Risk of Arterial and Venous Thrombotic Events Among Patients with COVID-19: A Multi-National Collaboration of Regulatory Agencies from Canada, Europe, and United States

Purpose

Few studies have examined how the absolute risk of thromboembolism with COVID-19 has evolved over time across different countries. Researchers from the European Medicines Agency, Health Canada, and the United States (US) Food and Drug Administration established a collaboration to evaluate the absolute risk of arterial (ATE) and venous thromboembolism (VTE) in the 90 days after diagnosis of COVID-19 in the ambulatory (eg, outpatient, emergency department, nursing facility) setting from seven countries across North America (Canada, US) and Europe (England, Germany, Italy, Netherlands, and Spain) within periods before and during COVID-19 vaccine availability.

Patients and Methods

We conducted cohort studies of patients initially diagnosed with COVID-19 in the ambulatory setting from the seven specified countries. Patients were followed for 90 days after COVID-19 diagnosis. The primary outcomes were ATE and VTE over 90 days from diagnosis date. We measured country-level estimates of 90-day absolute risk (with 95% confidence intervals) of ATE and VTE.

Results

The seven cohorts included 1,061,565 patients initially diagnosed with COVID-19 in the ambulatory setting before COVID-19 vaccines were available (through November 2020). The 90-day absolute risk of ATE during this period ranged from 0.11% (0.09-0.13%) in Canada to 1.01% (0.97-1.05%) in the US, and the 90-day absolute risk of VTE ranged from 0.23% (0.21-0.26%) in Canada to 0.84% (0.80-0.89%) in England. The seven cohorts included 3,544,062 patients with COVID-19 during vaccine availability (beginning December 2020). The 90-day absolute risk of ATE during this period ranged from 0.06% (0.06-0.07%) in England to 1.04% (1.01-1.06%) in the US, and the 90-day absolute risk of VTE ranged from 0.25% (0.24-0.26%) in England to 1.02% (0.99-1.04%) in the US.

Conclusion

There was heterogeneity by country in 90-day absolute risk of ATE and VTE after ambulatory COVID-19 diagnosis both before and during COVID-19 vaccine availability.

Epigenome-wide association study of biomarkers of liver function identifies albumin-associated DNA methylation sites among male veterans with HIV

Background: Liver disease (LD) is an important cause of morbidity and mortality for people with HIV (PWH). The molecular factors linked with LD in PWH are varied and incompletely characterized. We performed an epigenome-wide association study (EWAS) to identify associations between DNA methylation (DNAm) and biomarkers of liver function-aspartate transaminase, alanine transaminase, albumin, total bilirubin, platelet count, FIB-4 score, and APRI score-in male United States veterans with HIV. Methods: Blood samples and clinical data were obtained from 960 HIV-infected male PWH from the Veterans Aging Cohort Study. DNAm was assessed using the Illumina 450K or the EPIC 850K array in two mutually exclusive subsets. We performed a meta-analysis for each DNAm site measured by either platform. We also examined the associations between four measures of DNAm age acceleration (AA) and liver biomarkers. Results: Nine DNAm sites were positively associated with serum albumin in the meta-analysis of the EPIC and 450K EWAS after correcting for multiple testing. Four DNAm sites (cg16936953, cg18942579, cg01409343, and cg12054453), annotated within the TMEM49 and four of the remaining five sites (cg18181703, cg03546163, cg20995564, and cg23966214) annotated to SOCS3, FKBP5, ZEB2, and SAMD14 genes, respectively. The DNAm site, cg12992827, was not annotated to any known coding sequence. No significant associations were detected for the other six liver biomarkers. Higher PhenoAA was significantly associated with lower level of serum albumin (β = -0.007, p-value = 8.6 × 10^-4, CI: -0.011116, -0.002884). Conclusion: We identified epigenetic associations of both individual DNAm sites and DNAm AA with liver function through serum albumin in men with HIV. Further replication analyses in independent cohorts are warranted to confirm the epigenetic mechanisms underlying liver function and LD in PWH.

2896. Reduction in Liver-related Mortality Among HCV Infected Persons Is Driven by Attainment of SVR Independent of the Regimen Used: Results from the ERCHIVES Cohort

Background

Beneficial effect of hepatitis C virus (HCV) treatment with directly acting antiviral agents (DAAs) upon overall mortality is well-established. However, the effect of treatment upon liver-related mortality is not well documented.

Methods

We used ERCHIVES database to identify all chronic HCV-infected persons between January 1, 2002 and December 31, 2016. We excluded those with HIV or HBV coinfection or hepatocellular carcinoma. HCV treatment status was defined as prescription of pegylated interferon (PEG)/ribavirin (RBV) for >24 weeks, PEG/RBV plus boceprevir or telaprevir, or a newer DAA regimen for >8 weeks. Propensity score-matched untreated controls were identified for each treated person. We linked HCV+ cases to the National Death Index (NDI) data updated to the end of 2016. Cause of death was retrieved from the underlying cause listed on the death certificate by using ICD‐10 codes. The listed primary cause was assigned as the cause of death. Each cause of death was categorized as “Liver related” or “Not liver related” by two physician members of the study team. Liver-related causes included viral hepatitis-related causes, complications of liver disease, and hepatocellular carcinoma, but excluded any cause where alcohol or any other known liver disease other than viral hepatitis was specified. Discordant results were adjudicated by a third physician member.

Results

Among 34,412 treated and 21,287 untreated controls, there were 13,098 deaths, of which 2,474 (18.9%) were liver related. Overall liver-related mortality rate per 100 person-years of follow-up was 0.64 in the treated and 1.24 in the untreated group (P). Among the treated group, the liver-related mortality rate per 100 person-years was 0.14 for those who achieved SVR and 1.26 among those who did not achieve SVR. When stratified by treatment regimen, those treated with PG/RBV had a mortality rate of 0.73 vs. 0.24 for those treated with a DAA regimen. However, further stratification by attainment of SVR revealed that the difference between regimens was almost entirely driven by the difference in SVR rates (see table).

Conclusion

HCV-infected persons who receive treatment have a substantial reduction in liver-related mortality. This reduction is largely driven by attainment of SVR and is independent of the regimen use when stratified by SVR attainment.

Disclosures

All Authors: No reported Disclosures.