Ask The Doctors: April 2018
Q: My mother thought she was having a heart attack and called 911. By the time I got to the hospital, they had released her with medication for heartburn. They told me her troponin levels indicated she was not having a heart attack. Later that night she experienced the same symptoms and went back to the ER. She did, indeed, have a heart attack. We later found out the biotin she takes to make her nails stronger interfered with the blood tests. Have you ever heard of this? I thought biotin was a vitamin!
A: Yes, I have heard of this. Biotin is vitamin B7. There are some interesting data confirming that high levels of vitamin B7 can cause incorrect results from cardiovascular diagnostic tests and hormone tests, among other tests. In some cases, the results can be falsely high, which could lead to unnecessary testing, treatment and worry. In the case of troponin, the test given to diagnose heart attack, high biotin levels can produce falsely low readings, leading medical personnel to believe the patient is not having a heart attack. The FDA has received at least one report of a death from heart attack caused by this false reading. Biotin in itself is not harmful. Ingesting the recommended daily allowance (RDA) of 0.03 mg is unlikely to interfere with test results. But biotin supplements marketed for improving hair, nails and skin can contain doses up to 650 times the RDA.
If you experience the symptoms of heart attack and you are taking biotin, be sure to tell the physicians who see you in the emergency department. They will use a different assay for your blood tests that will provide accurate results.
Q: Is mitral valve prolapse genetic? My father had it, and now I think I might have it, too.
A: Mitral valve (MV) prolapse is not genetic in the way we think of genetic diseases. However, MV prolapse is genetically linked to connective tissue disorders, such as Marfan’s syndrome and Ehlers-Danlos syndrome. If your father had MV prolapse but did not a connective tissue disease, you are unlikely to develop MV prolapse yourself. There is no good genotype test for MV prolapse, so you won't be able to find out if you have a gene for it. If you have a connective tissue disorder, however, we would suggest you have a screening echocardiogram to evaluate the health of your mitral valve.
Q: Last year I had a heart attack. They took me to the cath lab to locate the blockage and stent it, but found my arteries were clean. If I didn’t have a blockage, did I really have a heart attack? I don't understand what happened to me.
A: It sounds like you have a condition known as myocardial ischemia without obstructive coronary disease. This condition is specific to women and raises the risk of having a cardiovascular event (heart attack or stoke), as well as needing revascularization or developing heart failure.
In essence, this condition is characterized by microvessel disease. Although an angiogram taken during cardiac catheterization looks normal, women with microvessel disease have plaque obstructing the smaller vessels in their heart, which cannot be seen on an angiogram taken during a cardiac catheterization.
Microvessel disease is diagnosed with invasive cardiac testing. First, the patient must have a negative catheterization—that is, no significant epicardial disease is seen on angiography. Second, other potential causes, such as a viral infection, must be ruled out. At this point, a coronary flow reserve (CFR) study will be done. (Magnetic resonance imaging is sometimes used instead, but it is not the gold standard). In a CFR study, an agent such as acetlycholine is used to raise the heart rate. The degree to which the heart is able to improve blood flow in response to exercise is measured.
At Cleveland Clinic, we will treat presumed microvessel disease with medications, if another cause is ruled out. Treatment includes aspirin, an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB), statin and calcium-channel blocker. These are standard medications for patients with coronary artery disease. If you have not undergone these tests, or have not been put on this medical regimen, you may want to seek care at a clinic for women with heart disease.