Changes in anticoagulant and antiplatelet drug supply at US hospitals before and during the COVID-19 pandemic (2018-2021).

PURPOSE: Antithrombotic agents have a role in coronavirus disease 2019 (COVID-19) treatment, but the pandemic disrupted medication supply. This study examined changes in the volume of oral and parenteral anticoagulant and antiplatelet medications at US hospitals during the pandemic. METHODS: IQVIA National Sales Perspective (NSP) data was used to determine the monthly volume of anticoagulants and antiplatelets purchased at US hospitals between January 2018 and February 2021. Mean monthly medication volumes, reported as extended units (EUs), and year-over-year changes in medication volume were determined. A single-group interrupted time series analysis was used to evaluate changes in the rate of growth of monthly medication volumes before (January 2019-February 2020) and during (March 2020-February 2021) the COVID-19 pandemic. RESULTS: Overall, there was a 43.4% decline in the total volume of anticoagulants and antiplatelets at US hospitals in March 2020, driven by a decrease in heparin volume. Mean monthly volumes decreased significantly (P < 0.05) for parenteral anticoagulants (-106,691,340 EU [95% CI, -200,033,910 to -13,348,780]), oral anticoagulants (-354,800 EU [95% CI, -612,180 to -97,420]), and parenteral antiplatelets (-391,880 EU [95% CI, -535,420 to -248,330]). During the pandemic, the monthly volume of oral anticoagulants, parenteral anticoagulants, and parenteral antiplatelets grew significantly more than in the prepandemic period. This growth was primarily seen in volumes of apixaban, argatroban, enoxaparin, heparin, eptifibatide, and tirofiban. Apixaban and heparin volumes continued a prepandemic uptrend, while argatroban and eptifibatide volumes reversed trend. CONCLUSION: Rapid changes in anticoagulant and antiplatelet volume at US hospitals during the COVID-19 pandemic highlight the need for institutional protocols to manage fluctuating medication volume demands.

Platelet-monocyte aggregates: molecular mediators of thromboinflammation.

Platelets, key facilitators of primary hemostasis and thrombosis, have emerged as crucial cellular mediators of innate immunity and inflammation. Exemplified by their ability to alter the phenotype and function of monocytes, activated platelets bind to circulating monocytes to form monocyte-platelet aggregates (MPA). The platelet-monocyte axis has emerged as a key mechanism connecting thrombosis and inflammation. MPA are elevated across the spectrum of inflammatory and autoimmune disorders, including cardiovascular disease, systemic lupus erythematosus (SLE), and COVID-19, and are positively associated with disease severity. These clinical disorders are all characterized by an increased risk of thromboembolic complications. Intriguingly, monocytes in contact with platelets become proinflammatory and procoagulant, highlighting that this interaction is a central element of thromboinflammation.

A randomized controlled trial to investigate the use of acute coronary syndrome therapy in patients hospitalized with COVID-19: the COVID-19 Acute Coronary Syndrome trial.

BACKGROUND: Patients hospitalized with COVID-19 suffer thrombotic complications. Risk factors for poor outcomes are shared with coronary artery disease. OBJECTIVES: To investigate the efficacy of an acute coronary syndrome regimen in patients hospitalized with COVID-19 and coronary disease risk factors. METHODS: A randomized controlled, open-label trial across acute hospitals (United Kingdom and Brazil) added aspirin, clopidogrel, low-dose rivaroxaban, atorvastatin, and omeprazole to standard care for 28 days. Primary efficacy and safety outcomes were 30-day mortality and bleeding. The key secondary outcome was a daily clinical status (at home, in hospital, on intensive therapy unit admission, or death). RESULTS: Three hundred twenty patients from 9 centers were randomized. The trial terminated early due to low recruitment. At 30 days, there was no significant difference in mortality (intervention vs control, 11.5% vs 15%; unadjusted odds ratio [OR], 0.73; 95% CI, 0.38-1.41; p = .355). Significant bleeds were infrequent and were not significantly different between the arms (intervention vs control, 1.9% vs 1.9%; p > .999). Using a Bayesian Markov longitudinal ordinal model, it was 93% probable that intervention arm participants were more likely to transition to a better clinical state each day (OR, 1.46; 95% credible interval [CrI], 0.88-2.37; Pr [beta > 0], 93%; adjusted OR, 1.50; 95% CrI, 0.91-2.45; Pr [beta > 0], 95%) and median time to discharge to home was 2 days shorter (95% CrI, -4 to 0; 2% probability that it was worse). CONCLUSION: Acute coronary syndrome treatment regimen was associated with a reduction in the length of hospital stay without an excess in major bleeding. A larger trial is needed to evaluate mortality.

Racial and ethnic differences in pharmacotherapy to prevent coronary artery disease and thrombotic events.

Awareness of racial/ethnic disparities represents a key challenge for healthcare systems that attempt to provide effective healthcare and to reduce existing inequalities in the use of and adherence to guideline-recommended cardiovascular drugs to improve clinical outcomes for cardiovascular disease (CVD). In this review, we describe important racial/ethnic differences between and within ethnic groups in the prevalence, risk factors, haemostatic factors, anti-inflammatory and endothelial markers, recurrence, and outcomes of CVD. We discuss important differences in the selection, doses, and response [efficacy and adverse drug reactions (ADRs)] in ethnically diverse patients treated with antithrombotics or lipid-lowering drugs. Differences in drug response are mainly related to racial/ethnic differences in the frequency of polymorphisms in genes encoding drug-metabolizing enzymes (DMEs) and drug transporters. These polymorphisms markedly influence the pharmacokinetics, dose requirements, and safety of warfarin, clopidogrel, and statins. This review aims to support a better understanding of the genetic differences between and among populations to identify patients who may experience an ADR or a lack of drug response, thus optimizing therapy and improving outcomes. The greater the understanding of the differences in the genetic variants of DMEs and transporters that determine the differences in the exposure, efficacy, and safety of cardiovascular drugs between races/ethnicities, the greater the probability that personalized medicine will become a reality.

Application of a Novel Swallowable Telemetric Device for Real Time Luminal Blood Detection to Guide Timing of Enteroscopy in a Patient with Obscure-Occult Gastrointestinal Bleeding: A Case Report

Background and aim: Gastrointestinal (GI) bleeding is deemed "obscure" when upper and lower GI endoscopy reveal no bleeding site. While the term "overt" is used in cases where visible blood passage is observed or reported, cases without macroscopic bleeding stigmata are defined "occult". Although small bowel origin accounts for only about 5% of all GI bleedings, it makes up the majority of obscure GI bleedings. Diagnostic work-up and treatment of small bowel GI bleedings can be challenging, especially when overt bleeding symptoms are absent. Material(s) and Method(s): We report the case of a frail patient with multiple comorbidities and evidence of bleeding small bowel angiodysplastic lesions on videocapsule assisted enteroscopy (VCE). Device assisted enteroscopy (DAE), planned in order to treat the bleeding lesions, was delayed after the patient contracted SARSCoV- 2 infection. Eight weeks after, in the absence of clinical signs of bleeding, a device for real time luminal blood detection (HemoPillR acute, Ovesco) was applied to guide timing of enteroscopy. Result(s): The 71 year old male patient was on dual anti platelet therapy and had persistent clinical features of iron deficiency anemia (Hemoglobin 8,0g/dl). Upper and lower GI endoscopy were negative for potential bleeding sources. VCE showed three small lesions suspect for angiodysplasia within 1 to 13 minutes after pylorus passage. Upon recovery from SARS-CoV-2 infection and congestive heart failure with respiratory insufficiency, we administered HemoPillRacute orally, without previous bowel preparation. The measurement showed a peak HemoPillR-Index (HI max) at 1h 47min after capsule administration (Fig. 1) and was therefore indicative of a small bowel bleeding site, best approachable by antegrade oral route, in keeping with the prior VCE findings. On subsequent DAE, performed through spiral enteroscopy, the small bowel angiodysplastic lesions were successfully treated. [Figure presented] Conclusion(s): Our case report illustrates how a novel telemetric blood detection measurement was able to confirm luminal blood presence and successfully guide timing of therapeutic DAE in a patient with obscure-occult GI bleeding, without the need for repetition of VCE.Copyright © 2023. Editrice Gastroenterologica Italiana S.r.l.

Superior Cerebellar Artery Dissection in a Patient Diagnosed with Reversible Cerebral Vasoconstriction Syndrome: A Case Report

Arterial dissection is an uncommon complication of reversible cerebral vasocon-striction syndrome (RCVS). We describe the case of a 35-year-old woman with a migraine history who presented with recurrent thunderclap headache and focal neurological signs, including right hemiataxia. She had been diagnosed with COVID-19 disease two weeks earlier. Neuroimaging revealed multifocal stenosis of the posterior circulation arteries and dissection of the right superior cerebellar artery. She improved significantly throughout her one-week hospitalization and maintained only mild ataxia. The interplay between COVID-19 disease, RCVS, and arterial dissection requires further investigation.Copyright © Author(s) (or their employer(s)) and Sinapse 2022.

Potentials for health and therapeutic benefits of garlic essential oils: Recent findings and future prospects

Garlic (Allium sativum) has been known for its potent medicinal activities and its interesting culinary role since ancient times. With over 200 phytochemicals and flavoring compounds elucidated and many others yet to, garlic promises to improve human health and vitality. Just like other phytochemical classes, essential oils for garlic have been reported to show interesting medical activities delving across diverse antimicrobial, cardio-protective, anti-cancer, anti-Alzheimer, anti-diabetic, and immunomodulatory activities. Garlic essential oils contain mainly volatile and non-volatile allyl-sulphur-based compounds, which are a product of the stream decomposition of Allicin (a major component of garlic extract). Although a lot of work has been done on Allicin, there is little substantive work on the bio-availability and toxicities of its essential oil. This study, however, reviewed the methods that in recent times have been used to extract essential oils from garlic, recent studies on composition and therapeutic activities of Garlic essential oils, and a predictive overview of their bioavailability and toxicity. Finally, recommendations for future studies and other interesting prospects of garlic were also highlighted.Copyright © 2022

Assessing the safety of continued perioperative antithrombotic therapy in endoscopic airway surgery for laryngotracheal stenosis.

PURPOSE: Given the increasing utilization of endoscopic surgery, particularly for airway stenosis management in the era of COVID-19 due to prolonged intubation, it is important to examine whether continuing antithrombotic therapy perioperatively influences bleeding complications. We examined the impact of perioperative antithrombotic use on postoperative bleeding complications following endoscopic airway surgery for laryngotracheal stenosis. MATERIALS AND METHODS: Retrospective study from January 2016 to December 2021 of cases of patients ≥18 years who underwent endoscopic airway surgery for posterior glottic, subglottic, and tracheal stenosis at a single institution. Cases were excluded if they were an open airway surgery. The primary outcome was the occurrence of postoperative bleeding complications across cases of patients naive to and on baseline antithrombotic therapy, and those with preoperative continuation versus cessation of antithrombotic therapy. RESULTS: 258 cases across 96 patients met inclusion criteria. Of these 258 cases, 43.4 % (n = 112) were performed for patients on baseline antithrombotic therapy and 56.6 % (n = 146) for those not on antithrombotic therapy. Likelihood of perioperative continuation of apixaban was 0.052 (odds ratio, 95 % Confidence Interval: 0.002-0.330, p < 0.001). Likelihood of perioperative continuation of aspirin was 9.87 (odds ratio, 95 % Confidence Interval: 2.32-43.0, p < 0.001). Two instances of postoperative bleeding were found: both in patients who were on aspirin without perioperative cessation for COVID-related coagulopathy. CONCLUSIONS: Our findings suggest that perioperative continuation of aspirin is relatively safe in the setting of endoscopic surgery for airway stenosis management. Prospective investigations to increase understanding of perioperative antithrombotics for COVID-related coagulopathy are warranted.

The Signaling Pathway of the ADP Receptor P2Y12 in the Immune System: Recent Discoveries and New Challenges.

P2Y12 is a G-protein-coupled receptor that is activated upon ADP binding. Considering its well-established role in platelet activation, blocking P2Y12 has been used as a therapeutic strategy for antiplatelet aggregation in cardiovascular disease patients. However, receptor studies have shown that P2Y12 is functionally expressed not only in platelets and the microglia but also in other cells of the immune system, such as in monocytes, dendritic cells, and T lymphocytes. As a result, studies were carried out investigating whether therapies targeting P2Y12 could also ameliorate inflammatory conditions, such as sepsis, rheumatoid arthritis, neuroinflammation, cancer, COVID-19, atherosclerosis, and diabetes-associated inflammation in animal models and human subjects. This review reports what is known about the expression of P2Y12 in the cells of the immune system and the effect of P2Y12 activation and/or inhibition in inflammatory conditions. Lastly, we will discuss the major problems and challenges in studying this receptor and provide insights on how they can be overcome.

A Case of Vaccine-Induced Thrombocytopenic Thrombosis Manifesting as Cerebral Venous Thrombosis and Intracerebral Bleed.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but detrimental syndrome that has been most commonly reported after the administration of vaccination for the prevention of viral infections. VITT often presents with thrombosis at unusual sites such as cerebral venous sinuses, portal, splanchnic or hepatic veins, in association with thrombocytopenia and elevated anti-platelet factor 4 (aPF-4) antibodies. We describe the case of a young male patient who developed thrombocytopenia, cerebral sinus venous thrombosis, and intracerebral bleed 12 days after receiving the Ad26.COV2.S (Janssen/Johnson&Johnson) COVID-19 vaccine.

Flavonoids as a therapeutical option for the treatment of thrombotic complications associated with COVID-19.

The SARS-CoV-2 outbreak has been one of the largest public health crises globally, while thrombotic complications have emerged as an important factor contributing to mortality. Therefore, compounds that regulate the processes involved in thrombosis could represent a dietary strategy to prevent thrombotic complications involved in COVID-19. In August 2022, various databases were consulted using the keywords "flavonoids", "antiplatelet", "anticoagulant", "fibrinolytic", and "nitric oxide". Studies conducted between 2019 and 2022 were chosen. Flavonoids, at concentrations mainly between 2 and 300 µM, are capable of regulating platelet aggregation, blood coagulation, fibrinolysis, and nitric oxide production due to their action on multiple receptors and enzymes. Most of the studies have been carried out through in vitro and in silico models, and limited studies have reported the in vivo and clinical effect of flavonoids. Currently, quercetin has been the only flavonoid evaluated clinically in patients with COVID-19 for its effect on D-dimer levels. Therefore, clinical studies in COVID-19 patients analyzing the effect on platelet, coagulant, fibrinolytic, and nitric oxide parameters are required. In addition, further high-quality studies that consider cytotoxic safety and bioavailability are required to firmly propose flavonoids as a treatment for the thrombotic complications implicated in COVID-19.

COVID-19 and the Response to Antiplatelet Therapy.

The coronavirus SARS-CoV2 disease (COVID-19) is connected with significant morbidity and mortality (3.4%), disorders in hemostasis, including coagulopathy, activation of platelets, vascular injury, and changes in fibrinolysis, which may be responsible for an increased risk of thromboembolism. Many studies demonstrated relatively high rates of venous and arterial thrombosis related to COVID-19. The incidence of arterial thrombosis in severe/critically ill intensive care unit-admitted COVID-19 patients appears to be around 1%. There are several ways for the activation of platelets and coagulation that may lead to the formation of thrombi, so it is challenging to make a decision about optimal antithrombotic strategy in patients with COVID-19. This article reviews the current knowledge about the role of antiplatelet therapy in patients with COVID-19.

The impact of platelets on pulmonary microcirculation throughout COVID-19 and its persistent activating factors.

Patients with COVID-19 often have hypoxemia, impaired lung function, and abnormal imaging manifestations in acute and convalescent stages. Alveolar inflammation, pulmonary vasculitis, and thromboembolism synergistically damage the blood-air barrier, resulting in increased pulmonary permeability and gas exchange disorders. The incidence of low platelet counts correlates with disease severity. Platelets are also involved in the impairment of pulmonary microcirculation leading to abnormal lung function at different phases of COVID-19. Activated platelets lose the ability to protect the integrity of blood vessel walls, increasing the permeability of pulmonary microvasculature. High levels of platelet activation markers are observed in both mild and severe cases, short and long term. Therefore, the risk of thrombotic events may always be present. Vascular endothelial injury, immune cells, inflammatory mediators, and hypoxia participate in the high reactivity and aggregation of platelets in various ways. Microvesicles, phosphatidylserine (PS), platelets, and coagulation factors are closely related. The release of various cell-derived microvesicles can be detected in COVID-19 patients. In addition to providing a phospholipid surface for the synthesis of intrinsic factor Xase complex and prothrombinase complex, exposed PS also promotes the decryption of tissue factor (TF) which then promotes coagulant activity by complexing with factor VIIa to activate factor X. The treatment of COVID-19 hypercoagulability and thrombosis still focuses on early intervention. Antiplatelet therapy plays a role in relieving the disease, inhibiting the formation of the hypercoagulable state, reducing thrombotic events and mortality, and improving sequelae. PS can be another potential target for the inhibition of hypercoagulable states.

Post-COVID-19 non-traumatic iliopsoas hematoma: A case report

Background: Critically ill COVID-19 patients have an elevated risk of experiencing hypercoagulable conditions. Currently, many COVID-19 patients have been administered anticoagulation or antiplatelet therapies to lower the risk of systematic thrombosis. Iliopsoas hematoma is a potentially fatal and rare complication of bleeding disorders or anticoagulation therapy which sometimes grows to become clinically significant. The main purpose of this case review is to emphasize the importance of diagnosing iliopsoas hematomas and the possibility of antiplatelet contribution to its development. Case Presentation: We are reporting a rare presentation of non-traumatic iliopsoas hematoma in a non-anticoagulated patient. The patient is a 59-year-old male, with known type-2 diabetes, on oral hypoglycemic medications, 3-weeks post-COVID-19. He had started aspirin 81 mg orally, once daily, to prevent thrombotic events associated with COVID 19 infection, with no anticoagulant use and no other medications. He came in through the ED, presenting with two weeks history of progressive right lower limb weakness in which an iliopsoas hematoma diagnosis was confirmed based on radiological investigation. Conclusion: The possibility of iliopsoas hematoma should be considered in non-anticoagulated patients with no inherited or acquired coagulation disorders presenting with limb weakness. The link between antiplatelet use in a COVID-19 patient and the development of soft tissue bleeding (e.g., iliopsoas hematoma) must be studied further. © 2022 [The Author/The Authors]

Thromboprophylaxis in Pregnant Women with COVID-19: An Unsolved Issue.

SARS-CoV-2 infection in pregnant women is of growing interest due to controversy over the use of antiplatelet and/or anticoagulant drugs during pregnancy and postpartum. Pregnant women are susceptible to develop severe forms of viral infections due to pregnancy-related immune alterations, changes in lung functions, and hypercoagulability. The association of pregnancy with SARS-CoV-2 infection can cause an increased incidence of thrombotic complications, especially in the case of patients with some genetic variants that favor inflammation and thrombosis. Compared to the general population, pregnant women may be at increased risk of thrombotic complications related to COVID-19. The lack of extensive clinical trials on thromboprophylaxis and extrapolating data from non-pregnant patients lead to major discrepancies in treating pregnant women with COVID-19. Currently, a multidisciplinary team should determine the dose and duration of prophylactic anticoagulant therapy for these patients, depending on the disease severity, the course of pregnancy, and the estimated due date. This narrative review aims to evaluate the protective effect of thromboprophylaxis in pregnant women with COVID-19. It is unknown at this time whether antiplatelet or anticoagulant therapy initiated at the beginning of pregnancy for various diseases (preeclampsia, intrauterine growth restriction, thrombophilia) offers a degree of protection. The optimal scheme for thromboprophylaxis in pregnant women with COVID-19 must be carefully established through an individualized decision concerning gestational age and the severity of the infection.

Platelet activation and coronavirus disease 2019 mortality: Insights from coagulopathy, antiplatelet therapy and inflammation.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with an inflammatory cytokine burst and a prothrombotic coagulopathy. Platelets may contribute to microthrombosis, and constitute a therapeutic target in COVID-19 therapy. AIM: To assess if platelet activation influences mortality in COVID-19. METHODS: We explored two cohorts of patients with COVID-19. Cohort A included 208 ambulatory and hospitalized patients with varying clinical severities and non-COVID patients as controls, in whom plasma concentrations of the soluble platelet activation biomarkers CD40 ligand (sCD40L) and P-selectin (sP-sel) were quantified within the first 48hours following hospitalization. Cohort B was a multicentre cohort of 2878 patients initially admitted to a medical ward. In both cohorts, the primary outcome was in-hospital mortality. RESULTS: In cohort A, median circulating concentrations of sCD40L and sP-sel were only increased in the 89 critical patients compared with non-COVID controls: sP-sel 40,059 (interquartile range 26,876-54,678)pg/mL; sCD40L 1914 (interquartile range 1410-2367)pg/mL (P<0.001 for both). A strong association existed between sP-sel concentration and in-hospital mortality (Kaplan-Meier log-rank P=0.004). However, in a Cox model considering biomarkers of immunothrombosis, sP-sel was no longer associated with mortality, in contrast to coagulopathy evaluated with D-dimer concentration (hazard ratio 4.86, 95% confidence interval 1.64-12.50). Moreover, in cohort B, a Cox model adjusted for co-morbidities suggested that prehospitalization antiplatelet agents had no significant impact on in-hospital mortality (hazard ratio 1.05, 95% CI 0.80-1.37; P=0.73). CONCLUSIONS: Although we observed an association between excessive biomarkers of platelet activation and in-hospital mortality, our findings rather suggest that coagulopathy is more central in driving disease progression, which may explain why prehospitalization antiplatelet drugs were not a protective factor against mortality in our multicentre cohort.

Spontaneous Pulmonary Hematoma: Case Report of a Giant Post-COVID-19 Hematoma and Literature Review.

Pulmonary hematomas are a rare pathology. Although they are usually reported post-traumatically, there are also spontaneous forms in pulmonary pathologies or during drug therapy. In these spontaneous entities, primitive forms are rarely described, although the contributory local pulmonary pathological terrain or a specific associated medication has not yet been identified. We present the case of a patient who developed a giant pulmonary hematoma that appeared spontaneously during recovery from COVID-19 infection. It appeared in one of the two bullae-like cystic lung lesions developed during secondary COVID-19 infection. The clinical impact was major, with hypotension and anemia being observed, requiring hemodynamic support and the adjustment of drug therapy. The clinical course was favorable, with a quasi-complete resolution of both the hematoma and a second cystic lesion being observable at 8 months by pulmonary remodeling. Spontaneous pulmonary hematomas may constitute a pathological entity associated with a post-COVID-19 remodeling process of the lung and the related anticoagulant treatment, which should be recognized, especially in the actual COVID-19 pandemic or in the widespread use of anticoagulant treatment. Conservative treatment is the method of choice, even in giant lung forms.

Prevalence of venous thromboembolism in patients undergoing diagnostic venous ultrasound during the first SARS-CoV-2 pandemic.

Background: Venous thromboembolism appears to be associated with severe COVID-19 infection than in those without it. However, this varies considerably depending on the cohort studied. The aims of this single-centre, multi-site retrospective cross-sectional study were to assess the number of all venous scans performed in the first month of pandemic in a large university teaching hospital, to evaluate the incidence of deep venous thrombosis (DVT), and assess the predictive ability of the clinical information available on the electronic patient record in planning work-up for DVT and prioritising ultrasound scans. Patients and methods: All consecutive patients undergoing venous ultrasound for suspected acute DVT between 1st of March and 30th of April 2020 were considered. Primary outcome was the proportion of scans positive for DVT; the secondary outcomes included association of a positive SARS-CoV-2 PCR test, demographic, clinical factors, and Wells scores. Results: 819 ultrasound scans were performed on 762 patients across the Trust in March and April 2020. This number was comparable to the corresponding pre-pandemic cohort from 2019. The overall prevalence of DVT in the studied cohort was 16.1% and was higher than before the pandemic (11.5%, p=.047). Clinical symptoms consistent with COVID-19, irrespective of the SARS-CoV-2 PCR test result (positive_COVID_PCR OR 4.97, 95%CI 2.31-10.62, p<.001; negative_COVID_PCR OR 1.97, 95%CI 1.12-3.39, p=.016), a history of AF (OR 0.20, 95%CI 0.03-0.73, p=.037), and personal history of venous thromboembolism (VTE) (OR 1.95, 95%CI 1.13-3.31, p=.014), were independently associated with the diagnosis of DVT on ultrasound scan. Wells score was not associated with the incidence of DVT. Conclusions: Amongst those referred for the DVT scan, SARS-CoV-2 PCR test was associated with an increased risk of VTE and should be taken into consideration when planning DVT work-up and prioritising diagnostic imaging. We postulate that the threshold for imaging should possibly be lower.