Achieving equity in dialysis care and outcomes: The role of policies

Socially disadvantaged persons, including racial and ethnic minorities, individuals with low incomes, homeless persons, and non-US citizens bear a disproportionate burden of end-stage kidney disease (ESKD). Inequities in nephrology referral, vascular access, use of home dialysis modalities, kidney transplantation, and mortality are prominent. Public policies, including the Patient Protection and Affordable Care Act, end-stage renal disease Quality Incentive Program, and the Prospective Payment System, were enacted to improve healthcare access and dialysis care. Here, we highlight inequities in dialysis care and outcomes, how current ESKD and other public policies may influence or exacerbate these inequities, and gaps in the literature needed to inform future policies toward achieving equity in ESKD. We give special attention to the 2019 Advancing American Kidney Health Executive Order, which has high potential to radically transform dialysis care.     

Impact of left ventricular assist device therapy on the cardiac proteome and metabolome composition in ischemic cardiomyopathy

The changes in the myocardial proteome and metabolome associated with left ventricular assist device (LVAD) therapy in patients with ischemic cardiomyopathy (ICM) are poorly characterized. We investigated the impact of mechanical unloading following LVAD therapy on the myocardial proteome and metabolome. Matched samples of 5 patients’ myocardial tissue, harvested at the time of LVAD implant (“pre-LVAD”) or heart transplant (“post-LVAD”), were studied by quantitative proteomics and metabolomics as well as being probed for T-tubule structure and connexin-43 distribution. Moreover, pre-LVAD proteome profiles of ICM context were bioinformatically compared to pre-LVAD proteome profiles of dilated cardiac myopathy (DCM). More than 2120 proteins were reliably identified and quantified in paired patient samples. LVAD therapy led to proteomic remodeling, including reduced levels of α-1-antichymotrypsin together with an overall decrease of immune response proteins and an increase of proteins involved in membrane biology. Metabolomics highlighted increased glucose and glucose-6-phosphate levels in the left ventricle upon LVAD therapy. Wheat germ agglutinin staining demonstrated improved T-tubule structure. Connexin-43 displayed a trend for more pronounced intercalated disc localization. In comparing pre-LVAD proteome profiles of ICM context with pre-LVAD proteome profiles of dilated cardiac myopathy (DCM), we noticed an overrepresentation in ICM of proteins associated with humoral immune response. Our findings underline an impact of LVAD therapy on left ventricular biology in ICM. The proteomic, metabolomic, and structural alterations described here are typically associated with cardiac recovery. On the molecular level, our findings indicate the possibility of cardiac remodeling under LVAD therapy in ICM.     

Extracorporeal carbon dioxide removal requirements for ultraprotective mechanical ventilation: Mathematical model predictions

Extracorporeal carbon dioxide (CO₂) removal (ECCO₂R) facilitates the use of low tidal volumes during protective or ultraprotective mechanical ventilation when managing patients with acute respiratory distress syndrome (ARDS); however, the rate of ECCO₂R required to avoid hypercapnia remains unclear. We calculated ECCO₂R rate requirements to maintain arterial partial pressure of CO₂ (PaCO₂) at clinically desirable levels in mechanically ventilated ARDS patients using a six-compartment mathematical model of CO₂ and oxygen (O₂) biochemistry and whole-body transport with the inclusion of an ECCO₂R device for extracorporeal veno-venous removal of CO₂. The model assumes steady state conditions. Model compartments were lung capillary blood, arterial blood, venous blood, post-ECCO₂R venous blood, interstitial fluid and tissue cells, with CO₂ and O₂ distribution within each compartment; biochemistry included equilibrium among bicarbonate and non-bicarbonate buffers and CO₂ and O₂ binding to hemoglobin to elucidate Bohr and Haldane effects. O₂ consumption and CO₂ production rates were assumed proportional to predicted body weight (PBW) and adjusted to achieve reported arterial partial pressure of O₂ and a PaCO₂ level of 46 mmHg at a tidal volume of 7.6 mL/kg PBW in the absence of an ECCO₂R device based on average data from LUNG SAFE. Model calculations showed that ECCO₂R rates required to achieve mild permissive hypercapnia (PaCO₂ of 46 mmHg) at a ventilation frequency or respiratory rate of 20.8/min during mechanical ventilation increased when tidal volumes decreased from 7.6 to 3 mL/kg PBW. Higher ECCO2R rates were required to achieve normocapnia (PaCO2 of 40 mmHg). Model calculations also showed that required ECCO2R rates were lower when ventilation frequencies were increased from 20.8/min to 26/min. The current mathematical model predicts that ECCO2R rates resulting in clinically desirable PaCO2 levels at tidal volumes of 5-6 mL/kg PBW can likely be achieved in mechanically ventilated ARDS patients with current technologies; use of ultraprotective tidal volumes (3-4 mL/kg PBW) may be challenging unless high mechanical ventilation frequencies are used.     

Out of hospital management of LVAD patients during COVID-19 outbreak

Coronavirus disease 2019 (COVID-19) is a pandemic touching thousands of people all around the world. Patients supported with left ventricular assist devices (LVADs) are affected by long-standing cardiovascular diseases and subjected to variations of the normal cardiovascular physiology, thus requiring an even closer monitoring during the COVID-19 outbreak. Nevertheless, the COVID-19 pandemic led to a drastic reduction in routine clinical activities and a consequent risk of looser connections between LVAD patients and their referring center. Potential deleterious effects of such a situation can be a delayed recognition of LVAD-related complications, misdiagnosis of COVID-19, and impaired social and psychological well-being for patients and families. As one of the largest LVAD programs worldwide, we designed a sustainable and enforceable telemonitoring algorithm which can be easily adapted to every LVAD center so as to maintain optimal quality of care for LVAD patients during the COVID-19 pandemic.     

Acute heart failure after liver transplantation: A narrative review

Acute heart failure (AHF) is an under recognized yet potentially lethal complication after liver transplantation (LT) surgery. The increase in incidence of liver transplantation amongst high-risk patients and the leniency in the criteria for transplantation, predisposes these patients to postoperative AHF and the antecedent morbidity and mortality. The inability of conventional preoperative cardiovascular testing to accurately identify patients at risk for post-LT AHF poses a considerable challenge to clinicians caring for these patients. Even if high-risk patients are identified, there is considerable ambiguity in the candidacy for transplantation as well as optimization strategies that could potentially prevent the development of AHF in the postoperative period. The intraoperative and postoperative management of patients who develop AHF is also challenging and requires a well-coordinated multidisciplinary approach. The use of mechanical circulatory support in patients with refractory heart failure has the potential to improve outcomes but its use in this complex patient population can be associated with significant complications and requires a stringent risk-benefit analysis on a case-by-case basis.     

急性下肢静脉血栓处理策略

急性下肢静脉血栓是血管外科最常见的静脉急症,发病率较高。如处理得当,血栓急性期脱落会造成肺栓塞,部分慢性期病人合并血栓复发、血栓后综合征等并发症,严重影响病人生活质量。因此,明确下肢静脉血栓的危险因素,对于高龄、制动、手术、创伤、产后、恶性肿瘤等病人提高警惕,进行合理预防与评估,降低院内血栓的发生率。一旦血栓形成,如无抗凝禁忌,立即行抗凝治疗,出血风险评估后,选择合适的腔内治疗手段,如导管接触性溶栓或经皮机械血栓清除术。对于合并髂静脉狭窄或闭塞的病人,可行支架植入术。对于抗凝禁忌或下腔静脉漂浮血栓的病人,可行腔静脉滤器植入术。院内层面血栓防控体系的建立,有利于对血栓病人早发现、早诊断、早治疗,意义深远。