The Observatory

Dec. 21, 2017
Fast Facts: Heart Disease

The #1 cause of death
in the U.S. is heart disease (which includes coronary heart disease, hypertension, and stroke).

1 in 7
U.S. deaths are from coronary heart disease.

people a year are killed by coronary heart disease.

people a year have heart attacks.

people a year die of a heart attack.

is the annual incidence of first-time heart attacks in the U.S.

is the annual incidence of recurrent heart attacks in the U.S.

65.3 years
is the average age of first heart attack for males.

71.8 years
is the average age of first heart attack for females.

Every 40 seconds
an American has a heart attack.

100 percent
is the projected increase in medical costs of heart disease between
2013 and 2030.



Biotin (vitamin B7) may interfere with lab tests. The FDA is alerting the public, healthcare providers, lab personnel, and lab test developers that biotin can significantly interfere with certain lab tests and cause incorrect test results which may go undetected.

Biotin in blood or other samples taken from patients who are ingesting high levels of biotin in dietary supplements can cause clinically significant incorrect lab test results. The FDA has seen an increase in the number of reported adverse events, including one death, related to biotin interference with lab tests.

Biotin in patient samples can cause falsely high or falsely low results, depending on the test. For example, a falsely low result for troponin, a clinically important biomarker to aid in the diagnosis of heart attacks, may lead to a missed diagnosis and potentially serious clinical implications. The FDA has received a report that one patient taking high levels of biotin died following falsely low troponin test results when a troponin test known to have biotin interference was used.

The FDA is aware of people taking high levels of biotin that would interfere with lab tests. Many dietary supplements promoted for hair, skin, and nails contain biotin levels up to 650 times the recommended daily intake of biotin. Physicians may also be recommending high levels of biotin for patients with certain conditions such as multiple sclerosis (MS).

Patients and physicians may be unaware of biotin interference in laboratory assays. Even physicians who are aware of this interference are likely unaware of whether patients are taking biotin, and how much. Since patients are unaware of biotin interference, patients may not report taking biotin supplements to their physicians, and may even be unaware they are taking biotin.

The FDA is working with stakeholders to better understand biotin interference with laboratory tests, and to develop additional future recommendations for safe testing in patients who have taken high levels of biotin when using lab tests that use biotin technology. The FDA is monitoring reports of adverse events associated with biotin interference with lab tests and will update the public if new information becomes available.

The FDA’s recommendations and information for lab personnel includes:

  • If you use assays with biotin technology, be aware that it is difficult to identify samples that contain biotin; therefore, it is important to communicate with healthcare providers and patients to prevent incorrect test results.
  • If you are collecting samples in the lab, ask whether the patient is taking biotin.
  • Educate healthcare providers about biotin interference with certain tests used in your lab.
  • Consider that the recommended daily allowance (RDA) for biotin is 0.03 mg and that this biotin level does not typically cause significant interference. However, supplements containing high biotin levels, including those marketed for hair, skin, and nails, may contain up to 20 mg of biotin, and physicians may recommend up to 300 mg per day for conditions such as MS. Biotin levels higher than the RDA may cause significant interference with affected lab tests.
  • Specimens collected from patients taking high levels of biotin may contain more than 100 ng/mL biotin. Concentrations of biotin up to 1200 ng/mL may be present in specimens collected from patients taking up to 300 mg per day.
  • Currently available data is insufficient to support recommendations for safe testing using affected tests in patients taking high levels of biotin, including about the length of time for biotin clearance from the blood.
  • Communicate with the lab test manufacturer if you have questions about biotin interference.

Transfusion Medicine

Prehospital blood transfusion among combat casualties associated with improved survival. Among medically evacuated U.S. military combat causalities in Afghanistan, blood product transfusion within minutes of injury or prior to hospitalization was associated with greater 24-hour and 30-day survival than delayed or no transfusion, according to a study published in JAMA.

Hemorrhage is a leading cause of preventable death in both military and civilian trauma care. It is intuitive that early transfusion for hemorrhagic shock should improve survival, but published data on prehospital transfusion to date has not demonstrated a
survival advantage.

Stacy A. Shackelford, MD, of Ft. Sam Houston, San Antonio, and colleagues examined the association of prehospital transfusion and time to initial transfusion with injury survival. The study included U.S. military combat casualties in Afghanistan between April 2012 and August 2015. Eligible patients were rescued by medical evacuation (MEDEVAC) from point of injury with either a traumatic limb amputation at or above the knee or elbow or shock, defined as a systolic blood pressure of less than 90 mm Hg or a heart rate of greater than 120 beats per minute.

For the 386 patients without missing data among the 400 patients within the matched groups, prehospital transfusion was associated with a 74 percent lower risk of death over 24 hours, and a 61 percent lower risk of death over 30 days. Time to initial transfusion, regardless of location (prehospital or during hospitalization), was associated with reduced 24-hour mortality only up to 15 minutes after MEDEVAC rescue (median, 36 minutes after injury).


New asthma biomarkers identified from lung bacteria. While the microbiome has gained significant attention for its impact on digestive health in recent years, its effect on lung disease has largely remained unstudied.

Dr. Patricia Finn says this is a missed opportunity. “The microbiome is the ecosystem of good and bad bacteria living in the body,” says Finn, a professor of medicine at the University of Illinois at Chicago. “Because the lungs continuously and automatically draw air, and any number of environmental agents, into the body, the composition and balance of microbes in the lungs may have a profound effect on many respiratory conditions.” Research from Finn and colleagues suggests the lung microbiome plays a significant role in asthma severity and response to treatment.

In a group of clinically similar patients with asthma, researchers identified two asthma phenotypes by assessing the microbiome and airway inflammation. The patients were ages 18 to 30 with mild or moderate atopic asthma.

These two phenotypes, called asthma phenotype one and two, or AP1 and AP2, are demarcated by the prevalence and dominance of different bacteria in the lung. When compared, patients in the two groups performed differently on pulmonary function tests.

AP1 was associated with less severe asthma; it showed decreased T helper cytokines and increased enterococcus bacteria, but normal pulmonary function tests. AP2 was associated with increased pro-inflammatory cytokines, increased oral taxa and strep pneumonia bacteria, and decreased pulmonary function tests, or more severe asthma.

In both AP1 and AP2, the associations between the composition of the microbiome and specific inflammatory cytokines were decreased after treatment with an inhaled corticosteroid (ICS), a common asthma therapy. Researchers say this suggests that ICS may function by dampening responses to microbes.

Finn says that asthma research has increasingly focused on the differences among seemingly similar patients, and that this study adds to the growing body of evidence that patients benefit from precision medicine approaches to common chronic diseases such as asthma.


Frequency of HIV testing and time from infection to diagnosis improve. A new CDC Vital Signs report found that HIV is being diagnosed sooner after infection than was previously reported. According to the report, the estimated median time from HIV infection to diagnosis was three years in 2015. The CDC previously estimated that, in 2011, the median time from HIV infection to diagnosis was three years and seven months.

The seven-month improvement is a considerable decrease over a four-year period, and it reinforces other recent signs that the nation’s approach to HIV prevention is paying off. Overall, 85 percent of the estimated 1.1 million people living with HIV in 2014 knew their HIV status. The CDC estimates that about 40 percent of new HIV infections originate from people who don’t know they have HIV.

The Vital Signs analysis found that the percentage of people at increased risk for HIV who reported getting an HIV test the previous year has increased. Despite that progress, too few are tested. A multicity study found that people who reported that they did not get an HIV test in the last year included 29 percent of gay and bisexual men, 42 percent of people who inject drugs, and 59 percent of heterosexuals at increased risk for HIV. The same study also found that seven in 10 people at high risk who were not tested for HIV in the past year saw a healthcare provider during that time—signaling a missed opportunity to get high-risk individuals tested as frequently as needed.

In 2015, estimated time from HIV infection to diagnosis varied by risk group and by race/ethnicity. Estimated time from HIV infection to diagnosis ranged from a median of five years for heterosexual males to two-and-a-half years for heterosexual females and females who inject drugs. The median was three years for gay and bisexual males. Estimated time from HIV infection to diagnosis ranged from a median of four years for Asian Americans to two years for white Americans and about three years for African Americans and Latinos.


Questioning the value of routine laboratory screenings for children entering foster care. Routine laboratory screening recommended for children entering foster care carries high costs and questionable medical benefits. A new study, published online in Pediatrics, suggests that targeted screening may be a more clinically meaningful approach and reduce costs.

The researchers studied data between 2012 and 2015 from the medical records of nearly 2,000 children and young adults less than 21 years old. These individuals were in the legal custody of Jobs and Family Services, the child protective agency of Hamilton County, Ohio, and seen at the Cincinnati Children’s foster care clinic. The clinic evaluates children in the region when they enter foster care and at every change in placement.

Clinic visits include a medical record review, physical examination, and laboratory screening to test for hepatitis B and C, syphilis, tuberculosis and HIV. Clinicians obtain hemoglobin concentrations for all children and measure lead levels in children six months to six years. They screen those 12 and older who were sexually active for gonorrhea and chlamydia.

Nearly five percent of those screened were identified to have anemia, 2.9 percent infectious disease, and 2.6 percent had elevated lead levels. Seven percent of teens tested positive for chlamydia. The prevalence for hepatitis B and C, syphilis, and tuberculosis was less than one percent. There were no cases of HIV.

Researchers identified costs for each screening test using published Medicaid reimbursement rates. They found, for example, that the cost of screening for chlamydia in the population they studied was less than the cost of failing to diagnose and treat infection. The cost of treating active cases of tuberculosis, on the other hand, would be less than the cost of routine screening for the whole population. They suggested that more targeted screening for tuberculosis may be appropriate.

Study findings suggest that routine screening for anemia, lead (in children six months to six years old), and chlamydia and gonorrhea (in sexually active adolescents) in this community is useful and cost-effective. More targeted screening may be appropriate for hepatitis B and C, tuberculosis, HIV, and syphilis.