Thromboembolic Risk in Hospitalized and Nonhospitalized COVID-19 Patients

Abstract

Objective An unexpectedly large number of people infected with Covid-19 had experienced a thrombotic event. This study aims to assess the associations between Covid-19 infection and thromboembolism including myocardial infarction (MI), ischaemic stroke, deep-vein thrombosis (DVT), and pulmonary embolism (PE). Patients and Methods A self-controlled case-series study was conducted covering the whole of Scotland’s general population. The study population comprised individuals with confirmed (positive test) Covid-19 and at least one thromboembolic event between March 2018 and October 2020. Their incidence rates during the risk interval (5 days before to 56 days after the positive test) and the control interval (the remaining periods) were compared intra-personally. Results Across Scotland, 1,449 individuals tested positive for Covid-19 and experienced a thromboembolic event. The risk of thromboembolism was significantly elevated over the whole risk period but highest in the 7 days following the positive test (IRR 12.01, 95% CI 9.91-14.56) in all included individuals. The association was also present in individuals not originally hospitalised for Covid-19 (IRR 4.07, 95% CI 2.83-5.85). Risk of MI, stroke, PE and DVT were all significantly higher in the week following a positive test. The risk of PE and DVT was particularly high and remained significantly elevated even 56 days following the test. Conclusion Confirmed Covid-19 infection was associated with early elevations in risk with MI, ischaemic stroke, and substantially stronger and prolonged elevations with DVT and PE both in hospital and community settings. Clinicians should consider thromboembolism, especially PE, among people with Covid-19 in the community.

Pulmonary thromboembolic events in COVID‐19—A systematic literature review

“…7 Consistent with this, a self-controlled study of the Scottish general population has found that while the likelihood of thromboembolism was highest in the 7 days following a positive test, the risk remained significantly elevated 8 weeks later. 51 Similarly, a recent study using the US Veterans Affairs health databases showed an increased risk of PE beyond the first 30 days after a positive COVID-19 test compared with contemporary and historical controls. 52 Another USA-based study showed an increased risk of PE and pulmonary hypertension beyond the acute phase of COVID-19 infection, compared with contemporary and historical controls.…”

Clinical and Genetic Risk Factors for Acute Incident Venous Thromboembolism in Ambulatory Patients With COVID-19

“…5 In contrast, fewer clinical interventions have been implemented to prevent VTE among ambulatory patients with SARS-CoV-2 infection, partially because of conflicting findings on the association between the infection and VTE occurrence, with cohort studies showing no elevated risk 6 but self-controlled case series studies consistently showing a substantial increase of short-term risk. [7][8][9] Also, mixed evidence of benefit from oral anticoagulation complicated clinical decisions for ambulatory COVID-19. 10 Given the ongoing global rollout of vaccines, relaxation of public health restrictions, and the widespread highly transmissible Omicron variant, the absolute number of milder COVID-19 cases treated in ambulatory settings continues to rise worldwide.…”

Myocardial Infarction During the COVID-19 Pandemic

“…Early during the COVID-19 pandemic, it was recognized that infection with SARS-CoV-2 was associated with an increased risk of both arterial and venous thrombotic complications. This association is strongest for venous thromboembolic disease, but the risk of myocardial infarction (MI) is approximately doubled in the 7 days after COVID-19 diagnosis . Multiple studies have suggested worse outcomes in patients with COVID-19 and MI, with direct effects of the virus on endothelial cells, increased propensity for vascular thrombosis, and deficient care delivery all mechanistically implicated …”