NEWS & PERSPECTIVE
High prevalence of thrombotic complications found in ICU-admitted COVID-19 patients, systematic screening warranted
Ever since the report of the very first case of coronavirus disease 2019 (COVID-19) in Wuhan back in December 2019, increasing evidence indicates that COVID-19 is associated with a high thrombotic risk.1,2 While the underlying mechanism of thrombus formation among COVID-19 patients had been well-investigated, the prevalence of detectable thrombus and its associated complications are yet to be fully explored and understood.3 In view of the missing data, a study was conducted in critically ill, COVID-19-infected patients who were hospitalized in the intensive care unit (ICU).3 In this study, a high prevalence of thrombotic complications was observed despite many patients were anticoagulated beforehand.3 To minimize the risk of thrombosis-associated death, a more proactive systematic screening of possible underlying thrombosis is thus recommended.3
COVID-19 is characterized by a myriad of clinical manifestations, which can progress from an initial asymptomatic state to subsequent multi-organ failure and death.4 While being regarded primarily as a respiratory illness, mounting evidence also suggests that COVID-19 can give rise to a hypercoagulable state attributable to pulmonary injury and inflammation that can lead to arterial and venous thrombosis.4,5 Though the possible underlying pathophysiology of COVID-19-induced thrombosis and its complications were proposed in literature, other areas such as the prevalence of thrombotic complications remain understudied.3
In this regard, a single-center, retrospective analytical study was conducted in 72 critically ill patients admitted to the ICU who had COVID-19-associated acute respiratory distress syndrome, with or without extracorporeal membrane oxygenation.3 Recruited patients underwent computed tomography (CT) angiography of the thorax, abdomen and pelvis, as well as other clinically indicated imaging as per the routine institution protocols at the study hospital.3 The primary endpoint was the detection of any venous or arterial thrombus or associated complications such as deep vein thrombosis, pulmonary embolism or cerebral ischemic attack.3 The relationship between the thrombotic complications and coagulation parameters, biomarkers and survival was also evaluated.3
Out of the 72 patients, only one patient did not receive prior thromboprophylaxis or therapeutic anticoagulation.3 54 thrombotic complications were identified in 42 patients (58%), which consisted of 34 pulmonary arterial (47%), 15 peripheral venous (21%) and 5 (7%) systemic arterial thromboses/end-organ embolic complications.3 Among the patients with pulmonary arterial thromboses, only a minority (7%) were clinically suspected with the remaining cases (93%) being identified incidentally through CT screening.3
When assessing the role of biomarkers in thrombotic complications, neither the coagulation biomarkers (D-dimer, fibrinogen level and activated partial thromboplastin time) nor the inflammation biomarkers (white blood cell count and C-reactive protein) could significantly predict thrombotic complications (p≥0.05).3
Regarding survival, 33% of patients positive for thrombotic events died versus only 10% among those who were negative for any thrombotic events.3 Therefore, patients with detectable thrombus were associated with significant mortality risk (p=0.022).3
Given that the strong association between thrombotic complications, in particular pulmonary arterial events and mortality among the critically ill, ICU-admitted COVID-19 patients in spite of prior thromboprophylaxis, the investigators recommended clinicians to better utilize systematic CT imaging to reveal potential thrombosis earlier and accurately to minimize the risk of complications and deaths, instead of solely relying on clinical features to help identify any thromboembolic disease.3
While the study was limited by its 3-month study duration and ICU setting, it has nonetheless emphasized the high prevalence of thrombotic risk among specific groups of COVID-19 patients and highlighted the importance of proactive systematic screening among these patients. With earlier diagnosis and intervention, these at-risk COVID-19 patients may have a better chance of complication-free survival.
- Zhou F et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020;395(10229):1054-1062.
- Malas MB et al. Thromboembolism risk of COVID-19 is high and associated with a higher risk of mortality: A systematic review and meta-analysis. EClinicalMedicine. 2020; 29-30:100639.
- Mirsadraee S et al. Prevalence of thrombotic complications in ICU-treated patients with coronavirus disease 2019 detected with systematic CT scanning. Crit Care Med. 2021;49(5):804-815.
- Abou-Ismail MY et al. The hypercoagulable state in COVID-19: Incidence, pathophysiology, and management. Thromb Res. 2020;194:101–115.
- Khan IH et al. The need to manage the risk of thromboembolism in COVID-19 patients. J Vasc Surg. 2020;72(3):799-804.
SARS-CoV-2 infection on pregnancy: A genomic perspective on fetal health
A recent local study published in Nature Cell Biology has revealed transcriptomic and epigenomic dysregulation on the maternal-fetal interface (MFI) caused by maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.1 Jointly conducted by the Department of Obstetrics and Gynecology at the Chinese University of Hong Kong (CUHK) and the Division of Life Science at the Hong Kong University of Science and Technology (HKUST), this research was first of its kind in assessing epigenetic alterations for coronavirus disease 2019 (COVID-19)-associated pregnancy.1
Bivalent BNT162b2 and the future directions of COVID-19 vaccination
Since early March 2023 when COVID-19 restriction measures in Hong Kong were abated, a resurgence of local cases, caused predominantly by Omicron XBB and its descendant lineages, has been observed.1,2 Given the enduring threat of COVID-19 infection and long COVID, vaccination remains the key prevention strategy to safeguard public health, particularly the high risk group. In a recent interview with Omnihealth Practice, Prof. Thomas, Professor of Microbiology and Immunology in SUNY Upstate Medical University, shared his insights on the effectiveness of the new bivalent BNT162b2 vaccine (original/BA.4-5 strains) and the future global vaccination strategies in response to the emerging SARS-CoV-2 variants.
Foresight: The future directions of COVID-19 vaccination with bivalent BNT162b2 vaccine
From March 1, 2023, all the Coronavirus disease 2019 (COVID-19) restriction measures have been lifted in Hong Kong including the mask mandate, getting the society back to normal.1 However, there is a rebound of local COVID-19 cases caused by predominantly XBB, an Omicron sub-variant, and its descend
Early molnupiravir and nirmatrelvir-ritonavir show substantial clinical benefits in local hospitalized COVID-19 patients
In a local retrospective cohort study analyzing data during Hong Kong’s omicron BA.2 wave, molnupiravir and nirmatrelvir-ritonavir were found to be effective in reducing the risks of all-cause mortality and disease progression, as well as the need for oxygen therapy among hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and without supplemental oxygen requirement.1 The study revealed the substantial clinical benefits of oral antivirals, supporting their early use among Coronavirus disease 2019 (COVID-19) patients in Hong Kong.1
Early molnupiravir and nirmatrelvir-ritonavir show substantial clinical benefits in local hospitalized COVID-19 patients
In a local retrospective cohort study analyzing data during Hong Kong’s omicron BA.2 wave, molnupiravir and nirmatrelvir-ritonavir were found to be effective in reducing the risks of all-cause mortality and disease progression, as well as the need for oxygen therapy among hospitalized patients due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and without supplemental oxygen requirement.1 The study revealed the substantial clinical benefits of oral antivirals, serving as evidence to support their early use among Coronavirus disease 2019 (COVID-19) patients in Hong Kong.1
Safeguard children’s health from Omicron-associated complications with BNT162b2
The fifth wave of Coronavirus disease 2019 (COVID-19) has caused more than a million people being infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Omicron BA.2, predominant) and over 9,000 COVID-19-associated deaths in Hong Kong.1 Children, a subgroup of the population who had experienced more favorable outcomes vs. the older adults during the first 4 waves of the pandemic, were reported to have disproportionately higher hospitalization rates under the Omicron era.2 Some studies revealed that seizure and laryngotracheobronchitis, or croup, were common severe complications which led to pediatric hospitalization.2 The findings highlighted the importance of COVID-19 vaccination among children, but those aged <5 years were still not eligible for this mitigation measure. In an interview with Omnihealth Practice, Dr. Leung, Sze-Yin Agnes presented the latest safety and efficacy data of BNT162b2 among children aged ≥6 months and encouraged parents to arrange COVID-19 vaccination for their children to reduce the negative impact of this pandemic in young children.
Multi-peptide CoVac-1 vaccine induces T-cell immunity in immunoglobulin-deficient cancer patients
In the American Association for Cancer Research (AACR) annual meeting 2022, Dr. Claudia Tandler from the University of Tübingen, Germany, discussed the safety and immunogenicity of a novel multi-peptide vaccine, CoVac-1, for the induction of a (SARS-CoV-2) T-cell immunity in cancer patients with dis
BNT162b2 boosters and beyond: Strategies to overcome waning immune responses against omicron variant
During the fifth wave of Coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [B.1.1.529 (Omicron), predominant] infected over a million people and claimed more than 9,000 lives in Hong Kong.1 Elderly people aged ≥60 years were the most vulnerable population and accounted for ≥95% of the total death cases.1 Among the deceased, most were unvaccinated (>70%), or had received only 1 dose of COVID-19 vaccine, and/or were with known chronic diseases.1 Even for people who have received 2 doses of vaccines, increasing evidence showed that protection against severe COVID-19 would be reduced due to the waning immune responses against the Omicron variant.2 As such, in an interview with Omnihealth Practice, Professor HUNG, Fan-Ngai Ivan, addressed the rising concern about Omicron and presented the latest data showing that BNT162b2 boosters are still highly effective against the new threat. He also provided some updates on the development of new Omicron-adapted vaccines for conferring better protection to people.
Emerging from covid-19 predicament: An update on its management and vaccination
The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has afflicted more than 200 million people, with a death toll of more than 4 million people worldwide.1 As of September 29, 2021, Hong Kong has recorded 12,210 COVID-19 cases with 213 deaths.2 Although the situation in Hong Kong has been stabilized since the end of the fourth wave of epidemic in May 2021, the emergence of variants, especially the Delta variants, could be another threat to our society.3,4 In a lecture held by the Macau Association of Health Service Executives (MAHSE), Professor Hung, Fan-Ngai Ivan addressed the concerns over the emergence of the Delta variant and provided an update on the COVID-19 management and vaccination.
Latest updates: Six-month safety and efficacy of BNT162b2 mRNA COVID-19 vaccine
In brief With up to 6 months of follow-up in an ongoing, placebo-controlled, observer-blinded, multinational, pivotal efficacy study, the 6-month safety and efficacy data of BNT162b2 mRNA COVID-19 have been updated and summarized in this report.1 Background The current outbreak of the novel coron