COVID-19 infection did not exacerbate the risk for venous thromboembolism (VTE) among patients with sickle cell disease (SCD), according to data from a retrospective study published in Blood Advances.
Ashima Singh, PhD, of the Medical College of Wisconsin, and colleagues used electronic health records from a multisite research network to identify two groups of patients with SCD hospitalized during 2020 with COVID-19 (n=281) and without COVID-19 (n=4,873) and compared rates of VTE.
“Hospitalizations increase VTE risk in the general population. This risk is further increased in individuals with SCD who have a hypercoagulable state,” Dr. Singh explained. “Since COVID-19 infection in the general population has been associated with clinical thrombosis, we hypothesized that patients with SCD [and] COVID-19 would have higher VTE rates.”
In the analysis, patients with COVID-19 were older compared to those without COVID-19 (mean age = 31.3 vs. 28.0 years; p=0.0021) and a higher proportion of them had a history of hypertension (35.2% vs. 25.7%; p=0.0004), acute or chronic kidney disease (29.2% vs. 19.5%; p<0.001), obesity (20.6% vs. 13.1%; p=0.0003), and prior deep vein thrombosis (DVT) or pulmonary embolism (PE; 22.8% vs. 15.3%; p=0.0009).
Among patients with SCD who were hospitalized with COVID-19, 7.12% had an incidence of VTE at one month, 9.96% at three months, and 12.46% at six months of their COVID-19 diagnosis. In comparison, among patients with SCD without COVID-19, 5.27% had an incidence of VTE at one month, 6.81% at three months, and 8.58% at six months.
In an unadjusted analysis, patients hospitalized with COVID-19 had a significantly increased risk for VTE at three months (relative risk [RR] = 1.46, 95% CI 1.01-2.11; p=0.0420) and six months (RR=1.45, 95% CI 1.05-2.00; p=0.0237). However, when the researchers adjusted for age, history of hypertension, acute or chronic kidney disease, obesity, and prior VTE or PE, there was no significant difference in VTE risk between the two study groups.
“Our models identified many risk factors for VTE among individuals with SCD, which are consistent with prior published literature,” Dr. Singh said. “Surprisingly, COVID-19 did not significantly increase the VTE risks after adjusting for other factors.”
Instead, the researchers found that age, prior history of DVT or PE, and prior history of acute or chronic kidney disease were significantly associated with VTE risk at all time points. Specifically, history of prior DVT or PE had a large effect size, which the researchers noted was “consistent with the observation of high VTE recurrence rate in patients with SCD.”
Additionally, the researchers noted that a large proportion of VTE occurred in July 2020 (20%), November 2020 (22.8%), and December 2020 (20%) when there was widespread use of “intermediate doses” of anticoagulation therapy to prevent VTE in patients with COVID-19.
According to Dr. Singh, the data indicate that when treating patients with SCD who are hospitalized for COVID-19 infection, anticoagulation management decisions should be based on individual risk factors including prior history of VTE, acute or chronic kidney disease, obesity, and age.
“These results could provide guidance for clinicians when they apply current clinical anticoagulation guidelines for COVID-19 in the general population to patients with SCD,” Dr. Singh said.
Dr. Singh and colleagues acknowledged that the analysis could have missed incident VTE that occurred in patients seeking treatment at institutions that were not part of the network included in the study. There was also a lack of patient identifiers in the database, which prevented the researchers from being able to differentiate prior residual VTE and new onset recurrent VTE.
Any conflicts of interest declared by the authors can be found in the original article.
Reference
Singh A, Brandow AM, Wun T, Shet AS. COVID-19 and venous thromboembolism risk in patients with sickle cell disease [published online, 2022 Aug 1]. Blood Adv. doi: 10.1182/bloodadvances.2022007219.