Bacteria are everywhere, and from time to time they make us sick. Yet few people become alarmed when bacteria settle in their throat or lungs. After a few days of antibiotics, their sore throat or flu-like symptoms disappear, and they feel fine.
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But when bacteria invade the heart, the results can be devastating. They can cause a disease called infective endocarditis (IE), which is being seen with increasing frequency. Knowing that you are at risk will allow you to seek immediate care if you develop the symptoms of IE. It’s a disease that can’t wait.
“For the best chance of a cure, antibiotics should be started very early after symptoms appear,” says cardiac surgeon Gösta Pettersson, MD, PhD. “Without treatment, it is uniformly fatal.”
How you get IE
Whenever bacteria enter the bloodstream, often through a small scratch in the gums that occurs during tooth brushing, heart valves may become infected. The microbes will attach to any damaged tissue on a valve or lining of the heart muscle, where they attract platelets and other components of the blood and form colonies. The bacteria in these colonies, known as vegetations, produce toxins and enzymes that kill normal cells and disintegrate tissue, further damaging valve leaflets and preventing tissue from healing.
In addition, pieces of vegetation can break off, enter the bloodstream and cause stroke or damage other organs. Individuals at highest risk of IE are those who have valve disease, a prosthetic (artificial) valve or congenital heart defect, or have undergone valve surgery or organ transplantation. Anyone who uses intravenous medications for long periods of time is at increased risk of IE. Those who use unsterile needles or share needles for injecting illicit drugs are at very high risk, even if their valves are normal.
Why IE is an easy diagnosis to miss
IE usually starts with a fever. Patients also complain of aching muscles and joints and lack of appetite. Some may experience chills, a rapid heart rate, fatigue, night sweats or persistent cough or swelling in the abdomen, legs or feet.
These nonspecific symptoms make IE an easy diagnosis to overlook.
“The symptoms are often ascribed to influenza or upper respiratory infection, and the patient is treated with oral antibiotics,” says Dr. Pettersson. “This may temporarily suppress the infection, but it doesn’t cure it. Symptoms return in a week or two.”
Why IE can be tough to beat
Bacteria form biofilm (vegetations), which are matrix-like nests in which they can hide from antibiotics.
If antibiotics are started before the vegetation becomes too large, IE can be cured. If the vegetations have grown large, and the infection has penetrated the wall of the aorta or the valve, antibiotics alone may not be sufficient. Surgery will be needed to remove the biofilm, along with any dead tissue or prosthetic valve, and restore valve function and the integrity of the heart.
Treatment requires skill
Because IE is a complex, rapidly progressing disease, it is best treated by a multidisciplinary team of experienced clinicians who understand the disease process and know how to treat it and its complications.
“The antibiotics may not be effective, and the infected tissue may need to be removed without delay,” says Dr. Pettersson. “Waiting for antibiotics to clear the infection before taking further action can be a mistake.
“Not every patient needs surgery, but every patient should be evaluated by an experienced cardiac surgeon,” he adds. “If the infected valve is artificial, surgery most certainly will be required.”
Surgical removal of IE is a difficult procedure that most heart surgeons rarely perform. Every last bit of the vegetation must be removed to keep IE from relapsing. The damage it has caused then must be repaired.
As one of the most experienced IE surgeons in the world, Dr. Pettersson last year helped write guidelines that advise cardiac surgeons how to evaluate and treat IE properly.
How to protect yourself from IE
Although most patients with IE have no opportunity to choose their hospital and treatment team, they can take some steps to help protect themselves.
“If you know you are at risk of IE and develop the symptoms of IE, seek medical care immediately. You should be particularly wary if you have a history of valve surgery, have a prosthetic valve or have undergone a recent interventional procedure and have had dental work,” says Dr. Pettersson.
It’s in your best interest to ask your doctor if IE can be ruled out, so if you are diagnosed with flu or pneumonia, insist on having blood cultures drawn before being started on antibiotics,” he advises.
This article first appeared in Cleveland Clinic Heart Advisor.