Post-surgery risks after COVID-19 infection may linger many months

Dec. 14 (UPI) -- It may be wise to wait for non-urgent surgery following COVID-19 infection because the odds of significant postoperative heart problems will diminish over time.

That's the gist of a study that found this trend of decreasing cardiovascular risk persists longer than previously known -- for as long as 13 months after a COVID-19 diagnosis.

Compared to previous studies of this issue, the new research tracked surgical outcomes more broadly and used a longer timeline out from COVID-19 diagnosis, the scientists said.

The findings were published Wednesday in JAMA Network Open.

"Patients undergoing surgery after COVID-19 infection should speak with their providers and make sure they are aware of how recently they had COVID-19," Dr. Robert Freundlich, chief of the division of anesthesiology informatics research at Vanderbilt University Medical Center, told UPI.

"This may be an important consideration for deciding whether the surgery should be delayed to reduce the risk of major complications."

Freundlich, also an associate professor of anesthesiology and biomedical informatics, led the study with critical care medicine fellow Dr. John Bryant.

According to the researchers, the pandemic has disrupted, either postponing or cancelling, millions of surgeries. And recent evidence has shown increased deaths for surgical patients who were infected with COVID-19 within six weeks of their operation.

The American Society of Anesthesiologists and the Anesthesia Patient Safety Foundation jointly recommend delaying surgery for four to 12 weeks after a COVID-19 diagnosis, based on the severity of the infection and person's vaccination status.

Their recommendation was first made in March 2021, and then updated in February.

The ASA/APSF guidelines are largely based on studies of postoperative pulmonary complications after COVID-19 infection, "and propose what they consider to be an 'optimal' duration for delaying surgery that could be easily misinterpreted," Freundlich said in an email.

As an alternative, he said patients and providers could use the new study's findings to better understand a patient's individual risk and decide how long surgery should be delayed, if at all.

"Every patient and every surgery are different," Freundlich said in an email.

For the study, the researchers used electronic health-record data from roughly 4,000 adult surgical patients with a history of SARS-CoV-2 infection who underwent surgery at the medical center from March 2020 to December 2021.

Freundlich said the researchers included all adult patients who underwent any surgery after any Vanderbilt University Medical Center laboratory-confirmed COVID-19 infection, regardless of severity of illness.

The time from COVID-19 diagnosis to surgery was a median of 98 days.

The scientists analyzed the odds of various cardiovascular problems arising within 30 days after surgery, including deep venous thrombosis, pulmonary embolism, cerebrovascular accident, myocardial injury, acute kidney injury and death.

Such adverse cardiovascular events were identified in 485 patients, or 12.1% of them.

Freundlich said that existing guidance on delaying surgery after COVID-19 infection has been based almost exclusively on the risk of postoperative pulmonary complications, "despite a large body of evidence in the medical literature that recent COVID-19 infection may place other organs at risk after surgery."

He added: "COVID-19 is thought to cause major changes in the body's blood vessels and ability to clot, which may at least partially explain why it is associated with life threatening blood clots, heart attacks, kidney damage, and stroke."

He said the researchers' analysis also explored the risk of post-operative pulmonary complications.

The incidence of post-operative heart problems fell steeply at first, from about 18% to 10% over the first 100 days after COVID-19 diagnosis, the researchers found. It then decreased steadily over the next 10 months, to roughly 8% by 400 days after such a diagnosis.

Freundlich said the investigators were surprised the data indicated a trend of subsiding risk that still was discernable more than a year after a patient's COVID-19 diagnosis.

He told UPI he was most surprised by "the magnitude of the relationship."

"I hoped that, given the size of our dataset, we might be able to detect what I thought was likely a small difference," he said. "In fact, the risk is considerably larger than we expected and could have likely been detected in a much smaller dataset."

He also said he was surprised by the duration of risk.

"We were able to detect risk out to approximately 400 days past COVID-19 infection. ... While the risk at 400 days is likely quite small, it isn't zero, according to our results.

"Alternatively, however, the risk of delaying many surgeries 400 days is quite high and, depending on the reason for the surgery, may be unacceptable."

Freundlich said it remains unclear whether the experiences among Vanderbilt's surgery patients following a COVID-19 diagnosis are broadly applicable.

"While Vanderbilt University Medical Center sees patients from around the country, if not the world, we still can't say with absolute certainty that the relationship we found in this study exists elsewhere. As medical societies consider how to incorporate our findings into existing guidelines, this will be an important consideration," he said.