Establishing a nationwide pediatric heart transplantation program with mid-term results comparable to worldwide data - The Czech experience.

BACKGROUND: Heart transplantation (HTx) is an established therapeutic option for children with end-stage heart failure. Comprehensive pediatric nationwide HTx program was introduced in 2014 in the Czech Republic. The aim of this study was to evaluate its mid-term characteristics and outcomes and to compare them with international data. METHODS: Retrospective observational study, including all patients who underwent HTx from June 2014 till December 2022. Data from the institutional database were used for descriptive statistics and survival analyses. RESULTS: A total of 30 HTx were performed in 29 patients with congenital heart disease (CHD, N = 15, single ventricular physiology in 10 patients) and cardiomyopathy (CMP, N = 14). Ten patients were bridged to HTx by durable left ventricular assist devices (LVADs) for a mean duration of 104 (SD 89) days. There was one early and one late death during median follow-up of 3.3 (IQR 1.3-6.1) years. Survival probability at 5 years after HTx was 93%. Two patients underwent re-transplantation (one of them in an adult center). Significant rejection-free survival at 1, 3, and 6 years after HTx was 76%, 63%, and 63%, respectively. CONCLUSIONS: The introduced pediatric HTx program reflects the complexity of the treated population, with half of the patients having complex CHD and one-third being bridged to HTx by LVADs. Mid-term results are comparable to worldwide data. The data confirm the possibility of establishing a successful nationwide pediatric HTx program in a relatively small population country with well-developed pediatric cardiovascular care and other transplantation programs.

False aneurysms of the thoracic aorta: anastomosis investigation using the inflation-extension test.

INTRODUCTION: False aneurysms in the thoracic aorta are dangerous complications that can occur after cardiac surgery. They often result in high mortality rates. These aneurysms are caused by damage to all layers of the aortic wall. This study aimed to pinpoint the area of the experimental specimen (native vessel, anastomosis, or prosthetic graft) with the greatest deformation, to determine whether a false aneurysm is likely to develop in the anastomotic portion. METHODS: We conducted the inflation-extension test by performing eight cycles ranging from 0 to 20. The pressure sampling frequency was 100 Hz, and each cycle lasted approximately 34 seconds, resulting in a loading frequency of 0.03 Hz. During the experiment, each camera captured 3,000 frames. Based on the data collected, we evaluated and compared the loading stages of cycle 1 and cycle 8. RESULTS AND DISCUSSION: During loading, the native vessel experienced a dominant deformation of approximately 7% in the circumferential direction. The prosthetic graft, which had a longitudinal construction, deformed by approximately 8% in the axial direction. The prosthetic graft, on the other hand, only experienced a deformation of up to 1.5% in the circumferential direction, which was about 5 times smaller than the deformation of the native vessel. The anastomosis area was very stiff and showed minimal deformation. Additionally, there was little difference in the mechanical response between the first C1 and the eighth C8 cycle. CONCLUSION: Based on the available evidence, it can be inferred that aortic false aneurysms are more likely to form just behind the suture lines in the native aorta, which is more elastic compared to stiff sections of anastomosis and prosthetic graft. Numerous pulsations of the native vessel will likely cause the impairment of the aorta at the margin of the anastomosis. This will lead to disruption of the aortic wall and false aneurysm formation in the native vessel near the area of anastomosis.

Comprehensive multi-modality treatment of thoracic aorta pseudoaneurysms: a single-center experience.

INTRODUCTION: Thoracic aorta false aneurysms (TAFA) are unexplored complications after cardiac surgery associated with significant morbidity and mortality. Therefore, the purpose of this study was to examine the clinical profiles, surgical techniques, and operative outcomes, of patients treated for TAFA at a single institution. METHODS: From 1996 to 2022, 112 patients were treated for aortic pseudoaneurysm (mean age 55 ± 14 years, 78 patients were male). In the majority of the patients (90%) TAFA developed after previous cardiovascular surgery, the most common diagnosis and surgical procedure preceding the TAFA development was an aortic dissection (52%) and Bentall procedure (47%). In the rest of the cohort, the leading cause was trauma. RESULTS: Sixty-one percent of patients were indicated for reintervention (surgical reoperation, endoluminal graft implantation, septal occluder implantation, coil embolization, or a combination of procedures). Overall, 52 patients had undergone cardiac reoperation. TAFA was resected and the aorta was repaired in 55% or replaced in 45%. Operative mortality was 5.7%. In postoperative follow-up, a hypoechogenic lesion encircling aortic prosthesis was present in 94%, therefore it was determined as a negative prognostic factor. The mean follow-up was 13.2 ± 19.4 years. CONCLUSION: Although there is no specific approach how to prevent TAFA development, maintaining normal blood pressure and regular follow-up should be applied. More frequent follow-ups should be performed in patients with a hypoechogenic lesion encircling and aortic prosthesis. Early detection during long-term postoperative follow-up, an individually tailored approach of a multidisciplinary team is necessary for favorable treatment outcomes.

Aspirin and Hemocompatibility Events With a Left Ventricular Assist Device in Advanced Heart Failure: The ARIES-HM3 Randomized Clinical Trial.

IMPORTANCE: Left ventricular assist devices (LVADs) enhance quality and duration of life in advanced heart failure. The burden of nonsurgical bleeding events is a leading morbidity. Aspirin as an antiplatelet agent is mandated along with vitamin K antagonists (VKAs) with continuous-flow LVADs without conclusive evidence of efficacy and safety. OBJECTIVE: To determine whether excluding aspirin as part of the antithrombotic regimen with a fully magnetically levitated LVAD is safe and decreases bleeding. DESIGN, SETTING, and PARTICIPANTS: This international, randomized, double-blind, placebo-controlled study of aspirin (100 mg/d) vs placebo with VKA therapy in patients with advanced heart failure with an LVAD was conducted across 51 centers with expertise in treating patients with advanced heart failure across 9 countries. The randomized population included 628 patients with advanced heart failure implanted with a fully magnetically levitated LVAD (314 in the placebo group and 314 in the aspirin group), of whom 296 patients in the placebo group and 293 in the aspirin group were in the primary analysis population, which informed the primary end point analysis. The study enrolled patients from July 2020 to September 2022; median follow-up was 14 months. Intervention: Patients were randomized in a 1:1 ratio to receive aspirin (100 mg/d) or placebo in addition to an antithrombotic regimen. MAIN OUTCOMES AND MEASURES: The composite primary end point, assessed for noninferiority (-10% margin) of placebo, was survival free of a major nonsurgical (>14 days after implant) hemocompatibility-related adverse events (including stroke, pump thrombosis, major bleeding, or arterial peripheral thromboembolism) at 12 months. The principal secondary end point was nonsurgical bleeding events. RESULTS: Of the 589 analyzed patients, 77% were men; one-third were Black and 61% were White. More patients were alive and free of hemocompatibility events at 12 months in the placebo group (74%) vs those taking aspirin (68%). Noninferiority of placebo was demonstrated (absolute between-group difference, 6.0% improvement in event-free survival with placebo [lower 1-sided 97.5% CI, -1.6%]; P < .001). Aspirin avoidance was associated with reduced nonsurgical bleeding events (relative risk, 0.66 [95% confidence limit, 0.51-0.85]; P = .002) with no increase in stroke or other thromboembolic events, a finding consistent among diverse subgroups of patient characteristics. CONCLUSIONS AND RELEVANCE: In patients with advanced heart failure treated with a fully magnetically levitated LVAD, avoidance of aspirin as part of an antithrombotic regimen, which includes VKA, is not inferior to a regimen containing aspirin, does not increase thromboembolism risk, and is associated with a reduction in bleeding events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04069156.

Impact of preoperative mitral regurgitation on left ventricular assist device patients: propensity score-matched analysis of the EUROMACS dataset.

OBJECTIVES: Mitral regurgitation (MR) is frequently observed in patients undergoing left ventricular assist device implantation. We investigated the impact of preoperative MR on left ventricular assist device patients. METHODS: A retrospective propensity score-matched analysis of adult patients enrolled in the EUROMACS registry between 1 January 2011 and 30 November 2021 was performed. Patients were divided into 2 groups according to the grade of preoperative MR: none-to-mild (MR 0-II) or moderate-to-severe (MR III-IV). RESULTS: Following 1:1 propensity score matching, each group consisted of 914 patients. Incidence of postoperative temporary right ventricular support, reoperation for bleeding and dialysis was similar. MR III-IV demonstrated shorter median intensive care unit stay [14 days (6; 27.8) vs 10 days (5; 22), P = 0.004] and ventilation time [72 h (22, 320) vs 31 h (18, 150), P < 0.001]. Mortality was lower for MR III-IV patients [subdistribution hazard ratio: 0.66, 95% confidence interval (CI): 0.59-0.73, P < 0.001]. The 1-year survival was 68.1% (95% CI: 65.1-71.3%) in MR 0-II and 75% (95% CI: 72.1-78%) in MR III-IV. A lower incidence of total complications [odds ratio (OR): 0.93 (0.89-0.98), P = 0.003] and trend towards a lower risk of neurological dysfunction (subdistribution hazard ratio: 0.79; 95% CI: 0.61-1.01, P = 0.063) and sustained ventricular tachycardia [OR: 0.93 (0.54-1.03), P = 0.074] were demonstrated for MR III-IV. The risk of fatal stroke and pump thrombosis was similar. CONCLUSIONS: Moderate-to-severe MR in patients undergoing left ventricular assist device implantation is associated with better mid-term survival and lower incidence of total major adverse events and complications. The incidence of severe postoperative complications including fatal stroke and device thrombosis was similar.

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.

Bioprosthetic Total Artificial Heart Implantation Does Not Induce Chronic Inflammation.

The Aeson total artificial heart (A-TAH) has been developed for patients at risk of death from biventricular failure. We aimed to assess the inflammatory status in nine subjects implanted with the A-TAH in kinetics over one year. Laboratory assessment of leukocyte counts, inflammatory cytokines assay, and peripheral blood mononuclear cell collection before and after A-TAH implantation. Leukocyte counts were not significantly modulated according to time after A-TAH implantation (coefficient of the linear mixed effect model with 95% CI, -0.05 (-0.71 to -0.61); p = 0.44). We explored inflammatory cytokine after A-TAH and did not observe, at any time, a modified profile compared to pre-implantation values (all p -values > 0.05). Finally, we compared the distribution of circulating immune cell subpopulations identified based on sequential expression patterns for multiple clusters of differentiation. None of the population explored had significant modulation during the 12-month follow-up (all p -values > 0.05). In conclusion, using a cytokine multiplex assay combined with a flow cytometry approach, we demonstrated the absence of inflammatory signals in peripheral blood over a period of 12 months following A-TAH implantation.

Decreased Epicardial CTRP3 mRNA Levels in Patients with Type 2 Diabetes Mellitus and Coronary Artery Disease Undergoing Elective Cardiac Surgery: A Possible Association with Coronary Atherosclerosis.

(1) Background: C1q TNF-related protein 3 (CTRP3) is an adipokine with anti-inflammatory and cardioprotective properties. In our study, we explored changes in serum CTRP3 and its gene expression in epicardial (EAT) and subcutaneous (SAT) adipose tissue in patients with and without coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) undergoing elective cardiac surgery. (2) Methods: SAT, EAT, and blood samples were collected at the start and end of surgery from 34 patients: (i) 11 without CAD or T2DM, (ii) 14 with CAD and without T2DM, and (iii) 9 with both CAD and T2DM. mRNA levels of CTRP3 were assessed by quantitative reverse transcription PCR. Circulating levels of CTRP3 and other factors were measured using ELISA and Luminex Multiplex commercial kits. (3) Results: Baseline plasma levels of TNF-α and IL6 did not differ among the groups and increased at the end of surgery. Baseline circulating levels of CTRP3 did not differ among the groups and decreased after surgery. In contrast, baseline CTRP3 mRNA levels in EAT were significantly decreased in CAD/T2DM group, while no differences were found for TNF-α and IL6 gene expression. (4) Conclusions: Our data suggest that decreased EAT mRNA levels of CTRP3 could contribute to higher risk of atherosclerosis in patients with CAD and T2DM.

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): third Paediatric (Paedi-EUROMACS) report.

OBJECTIVES: A third paediatric report has been generated from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). The purpose of EUROMACS, which is operated by the European Association for Cardio-Thoracic Surgery, is to gather data related to durable mechanical circulatory support for scientific purposes and to publish reports with respect to the course of mechanical circulatory support therapy. Since the first report issued, efforts to increase compliance and participation have been extended. Additionally, the data provided the opportunity to analyse patients of younger age and lower weight. METHODS: Participating hospitals contributed pre-, peri- and long-term postoperative data on mechanical circulatory support implants to the registry. Data for all implants in paediatric patients (<19 years of age) performed from 1 January 2000 to 31 December 2020 were analysed. This report includes updates of patient characteristics, implant frequency, outcome (including mortality rates, transplants and recovery rates) as well as adverse events including neurological dysfunction, device malfunction, major infection and bleeding. RESULTS: Twenty-five hospitals contributed 537 registered implants in 480 patients. The most frequent aetiology of heart failure was any form of cardiomyopathy (59%), followed by congenital heart disease and myocarditis (15% and 14%, respectively). Competing outcomes analysis revealed that a total of 86% survived to transplant or recovery or are ongoing; at the 2-year follow-up examination, 21.9% died while on support. At 12 months, 45.1% received transplants, 7.5% were weaned from their device and 20.8% died. The 3-month adverse events rate was 1.59 per patient-year for device malfunction including pump exchange, 0.7 for major bleeding, 0.78 for major infection and 0.71 for neurological events. CONCLUSIONS: The overall survival rate was 79.2% at 12 months following ventricular assist device implant. The comparison of survival rates of the early and later eras shows no significant difference. A focus on specific subgroups showed that survival was less in patients of younger age (<1 year of age; P = 0.01) and lower weight (<20 kg; P = 0.015). Transplant rates at 6 months continue to be low (33.2%).

Trends and Outcomes of Left Ventricular Assist Device Therapy: JACC Focus Seminar.

As the prevalence of advanced heart failure continues to rise, treatment strategies for select patients include heart transplantation or durable left ventricular assist device (LVAD) support, both of which improve quality of life and extend survival. Recently, the HeartMate 3 has been incorporated into clinical practice, the United Network for Organ Sharing donor heart allocation system was revised, and the management of LVAD-related complications has evolved. Contemporary LVAD recipients have greater preoperative illness severity, but survival is higher and adverse event rates are lower compared with prior eras. This is driven by advances in device design, patient selection, surgical techniques, and long-term management. However, bleeding, infection, neurologic events, and right ventricular failure continue to limit broader implementation of LVAD support. Ongoing efforts to optimize management of patients implanted with current devices and parallel development of next-generation devices are likely to further improve outcomes for patients with advanced heart failure.

Bioprosthetic Total Artificial Heart in Autoregulated Mode Is Biologically Hemocompatible: Insights for Multimers of von Willebrand Factor.

BACKGROUND: Carmat bioprosthetic total artificial heart (Aeson; A-TAH) is a pulsatile and autoregulated device. The aim of this study is to evaluate level of hemolysis potential acquired von Willebrand syndrome after A-TAH implantation. METHODS: We examined the presence of hemolysis and acquired von Willebrand syndrome in adult patients receiving A-TAH support (n=10) during their whole clinical follow-up in comparison with control subjects and adult patients receiving Heartmate II or Heartmate III support. We also performed a fluid structure interaction model coupled with computational fluid dynamics simulation to evaluate the A-TAH resulting shear stress and its distribution in the blood volume. RESULTS: The cumulative duration of A-TAH support was 2087 days. A-TAH implantation did not affect plasma free hemoglobin over time, and there was no association between plasma free hemoglobin and cardiac output or beat rate. For VWF (von Willebrand factor) evaluation, A-TAH implantation did not modify multimers profile of VWF in contrast to Heartmate II and Heartmate III. Furthermore, fluid structure interaction coupled with computational fluid dynamics showed a gradually increase of blood damage according to increase of cardiac output (P<0.01), however, the blood volume fraction that endured significant shear stresses was always inferior to 0.03% of the volume for both ventricles in all regimens tested. An inverse association between cardiac output, beat rate, and high-molecular weight multimers ratio was found. CONCLUSIONS: We demonstrated that A-TAH does not cause hemolysis or AWVS. However, relationship between HMWM and cardiac output depending flow confirms relevance of VWF as a biological sensor of blood flow, even in normal range.

Comparative analysis of LVAD patients in regard of ischaemic or idiopathic cardiomyopathy: A propensity-score analysis of EUROMACS data.

BACKGROUND: Despite recent advances in management of patients with advanced heart failure, mortality remains high. Aim of this study was to compare impact of different aetiology of ischaemic and idiopathic cardiomyopathy on early outcomes and long-term survival of patients after left ventricular assist device implantation. METHODS: European Registry for Patients with Mechanical Circulatory Support (EUROMACS) gathers clinical data and follow-up parameters of LVAD recipients. Patients enrolled in the EUROMACS registry with primary diagnosis of either ischaemic (n = 1190) or idiopathic (n = 812) cardiomyopathy were included. Primary Endpoints were early mortality as well as long-term survival. Secondary endpoint were major postoperative adverse events, such as need for rethoracotomy. Additionally, a propensity-score matching analysis was performed for patients with ischaemic (n = 509) and idiopathic (n = 509) cardiomyopathy. RESULTS: In terms of basic demographics and baseline parameters the two groups significantly differed as expected before propensity-score matching due to different aetiology of cardiomyopathy. Seven-day (52 (4.4%) versus 18 (2.2%); p = 0.009), 30-day (153 (12.9%) versus 73 (9.0%); p = 0.008) and in-hospital mortality (253 (19.7%) versus 123 (15.1%); p = 0.009) were significantly lower in the idiopathic cardiomyopathy group compared to the ischaemic cardiomyopathy group, whereas after propensity-score matching 30-day (p = 0.169) was comparable and in-hospital mortality (p = 0.051) was almost significant. Kaplan-Meier survival analysis revealed no significant difference in regard of long-term survival after propensity-score matching (Breslow-test p = 0.161 and LogRank-test p = 0.113). CONCLUSION: Though patients with ischaemic and idiopathic cardiomyopathy suffer from different cardiomyopathy aetiologies, 30-day-mortality and long-term survival of both groups were similar leading to the conclusion that covariates predominately influence mortality and survival of ischaemic and idiopathic cardiomyopathies.

The European Registry for Patients with Mechanical Circulatory Support of the European Association for Cardio-Thoracic Surgery: third report.

OBJECTIVES: In the third report of the European Registry for Patients with Mechanical Circulatory Support of the European Association for Cardio-Thoracic Surgery, outcomes of patients receiving mechanical circulatory support are reviewed in relation to implant era. METHODS: Procedures in adult patients (January 2011-June 2020) were included. Patients from centres with <60% follow-ups completed were excluded. Outcomes were stratified into 3 eras (2011-2013, 2014-2017 and 2018-2020). Adverse event rates (AERs) were calculated and stratified into early phase (<3 months) and late phase (>3 months). Risk factors for death were explored using univariable Cox regression with a stepwise time-varying hazard ratio (<3 vs >3 months). RESULTS: In total, 4834 procedures in 4486 individual patients (72 hospitals) were included, with a median follow-up of 1.1 (interquartile range: 0.3-2.6) years. The annual number of implants (range: 346-600) did not significantly change (P = 0.41). Both Interagency Registry for Mechanically Assisted Circulatory Support class (classes 4-7: 23, 25 and 33%; P < 0.001) and in-hospital deaths (18.5, 17.2 and 11.2; P < 0.001) decreased significantly between eras. Overall, mortality, transplants and the probability of weaning were 55, 25 and 2% at 5 years after the implant, respectively. Major infections were mainly noted early after the implant occurred (AER<3 months: 1.44 vs AER>3 months: 0.45). Bilirubin and creatinine levels were significant risk factors in the early phase but not in the late phase after the implant. CONCLUSIONS: In its 10 years of existence, EUROMACS has become a point of reference enabling benchmarking and outcome monitoring. Patient characteristics and outcomes changed between implant eras. In addition, both occurrence of outcomes and risk factor weights are time dependent.

Impact of concomitant cardiac valvular surgery during implantation of continuous-flow left ventricular assist devices: A European registry for patients with mechanical circulatory support (EUROMACS) analysis.

BACKGROUND: We investigated the clinical outcomes after cardiac valvular surgery procedures concomitant (CCPs) with left ventricular assist device (LVAD) implantation compared to propensity score (PS) matched controls using the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) data. METHODS: Between 2006 and 2018, 2760 continuous-flow LVAD patients were identified. Of these, 533 underwent a CCP during the LVAD implant. RESULTS: Cardiopulmonary bypass time (p < 0.001) and time for implant (p < 0.001) were both significantly longer in the LVAD+CCP group. Hospital mortality was comparable between the two groups from the unmatched population (15.7% vs. 14.1%, p = 0.073). Similarly, short-to-mid-term survival was similar in both groups, with 1-year, 3-year, and 5-year survival rates of 67.9%, 48.2%, and 27.7% versus 66.4%, 46.1%, and 26%, respectively (log-rank, p = 0.25). The results were similar in the PS-matched population. Hospital mortality was comparable between the two groups (18.9% vs. 17.4%, p = 0.074). The short-to-mid-term Kaplan-Meier survival analysis was similar for both groups, with 1-year, 3-year, and 5-year survival rates of 63.4%, 49.2%, and 24.7% versus 66.5%, 46%, and 25.1%, respectively (log-rank, p = 0.81). In the unmatched population, LVAD+CCP patients had longer intensive care unit (ICU) stays (p < 0.0001), longer mechanical ventilation time (p = 0.001), a higher rate of temporary right ventricular assist device (RVAD) support (p = 0.033), and a higher rate of renal replacement therapy (n = 35, 6.6% vs. n = 89, 4.0%, p = 0.014). In the PS-matched population, the LVAD+CCP patients had longer ICU stays (p = 0.019) and longer mechanical ventilation time (p = 0.002). CONCLUSIONS: The effect of additive valvular procedures (CCPs) does not seem to affect short-term survival, significantly, based on our registry data analysis. However, the decision to perform CCPs should be balanced with the projected type of surgery and preoperative characteristics. LVAD+CCP patients remain a delicate population and adverse device-related events should be strictly monitored and managed.

Elevated Circulating Stem Cells Level is Observed One Month After Implantation of Carmat Bioprosthetic Total Artificial Heart.

The Aeson® total artificial heart (A-TAH) has been developed as a total heart replacement for patients at risk of death from biventricular failure. We previously described endothelialization of the hybrid membrane inside A-TAH probably at the origin of acquired hemocompatibility. We aimed to quantify vasculogenic stem cells in peripheral blood of patients with long-term A-TAH implantation. Four male adult patients were included in this study. Peripheral blood mononuclear cells were collected before A-TAH implantation (T0) and after implantation at one month (T1), between two and five months (T2), and then between six and twelve months (T3). Supervised analysis of flow cytometry data confirmed the presence of the previously identified Lin-CD133+CD45- and Lin-CD34+ with different CD45 level intensities. Lin-CD133+CD45-, Lin-CD34+CD45- and Lin-CD34+CD45+ were not modulated after A-TAH implantation. However, we demonstrated a significant mobilization of Lin-CD34+CD45dim (p = 0.01) one month after A-TAH implantation regardless of the expression of CD133 or c-Kit. We then visualized data for the resulting clusters on a uniform manifold approximation and projection (UMAP) plot showing all single cells of the live Lin- and CD34+ events selected from down sampled files concatenated at T0 and T1. The three clusters upregulated at T1 are CD45dim clusters, confirming our results. In conclusion, using a flow cytometry approach, we demonstrated in A-TAH-transplanted patients a significant mobilization of Lin-CD34+CD45dim in peripheral blood one month after A-TAH implantation. Using a flow cytometry approach, we demonstrated in A-TAH transplanted patients a significant mobilization of Lin-CD34+CD45dim in peripheral blood one month after A-TAH implantation. This cell population could be at the origin of newly formed endothelial cells on top of hybrid membrane in Carmat bioprosthetic total artificial heart.

Association of thrombophilia prospective detection with hemocompatibility related outcomes in left ventricular assist device patients.

INTRODUCTION: Inherited thrombophilias represent a concerning risk factor due to a proclivity to an aberrant clot formation. However, in patients with left ventricular assist device (LVAD), their impact on bleeding and thrombotic complications remains still poorly understood. The aim of the present study was to evaluate the effect of thrombophilic mutation directed anticoagulation therapy on adverse clinical outcomes in LVAD patients. MATERIALS AND METHODS: About 138 consecutive patients indicated for LVAD implant (HeartMate II, Abbott, Plymouth, USA) were prospectively screened for three major thrombophilic mutations: factor II (prothrombin), factor V Leiden, and homozygous methylenetetrahydrofolate reductase (MTHFR). Subsequently, discordant individualized anticoagulation targets of INR 2.5-3.0 in thrombophilia positive and INR 1.8-2.2 in negative patients were established; notably without anti-platelet agents given the center standard of care. RESULTS: Mean age was 50 ± 12.7 years, 83% male. Mean duration of support was 464.5 days (SD 482.9; SEM 41.1) and median of 310 days (IQR 162; 546). Full thrombophilia positive cohort analysis has not revealed any significant impact on event free survival. In contrast, detailed analysis of specific thrombophilias subsets has revealed Factor II prothrombin mutation as a significant predisposition for the pump thrombosis risk (SHR 10.48; p = 0.001) despite more aggressive prespecified anticoagulation target. Moreover, the incidence of bleeding events in prothrombin group was also significantly increased (SHR 6.0; p = 0.03). CONCLUSIONS: Our observations suggest that specific thrombophilias in LVAD patients may pose different intensity predisposition for thrombotic complications. Factor II (prothrombin) positive mutation was identified as significant risk factor associated with the pump thrombosis.

Increased pulsatility index is associated with adverse outcomes in left ventricular assist device recipients.

AIMS: Recipients of left ventricular assist devices (LVAD) are exposed to increased risk of adverse clinical events. One of the potential contributing factors is non-pulsatile flow generated by LVAD. We evaluated the association of flow patterns in carotid arteries and of increased arterial stiffness with death and cerebrovascular events in LVAD recipients. METHODS AND RESULTS: We analysed data from 83 patients [mean age 54 ± 15 years; 12 women; HeartMate II (HMII), n = 34; HeartMate 3 (HM3), n = 49]. Pulsatile and resistive indexes, atherosclerotic changes in carotid arteries (measured by duplex ultrasound), and arterial stiffness [measured by Endo-PAT 2000 as the augmentation index standardized for heart rate (AI@75)] were evaluated 3 and 6 months after LVAD implantation. Sixteen patients died during follow-up (27.3 months; interquartile range 15.7-44.3). After adjusting for the main variables examined, the pulsatility index measured at 3 months was positively associated with increased hazard ratios (HR) for death and cerebrovascular events [HR 9.8, 95% confidence interval (CI) 1.62-59.42], with HR increasing after adding AI@75 to the model (HR 18.8, 95% CI 2.44-145.50). In HM3 recipients, HR was significantly lower than in HMII recipients (HR 0.31, 95% CI 0.11-0.91), but the significance disappeared after adding AI@75 to the model (HR 0.33, 95% CI 0.09-1.18). CONCLUSIONS: The risk of death and cerebrovascular events in LVAD recipients is associated with increased pulsatility index in carotid arteries and potentiated by increased arterial stiffness. The same risk is attenuated by HM3 LVAD implantation, but this effect is weakened by increased arterial stiffness.