METHODS

The cohort consisted of 112 patients who underwent aortic valve intervention for infective endocarditis or structural valve deterioration between 2001 and 2020. One hundred patients received a stented valve (stented group) and 12 patients received a stentless valve (stentless group) during the initial surgery. Early and late outcomes were evaluated.

RESULTS

The mean [IQR] ages during the current interventions were 66 [54, 77] years in the stented group and 74 [67, 79] years in the stentless group (P = 0.13). In the stented group, aortic valve interventions included redo AVRs with stented valves (n = 54), mechanical valves (n = 26), stentless valves (n = 16), and transcatheter aortic valve implantations (n = 4). In the stentless group, redo AVRs were performed with stented valves (n = 4), mechanical valves (n = 2), stentless valves (n = 1), and transcatheter valve implantations (n = 5). Hospital mortality was observed in 2 (2%) patients in the stented group and 1 (8%) patients in the stentless group (P = 0.29). The 5-year survival was 80.8% [66.8, 88.5] in the stented group and 91.7% [53.9, 98.8] in stentless group. Statistically significant differences in thromboembolisms were observed between the groups.

CONCLUSIONS

No significant differences in early and mid-term outcomes (except thromboembolism) after aortic valve interventions were detected between patients with stented and stentless AVRs.

The Parasternal Technique: Alternative Technique for Temporary Right Ventricular Assist Device Implantation

Right heart failure is a feared complication in cardiac surgery especially after heart failure surgery. Right ventricular assist devise (RVAD) implantation is inevitable in severe forms of right heart failure. Different techniques for RVAD implantation exist. We here present our experience with a novel parasternal cannulation technique that allows early mobilization, high RVAD flow rates and easy RVAD removal.

Long-Term Follow-Up of Mechanical Circulatory Support in Peripartum Cardiomyopathy (PPCM) Refractory to Medical Management: A Multicenter Study

Background: Peripartum cardiomyopathy (PPCM) is a rare, life-threatening form of heart disease, frequently associated with gene alterations and, in some cases, presenting with advanced heart failure. Little is known about ventricular assist device (VAD) implantation in severe PPCM cases. We describe long-term follow-up of PPCM patients who were resistant to medical therapy and received mechanical circulatory support or heart transplant. Methods and results: A total of 13 patients were included with mean follow-up of eight years. Mean age of PPCM onset was 33.7 ± 7.7 years. All patients were initially treated with angiotensin-converting enzyme inhibitors and beta-blockers, and four received bromocriptine. Overall, five patients received VADs (three biventricular, two isolated left ventricular) at median 27 days (range: 3 to 150) following childbirth. Two patients developed drive line infection. Due to the short support time, none of those patients had a stroke or VAD thrombosis. In total, five patients underwent heart transplantation, of which four previously had implanted VADs. Median time to transplantation from PPCM onset was 140 days (range: 43 to 776), and time to transplantation from VAD implantation were 7, 40, 132, and 735 days, respectively. All patients survived until most recent follow up, with the exception of one patient who died following unrelated abdominal surgery two years after PPCM recovery. Conclusions: In patients with severe, life-threatening PPCM refractory to medical management, mechanical circulatory support with or without heart transplantation is a safe therapeutic option.

Differential Regulation of Myocardial E3 Ligases and Deubiquitinases in Ischemic Heart Failure

The pathological changes of ubiquitination and deubiquitination following myocardial infarction (MI) and chronic heart failure (CHF) have been sparsely examined. We investigated the expression of muscle-specific E3 ubiquitin ligases and deubiquitinases in MI and CHF. Therefore, mice were assigned to coronary artery ligation for 3 days or 10 weeks as well as for sham operation (each n = 10). Expression of E3 ligases (MAFBX, MURF1, CHIP, ITCH, MDM2) and deubiquitinases (A20, CYLD, UCH-L1, USP14, USP19) was determined. After MI and in CHF, the mRNA expression of MURF1, CHIP and MDM2 (all p < 0.05) was decreased. Protein expression analyses revealed that ITCH expression decreased in CHF (p = 0.01), whereas MDM2 expression increased in MI (p = 0.02) and decreased in CHF (p = 0.02). Except for USP19 mRNA expression that decreased at 3 days and 10 weeks (both p < 0.01), the expression of other deubiquitinases remained unaffected after MI and CHF. The expression of myocardial E3 ligases is differentially regulated following MI, raising the question of whether an upstream regulation exists that is activated by MI for tissue protection or whether the downregulation of E3 ligases enables myocardial hypertrophy following MI.

Everolimus-Induced Immune Effects after Heart Transplantation: A Possible Tool for Clinicians to Monitor Patients at Risk for Transplant Rejection

Background: Patients treated with an inhibitor of the mechanistic target of rapamycin (mTORI) in a calcineurin inhibitor (CNI)-free immunosuppressive regimen after heart transplantation (HTx) show a higher risk for transplant rejection. We developed an immunological monitoring tool that may improve the identification of mTORI-treated patients at risk for rejection. Methods: Circulating dendritic cells (DCs) and regulatory T cells (T_regs) were analysed in 19 mTORI- and 20 CNI-treated HTx patients by flow cytometry. Principal component and cluster analysis were used to identify patients at risk for transplant rejection. Results: The percentages of total T_regs (p = 0.02) and CD39⁺ T_regs (p = 0.05) were higher in mTORI-treated patients than in CNI-treated patients. The principal component analysis revealed that BDCA1⁺, BDCA2⁺ and BDCA4⁺ DCs as well as total T_regs could distinguish between non-rejecting and rejecting mTORI-treated patients. Most mTORI-treated rejectors showed higher levels of BDCA2⁺ and BDCA4⁺ plasmacytoid DCs and lower levels of BDCA1⁺ myeloid DCs and T_regs than mTORI non-rejectors. Conclusion: An mTORI-based immunosuppressive regimen induced a sufficient, tolerance-promoting reaction in T_regs, but an insufficient, adverse effect in DCs. On the basis of patient-specific immunological profiles, we established a flow cytometry-based monitoring tool that may be helpful in identifying patients at risk for rejection.

Outflow cannula position for left ventricular assist device: A propensity score-matched study

OBJECTIVE

The clinical consequences of alternative outflow cannula positioning in patients undergoing left ventricular assist device implantation are unknown. We evaluated clinical outcomes in patients who underwent implantation with the outflow cannula implanted from the right side into the ascending aorta versus the left side of the pericardium.

METHODS

Fifty consecutive patients with terminal left heart failure underwent implantation using the Medtronic Heartware Ventricular Assist Device at Toronto General Hospital. Patients were divided between left and right outflow cannula positioning during implantation where anastomosis occurred in the ascending aorta. Propensity score matching using exact matching on the following pre-specified covariates: Interagency Registry for Mechanically Assisted Circulatory Support score, previous cardiac surgery, and preoperative inotrope use.

RESULTS

Fifty consecutive patients (25 left implantation and 25 right implantation) were included in the unmatched cohort and 45 patients (25 left implantation and 20 right implantation) were included in the matched cohort. No significant differences in baseline demographics. Pump thrombosis occurred in 10% (n = 2) receiving right-sided implantation and 8% (n = 2) with left implantation (p = 1.00). Postoperative stroke occurred in 10% (2/20) with right implantation and 16% (4/25) with left implantation (p = .88). No difference in 1-year mortality between right 20% (5/25) and left 25% (5/20) implantation (p = .97).

CONCLUSION

No observed difference in mortality when adjusting for competing risk of heart transplantation. There was also no difference in stroke, pump thrombosis, driveline infection. Larger studies are required to confirm these findings. These preliminary data support the use of left-sided anastomoses to facilitate subsequent re-entry during heart transplantation.

Device-induced platelet dysfunction in patients after left ventricular assist device implantation

BACKGROUND

Non-surgical bleeding (NSB) is a major complication after left ventricular assist device (LVAD) implantation. It has been reported that non-physiological shear stress caused by LVADs could alter platelet receptor expression, which leads to bleeding disorders caused by coagulation dysfunctions.

OBJECTIVES

Because bleeding diathesis could be multifactorial, we focused on the combined characterization of platelet receptor expression patterns and oxidative stress to compare patients with NSB and patients without coagulation disorder in a monocentric, prospective study.

METHODS

Blood samples were obtained from LVAD patients with NSB (bleeder group, n = 19) and without NSB (non-bleeder group, n = 20). The platelet receptors platelet endothelial cell adhesion molecule-1 (PECAM-1), glycoprotein (GP)Ibα, P-selectin, CD63, and GPIIb/IIIa, as well as the production of intraplatelet reactive oxygen species (ROS) were quantified by flow cytometry. Aggregation capacity was evaluated by aggregometry.

RESULTS

The surface expression level of P-selectin and GPIbα on platelets was decreased in bleeders (P-selectin: 465 ± 72 U; GPIbα: 435 ± 41 U) compared to non-bleeders (P-selectin: 859 ± 115 U, P < .01; GPIbα: 570 ± 49 U, p = .04). Additionally, the mean fluorescence intensity of ADP-stimulated P-selectin and PECAM-1 expressing platelets were reduced in bleeders (P-selectin: 944 ± 84 U; PECAM-1: 6722 ± 419 U) compared to non-bleeders (P-selectin: 1269 ± 130 U, P = .04; PECAM-1: 8542 ± 665 U, P = .03). Bleeders showed a higher amount of ROS formation in platelets (88.0 ± 2.6%) than non-bleeders (81.5 ± 2.1%, P = .05).

CONCLUSIONS

These findings suggested that changes of three platelet receptors (GPIbα, P-selectin, and PECAM-1) and elevated oxidative stress may play a role in patients with bleeding complications following LVAD implantation. These results might help to explain the high incidence of spontaneous hemorrhage during LVAD support through an altered platelet function.

Transition From Temporary to Durable Circulatory Support Systems

BACKGROUND

The decision to implant durable mechanical circulatory systems (MCSs) in patients on extracorporeal life support (ECLS) is challenging due to expected poor outcomes in these patients.

OBJECTIVES

The aim of this study was to identify outcome predictors that may facilitate future patient selection and decision making.

METHODS

The Durable MCS after ECLS registry is a multicenter retrospective study that gathered data on consecutive patients who underwent MCS implantation after ECLS between January 2010 and August 2018 in 11 high-volume European centers. Several perioperative parameters were collected. The primary endpoint was survival at 1 year after durable MCS implantation.

RESULTS

A total of 531 durable MCSs after ECLS were implanted during this period. The average patient age was 53 ± 12 years old. ECLS cannulation was peripheral in 87% of patients and 33% of the patients had history of cardiopulmonary resuscitation before ECLS implantation. The 30-day, 1-year, and 3-year actuarial survival rates were 77%, 53%, and 43%, respectively. The following predictors for 1-year outcome have been observed: age, female sex, lactate value, Model of End-Stage Liver Disease XI score, history of atrial fibrillation, redo surgery, and body mass index >30 kg/m². On the basis of this data, a risk score and an app to estimate 1-year mortality was created.

CONCLUSIONS

The outcome in patients receiving durable MCS after ECLS remains limited, yet preoperative factors may allow differentiating futile patients from those with significant survival benefit.

Minimally invasive ventricular assist device implantation

Durable mechanical circulatory support (MCS) systems are established therapy option in patients with end-stage heart failure, with increasing importance during the last years due to donor organ shortage. Left ventricular assist devices (LVADs) are traditionally implanted through median sternotomy (MS). However, improvement in the pump designs during the last years led to evolvement of new surgical approaches that aim to reduce the invasiveness of the procedure. Numerous reports and studies have shown the viability and possible advantages of less-invasive approach compared to the sternotomy approach. The less invasive implant strategies for LVADs, while vague in definition, are characterized by minimizing surgical trauma and if possible, cardio-pulmonary bypass related complications. Usually it involves minimizing or completely avoiding sternal trauma, avoiding heart luxation while simultaneously leaving the major part of pericardium intact. There is no consensus between the centers regarding the ideal approach for LVAD implantation. Some centers, like our center, perform by default VAD implantation using less invasive approach in almost all patients and some centers use only sternotomy approach. The aim of this review article is to shed light on the currently available less invasive options of LVAD implantation, with particular focus on the centrifugal pumps, and their possible advantages compared to traditional sternotomy approach.

Less invasive surgical implant strategy and right heart failure after LVAD implantation

BACKGROUND

Conventional median sternotomy (CMS) is still the standard technique utilized to implant left ventricular assist devices (LVADs). Recent studies suggest that less invasive surgery (LIS) may be beneficial; however, robust data on differences in right heart failure (RHF) are lacking. This study aimed to determine the impact of LIS compared with that of CMS on RHF outcomes after LVAD implantation.

METHODS

An international multicenter retrospective cohort study was conducted across 5 centers. Patients were grouped according to their implantation technique (LIS vs CMS). Only centrifugal devices were included. RHF was defined as severe or severe acute RHF according to the 2013 Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definition. Logistic multivariate regression and propensity score‒matched analyses were performed to account for confounding.

RESULTS

Overall, 427 implantations occurred during the study period, with 305 patients implanted using CMS and 122 using LIS. Pre-operative extracorporeal membrane oxygenation (ECMO) and intra-aortic balloon pump (IABP) use was more common in the CMS group; off-pump implantation was more common in the LIS group. Other pre-implant variables, including age, creatinine, hemodynamics, and tricuspid regurgitation, did not differ between the 2 groups. Post-operative RHF was less common in the patients who underwent LIS than in those who underwent CMS as was post-operative right ventricular assist device (RVAD) use. LIS remained associated with less RHF in the multivariate analysis. After propensity score matching conditional for age, sex, INTERMACS profile, ECMO, and IABP use in a ratio of 2:1 (CMS to LIS), RHF (29.9% vs 18.6%, p = 0.001) and the need for post-operative RVAD (18.6% vs 8.2%; p = 0.009) remained more common in the CMS group than in the LIS group. There were no significant differences in survival up to 1 year between the groups.

CONCLUSIONS

LIS may be associated with less RHF after LVAD implantation compared with CMS. Despite the possible reduction in RHF, there was no difference in 1-year survival. LIS is an alternative to traditional CMS.

Less-invasive ventricular assist device implantation: A multicenter study

BACKGROUND

Left ventricular assist device has been shown to be a safe and effective treatment option for patients with end-stage heart failure. However, there is limited evidence showing the effect of the implantation approach on postoperative morbidities and mortality. We aimed to compare left ventricular assist device implantation using conventional sternotomy versus less-invasive surgery including hemi-sternotomy and the minithoracotomy approach.

METHODS

Between January 2014 and December 2018, 342 consecutive patients underwent left ventricular assist device implantation at 2 high-volume centers. Patient characteristics were prospectively collected. The propensity score method was used to create 2 groups in a 1:1 fashion. A competing risk regression model was used to evaluate time to death adjusting for competing risk of heart transplantation.

RESULTS

The unmatched cohort included 241 patients who underwent left ventricular assist device implantation with the conventional sternotomy technique and 101 patients who underwent left ventricular assist device implantation with the less-invasive surgery technique. Propensity matching produced 2 groups each including 73 patients. In the matched groups, reexploration rate for bleeding was necessary in 17.9% (12/67) in the conventional sternotomy group compared with 4.1% (3/73) the less-invasive surgery group (P = .018). Intensive care unit stay for the less-invasive surgery group was significantly lower than for the sternotomy group (10.5 [interquartile range, 2-25.75] days vs 4 [interquartile range, 2-9.25] days, P = .008), as was hospital length of stay (37 [interquartile range, 27-61] days vs 25.5 [interquartile range, 21-42] days, P = .007). Mortality cumulative incidence for conventional surgery was 24% (95% confidence interval, 14.3-34.8) at 1 year and 26% (95% confidence interval, 15.9-37.4) at 2 years for patients without heart transplantation. Mortality cumulative incidence for less-invasive surgery was 22.5% (95% confidence interval, 12.8-33.8) at 1 year and 25.2% (95% confidence interval, 14.5-37.4) at 2 years for patients without heart transplantation. There was no difference in cumulative mortality incidence when adjusting for competing risk of heart transplantation (subdistribution hazard, 0.904, 95% confidence interval, 0.45-1.80, P = .77).

CONCLUSIONS

The less-invasive surgery approach is a safe technique for left ventricular assist device implantation. Less-invasive surgery was associated with a significant reduction in the postoperative bleeding complications and duration of hospital stay, with no significant difference in mortality incidence.

Benefit of Self-Managed Anticoagulation in Patients with Left Ventricular Assist Device

BACKGROUND

 The exact monitoring of the therapeutic-range international normalized ratio (INR) after left ventricular assist device (LVAD) implantation is an important aim to reduce the risk of thrombosis or bleeding complications. Service providers offer a telemedical anticoagulation service (CS).

METHODS

 We compared LVAD patients using the CS (n = 15) to those who received regular medical care (RMC; n = 15) to investigate if telemedicine supervision increased the INR-specific time in the therapeutic range (TTR) during anticoagulation. All patients received self-management training for phenprocoumon medication according to their INR value. INR values were documented for 12 months. A survey (scale: 1 = not satisfied and 10 = very satisfied) was used to determine patient's satisfaction and psychological well-being.

RESULTS

 A total of 1,798 INR measurements were analyzed. The TTR_Rosendaal was higher in patients undergoing RMC (78.1 ± 14.3%) compared with that in patients using the CS (58.3 ± 28.0%, p = 0.03). The patient's satisfaction with the coagulation setting at the beginning of the study (RMC: 6.7 ± 3.1, CS: 7.2 ± 3.0, p = 0.74) and psychological wellbeing (RMC: 6.5 ± 1.9, CS: 6.5 ± 2.7, p = 0.97) were comparable between both groups.

CONCLUSION

 We found that INR self-management is superior regarding the efficiency of post-LVAD anticoagulation therapy when compared with telemedical (CS)-based INR management in a small study cohort. Intensive training by experienced staff was able to replace CS.

Midterm results after St Jude Medical Epic porcine xenograft for aortic, mitral, and double valve replacement

BACKGROUND

The aim of this study was to evaluate the results after stented porcine xenograft implantation (Epic, SJM, St Paul, MN) with Linx anticalcification treatment in elderly patients at our high-volume tertiary care center.

METHODS

A total of 3825 patients undergoing aortic (AVR = 2441), mitral (MVR = 892), or double valve (DVR = 492) replacement between 11/2001 and 12/2017 with Epic xenografts were evaluated. Outcomes were assessed by reviewing the prospectively acquired hospital database results, and regular annual follow-up information was acquired from questionnaires or telephone interviews.

RESULTS

For patients undergoing AVR, MVR, DVR, age at surgery were 76.4 ± 6, 71.2 ± 9, 72.9 ± 8 years; active endocarditis was an indication for valve surgery in 4.5%, 20.7%, 19.7%; and the predicted median (interquartile range [IQR]) mortality risk (EuroSCORE II) was 5.2% (3.1%-9.4%), 7.5% (3.9%-16.2%), 9.9% (6.0%-19.6%), respectively. Median follow-up was 3.04 (IQR: 0.18-5.21). Thirty-day survival was 91.2% ± 0.6%, 87.6% ± 0.1.1%, 84.7% ± 1.6%; and 10-year survival was 56.7% ± 1.0%, 59.4% ± 2.5%, 50.45% ± 3.1%, respectively. Patients who underwent MVR versus AVR were at significant increased risk for reoperation for endocarditis (adjusted odds ratio; 2.2, 95% confidence interval; 1.29-3.7; P = .003). There was no significant difference in all-cause mortality at midterm in AVR vs MVR in the matched cohort (P = .85).

CONCLUSIONS

Implantation of the Epic stented porcine xenograft is associated with acceptable survival and freedom from valve-related complications or reoperation due to structural valve disease at midterm follow-up.

Diagnostic tools in surgically treated patients with infective valve endocarditis

Background

Infective valve endocarditis (IE) is associated with significant mortality and complication rates. The diagnosis impacts not only the prognosis but also the management of the disease. The aim of this article is to show the findings obtained from the implementation of our most important diagnostic tools and discuss our standard diagnostic process for patients with IE who underwent surgical treatment between 1994 and 2017.

Methods

Between December 1994 and January 2017 a total of 2,458 patients with IE underwent surgery at our institution. We analyzed clinical, microbiological, echocardiographic, and multi slice computer tomographic (MSCT) features in this group.

Results

The most often isolated involved valve was the aortic valve (59%). Prosthetic valve endocarditis (PVE) was present in almost one third of all cases. The most common valve failures were mitral valve insufficiency (MI) and aortic valve insufficiency (AI) (65% and 57% respectively). Almost one half of the aortic insufficiencies were severe. 63% of all vegetations assessed by echocardiography were larger than 1 cm. We detected a septic embolism in 44% of patients and the most common target organ was the spleen (25%). The most common isolated pathogen was Staphylococcus aureus (26%) and affected patients had a significant correlation with in-hospital mortality (P=0.004).

Conclusions

Echocardiography offers valuable information and is the most important diagnostic method in patients with IE. Preoperative MSCT contributes to the entire perioperative decision-making process. Microbiological diagnosis is mandatory in choosing and adjusting antibiotic therapy and also has prognostic value.

Surgical options in infective valve endocarditis with neurological complications

Background

Surgery is a common treatment option for patients with infective endocarditis. We present a large cohort of surgically managed patients with infective endocarditis and evaluate the long-term mortality of those with and without neurological complications.

Methods

We performed a retrospective review of patients surgically managed for infective endocarditis between 1994 and 2017. Demographic and outcome data were collected using a hospital database. Time-to-event analysis was performed with Kaplan-Meier curve and compared statistically with log-rank testing.

Results

At the time of admission, 680 (27.7%) patients with infective endocarditis showed neurological complications. The mean age was 62.6±14.0 years and 70% were male. Two thousand two hundred and sixty-one (92%) patients had left-sided valve endocarditis. Isolated aortic valve endocarditis was present in 59% of patients and 35% of patients had isolated infective endocarditis of the mitral valve. Mean logistic EuroSCORE was 21.2±21.6. Microbiologic cultures were positive in 1,939 patients (79%). The most common bacteria were Staphylococcus aureus (26%). In-hospital mortality in the group of patients with Staphylococcus aureus was significantly higher than in the group infected with other pathogens (18.2% vs. 13.4%, P=0.004). Patients with vegetations ≥1 cm had significantly more systemic embolization (P<0.001). 44% of patients had septic embolization with the most common site being the spleen, followed by the brain. Patients presenting with neurological complications had significantly higher in-hospital and long-term mortality (P<0.0001).

Conclusions

Infective endocarditis patients with neurological complications have a significantly higher risk of mortality than patients without neurological complications. Surgery is an effective treatment in patients presenting with infective endocarditis, and may be undertaken in patients with neurological complications to prevent poorer prognosis.

Curative therapy of a hepatitis C infection due to an infected heart donor: 5-year outcomes after heart transplantation

Heart transplantation is the gold standard therapy for patients diagnosed with end-stage heart failure. Despite the shortage of appropriate donor organs, the transplantation of hepatitis C-infected hearts is disputed. Previous research has shown that long-term results are controversial, and the risk of severe clinical infection should not be underestimated.

Ischemic Cardiomyopathy Affects the Thioredoxin System in the Human Myocardium

BACKGROUND

Oxidative stress due to reactive oxygen species (ROS) production is a key factor in the development of heart failure (HF). This study investigated the thioredoxin (Trx) system, which plays a major role in antioxidant defense, in patients suffering from ischemic (ICM) or dilated (DCM) cardiomyopathy.

METHODS AND RESULTS

Myocardial tissue from ICM (n = 13) and DCM (n = 13) patients, as well as septal tissue of patients with aortic stenosis but without diagnosed hypertrophic cardiomyopathy or subaortic stenosis (control; n = 12), was analyzed for Trx1, Trx-interacting protein (TXNIP) and E3 ligase ITCH (E3 ubiquitin-protein ligase Itchy homolog) expression. Trx-reductase 1 (TXNRD1) amount and activity, cytosolic cytochrome C content, and apoptosis markers were quantified by means of enzyme-linked immunosorbent assay and multiplexing. Compared with control samples, ITCH and Trx1 expression, TXNRD1 amount and activity were reduced and TXNIP expression was increased in ICM (ITCH: P = .013; Trx1: P = .028; TXNRD1 amount: P = .035; TXNRD1 activity: P = .005; TXNIP: P = .014) but not in DCM samples. A higher level of the downstream apoptosis marker caspase-9 (ICM: 582 ± 262 MFI [P = .995]; DCM: 1251 ± 548 MFI [P = .002], control: 561 ± 214 MFI) was detected in DCM tissue. A higher expression of Bcl-2 was found in DCM (P = .011).

CONCLUSION

The Trx system was impaired in ICM but not in DCM. ITCH appeared to be responsible for the down-regulation of the Trx system. ROS-induced mitochondrial instability appeared to play a role in DCM.

Differences of early immunological responses in on-pump versus off-pump cardiac surgery

INTRODUCTION

Cardiopulmonary bypass surgery is accompanied by an inflammatory response and pulmonary dysfunction that renders patients vulnerable to postoperative complications. The majority of studies investigating the inflammatory response in cardiopulmonary bypass focus on cytokine measurements. This study investigated the early response of peripheral blood cell types and early changes in lung tissue in on-pump versus off-pump cardiopulmonary bypass surgery.

METHODS

Landrace pigs were assigned to the following groups (n = 6 per group): 1. off-pump cardiopulmonary bypass, 2. conventional cardiopulmonary bypass, 3. heparin-coated cardiopulmonary bypass, 4. surface-reduced cardiopulmonary bypass, and 5. surface-reduced cardiopulmonary bypass plus lung perfusion. Surgery was performed under mild hyperthermia (32°C), with 90-minute ischemia and 180-minute reperfusion. Histological and flow cytometric analyses were performed.

RESULTS

Lung water content increased during reperfusion in heparin-coated (84.63 ± 2.99%) compared to conventional cardiopulmonary bypass (76.33 ± 4.56%, p = 0.04). Alveolar septal thickness increased during ischemia at heparin-coated (p < 0.01) and surface-reduced cardiopulmonary bypass plus lung perfusion (p = 0.05). Tumor necrosis factor expression increased significantly (p < 0.01) in peribronchial, perivascular, and peripheral lung areas in all on-pump groups, but not in off-pump cardiopulmonary bypass. The usage of heparin-coated cardiopulmonary bypass led to increased percentages of CD3⁺CD4⁺ (p = 0.03) and CD3⁺CD8⁺ (p = 0.01) T cells compared to an uncoated device. Natural killer and mature B lymphocytes decreased at conventional and surface-reduced cardiopulmonary bypass plus lung perfusion. Activated granulocytes and macrophages increased at conventional cardiopulmonary bypass and heparin-coated cardiopulmonary bypass.

CONCLUSION

Off-pump cardiopulmonary bypass induces less immunological response and lung injury than on-pump surgery. The reduction of cardiopulmonary bypass surface reduces the inflammatory immune response induced by cardiopulmonary bypass. Lung perfusion of surface-reduced cardiopulmonary bypass diminished the extravasation caused by surface reduction of the cardiopulmonary bypass.