Scientists have developed a wrist-worn device that could revolutionize the treatment of heart attacks by speeding up diagnosis — without the need to draw blood — one of the current methods.
More than 700,000 people visit emergency hospitals in England and Wales for chest pain. They represent 25% of hospital admissions.
These patients often have varying symptoms, related complex health issues, and are often on multiple medications. Analyzing them is a difficult task.
This usually includes reviewing the medical history, having a cardiac trace of the heart’s electrical activity (the electrocardiogram), and having a chest X-ray.
The electrocardiogram, or ECG, can show changes in heart rhythm associated with a heart attack in about 50% of patients.
The rest do not have an altered rhythm and need further investigations, which include important blood tests.
One of the tests is for a protein found in heart cells called troponin. This protein plays a key role in causing heart muscle cells to contract and relax.
When cells run out of oxygen due to a blockage in the arteries that supply blood to the heart, cells begin to die and release troponin into the blood.
Troponin can be measured in a hospital laboratory from a sample taken from a patient—usually from a vein in the crook of the elbow or a catheter in the back of the hand.
This test is repeated two to three hours after the patient is admitted to the hospital.
A change in the amount of troponin in the blood can indicate a heart attack. This is especially useful for patients who do not have ECG changes.
Patients diagnosed with a heart attack need urgent treatment, usually surgery, where a catheter is inserted into the blocked artery in the heart and a balloon is inflated to open the blockage. This procedure is called angioplasty.
In many cases, a device called a stent is inserted along with the balloon. When the balloon is deflated, the stent stays in place to keep the artery open.
But this troponin blood test requires someone to draw blood. It’s common for people to be afraid of needles — needle phobia affects between 4% and 10% of the population. Anxiety and stress can make chest pain worse.
No blood test required
The new wrist-worn device can measure troponin without taking a blood sample.
This device is worn on the wrist like a smartwatch. It uses infrared light through the layers of the skin (transdermally) to detect troponin in the bloodstream.
A recent study, published in the European Heart Journal – Digital Health, showed that this device can detect 90% of heart attacks within five minutes.
“With this level of accuracy, if you use this device and the result is positive, you are almost certain that this patient can be admitted for rapid diagnostic testing, treatment and intervention,” says lead study author Partho P. Sengupta.
If larger studies confirm these initial findings, this revolutionary troponin detection device could be useful for detecting heart attacks in outpatient clinics or emergency departments caring for patients with chest pain.
It also means that patients would not have to wait for blood samples to be sent to the laboratory, analyzed and returned to the hospital.
It is important for patients to have a fully functioning blood supply to the heart as soon as possible to prevent more heart cells from dying. As the saying goes in cardiology: time is muscle.
This new wrist-worn device could speed up the diagnosis and treatment of patients with chest pain.
The technology could also be used for other tests to detect blood clots, ectopic pregnancy or sepsis. And it can be the salvation for those who have a severe needle phobia.
* David C Gaze is Professor of Chemical Pathology at the University of Westminster.
By David C. Gaze