Major Risk Factors for VTE After COVID Discharge Identified

By Megan Brooks

November 23, 2021

NEW YORK (Reuters Health) - A new study helps pinpoint which patients with COVID-19 may benefit from extended thromboprophylaxis after they leave the hospital.

Among 2,832 patients hospitalized with COVID-19 in Detroit's Henry Ford Health System, venous thromboembolic events after discharge occurred more often in those with a history of venous thromboembolism, peak dimerized plasmin fragment D (D-dimer) level above 3 ug/mL, and predischarge C-reactive protein level above 10 mg/dL.

"Several studies have attempted to quantify the incidence of venous thromboembolism events and address the controversy of extended thromboprophylaxis in patients with COVID-19," Dr. Wei Zhao of Ascension St John Hospital, in Detroit, told Reuters Health by email.

"Compared with other studies, our study is the first so far that identified the major factors associated with the increased risk of developing new onset of venous thromboembolism in patients with COVID-19 after their hospital discharge," Dr. Zhao said.

Patients in the study had a mean age of 63 years and 48% were men; 36 patients (1.3%) had venous thromboembolic events after leaving the hospital (16 pulmonary embolisms, 18 deep vein thromboses, and two portal vein thromboses).

There were also 15 (0.5%) arterial thromboembolic events after discharge (14 acute coronary syndromes and one transient ischemic attack).

The risk of venous thromboembolism decreased with time, with no change in risk of arterial thromboembolism.

Factors associated with a greater risk of venous thromboembolism after discharge included history of venous thromboembolism (odds ratio, 3.24; 95% confidence interval, 1.34 to 7.86), D-dimer level greater than 3 ug/mL (OR, 3.76; 95% CI, 1.86 to 7.57), and predischarge CRP level greater than 10 mg/dL (OR, 3.02; 95% CI, 1.45 to 6.29).

Patients who received a prescription for anticoagulant therapy at discharge had fewer venous thromboembolic events (OR, 0.18; 95% CI, 0.04 to 0.75; P=0.02).

"Our study is the first to examine the treatment effect of anticoagulation on the patients who received it after discharge," corresponding author Dr. Pin Li, Department of Public Health Sciences, Henry Ford Health System, told Reuters Health by email.

"After weighting the factors influencing the probability of receiving anticoagulation, therapeutic anticoagulation was associated with significantly lower risk of venous thromboembolism," Dr. Li said.

"We propose that postdischarge anticoagulation be considered in patients who had a history of venous thromboembolism, elevated D-dimer level during hospitalization and elevated C-reactive protein level before discharge, if their bleeding risk is low," Dr. Zhao told Reuters Health.

"Our study has provided the first evidence that helps establish the future guideline of venous thromboembolism prophylaxis in patients hospitalized with COVID-19 after their hospital discharge," Dr. Zhao added.

SOURCE: JAMA Network Open, online November 22, 2021.


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