ABSTRACT
The thirteenth annual report from The Society of Thoracic Surgeons (STS) Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) highlights outcomes for 27,314 patients receiving continuous flow durable left ventricular assist devices (LVAD) over the last decade (2012-2021). In 2021, 2,464 primary LVADs were implanted, representing a 23.5% reduction in the annual volume compared to peak implantation in 2019 and an ongoing trend from the prior year. This decline is likely a reflection of the untoward effects of the COVID-19 pandemic and the change in the US heart transplant allocation system in 2018. The last several years have been characterized by a shift in device indication and type with 81.1% of patients now implanted as destination therapy and 92.7% receiving an LVAD with full magnetic levitation in 2021. However, despite an older, more ill population being increasingly supported pre-implant with temporary circulatory devices in the recent (2017-2021) vs prior (2012-2016) eras, the 1- and 5-year survival continues to improve at 83.0% and 51.9%, respectively. The adverse events profile has also improved, with significant reduction in stroke, gastrointestinal bleeding, and hospital readmissions. Finally, we examined the impact of the change in heart transplant allocation system in 2018 on LVAD candidacy, implant strategy, and outcomes. In the competing outcomes analysis, the proportion of transplant eligible patients receiving a transplant has declined from 56.5% to 46.0% at 3 years, while the proportion remaining alive with ongoing support has improved from 24.1% to 38.1% at 3 years, underscoring the durability of the currently available technology.
ABSTRACT
Background: The coronavirus disease 2019 (COVID-19) was first identified in December 2019 and is currently still a public health issue affecting millions of people worldwide. Heart failure patients are known to be at higher risk of morbidity and mortality in this case. Yet, few data exist concerning COVID-19 among patients with a left ventricular assistance device, and even less among those with a total artificial heart (TAH). Case summary: A 27-year-old man with Marfan syndrome underwent prophylactic ascending aorta replacement. Shortly after surgery completion, he developed refractory cardiogenic shock with biventricular dysfunction leading to veno-arterial extracorporeal membrane oxygenation (VA-ECMO) implantation. In the context of no appropriate eligible donor during the following 10 days while waiting on the heart transplantation list, the patient was scheduled for a TAH as a bridge to transplantation. Meanwhile, he developed an acute respiratory distress syndrome secondary to SARS-CoV-2. The patient was successfully treated with corticosteroids, prone positioning and mechanical ventilation, and heart transplantation occurred 5 weeks after COVID-19 onset. Discussion: Here, we report the first case of a patient presenting with COVID-19 infection following TAH implantation in a bridge to transplantation. We highlight that (i) cardiogenic shock patients simultaneously infected by COVID-19 should be treated instantly with all-time available technology to ensure best outcomes, including TAH and prone positioning, (ii) heart transplantation safety 5 weeks after COVID-19 onset.
ABSTRACT
Endothelial progenitor cells (EPCs) are involved in vasculogenesis and cardiovascular diseases. However, the phenotype of circulating EPCs remains elusive but they are more often described as CD34+KDR+. The aim of the study was to extensively characterize circulating potential vasculogenic stem cell candidates in two populations of patients with cardiovascular disease by powerful multidimensional single cell complementary cytometric approaches (mass, imaging and flow). We identified cellular candidates in one patient before and after bioprosthetic total artificial heart implantation and results were confirmed in healthy peripheral and cord blood by mass cytometry. We also quantified cellular candidates in 10 patients with different COVID-19 severity. Both C-TAH implantation and COVID-19 at critical stage induce a redistribution of circulating CD34+ and CD19+ sub-populations in peripheral blood. After C-TAH implantation, circulating CD34+ progenitor cells expressed c-Kit stem marker while specific subsets CD34+CD133-/+CD45-/dimc-Kit+KDR- were mobilized. KDR was only expressed by CD19+ B-lymphocytes and CD14+ monocytes subpopulations in circulation. We confirmed by mass cytometry this KDR expression on CD19+ in healthy peripheral and cord blood, also with a VE-cadherin expression, confirming absence of endothelial lineage marker on CD34+ subtypes. In COVID-19, a significant mobilization of CD34+c-Kit+KDR- cells was observed between moderate and critical COVID-19 patients regardless CD133 or CD45 expression. In order to better evaluate EPC phenotype, we performed imaging flow cytometry measurements of immature CD34+KDR+ cells in cord blood and showed that, after elimination of non-circular events, those cells were all CD19+. During COVID-19, a significant mobilization of CD19+KDR+ per million of CD45+ cells was observed between moderate and critical COVID-19 patients regardless of CD34 expression. CD34+c-Kit+ cells are mobilized in both cardiovascular disease described here. KDR cells in peripheral blood are CD19 positive cells and are not classic vasculogenic stem and/or progenitor cells. A better evaluation of c-Kit and KDR expressing cells will lead to the redefinition of circulating endothelial progenitors.Graphical abstract Central illustration figure. Multidimensional proteomic approach of endothelial progenitors demonstrate expression of KDR restricted to CD19 cells. Endothelial progenitor cells (EPCs) are involved in cardiovascular diseases, however their phenotype remains elusive. We elucidated here EPCs phenotype by a deep characterization by multidimensional single cell complementary cytometric approaches after Bioprosthetic total artificial heart implantation and during COVID-19. We showed a redistribution of circulating CD34+ and CD19+ sub-populations in both situations. None of the immature cell population expresses KDR. Mobilized CD34+ expressed c-Kit. Imaging flow cytometry demonstrated that CD34+KDR+ cells, after elimination of non-circular events, are all CD19+. Our results suggest a new definition of circulating EPCs and emphasize involvement of CD19 cells in cardiovascular disease.