Blood Clots More Likely With COVID Versus Pneumonia

— More testing needed in COVID patients, researchers say

MedicalToday
A computer rendering of a blood clot in a blood vessel.

Blood clots may be more common in patients with COVID-19 than in those with community-acquired pneumonia (CAP), a study conducted at a Utah hospital system suggested.

Among the study cohort, 6.2% of COVID patients tested positive for venous thromboembolism (VTE) compared with 3.9% of patients with CAP (adjusted OR 1.64, 95% CI 1.35-1.99, P<0.00001), reported Samuel Brown, MD, MS, of the Intermountain Medical Center in Murray, Utah, and colleagues.

The positivity rate for VTE was 16.3% for COVID-19 patients and 9.2% for CAP patients, they noted in the .

When looking at CT pulmonary angiogram results, which are used to diagnose pulmonary embolism, 3.2% of COVID patients had a positive diagnosis versus 1.7% of CAP patients (aOR 1.99, 95% CI 1.48-2.67, P<0.00001).

In addition, 3.3% of COVID patients were diagnosed with deep vein thrombosis using lower extremity Doppler ultrasound compared with 2.5% of CAP patients (aOR 1.40, 95% CI 1.09-1.79, P=0.008).

"This observation aligns with former reports that COVID-19 infection is uniquely thrombogenic among hospitalized medical patients," Brown and team wrote. "Our estimates may still be underestimates of the true incidence of VTE in COVID-19 since testing was done for clinical indications but suggests that VTE is more common in COVID-19 than in pneumonia caused by pathogens other than SARS-CoV-2."

The high positivity rate of 16.3% for VTE in COVID patients is much higher than the previously reported 5% positivity rate in all inpatients, "indicating testing is likely not done frequently enough for COVID-19 patients and there may be missed opportunities to diagnose and treat patients for VTE," they added.

Overall, 38% of COVID patients and 43% of CAP patients underwent VTE testing. Brown and colleagues noted that while there were some variations in how tests were performed during the pandemic, they were small and likely did not affect their estimates of VTE burden.

Previous studies have shown that for VTE. A few studies have suggested that VTE may be more prevalent in COVID-19 patients, with noting an incidence of 17%, but the comparative data are not strong, the authors said.

This retrospective cohort study included 7,509 hospitalized COVID patients from 23 hospitals in Utah in 2020, with 4,304 CAP patients at 16 hospitals from 2017 to 2019 serving as the control group. The mean age of COVID patients was 57, and 50% were female. For CAP patients, mean age was 67, and 48% were female.

Imaging to assess VTE was performed as indicated, 7 days prior through 90 days following the index admission date.

The study lacked a single group of radiologists interpreting VTE results, instead relying on radiologists from across the system, Brown and colleagues noted. The radiologists were not blinded to clinical status or COVID-19 diagnosis among the patients, introducing potential bias into the study, they acknowledged.

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    Lei Lei Wu is a staff writer for Medical Today. She is based in New Jersey.

Disclosures

The study authors reported no disclosures.

Primary Source

Annals of the American Thoracic Society

Hendrickson KW, et al "Comparative frequency of venous thromboembolism in patients admitted to the hospital with SARS-CoV-2 infection vs. community-acquired pneumonia" Ann Am Thorac Soc 2022; DOI: 10.1513/AnnalsATS.202108-953RL.