Hospitals throughout Tennessee and other states are warning past surgical patients about a risk of a potentially fatal heart infection.

At issue is a potential mycobacteria infection that can result from use of a particular surgical device, the Stöckert 3T heater-cooler made by LivaNova PLC.

These devices, which are commonly used during open heart surgery, may have been contaminated with nontuberculosis mycobacteria, or NTM.

Investigators believe the contamination in the affected Stöckert 3T systems may have originated at the facility in Germany where the devices are manufactured.

Such a contamination could lead to a post-operative NTM infection that can be seriously problematic or even deadly.

Warnings of Potentially Fatal Heart Infection Sent Out

So far, there has been one confirmed case of an NTM infection within the state of Tennessee. Even though the risk of infection is very low, many hospitals are playing it safe. They are now sending out warning letters to patients who underwent open-heart surgery within the past five years.

Vanderbilt University Medical Center in Nashville sent out a letter toward the end of last year warning about 400 patients. TriStar Centennial also reported sending out letters about the risk of fatal heart infection. The Department of Veterans Affairs says none of its hospitals were affected by the risk of infection.

Devices like the Stöckert 3T heater-cooler are in wide use throughout the world. In the U.S., over 250,000 heart bypass surgeries are performed every year using heater-cooler devices. Of those procedures, about 60 percent use the Stöckert system.

This system is used during open heart surgery to help regulate the patient’s temperature. It works by exchanging heat between the patient’s blood and temperature-controlled water. The water itself never comes into contact with the patient during normal use.

Officials fear the machine’s exhaust system could be what puts patients at risk for fatal heart infection. Mycobacteria inside the machine can colonize and multiply. During surgery, those mycobacteria may be blown out by the machine’s exhaust fan and into the air of the operating room. From there, they may find their way to the open surgical wound.

An NTM infection can take months or even years to develop – which is why hospitals are sending their warning letters to patients from as far back as 2012. Patients may not even become symptomatic for a long time after their surgery.

Symptoms to Look For

Following its own investigation, the Centers for Disease Control issued a notice in October 2016 alerting patients to the problem and the symptoms that might signal an NTM infection.

Patients are encouraged to seek medical care if they experience night sweats, fatigue, muscle aches, weight loss, or a fever that isn’t otherwise explainable. Some patients might observe a small, purulent wound.

The CDC notes that while some of the reported cases of infection ended in death, the risk of fatal heart infection remains low – between one in 100 and one in 1000.

Patients concerned about their own risk of NTM infection can ask their hospital if the Stöckert 3T was used during their open-heart surgery. NTM infection may also be detectable using a specific blood test.