Patients who had heart bypass surgery bypass in which a cardiac heater-cooler was used may be at an increased risk of developing a rare infection that they contracted during heart surgery. However, it may take several years to have this condition diagnosed.

The heart surgery infection caused as a result of the medical device used is related to a non-tuberculosis mycobacteria known as Mycobacterium chimaera, or M. chimaera. This type of mycobacteria infection is quite rare, and most doctors do not even think to check for this bacteria as a cause of disease unless they have been specifically instructed to do so.

M. chimaera infections have been linked to the heater-cooler medical device that is used during open-chest surgery. The device is used to warm or cool patients during surgery. When patients are kept at an ideal temperature during surgery, they are less likely to suffer from complications and the surgical outcome is more favorable.

The device uses water to heat and cool the patient. However, the water does not come into contact directly with the patient. It was determined that the heart surgery infection cases that were reported came from the aerosolized water forced out of the unit’s air exhaust. This contaminated water aerosol could then enter the operating room and eventually deposit into the patient’s open surgical wound.

The symptoms related to M. chimaera infection may not develop for months to years after exposure to the bacteria. The symptoms related to the bacteria are quite nonspecific and are seen in a number of different conditions, and it is unlikely that doctors would consider this rare bacterial infection as the culprit.

Symptoms of the heart surgery infection caused by this mycobacteria include fatigue, flu-like symptoms, fever of unknown origin, weight loss, pain, night sweats and muscle aches. These types of symptoms are associated with other, more common diseases that doctors are more likely to diagnose.

Most cases of this type of heart surgery infection caused by M. chimaera can be treated with a two-year course of antibiotics. However, if it is not treated in time, a number of health issues may result, and in severe cases, it can be fatal.

It was determined that the likely cause of heart surgery cases due to this mycobacteria infection were related to issues with the manufacturing process of the heater coolers — more specifically, with the LivaNova/Soren Stockert 3T heater-cooler device. It is estimated that these heater-cooler devices could’ve been contaminated as far back as from 2006. This means that approximately 2 million patients may have been exposed to the M. chimaera bacteria and could develop heart surgery infection even as much as seven years later.

It is estimated that at least 28 deaths have been the result of these heart surgery infection cases involving M. chimaera since 2006.

According to statistics from the Centers for Disease Control (CDC), the overall risk of contracting a heart surgery can infection from the heater-cooler device is approximately between 1 and 10 people for every thousand patients who had heart surgery at hospitals where contaminated heater-cooler devices were used.

The LivaNova/Soren Stockert 3T heater-cooler has been the most commonly cited device related to an increased risk of developing a heart surgery infection. However, a study conducted earlier this year in Denmark found that other coolers may also potentially he be contaminated. In general, the study concluded that 86% of the heater-cooler units were contaminated, including several by another manufacturer, Marquet.

Any and all patients who have had open heart surgery since 2006 should be on the lookout for potential signs and symptoms of a heart surgery infection related to M. chimaera. Patients should report any concerns directly to their doctor, being sure to inform medical professionals that exposure to this rare bacterial infection may have occurred.