New Ultrasound Study Shows Increased Liver Stiffness 10 Months After COVID-19 Infection

New research with ultrasound shear wave elastography (SWE) suggests that liver stiffness, a marker of fibrosis, increases in patients with a history of COVID-19 infection, according to a study presented at the Radiological Society of North America (RSNA) 2022 Annual Meeting.

“Our study is part of emerging evidence that COVID-19 infection may lead to liver injury that lasts well after the acute illness,” said Firouzeh Heidari, M.D., a post-doctorate research fellow at Massachusetts General Hospital in Boston.

Elevated transaminases in patients with COVID-19 suggest the presence of liver injury during acute infection, but whether this liver injury leads to lasting liver damage remains unknown. To identify lasting hepatic injury, Dr. Heidari and colleagues compared liver stiffness on ultrasound SWE in patients with a history of COVID-19 infection to that of healthy controls.

The retrospective cohort study included 131 patients (67 women) who underwent ultrasound SWE exams between January 2019 and January 2022 at Massachusetts General Hospital. Researchers assessed three groups of patients based on when they had an ultrasound SWE exam and whether they tested positive for COVID-19 on a polymerase chain reaction (PCR) test.

The COVID-19 positive group included 31 patients (mean age 53.1) who had a positive PCR test result at least 12 weeks prior to having ultrasound SWE. Elastography was performed at an average of 44 weeks (12 to 81 weeks) after a positive PCR test result. The pandemic control group was comprised of 50 patients (mean age 55.2) who had ultrasound SWE during the COVID-19 pandemic and had a history of only negative PCR test results. The pre-pandemic control group included 50 patients (mean age 58.2) who had ultrasound SWE before the pandemic. The primary endpoint was the average difference in median Young’s modulus between post-COVID-19 patients and controls after accounting for age, sex and time period.

COVID-19 infection was associated with an average increase in the median Young’s modulus of 1.71 kPa. The COVID-19 positive group had a higher median liver stiffness (7.68 kPa) in comparison to the pandemic control group (5.99 kPa). The pre-pandemic control group had a median liver stiffness of 7.01 kPa.

“The trend of declining liver stiffness among controls is not completely understood but it may be a consequence of changing referral patterns” during the COVID-19 pandemic, said Heidari and colleagues. They also noted that patients referred for ultrasound SWE before the pandemic were older than those referred after the start of the pandemic.

“We don’t yet know if elevated liver stiffness observed after COVID-19 infection will lead to adverse patient outcomes,” said Dr. Heidari. “We are currently investigating whether the severity of acute COVID-related symptoms is predictive of long-term liver injury severity. We hope to enrich our existing database with additional patient data and a broader scope of covariates to better understand the post-acute effects of COVID-19 within the liver.”