Background Venous thromboembolism (VTE) may complicate the course of Coronavirus Disease 2019 (COVID-19). Objectives To evaluate the incidence of VTE in patients with COVID-19. Methods MEDLINE, EMBASE, and PubMed were searched up to 24th June 2020 for studies that evaluated the incidence of VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), in patients with COVID-19. Pooled proportions with corresponding 95% confidence intervals (CI) and prediction intervals (PI) were calculated by random-effect meta-analysis. Results 3487 patients from 30 studies were included. Based on very low-quality evidence due to heterogeneity and risk of bias, the incidence of VTE was 26% (95% PI, 6%–66%). PE with or without DVT occurred in 12% of patients (95% PI, 2%–46%) and DVT alone in 14% (95% PI, 1%–75%). Studies using standard algorithms for clinically suspected VTE reported PE in 13% of patients (95% PI, 2%–57%) and DVT in 6% (95% PI, 0%–60%), compared to 11% (95% PI, 2%–46%) and 24% (95% PI, 2%–85%) in studies using other diagnostic strategies or patient sampling. In patients admitted to intensive care units, VTE occurred in 24% (95% PI, 5%–66%), PE in 19% (95% PI, 6%–47%), and DVT alone in 7% (95% PI, 0%–69%). Corresponding values in general wards were respectively 9% (95% PI, 0%–94%), 4% (95% PI, 0%–100%), and 7% (95% CI, 1%–49%). Conclusions VTE represents a frequent complication in hospitalized COVID-19 patients and often occurs as PE. The threshold for clinical suspicion should be low to trigger prompt diagnostic testing.

In ambulatory patients with solid cancer, routine thromboprophylaxis to prevent venous thromboembolism is not recommended. Several risk prediction scores to identify cancer patients at high risk of venous thromboembolism have been proposed, but their clinical usefulness remains a matter of debate. We evaluated and directly compared the performance of the Khorana, Vienna, PROTECHT, and CONKO scores in a multinational, prospective cohort study. Patients with advanced cancer were eligible if they were due to undergo chemotherapy or had started chemotherapy in the previous three months. The primary outcome was objectively confirmed symptomatic or incidental deep vein thrombosis or pulmonary embolism during a 6-month follow-up period. A total of 876 patients were enrolled, of whom 260 (30%) had not yet received chemotherapy. Fifty-three patients (6.1%) developed venous thromboembolism. The c-statistics of the scores ranged from 0.50 to 0.57. At the conventional positivity threshold of 3 points, the scores classified 13–34% of patients as high-risk; the 6-month incidence of venous thromboembolism in these patients ranged from 6.5% (95%CI: 2.8–12) for the Khorana score to 9.6% (95%CI: 6.6–13) for the PROTECHT score. High-risk patients had a significantly increased risk of venous thromboembolism when using the Vienna (subhazard ratio 1.7; 95%CI: 1.0–3.1) or PROTECHT (subhazard ratio 2.1; 95%CI: 1.2–3.6) scores. In conclusion, the prediction scores performed poorly in predicting venous thromboembolism in cancer patients. The Vienna CATS and PROTECHT scores appear to discriminate better between low- and high-risk patients, but further improvements are needed before they can be considered for introduction into clinical practice.

Background: The incidence of acute complications and mortality associated with COVID-19 remains poorly characterized. The aims of this systematic review and meta-analysis were to summarize the evidence on clinically relevant outcomes in hospitalized patients with COVID-19. Methods: MEDLINE, EMBASE, PubMed, and medRxiv were searched up to April 20, 2020, for studies including hospitalized symptomatic adult patients with laboratory-confirmed COVID-19. The primary outcomes were all-cause mortality and acute respiratory distress syndrome (ARDS). The secondary outcomes included acute cardiac or kidney injury, shock, coagulopathy, and venous thromboembolism. The main analysis was based on data from peer-reviewed studies. Summary estimates and the corresponding 95% prediction intervals (PIs) were obtained through meta-analyses. Results: A total of 44 peer-reviewed studies with 14,866 COVID-19 patients were included. In general, risk of bias was high. All-cause mortality was 10% overall (95% PI, 2 to 39%; 1687/14203 patients; 43 studies), 34% in patients admitted to intensive care units (95% PI, 8 to 76%; 659/2368 patients; 10 studies), 83% in patients requiring invasive ventilation (95% PI, 1 to 100%; 180/220 patients; 6 studies), and 75% in patients who developed ARDS (95% PI, 35 to 94%; 339/455 patients; 11 studies). On average, ARDS occurred in 14% of patients (95% PI, 2 to 59%; 999/6322 patients; 23 studies), acute cardiac injury in 15% (95% PI, 5 to 38%; 452/2389 patients; 10 studies), venous thromboembolism in 15% (95% PI, 0 to 100%; patients; 3 studies), acute kidney injury in 6% (95% PI, 1 to 41%; 318/4682 patients; 15 studies), coagulopathy in 6% (95% PI, 1 to 39%; 223/3370 patients; 9 studies), and shock in 3% (95% PI, 0 to 61%; 203/4309 patients; 13 studies). Conclusions: Mortality was very high in critically ill patients based on very low-quality evidence due to striking heterogeneity and risk of bias. The incidence of clinically relevant outcomes was substantial, although reported by only one third of the studies suggesting considerable underreporting. Trial registration: PROSPERO registration ID for this study is CRD42020177243 (https://www.crd.york.ac.uk/prospero/ display_record.php?RecordID=177243).

This study suggests that sCD40L may represent the molecular link between hypercholesterolemia and the prothrombotic state and demonstrates that statin therapy may significantly reduce sCD40L and the prothrombotic state.

Diabetes mellitus is associated with platelet hyperactivity, which leads to increased morbidity and mortality from cardiovascular disease. This is coupled with enhanced levels of thromboxane (TX), an eicosanoid that facilitates platelet aggregation. Although intensely studied, the mechanism underlying the relationship among hyperglycemia, TX generation, and platelet hyperactivity remains unclear. We sought to identify key signaling components that connect high levels of glucose to TX generation and to examine their clinical relevance. In human platelets, aldose reductase synergistically modulated platelet response to both hyperglycemia and collagen exposure through a pathway involving ROS/PLCγ2/PKC/p38α MAPK. In clinical patients with platelet activation (deep vein thrombosis; saphenous vein graft occlusion after coronary bypass surgery), and particularly those with diabetes, urinary levels of a major enzymatic metabolite of TX (11-dehydro-TXB 2 [TX-M]) were substantially increased. Elevated TX-M persisted in diabetic patients taking low-dose aspirin (acetylsalicylic acid, ASA), suggesting that such patients may have underlying endothelial damage, collagen exposure, and thrombovascular disease. Thus, our study has identified multiple potential signaling targets for designing combination chemotherapies that could inhibit the synergistic activation of platelets by hyperglycemia and collagen exposure. IntroductionAccelerated atherosclerosis and microvascular disease contribute to the morbidity and mortality associated with diabetes mellitus (DM) (1-3). Vascular inflammation, endothelial dysfunction associated with hyperglycemia, impaired fibrinolysis, and increased coagulation factors as well as abnormal platelet function are typical for DM, contributing to the increased thrombotic events and development of arteriosclerosis (4). Altered platelet function in DM, including altered adhesion and aggregation, may contribute to the pathogenesis of DM vascular complications by promoting microthrombus formation, contributing to enhanced risk of small vessel occlusions and accelerated atherothrombotic diseases (5, 6). Patients with type 2 DM (T2DM) exhibit platelet hyperreactivity both in vitro and in vivo, coupled with biochemical evidence of persistently increased thromboxane-dependent (TX-dependent) platelet activation (7,8). Despite many important studies, the mechanism by which platelets transduce glucose levels into enhanced TX generation independently of endothelial and other blood cell-derived factors remains unclear. Similarly, optimal antiplatelet therapy for DM patients remains to be achieved.Aldose reductase (AR) is the first enzyme of the polyol pathway, and it represents a minor source of glucose utilization, accounting for less than 3% of glucose consumption during euglycemia.