Postdischarge Anticoagulation Use Reduces VTE Risk After COVID-19 Hospitalization

Patients infected with COVID-19 frequently experience both arterial thromboembolism (ATE) and venous thromboembolism (VTE), due to induction of coagulopathy manifesting as elevation of dimerized plasmin fragment D level.

A recent study thus assessed the rate of postdischarge thrombosis in patients with COVID-19, identified factors associated with the risk of postdischarge VTE, and evaluated the association of postdischarge anticoagulation use with incidence of VTE.

Led by Pin Li, PhD, Department of Public Health Sciences, Henry Ford Health System, the team of investigators found that patients at high risk of new onset VTE following discharge from the hospital may benefit the most from postdischarge therapeutic anticoagulation use.

Methods

The analysis consisted of adult patients hospitalized with a diagnosis of COVID-19 confirmed by a positive polymerase chain reaction test at the 5 hospitals of Henry Ford Health System from March - November 2020. They noted that the first VTE or ATE events were identified up to 90 days after discharge from the index admission, with event and mortality rates calculated at 90 days.

The electronic health records obtained the patient's demographic characteristics, body mass index, pre existing medical conditions, inpatient data, peak and predischarge laboratory results, use of AC during hospitalization and following discharge.

The investigators noted that race was assessed in the study due to Black patients having higher rates of incident VTE and pulmonary embolism compared to patients of other races.

In statistical analysis, investigators used a nonparametric Mann-Kendall trend test to test the monotonic trend of event number over time after discharge.

Further, univariable and multivariable logistic regression methods assessed factors associated with the risk of and medications for thrombosis. Additionally, propensity scores were used to evaluate the association of postdischarge AC use with new onset of VTE.

Findings

The cohort study consisted of 2832 adult patients hospitalized with COVID-19, with a mean age of 63.4 years, 47.6% male (n = 1347), 38.9% Black (n = 1102), and 50.7% White (n = 1437).

From that total, 36 (1.3%) experienced new onset of VTE after discharge, of whom 16 had pulmonary embolism, 18 had deep vein thrombosis, and 2 had portal vein thrombosis. Additionally, 15 patients (0.5%) with COVID-19 had new onset of ATE after discharge, 1 had transient ischemic attack, and 14 had acute coronary syndrome.

Data show the incidence of VTE decreased with time, with a median time to event of 16 days (Mann-Kendall trend test, P <.001), but they observed no change in the risk of ATE with time (Mann-Kendall trend test, P = .37), at a median time to event of 37 days. Over time, mortality was shown to decrease (Mann-Kendall trend test, P <.001), with a median time to death of 17 days.

Among factors associated with increased risk, the results of the multivariable analysis showed that patients with predischarge CRP levels ≥10 mg/dL (OR, 3.02; 95% CI, 1.45 - 6.29), peak D-dimer levels ≥2 μg/mL (OR, 3.76; 95% CI, 1.86 - 7.57), and predischarge C-reactive protein level ≥10 mg/dL (OR, 3.02; 95% CI, 1.45 - 6.29) were more likely to experience VTE after discharge.

Li and colleagues noted that 682 patients (24.1%) received AC at discharge, with 188 patients (6.6%) receiving a prophylactic dose and 494 patients (17.4%) receiving a therapeutic dose.

Those who received the therapeutic AC at discharge had a reduced risk of experiencing new onset of VTE (OR, 0.18; 95% CI, 0.04 - 0.75, P = .02).

Takeaways

“Although extended thromboprophylaxis in unselected patients with COVID-19 is not supported, these findings suggest that postdischarge anticoagulation may be considered for high-risk patients who have a history of venous thromboembolism, peak D-dimer level greater than 3 μg/mL, and predischarge C-reactive protein level greater than 10 mg/dL, if their bleeding risk is low,” investigators wrote.

The study, “Factors Associated With Risk of Postdischarge Thrombosis in Patients With COVID-19,” was published in JAMA Network Open.