The rapid emergence of the COVID-19 pandemic is unprecedented and poses an unparalleled obstacle in the sixty-five year history of organ transplantation. Worldwide, the delivery of transplant care is severely challenged by matters concerning-but not limited to-organ procurement, risk of SARS-CoV-2 transmission, screening strategies of donors and recipients, decisions to postpone or proceed with transplantation, the attributable risk of immunosuppression for COVID-19 and entrenched health care resources and capacity. The transplant community is faced with choosing a lesser of two evils: initiating immunosuppression and potentially accepting detrimental outcome when transplant recipients develop COVID-19 versus postponing transplantation and accepting associated waitlist mortality. Notably, prioritization of health care services for COVID-19 care raises concerns about allocation of resources to deliver care for transplant patients who might otherwise have excellent 1-year and 10-year survival rates. Children and young adults with end-stage organ disease in particular seem more disadvantaged by withholding transplantation because of capacity issues than from medical consequences of SARS-CoV-2. This report details the nationwide response of the Dutch transplant community to these issues and the immediate consequences for transplant activity. Worrisome, there was a significant decrease in organ donation numbers affecting all organ transplant services. In addition, there was a detrimental effect on transplantation numbers in children with end-organ failure. Ongoing efforts focus on mitigation of not only primary but also secondary harm of the pandemic and to find right definitions and momentum to restore the transplant programs.
In the setting of myocardial infarction (MI), ischemia reperfusion injury (IRI) occurs due to occlusion (ischemia) and subsequent re-establishment of blood flow (reperfusion) of a coronary artery. A similar phenomenon is observed in heart transplantation (HTx) when, after cold storage, the donor heart is connected to the recipient’s circulation. Although reperfusion is essential for the survival of cardiomyocytes, it paradoxically leads to additional myocardial damage in experimental MI and HTx models. Damage (or danger)-associated molecular patterns (DAMPs) are endogenous molecules released after cellular damage or stress such as myocardial IRI. DAMPs activate pattern recognition receptors (PRRs), and set in motion a complex signaling cascade resulting in the release of cytokines and a profound inflammatory reaction. This inflammatory response is thought to function as a double-edged sword. Although it enables removal of cell debris and promotes wound healing, DAMP mediated signalling can also exacerbate the inflammatory state in a disproportional matter, thereby leading to additional tissue damage. Upon MI, this leads to expansion of the infarcted area and deterioration of cardiac function in preclinical models. Eventually this culminates in adverse myocardial remodeling; a process that leads to increased myocardial fibrosis, gradual further loss of cardiomyocytes, left ventricular dilation and heart failure. Upon HTx, DAMPs aggravate ischemic damage, which results in more pronounced reperfusion injury that impacts cardiac function and increases the occurrence of primary graft dysfunction and graft rejection via cytokine release, cardiac edema, enhanced myocardial/endothelial damage and allograft fibrosis. Therapies targeting DAMPs or PRRs have predominantly been investigated in experimental models and are potentially cardioprotective. To date, however, none of these interventions have reached the clinical arena. In this review we summarize the current evidence of involvement of DAMPs and PRRs in the inflammatory response after MI and HTx. Furthermore, we will discuss various current therapeutic approaches targeting this complex interplay and provide possible reasons why clinical translation still fails.
Aims Left ventricular assist device therapy has become the cornerstone in the treatment of end-stage heart failure and is increasingly used as destination therapy next to bridge to transplant or recovery. HeartMate 3 (HM3) and HeartWare (HVAD) are centrifugal continuous flow devices implanted intrapericardially and most commonly used worldwide. No randomized controlled trials have been performed yet. Analysis based on large registries may be considered as the best alternative but has the disadvantage of different standard of care between centres and missing data. Bias is introduced, because the decision which device to use was not random, even more so because many centres use only one type of left ventricular assist device. Therefore, we performed a propensity score (PS)-based analysis of long-term clinical outcome of patients that received HM3 or HVAD in a single centre. Methods and results Between December 2010 and December 2019, 100 patients received HVAD and 81 patients HM3 as primary implantation at the University Medical Centre Utrecht. We performed PS matching with an extensive set of covariates, resulting in 112 matched patients with a median follow-up of 28 months. After PS matching, survival was not significantly different (P = 0.21) but was better for HM3. The cumulative incidences for haemorrhagic stroke (P = 0.01) and pump thrombosis (P = 0.02) were significantly higher for HVAD patients. The cumulative incidences for major bleeding, ischaemic stroke, right heart failure, and driveline infection were not different between the groups. We found no interaction between the surgeon who performed the implantation and survival (P = 0.59, P = 0.78, and P = 0.89). Sensitivity analysis was performed, by PS matching without patients on preoperative temporary support resulting in 74 matched patients. This also resulted in a non-significant difference in survival (P = 0.07). The PS-adjusted Cox regression showed a worse but non-significant (P = 0.10) survival for HVAD patients with hazard ratio 1.71 (95% confidence interval 0.91-3.24). Conclusions Survival was not significantly different between both groups after PS matching, but was better for HM3, with a significantly lower incidence of haemorrhagic stroke and pump thrombosis for HM3. These results need to be interpreted carefully, because matching may have introduced greater imbalance on unmeasured covariates. A multicentre approach of carefully selected centres is recommended to enlarge the number of matched patients.
Objective: To investigate whether surfactant pretreatment provides lung protection in an animal model of lung ischemia-reperfusion injury (LIRI). Methods: Male Sprague-Dawley rats (nZ100) were randomised to receive intratracheally administered surfactant or no pretreatment. One hour thereafter, animals underwent 120 min of warm ischemia of the left lung, or were sham-operated. A third group served as healthy untreated controls. Animals were killed on day 1, 3 or 7. Blood gas values were measured and lung compliance was recorded. Broncho-alveolar lavage fluid (BALf) was obtained to assess the amount of alveolar protein, the ratio of small to large aggregate surfactant phospholipids (SA/LA ratio), and leukocyte infiltration (granulocytes, macrophages and lymphocytes, measured by Flow Cytometry). Results: LIRI resulted in a mortality rate of 17% and significantly decreased lung compliance and PaO 2 (day 1 and 3 P!0.001, day 7 P!0.05) as compared to sham-operated and healthy controls. On day 1 more protein was present in the alveoli of ischemic lungs (P!0.001) than in sham-operated and healthy controls. Furthermore, LIRI resulted in an increased SA/LA ratio in the left lung on day 1 (P!0.05) and caused infiltration of granulocytes (day 1, 3 and 7 (P!0.01)), macrophages (day 3 (P!0.05) and 7 (P!0.01) and lymphocytes (day 3 and 7 (P!0.01)) in the BALf as compared to sham-operated and healthy controls. Surfactant pretreatment improved survival, lung compliance (day 3 P!0.001) and PaO 2 (day 1, 3 (P!0.01 and 7 (P! 0.05)). It also reduced protein leakage (P!0.05) and prevented an increase in the SA/LA ratio (P!0.01). Although the number of macrophages and granulocytes in the BALF was increased on day 1 and 3 (P!0.01) after surfactant pretreatment as compared to all other groups, the number of lymphocytes was reduced on day 3 (P!0.05). Conclusions: The present study shows that surfactant pretreatment enhances recovery of lung function and lung mechanics after LIRI, resulting in normal parameters from day 3 onwards. Surfactant pretreatment in this LIRI model may provide useful information to improve donor lung function after lung transplantation. q
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