Risk Factors, Clinical Presentation, Therapeutic Trends, and Outcomes in Arterial Thrombosis Complicating Unvaccinated COVID-19 Patients: A Systematic Review.

Data on characteristics and outcomes of coronavirus (COVID)-19 patients complicated with arterial thrombosis (AT) are scarce. Therefore, we carried out a systematic review (PRISMA, PROSPERO statements; PubMed, Scopus, and Web of Science) to identify risk factors, clinical presentation, treatment, and outcomes. We included publications from December 2019 to October 2020. Groups: (a) ischemic stroke, (b) thrombotic storm, (c) peripheral vascular thrombosis, (d) myocardial infarction, and (e) left cardiac thrombus or in-transit thrombus (venous system thrombus floating or attaching to the right heart). We considered 131 studies. The most frequent cardiovascular risk factors were: hypertension, diabetes, and dyslipidemia. A high proportion presented with asymptomatic, mild, or moderate COVID-19 (n = 91, 41.4%). We identified a high percentage of isolated ischemic stroke and thrombotic storm. Groups with higher mortality rate: intracardiac thrombus (1/2, 50.0%), thrombotic storm (18/49, 36.7%), and ischemic stroke (48/131, 36.6%). A small number received thromboprophylaxis. Most patients received antithrombotic treatment. The most frequent bleeding complication was intracranial hemorrhage, primarily with isolated stroke. Overall mortality was 33.6% (74/220). Despite a wide range of COVID-19 severity, a high proportion had AT as a complication of non-severe disease. AT can affect different vascular territories; mortality is associated with stroke, intensive care unit stay, and severe COVID-19.

Pulmonary embolism response teams: Changing the paradigm in the care for acute pulmonary embolism.

Pulmonary embolism response teams (PERTs) have emerged as a multidisciplinary, multispecialty team of experts in the care of highly complex symptomatic acute pulmonary embolism (PE), with a centralized unique activation process, providing rapid multimodality assessment and risk stratification, formulating the best individualized diagnostic and therapeutic approach, streamlining the care in challenging clinical case scenarios (e.g., intermediate-high risk and high-risk PE), and facilitating the implementation of the recommended therapeutic strategies on time. PERTs are currently changing how complex acute PE cases are approached. The structure, organization, and function of a given PERT may vary from hospital to hospital, depending on local expertise, specific resources, and infrastructure for a given academic hospital center. Current emerging data demonstrate the value of PERTs in improving time to PE diagnosis; shorter time to initiation of anticoagulation reducing hospital length of stay; increasing use of advanced therapies without an increase in bleeding; and in some reports, decreasing mortality. Importantly, PERTs are positively impacting outcomes by changing the paradigm of care for acute PE through global adoption by the health-care community.

Oral treprostinil improves pulmonary vascular compliance in pulmonary arterial hypertension.

Oral treprostinil has been shown to improve exercise capacity and delay disease progression in patients with pulmonary arterial hypertension (PAH), but its effects on hemodynamics are not well-characterized. The FREEDOM-EV trial was a Phase III, international, placebo-controlled, double-blind, event-driven study in 690 participants with PAH who were taking a single oral PAH therapy. FREEDOM-EV demonstrated a significantly reduced risk for clinical worsening with oral treprostinil taken three times daily and did not uncover new safety signals in PAH patients. Sixty-one participants in the FREEDOM-EV trial volunteered for a hemodynamics sub-study. Pulmonary artery compliance (PAC), a ratio of stroke volume to pulmonary pulse pressure, significantly increased from Baseline to Week 24 in the oral treprostinil group compared with the placebo group (geometric mean 26.4% active vs. -6.0% placebo; ANCOVA p=0.007). There was a significant increase in cardiac output in the oral treprostinil group compared to the placebo group (geometric mean 11.3% active vs. -6.4% placebo; ANCOVA p=0.005) and a corresponding significant reduction in pulmonary vascular resistance (PVR) (geometric mean -21.5 active vs. -1.8% placebo; ANCOVA p=0.02) from Baseline to Week 24. These data suggest that increased compliance contributes to the physiological mechanism by which oral treprostinil improves exercise capacity and delays clinical worsening for patients with PAH.

Differences between surviving and non-surviving venous thromboembolism COVID-19 patients: a systematic review.

BACKGROUND: To our knowledge, the treatment, outcome, clinical presentation, risk stratification of patients with venous thromboembolism and COVID-19 have not been well characterized. METHODS: We searched for systematic reviews, cohorts, case series, case reports, editor letters, and venous thromboembolism COVID-19 patients' abstracts following PRISMA and PROSPERO statements. We analyzed therapeutic approaches and clinical outcomes of venous thromboembolism COVID-19 patients. Inclusion: COVID-19 patients with venous thromboembolism confirmed by an imaging method (venous doppler ultrasound, ventilation-perfusion lung scan, computed tomography pulmonary angiogram, pulmonary angiography). We assessed and reported the original Pulmonary Embolism Severity Index for each pulmonary embolism patient. In addition, we defined major bleedings according to the International Society of Thrombosis and Haemostasis criteria. RESULTS: We performed a systematic review from August 9 to August 30, 2020. We collected 1,535 papers from PubMed, Scopus, Web of Science, Wiley, and Opengrey. We extracted data from 89 studies that describe 143 patients. Unfractionated and low-molecular-weight heparin was used as parenteral anticoagulation in 85/143 (59%) cases. The Food and Drug Administration-approved alteplase regimen guided the advanced treatment in 39/143 (27%) patients. The mortality was high (21.6%, CI 95% 15.2-29.3). The incidence of major bleeding complications was 1 (0.9%) in the survival group and 1 (3.2%) in the death group. Pulmonary Embolism Severity Index was class I in 11.6% and II in 22.3% in survivors compared to 0% and 6.5% in non-survivors, respectively. Patients who experienced venous thromboembolism events at home were more likely to live than in-hospital events. CONCLUSIONS: We determined a high mortality incidence of pulmonary embolism and a low rate of bleeding. Unfractionated and low-molecular-weight heparin drove parenteral anticoagulation and alteplase the advanced treatment in both groups. The original Pulmonary Embolism Severity Index could be helpful in the risk stratification.

Unexpected arterial thrombosis and acute limb ischemia in COVID-19 patients. Results from the Ibero-Latin American acute arterial thrombosis registry in COVID-19: (ARTICO-19).

OBJECTIVE: Few studies have focused on arterial thrombosis and acute limb ischemia in COVID-19. This international registry intended to study the spectrum of clinical characteristics, therapeutic trends, and outcomes in a cohort of Ibero-Latin American patients with arterial thrombosis or acute limb ischemia and COVID-19. METHODS: Data were retrospectively obtained from 21 centers in 9 countries. Patients with proven COVID-19 and asymptomatic or symptomatic arterial thrombosis were included. COVID-19 diagnosis was established by RT-PCR assay or IgM serology plus suggestive clinical/radiographical findings. We recorded and analyzed variables related to demography, clinical presentation, therapeutic trends, and outcomes. RESULTS: Eighty one patients were included in the registry. In 38.3%, acute limb ischemia symptoms were the first manifestation of COVID-19. Non-surgical management was more frequent in severe cases than surgical interventions, 11.1% vs. 88.9%, respectively (p = 0.004). Amputation rates were similar between all COVID severity groups (p = 0.807). Treatment was classified as non-surgical, open surgical, and endovascular treatment. Further analysis revealed an equal frequency of major leg amputation between treatment groups and increased mortality in patients with non-surgical management. However, multivariate regression analysis showed that treatment choices are associated with disease severity, with significant non-surgical treatment in critical patients; thus, mortality is related to the severity and confounds treatment analysis. CONCLUSION: Arterial thrombosis can be the initial symptom of a patient presenting with COVID-19. Physicians and health workers should potentially suspect COVID-19 in acute ischemia cases without a known risk factor or embolic cause. More experimental and clinical research is required to understand the complex phenomenon of arterial COVID-19 induced coagulopathy fully.

In silico evidence of cardiac troponin non-classical secretion: new insights on the pathobiology of myocardial injury

Background Cardiac troponin is one of the most important biomarkers in cardiology. Traditionally, it has represented a biochemical sign of necrosis, a characteristic of acute myocardial infarction (AMI). However, with the arrival of high-sensitivity detection assays, cardiac troponin is now detected in healthy people and in a number of uncommon scenarios unrelated to AMI (such as strenuous exercise, rapid atrial pacing and COVID-19). This suggest that troponin could be released as a consequence of alternative processes other than the well-stablished necrotic cell death. To try to explain this phenomenon, multiple mechanisms of troponin release have been postulated, although there is still no consensus on this matter. Furthermore, the term myocardial injury was included in the Fourth Universal Definition of Myocardial Infarction. This entity is understood as a troponin determination above the upper reference limit, not necessarily associated with a specific diagnosis. Nonetheless, the histological or pathobiological process responsible of myocardial injury has not been determined. Here, we studied the possibility of troponin release through non-classical secretion, a pathway specially triggered by cellular stress and inflammation. Methods The protein sequences of the eight different isoforms of troponin (I, T and C of fast-twitch skeletal, slow-twitch skeletal and cardiac muscle) were retrieved from the UniProtKB database. SecretomeP 2.0, a neural networks-based program, was used to predict if any of these proteins undergoes non-classical release. SignalP 5.0 and TMHMM 2.0 were also applied to rule out the possibility of classical (endoplasmic reticulum/Golgi dependent) and Type IV (transmembrane) non-classical secretion. Results and Discussion After analyzing the sequences, the cardiac T isoform was predicted to be non-classically secreted, as well as the I, T and C subunits of the fast-twitch skeletal muscle and the I subunit of the slow-twitch skeletal muscle. Additionally, none of the troponin isoforms was found to be subject to classical or Type IV secretion. The present study provides in silico evidence of cardiac troponin T release by means of non-classical secretion. We believe that this potential new mechanism could contribute to the debate around cardiac troponin high-sensitivity assays. Thus, it might establish a theoretical frame capable of explaining troponin elevations by causes other than myocyte necrosis. Conclusions Troponin T secretion may help in the pathobiological definition of myocardial injury. There are already some experimental studies showing the release of troponin through extracellular microvesicles (a type of non-classical secretion) in various cell lines. Nonetheless, more work is needed to fully understand this intriguing phenomenon in cardiomyocytes.

Systemic thrombolysis and anticoagulation improved biomarker measurements in massive-like pulmonary embolism and severe COVID-19 pneumonia: a case report.

BACKGROUND: From asymptomatic patients to severe acute respiratory distress syndrome, COVID-19 has a wide range of clinical presentations, and venous thromboembolism has emerged as a critical and frequent complication. CASE SUMMARY: We present a case of a 69-year-old man with a clinical presentation of massive-like pulmonary embolism (PE) overlapping with severe COVID-19 pneumonia. The diagnosis was made based on hypotension, severe oxygen desaturation (33%), and right ventricular dysfunction (RVD). We used alteplase and low-molecular-weight heparin, obtaining immediate clinical improvement. Also, we identified an extremely elevated D-dimer (31.2 mcg/mL), and computed tomography pulmonary angiography (CTPA) revealed an unexpected low thrombus burden and a crazy-paving pattern. Considering this, we decided to discontinue the alteplase. Therefore, the mechanisms of pulmonary hypertension and RVD could be multifactorial. Despite the patient's respiratory status worsening and ongoing mechanical ventilation, biomarkers kept lowering to normal ranges. It appears a favourable outcome was related to early PE diagnosis and a multimodal therapeutic approach. DISCUSSION: Physicians in the ER should be warned about extremely high D-dimer measurements and severe oxygen desaturation as possible markers of severe COVID-19 pneumonia in patients with high-clinical suspicion of PE. Although ESC guidelines recommend immediate reperfusion in cardiogenic shock secondary to PE, we suggest initial CTPA in patients with high-clinical suspicion of severe COVID-19.