Impact of the post-COVID-19 condition on health care after the first disease wave in Lombardy.

BACKGROUND: Lombardy was affected in the early months of 2020 by the SARS-CoV-2 pandemic with very high morbidity and mortality. The post-COVID-19 condition and related public health burden are scarcely known. SETTING AND DESIGN: Using the regional population administrative database including all the 48,932 individuals who survived COVID-19 and became polymerase-chain-reaction negative for SARS-CoV-2 by 31 May 2020, incident mortality, rehospitalizations, attendances to hospital emergency room, and outpatient medical visits were evaluated over a mid-term period of 6 months in 20,521 individuals managed at home, 26,016 hospitalized in medical wards, and 1611 in intensive care units (ICUs). These data were also evaluated in the corresponding period of 2019, when the region was not yet affected by the pandemic. Other indicators and proxies of the health-care burden related to the post-COVID condition were also evaluated. MAIN RESULTS: In individuals previously admitted to the ICU and medical wards, rehospitalizations, attendances to hospital emergency rooms, and out-patient medical visits were much more frequent in the 6-month period after SARS-CoV-2 negativization than in the same prepandemic period. Performances of spirometry increased more than 50-fold, chest CT scans 32-fold in ICU-admitted cases and 5.5-fold in non-ICU cases, and electrocardiography 5.6-fold in ICU cases and twofold in non-ICU cases. Use of drugs and biochemical tests increased in all cases. CONCLUSIONS: These results provide a real-life picture of the post-COVID condition and of its effects on the increased consumption of health-care resources, considered proxies of comorbidities.

Thrombo-Inflammation in Cardiovascular Disease: An Expert Consensus Document from the Third Maastricht Consensus Conference on Thrombosis.

Thrombo-inflammation describes the complex interplay between blood coagulation and inflammation that plays a critical role in cardiovascular diseases. The third Maastricht Consensus Conference on Thrombosis assembled basic, translational, and clinical scientists to discuss the origin and potential consequences of thrombo-inflammation in the etiology, diagnostics, and management of patients with cardiovascular disease, including myocardial infarction, stroke, and peripheral artery disease. This article presents a state-of-the-art reflection of expert opinions and consensus recommendations regarding the following topics: (1) challenges of the endothelial cell barrier; (2) circulating cells and thrombo-inflammation, focused on platelets, neutrophils, and neutrophil extracellular traps; (3) procoagulant mechanisms; (4) arterial vascular changes in atherogenesis; attenuating atherosclerosis and ischemia/reperfusion injury; (5) management of patients with arterial vascular disease; and (6) pathogenesis of venous thrombosis and late consequences of venous thromboembolism.

Genetic risk stratification to reduce inhibitor development in the early treatment of hemophilia A: a SIPPET analysis.

A recent randomized trial, the Survey of Inhibitors in Plasma-Product Exposed Toddlers (SIPPET), showed a higher risk of inhibitor development with recombinant factor VIII (rFVIII) than plasma-derived concentrates (pdFVIII). We investigated whether risk stratification by F8 mutation identifies patients who do not suffer this deleterious effect of rFVIII. Among 235 randomized patients with severe hemophilia A previously untreated with FVIII concentrate, 197 with null mutations were classified as high risk and 38 with non-null mutations were classified as low risk. With pdFVIII, no inhibitors occurred in those with low genetic risk, whereas high-risk patients had a cumulative incidence of 31%. The risk among low- and high-risk patients did not differ much when they were treated with rFVIII (43% and 47%, respectively). This implies that patients with low genetic risk suffer disproportionate harm when treated with rFVIII (risk increment 43%), as also shown by the number needed to harm with rFVIII, which was 6.3 for genetically high-risk patients and only 2.3 for low-risk patients. Risk stratification by F8 mutation does not identify patients who can be safely treated with rFVIII, as relates to immunogenicity. This trial was registered at the European Clinical Trials Database (EudraCT) as #2009-011186-88 and at www.clinicaltrials.gov as #NCT01064284.

Changing Concepts of Cirrhotic Coagulopathy.

The state of clinical art of the coagulopathy of cirrhosis changed considerably over the last decade. Until 2005, cirrhosis was considered as the epitome of the hemorrhagic coagulopathies and the abnormal hemostasis tests associated with the disease were corrected with infusion of fresh frozen plasma or platelets to minimize the risk of bleeding. Since that time, a great deal of work has been done and there is now a change of paradigm. The prothrombin time once considered as an isolated measure of bleeding risk was rejected, and cirrhosis shifted from a purely hemorrhagic construct to a mixed and thrombosis-prone paradigm. In this article we examine the interesting history of how these conceptual changes came about.

A Randomized Trial of Factor VIII and Neutralizing Antibodies in Hemophilia A.

BACKGROUND: The development of neutralizing anti-factor VIII alloantibodies (inhibitors) in patients with severe hemophilia A may depend on the concentrate used for replacement therapy. METHODS: We conducted a randomized trial to assess the incidence of factor VIII inhibitors among patients treated with plasma-derived factor VIII containing von Willebrand factor or recombinant factor VIII. Patients who met the eligibility criteria (male sex, age <6 years, severe hemophilia A, and no previous treatment with any factor VIII concentrate or only minimal treatment with blood components) were included from 42 sites. RESULTS: Of 303 patients screened, 264 underwent randomization and 251 were analyzed. Inhibitors developed in 76 patients, 50 of whom had high-titer inhibitors (≥5 Bethesda units). Inhibitors developed in 29 of the 125 patients treated with plasma-derived factor VIII (20 patients had high-titer inhibitors) and in 47 of the 126 patients treated with recombinant factor VIII (30 patients had high-titer inhibitors). The cumulative incidence of all inhibitors was 26.8% (95% confidence interval [CI], 18.4 to 35.2) with plasma-derived factor VIII and 44.5% (95% CI, 34.7 to 54.3) with recombinant factor VIII; the cumulative incidence of high-titer inhibitors was 18.6% (95% CI, 11.2 to 26.0) and 28.4% (95% CI, 19.6 to 37.2), respectively. In Cox regression models for the primary end point of all inhibitors, recombinant factor VIII was associated with an 87% higher incidence than plasma-derived factor VIII (hazard ratio, 1.87; 95% CI, 1.17 to 2.96). This association did not change in multivariable analysis. For high-titer inhibitors, the hazard ratio was 1.69 (95% CI, 0.96 to 2.98). When the analysis was restricted to recombinant factor VIII products other than second-generation full-length recombinant factor VIII, effect estimates remained similar for all inhibitors (hazard ratio, 1.98; 95% CI, 0.99 to 3.97) and high-titer inhibitors (hazard ratio, 2.59; 95% CI, 1.11 to 6.00). CONCLUSIONS: Patients treated with plasma-derived factor VIII containing von Willebrand factor had a lower incidence of inhibitors than those treated with recombinant factor VIII. (Funded by the Angelo Bianchi Bonomi Foundation and others; ClinicalTrials.gov number, NCT01064284; EudraCT number, 2009-011186-88.).

Fibrin clot structure is affected by levels of particulate air pollution exposure in patients with venous thrombosis.

BACKGROUND: Particulate air pollution is a risk factor for cardiovascular diseases and thrombosis. Long-term exposure to particulate matter with a diameter<10µm (PM10) has been associated with an increased risk of venous thrombosis. OBJECTIVES: The aim of this study was to investigate whether or not particulate air pollution alters fibrin clot structure and thus modulates thrombosis risk. METHODS: We investigated fibrin polymerization by turbidity (maximum absorbance mOD), clot structure by confocal microscopy (fibre number per µm) and fibrin pore size by permeability (Ks×10(-10)cm(2)) in 103 patients with deep vein thrombosis and 121 healthy controls, for whom levels of air pollution exposure had been recorded. Exposure groups were defined by mean PM10 concentrations over the 730days before the event. RESULTS: We found a higher average number of fibres per clot area in patients than controls, but no difference in Ks or fibre thickness. When the two groups were divided into high or low exposure to PM10, a significantly denser fibrin clot network structure with thicker fibres (higher maximum absorbance, p<0.05), decreased permeability (lower Ks value, p<0.05) and higher average fibre numbers per clot area (p<0.05) was observed in patients in the high exposure group compared to those with low exposure. There were no significant differences in fibrin clot structure between the two exposure levels in healthy subjects. CONCLUSIONS: PM10 levels are associated with altered fibrin clot structure in patients with deep vein thrombosis but not in controls, suggesting that air pollution may trigger differences in fibrin clot structure only in patients predisposed to thrombotic disease.

Inherited risk factors for venous thromboembolism.

Venous thromboembolism (VTE) has important heritable components. In the past 20 years, knowledge in this field has greatly increased with the identification of a number of gene variants causing hypercoagulability. The two main mechanisms are loss-of-function of anticoagulant proteins and gain-of-function of procoagulants, the latter owing to increased synthesis or impaired downregulation of a normal protein or, more rarely, to synthesis of a functionally hyperactive molecule. Diagnosis of thrombophilia is useful to determine the causes of VTE, recognizing that this multifactorial disease can also be influenced by various acquired factors including cancer, surgery, trauma, prolonged immobilization, or reproduction-associated risk factors. Diagnosis of inherited thrombophilia rarely affects the acute or long-term management of VTE. However, the risk of recurrent VTE is increased in anticoagulant-deficient patients and in homozygotes for gain-of-function mutations. Screening for inherited thrombophilia in thrombosis-free individuals is indicated only for relatives of a proband who is anticoagulant-deficient or has a family history of VTE. In families with thrombophilia and VTE, primary antithrombotic prophylaxis during risk situations lowers the rate of incident VTE. In this Review, we discuss the main causes of inherited thrombophilia, the associated clinical manifestations, and the implications for antithrombotic prophylaxis in the affected individuals.

ADAMTS13 content in plasma-derived factor VIII/von Willebrand factor concentrates.

Thrombotic thrombocytopenic purpura (TTP) is a microangiopathy syndrome caused by a congenital or acquired deficiency of ADAMTS13, a plasma metalloprotease that cleaves von Willebrand factor (VWF) and thus prevents the formation of platelet-rich thrombi in the microcirculation. TTP can be fatal if not appropriately and timely treated with the infusion of fresh frozen plasma (FFP) or exchange plasmapheresis, that reverse the process of microangiopathy by removing anti-ADAMTS13 autoantibodies and replacing functional ADAMTS13. The treatment of TTP with FFP is not free from risks and must be administered in hospitals or clinics, owing to the substantial amount of plasma volume infused or exchanged and the frequent need of catheter application. Moreover, most FFPs are not subjected to treatments to remove or inactivate blood-borne infectious agents. A number of recent reports indicate that certain plasma-derived VWF-factor VIII (FVIII) concentrates are clinically effective in the treatment of congenital TTP. In this study, we measured ADAMTS13 levels in various plasma-derived VWF-FVIII concentrates, showing that Koate(®) -DVI (Grifols), contained relatively high amounts of ADAMTS13 and that Alphanate(®) (Grifols) was the closest other product in terms of protease content. Koate(®) -DVI contains, on average (five lots tested), 0.091 ± 0.007 Units of ADAMTS13 activity per IU of FVIII. On the basis of this analysis and other reports of VWF-FVIII concentrate utilization in congenital TTP, potential dosing, and future clinical developments are discussed.

Alloantibodies in von Willebrand disease.

The development of alloantibodies against von Willebrand factor (VWF) represents a rare but serious complication of treatment of von Willebrand disease (VWD), occurring in ~5% to 10% of type 3 VWD patients. Affected patients can present with a range of symptoms, including lack or loss of hemostatic response to infused VWF concentrates up to anaphylactic reactions in rare cases. It is classically reported in multitransfused patients and occurs most frequently in patients with partial or complete VWF gene deletions. A positive family history of anti-VWF antibodies also appears to be a risk factor. There is a lack of standardization of laboratory methods for antibody identification and characterization. Issues of variability in laboratory approaches as well as the rarity of the complication act as a barrier to future studies. Recombinant factor VIII as well as bypassing agents and immune tolerance have been reported as effective treatments; however, aside from case reports, little exists in the literature to guide management. The imminent clinical availability of recombinant VWF has prompted a resurgence of interest in this area. Additional study is warranted to address the deficiencies in our understanding of this treatment complication.

Global hemostasis tests in patients with cirrhosis before and after prophylactic platelet transfusion.

BACKGROUND/AIMS: Cirrhosis presents with variable degrees of thrombocytopenia that might cause bleeding during invasive procedures. Transfusion of one standard adult platelet dose is often employed to prevent bleeding in thrombocytopenia, but the threshold platelet count that is clinically effective is not well established because clinical studies and laboratory tools to judge on efficacy are insufficient. However, in vitro studies showed that patients with cirrhosis generate as much thrombin as healthy individuals provided that their platelet count is at least 100 × 10(9) /L. METHODS: To assess the in vivo relevance of these in vitro studies, we investigated 26 thrombocytopenic patients with cirrhosis, undergoing 36 variceal ligations, to see whether transfusion of one standard adult platelet dose was able to attain the above platelet count. We also evaluated the effect of platelet transfusion on such global hemostasis tests as thrombin generation and thromboelastometry. RESULTS: Transfusion did slightly increase platelet count [pre- vs. post-infusion: 39 × 10(9) /L(16-64) vs. 52 × 10(9) /L(19-91), P < 0.001], without significant effect on thrombin generation, probably because post-transfusion platelet count was less than the target of 100 × 10(9) /L in all patients. In addition, the percentage of patients with abnormal thrombin generation (i.e. below the lower limit of normal range) was scarcely affected by transfusion (pre- vs. post-infusion: 36% vs. 42%). The small post-transfusion increase in platelet count was paralleled by some degree of improvement of thromboelastometry, but none of the patients reached normal values after transfusion. CONCLUSIONS: Infusing one standard adult platelet dose secures only a small increase in platelet count without normalizing thrombin generation and thromboelastometry tests. To obtain greater increases in platelet count and normalization of laboratory tests more intensive platelet transfusions or treatment with non-transfusional drugs are probably needed.

Identification of genetic risk variants for deep vein thrombosis by multiplexed next-generation sequencing of 186 hemostatic/pro-inflammatory genes.

BACKGROUND: Next-generation DNA sequencing is opening new avenues for genetic association studies in common diseases that, like deep vein thrombosis (DVT), have a strong genetic predisposition still largely unexplained by currently identified risk variants. In order to develop sequencing and analytical pipelines for the application of next-generation sequencing to complex diseases, we conducted a pilot study sequencing the coding area of 186 hemostatic/proinflammatory genes in 10 Italian cases of idiopathic DVT and 12 healthy controls. RESULTS: A molecular-barcoding strategy was used to multiplex DNA target capture and sequencing, while retaining individual sequence information. Genomic libraries with barcode sequence-tags were pooled (in pools of 8 or 16 samples) and enriched for target DNA sequences. Sequencing was performed on ABI SOLiD-4 platforms. We produced > 12 gigabases of raw sequence data to sequence at high coverage (average: 42X) the 700-kilobase target area in 22 individuals. A total of 1876 high-quality genetic variants were identified (1778 single nucleotide substitutions and 98 insertions/deletions). Annotation on databases of genetic variation and human disease mutations revealed several novel, potentially deleterious mutations. We tested 576 common variants in a case-control association analysis, carrying the top-5 associations over to replication in up to 719 DVT cases and 719 controls. We also conducted an analysis of the burden of nonsynonymous variants in coagulation factor and anticoagulant genes. We found an excess of rare missense mutations in anticoagulant genes in DVT cases compared to controls and an association for a missense polymorphism of FGA (rs6050; p = 1.9 × 10(-5), OR 1.45; 95% CI, 1.22-1.72; after replication in > 1400 individuals). CONCLUSIONS: We implemented a barcode-based strategy to efficiently multiplex sequencing of hundreds of candidate genes in several individuals. In the relatively small dataset of our pilot study we were able to identify bona fide associations with DVT. Our study illustrates the potential of next-generation sequencing for the discovery of genetic variation predisposing to complex diseases.

Risk factors for postpartum hemorrhage in a cohort of 6011 Italian women.

INTRODUCTION: Postpartum hemorrhage is responsible for 25% of maternal pregnancy-related deaths and it is the first cause of maternal morbidity and mortality worldwide. OBJECTIVE: To define the prevalence of postpartum hemorrhage and associated risk factors after vaginal birth and to develop a risk model that improves postpartum hemorrhage prediction. PATIENTS AND METHODS: All women who underwent a vaginal delivery at the Obstetric Unit of a large University hospital in Milan (Italy) between July 2007 and September 2009 were enrolled. Postpartum hemorrhage was defined as ≥ 500 mL blood loss. A nomogram tailored to predict postpartum hemorrhage was developed, summarizing the impact of each covariate on the probability of postpartum hemorrhage. RESULTS: 6011 women were studied (24% had blood loss ≥ 500 mL and 4.8% ≥ 1000 mL). Nulliparity, episiotomy, retained placenta and high neonatal body weight were confirmed as risk factors for postpartum hemorrhage. The odds ratio of postpartum hemorrhage was 0.86 (95%CI 0.78-0.90) for each 1 gr/dL increase in ante-partum hemoglobin. An extensive internal validation of the developed nomogram demonstrated a good stability of the risk model. CONCLUSIONS: Low ante-partum hemoglobin is a new potentially modifiable risk factor for postpartum hemorrhage. A nomogram to predict the probability of postpartum hemorrhage is now available for external validation.

Management of inherited von Willebrand disease in Italy: results from the retrospective study on 1234 patients.

Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is due to quantitative and/or qualitative defects of von Willebrand factor (VWF). Despite the improved knowledge of the disease, detailed data on VWD types requiring specific treatments have not been reported thus far. To determine the number and types of VWD requiring therapy with desmopressin (DDAVP) and/or VWF/FVIII concentrates in Italy, a national registry on VWD (RENAWI) was organized. Only 16 of 48 centers included VWD in the RENAWI with diagnoses performed locally. Patients with uncertain results were retested by two expert laboratories using multimeric analysis and mutations of the VWF gene. A total of 1234 of 1529 (81%) cases satisfied the inclusion criteria and could be classified as VWD1 (63%), VWD2A (7%), VWD2B (6%), VWD2M (18%), VWD2N (1%), and VWD3 (5%). VWD types were also confirmed by DNA analyses and occur in young adults (83%), mainly in women (58%). Mucosal bleedings (32 to 57%) are more frequent than hematomas (13%) or hemarthrosis (6%). Most patients were exposed to an infusion trial with desmopressin (DDAVP) and found responsive with the following rates: VWD1 (69%), VWD2A (26%), VWD2M (29%), and VWD2N (71%). However, DDAVP was not always used to manage bleeding in all responsive patients and VWF/FVIII concentrates were given instead of or together with DDAVP in VWD1 (30%), VWD2A (84%), VWD2B (62%), VWD2M (63%), VWD2N (30%), and VWD3 (91%). Data of the RENAWI showed that correct VWD identification and classification might be difficult in many Italian centers. Therefore, evidence-based studies should be organized only in well-characterized patients tested by laboratories that are expert in the clinical, laboratory, and molecular markers of VWD.