How to manage COVID-19-positive patients who need cardiac surgery A modification of traditional workflow is mandatory during the COVID-19 outbreak, beginning with the assumption that asymptomatic persons may also be potential sources of SARS-CoV-2 [5]. Patients who need cardiac surgery are likely to be more susceptible to severe complications of COVID-19, as they are more likely to have pre-existing comorbidities such as pulmonary dysfunction, heart failure, kidney disease, arterial hypertension and multiple drug therapy. Moreover, cardiopulmonary bypass and the need of invasive mechanical ventilation can represent predisposing factors to lung disease. According to guidelines from the Lombardy Region [6], cardiac surgery hospitals have been organized in 'Hub Centres' for cardiovascular patients and 'Spoke Centres' that are satellites for †The last two authors contributed to this paper as co-senior authors. ‡ Members of the Italian Society for Cardiac Surgery Task Force on COVID-19 Pandemic are listed in the Acknowledgements section.

Background: Fractional flow reserve (FFR) is a reliable tool for the functional assessment of coronary stenoses. FFR computed tomography (CT) derived (FFR CT ) has shown to be accurate, but its clinical usefulness in patients with complex coronary artery disease remains to be investigated. The present study sought to determine the impact of FFR CT on heart team’s treatment decision-making and selection of vessels for revascularization in patients with 3-vessel coronary artery disease. Methods: The trial was an international, multicenter study randomizing 2 heart teams to make a treatment decision between percutaneous coronary interventions and coronary artery bypass grafting using either coronary computed tomography angiography or conventional angiography. The heart teams received the FFR CT and had to make a treatment decision and planning integrating the functional component of the stenoses. Each heart team calculated the anatomic SYNTAX score, the noninvasive functional SYNTAX score and subsequently integrated the clinical information to compute the SYNTAX score III providing a treatment recommendation, that is, coronary artery bypass grafting, percutaneous coronary intervention, or equipoise coronary artery bypass grafting-percutaneous coronary intervention. The primary objective was to determine the proportion of patients in whom FFR CT changed the treatment decision and planning. Results: Overall, 223 patients were included. Coronary computed tomography angiography assessment was feasible in 99% of the patients and FFR CT analysis in 88%. FFR CT was available for 1030 lesions (mean FFR CT value 0.64±13). A treatment recommendation of coronary artery bypass grafting was made in 24% of the patients with coronary computed tomography angiography with FFR CT . The addition of FFR CT changed the treatment decision in 7% of the patients and modified selection of vessels for revascularization in 12%. With conventional angiography as reference, FFR CT assessment resulted in reclassification of 14% of patients from intermediate and high to low SYNTAX score tertile. Conclusions: In patients with 3-vessel coronary artery disease, a noninvasive physiology assessment using FFR CT changed heart team’s treatment decision-making and procedural planning in one-fifth of the patients. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02813473.

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Background CD 34 + stem/progenitor cells are involved in vascular homeostasis and in neovascularization of ischemic tissues. The number of circulating CD 34 + stem cells is a predictive biomarker of adverse cardiovascular outcomes in diabetic patients. Here, we provide evidence that hyperglycemia can be “memorized” by the stem cells through epigenetic changes that contribute to onset and maintenance of their dysfunction in diabetes mellitus. Methods and Results Cord‐blood–derived CD 34 + stem cells exposed to high glucose displayed increased reactive oxygen species production, overexpression of p66 shc gene, and downregulation of antioxidant genes catalase and manganese superoxide dismutase when compared with normoglycemic cells. This altered oxidative state was associated with impaired migration ability toward stromal‐cell–derived factor 1 alpha and reduced protein and mRNA expression of the C‐X‐C chemokine receptor type 4 ( CXCR 4) receptor. The methylation analysis by bisulfite Sanger sequencing of the CXCR 4 promoter revealed a significant increase in DNA methylation density in high‐glucose CD 34 + stem cells that negatively correlated with mRNA expression (Pearson r =−0.76; P =0.004). Consistently, we found, by chromatin immunoprecipitation assay, a more transcriptionally inactive chromatin conformation and reduced RNA polymerase II engagement on the CXCR 4 promoter. Notably, alteration of CXCR 4 DNA methylation, as well as transcriptional and functional defects, persisted in high‐glucose CD 34 + stem cells despite recovery in normoglycemic conditions. Importantly, such an epigenetic modification was thoroughly confirmed in bone marrow CD 34 + stem cells isolated from sternal biopsies of diabetic patients undergoing coronary bypass surgery. Conclusions CD 34 + stem cells “memorize” the hyperglycemic environment in the form of epigenetic modifications that collude to alter CXCR 4 receptor expression and migration.

OBJECTIVES During the Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) pandemic, Northern Italy had to completely reorganize its hospital activity. In Lombardy, the hub-and-spoke system was introduced to guarantee emergency and urgent cardiovascular surgery, whereas most hospitals were dedicated to patients with coronavirus disease 2019 (COVID-19). The aim of this study was to analyse the results of the hub-and-spoke organization system. METHODS Centro Cardiologico Monzino (Monzino) became one of the four hubs for cardiovascular surgery, with a total of eight spokes. SARS-CoV-2 screening became mandatory for all patients. New flow charts were designed to allow separated pathways based on infection status. A reorganization of spaces guaranteed COVID-19-free and COVID-19-dedicated areas. Patients were also classified into groups according to their pathological and clinical status: emergency, urgent and non-deferrable (ND). RESULTS A total of 70 patients were referred to the Monzino hub-and-spoke network. We performed 41 operations, 28 (68.3%) of which were emergency/urgent and 13 of which were ND. The screening allowed the identification of COVID-19 (three patients, 7.3%) and non-COVID-19 patients (38 patients, 92.7%). The newly designed and shared protocols guaranteed that the cardiac patients would be divided into emergency, urgent and ND groups. The involvement of the telematic management heart team allowed constant updates and clinical discussions. CONCLUSIONS The hub-and-spoke organization system efficiently safeguards access to heart and vascular surgical services for patients who require ND, urgent and emergency treatment. Further reorganization will be needed at the end of this pandemic when elective cases will again be scheduled, with a daily increase in the number of operations.