What is Libman-Sacks Endocarditis?
Libman-Sacks endocarditis, often referred to as nonbacterial thrombotic endocarditis or marantic endocarditis, is a condition that was first identified in four patients in New York in 1924 by Emanuel Libman and Benjamin Sacks. This condition can cause a range of issues, from tiny particles that can only be seen under a microscope, to large growths on heart valves which were otherwise healthy. These growths are most commonly seen on the aortic and mitral heart valves.
Interestingly, these growths, also known as vegetations, aren’t accompanied by any signs of infection. This is because they’re what’s medically referred to as ‘sterile’, meaning they don’t contain any harmful bacteria. It’s thought that Libman-Sacks endocarditis starts with damage to the inner lining of the heart (endothelial injury) coupled with an increased tendency of the blood to clot (hypercoagulable state).
This condition is often seen in patients with cancer (mainly solid tumours such as adenocarcinoma), systemic lupus erythematosus (an autoimmune disease first described in women in 1985), and antiphospholipid antibody syndrome (a disorder of the immune system). Sometimes the vegetations related to this condition are also referred to as verrucous endocarditis.
Although it mostly affects the mitral and aortic valves in the heart, other heart valves may also be involved. Understanding this condition is important for proper diagnosis and treatment.
What Causes Libman-Sacks Endocarditis?
Nonbacterial thrombotic endocarditis is a condition often linked to a state where your blood clots more easily than normal. It typically appears in connection with:
* Certain types of cancer: People with cancer are five times more likely to have this condition than the general population – about 1.25% versus 0.25%. It’s mainly found in people who have solid tumors like cancer of the pancreas, colon, ovaries, lungs, bile duct, and prostate. In fact, among cancer patients, people with solid tumors are five times more likely to have this condition than those with other types of cancer – about 2.7% versus 0.47%.
* Systemic Lupus Erythematous (SLE): This condition occurs in 6% to 11% of lupus patients, according to studies. One autopsy study even found it in half of all lupus cases. There seems to be a strong connection between this condition and how long and how severely someone has had SLE.
Antiphospholipid Syndrome: This condition, which can happen for no apparent reason (primary) or as a result of SLE (secondary), is found in a third of these patients, versus 4% in a control group without the syndrome. The condition is even more common in people who have SLE and have tested positive for antiphospholipid.
There are also reports of it occurring in patients with widespread blood clotting within the blood vessels (disseminated intravascular coagulation), rheumatoid arthritis, and severe illness due to infection (sepsis).
Risk Factors and Frequency for Libman-Sacks Endocarditis
Libman-Sacks endocarditis is a rare condition that’s often only discovered after a person has passed away, showing in about 0.9% to 1.6% of autopsies. It mainly affects people who are between 40 to 80 years old, but it can occur at any age. It doesn’t favor any particular gender. Notably, conditions related to it, such as SLE and antiphospholipid, tend to be more common in females of child-bearing age, occurring 5 to 9 times more often in women than in men. Among these women, it’s more prevalent in Black and Hispanic women.
Signs and Symptoms of Libman-Sacks Endocarditis
Patients often don’t show symptoms and the condition is often discovered by chance when treating other heart-related illnesses or after death. Unhealthy growths, known as vegetations, can appear on any part of the heart valves, but are most likely to occur on the valves on the left side of the heart. If these growths break off, they can cause blockages that may result in symptoms such as a stroke, cold limbs or severe abdominal pain.
People with SLE, or systemic lupus erythematosus, can show signs of the condition such as fever, rashes, arthritis, mouth ulcers, kidney disorders, psychological issues, blood disorders, among other symptoms. To confirm a diagnosis, doctors can use ultrasound of the heart, analyze tissue samples and carry out immunology tests. Other criteria can also be used to confirm the clinical features of the disease.
- Fever
- Rashes
- Arthritis
- Mouth ulcers
- Kidney disorders
- Psychological issues
- Blood disorders
People with Antiphospholipid syndrome, another comorbidity often present in patients with lupus, might experience recurrent miscarriages, and blood clots in their veins or arteries. These symptoms usually occur alongside other manifestations like lupus anticoagulant and either IgG or IgM for anti-cardiolipin.
Libman-Sacks lesions, which are a form of heart valve disease, don’t often cause significant valve dysfunction or embolism. However, there’s evidence that suggests these lesions can increase the risk for stroke in patients with SLE.
In a six-year study, researchers found that NPSLE patients had more Libman-Sacks vegetations – abnormal growths on the valves of the heart, which can cause blockages in blood vessels leading to the brain. These patients showed more strokes/TIAs, brain lesions, and cognitive dysfunction. The abnormal growths were strongly associated with stroke/TIA, cognitive dysfunction, and brain lesions. It was also found that these growths improved with anti-inflammatory and/or antithrombotic therapy. However, patients with these growths also had a higher chance of having cerebrovascular events, cognitive impairment, or death.
According to another study with 76 SLE patients, the presence of LS endocarditis – an inflammation of the inner layer of the heart – was related to a higher risk for embolic cerebral vascular disease, a condition where the blood vessels in the brain become blocked.
Testing for Libman-Sacks Endocarditis
Nonbacterial Thrombotic Endocarditis (NBTE), also known as LS endocarditis, is a condition that’s tricky to diagnose. It’s essential to have a strong suspicion of this illness to track it down because there are no lab tests that can confirm it directly. Diagnosing NBTE relies primarily on excluding other possibilities, such as infectious endocarditis.
Your doctor may order complete blood counts, metabolic panels, and blood cultures if they suspect NBTE. These tests aim to rule out other conditions that might be causing your symptoms. You might also have tests to assess for a hypercoagulable state, a condition in which your blood clots more readily than it should. This set of tests includes lupus anticoagulant and antiphospholipid antibodies tests. These measures are necessary when NBTE is suspected since this condition often features these irregularities.
Before starting potential antibiotic treatments, your medical team will take at least three sets of blood cultures. It can help indicate whether or not another type of endocarditis, the disease caused by bacteria, causes your symptoms. If these cultures do not show any organisms typical for bacterial or other types of endocarditis, it can support the diagnosis of NBTE.
The main tool used to evaluate NBTE is the echocardiogram, which is an ultrasound of the heart. This imaging procedure can detect unusual formations called vegetations in the heart valves or lining. An echo that uses probes or sensors placed down the patient’s throat, known as a transesophageal echocardiogram (TEE), offers more clarity than one that uses sensors placed on the chest, known as a transthoracic echocardiogram (TTE).
In NBTE, the vegetations often appear as small irregular shapes or masses on the heart valves. Generally, they turn up on the aortic and mitral valves, which are located on the left side of the heart. The affected valves may also appear thick and can leak. Other heart complications that could possibly coexist with NBTE include thickening or fluid accumulation around the heart.
Furthermore, since conditions like blood clotting disorders, cancer, and lupus are associated with NBTE, your doctor will also thoroughly investigate these possibilities. These searches include comprehensive medical histories, physical exams, necessary cancer screenings, and lupus-specific blood tests. If any of these conditions are present, it lends further support to the diagnosis of NBTE.
To conclude, patients with suspected NBTE should have a TTE to look for vegetations in the heart valves. While this test can’t distinguish the cause of the vegetations, finding them contributes to potential signs pointing to a diagnosis of NBTE.
Treatment Options for Libman-Sacks Endocarditis
The best way to treat Libman-Sacks endocarditis, a condition that affects the heart’s valves, remains unclear. This is mainly because most guidelines are based on expert opinion and small case studies, rather than larger, randomized trials.
There’s no well-defined treatment for this specific type of endocarditis. This is partly because we do not fully understand what happens if the disease is left untreated. The underlying health conditions that often accompany it, Systemic Lupus Erythematosus (SLE) or Antiphospholipid Syndrome (APS), also need to be managed. If the patient has ever had a blood clot, anticoagulants (medications that prevent blood clots) might be considered to help prevent future clots from forming. Warfarin is a commonly used anticoagulant for people recently diagnosed with APS, who’ve had their first blood clot.
If the heart valves are seriously damaged, heart surgery may be required. This should be decided based on established guides for dealing with heart valve diseases. Patients with this condition must be carefully monitored during treatment to detect any blood clots forming, even while on anti-clotting medication. Regular heart scans (echocardiography) every 3 to 6 months might be advised to track the progress or resolution of the disease.
Surgery might be necessary sometimes to remove clumps of vegetation (a mass of platelets and clotting proteins) or to replace a heart valve. The reasons for conducting surgery for Libman-Sacks endocarditis are similar to those for infectious endocarditis, where an infection affects the heart’s inner lining. Reports indicate that preventing more blood clots from occurring is often the primary reason for surgical intervention. Unlike infectious endocarditis, it may be possible to preserve the existing valve in some cases of this non-infectious form of the disease. Post-surgery, if feasible, there’s often the use of anticoagulants, especially for those with illnesses known to cause blood clots, like Antiphospholipid Syndrome.
Doctors should also manage any underlying conditions (such as lupus or cancer) if they are present. However, for patients with certain types of cancer that have spread throughout the body (metastatic cancers), this approach might not be effective without effective treatment for the cancer itself.
What else can Libman-Sacks Endocarditis be?
Before diagnosing LSE, or Libman-Sacks endocarditis, a condition that occurs when clusters form on the heart valves, doctors need to rule out other conditions that could cause similar issues. These possible conditions include:
- Infective endocarditis, which can be identified through positive or negative cultures
- Rheumatic valvular disease, which affects the heart’s valves
- Atrial myxoma, a tumor in the heart
- Degenerative valvular disease, a condition where the heart valves begin to wear down over time
- Vasculitis, an inflammation of the blood vessels
- Cholesterol emboli syndrome, caused by plaque from the arteries breaking off and blocking blood flow, leading to varying symptoms depending on where the blockage happens
- Fibroelastoma, a benign tumor of the heart
Another condition to look at is Lamb’s excrescences, which are small growths on the heart valves. These usually develop at the places where the heart valves close, mostly on the aortic valve.
The doctor will perform a series of laboratory tests including a complete blood count, a complete metabolic panel, and blood cultures to rule out infective endocarditis. If the patient hasn’t been previously diagnosed, they may also need to be tested for systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) as these conditions are often related to LSE.
What to expect with Libman-Sacks Endocarditis
The long-term outlook or ‘prognosis’ for LS endocarditis, an infection in the lining of the heart, is not certain and needs more research. From the observations made in hospitals, it seems that LS endocarditis has a poor outlook. Patients could potentially experience repeated blood clotting events, cognitive disability, which means problems with the thought processes, and even death.
While formal studies have not yet been conducted, the prognosis of NBTE, a condition where abnormal clot formations develop on heart valves, appears to be quite grim based on clinical experiences and data from past studies. This is because NBTE is often associated with advanced cancer. In a similar case, patients with a disease called systemic lupus erythematosus (SLE), which is a condition where the body’s immune system mistakenly attacks healthy tissues, also show poor outcomes. From a six-year study, one in four patients suffered recurrent strokes or cognitive disabilities, and one in ten patients died.
When the cause is advanced cancer, the long-term outlook for patients with NBTE is usually poor, as this condition is often associated with widespread, incurable cancers.
Lastly, the prognosis of patients with systemic lupus erythematosus possibly depends on the degree of the disease’s activity and the associated kidney and heart dysfunction. This means that the more active the disease is, and the worse the condition of the kidneys and heart, the poorer the prognosis could be.
Preventing Libman-Sacks Endocarditis
If you’re given blood-thinning medication, your doctor will provide you written instructions that touch on possible interactions with other medicines, diet recommendations, and the need for regular check-ups to measure blood coagulation levels. Patients will also be educated on symptoms that could indicate bleeding. In some cases, your doctor might suggest you visit a clinic specialized in managing blood-thinning medication.
Your doctor will also educate you about the need for preventive antibiotic treatment if you get a cut or undergo procedures like dental work.
You can follow your usual diet, but there might be some exceptions. Those with heart failure should steer clear of too much salt. Moreover, if you’re taking drugs to suppress your immune system because of systemic lupus erythematosus – a disease in which your immune system mistakenly attacks your own body’s cells – you should avoid food with listeria bacteria such as soft cheeses.
If you’re pregnant and have a specific type of lupus that produces anti-Ro/SS-A autoantibodies, there is a risk that the baby could develop heart block. Also, patients suffering from antiphospholipid syndrome – a disorder that causes the blood to clot too easily – have an increased risk of miscarriage.
