Bracelet that can detect heart attacks in minutes and increase the chances of recovery

A high-tech bracelet is being developed that can detect a heart attack within minutes, thus increasing the patient’s chances of recovery.

The bracelet, called Tropsensor, can detect elevated levels of a protein called troponin in sweat on the skin. The test currently used in hospitals, which requires a blood sample, can take hours to confirm a result.

Troponin is released by heart muscle cells when they are damaged during a heart attack. It circulates in the bloodstream but can also be absorbed in sweat.

When a patient comes to the hospital suspected of having a heart attack, doctors usually take a blood sample to check for elevated protein levels. They’ll also do an electrocardiogram (ECG) — a measure of the heart’s electrical activity — to look for signs of a disorder that might indicate an attack.

However, it can take several hours for troponin test results to come back from the lab to confirm the diagnosis. During this time, the heart muscle can become further damaged, increasing the likelihood of long-term heart failure — where the organ is so weakened from the trauma that it can’t properly pump blood around the body.

Other common triggers of heart failure – which affects around 900,000 people in the UK – are high blood pressure, damaged heart valves and even viral infections like Covid-19.

There are an estimated 100,000 hospitalizations for heart attacks in the UK each year – one every five minutes on average.

In the 1960s, more than seven out of ten were fatal. Now seven out of 10 people survive, but experts hope to further increase that number with faster treatment. About 1.4 million Britons have survived a heart attack.

The scientists behind the Tropsensor bracelet hope it will help reduce the time it takes to confirm someone has had a heart attack to minutes, meaning doctors can start life-saving treatments much sooner , including giving drugs to break up blood clots or implanting a stent — to restore blood flow to the heart — before more heart muscle cells die.

The drop sensor is currently a matchbox-sized prototype that is attached to the patient with a bracelet. Scientists are now working to compress the technology into a simple bracelet.

The device works by emitting infrared light onto the skin’s surface. Sensors in the device then measure the rate at which the light is absorbed. In the absence of troponin, most of the light is simply reflected back to the device. If troponin is present, the light will be absorbed by it.

The device can also detect how much light is being absorbed – the more that is absorbed, the higher the protein content.

In a recent study of 239 patients in India suspected of having a heart attack, doctors looked at whether high skin troponin levels detected by the device correlated with those eventually found to have a blocked artery and a heart attack diagnosis. The results, presented earlier this month at the American College of Cardiology annual meeting in New Orleans, showed that the Dropsensor device provided a correct diagnosis 90 percent of the time.

When the device measured abnormal troponin levels, patients with a negative troponin result were four times more likely to have an artery blockage.

Researcher Professor Partho Sengupta, a cardiologist at Robert Wood University Hospital in New Brunswick, USA, said: “This is exciting – it improves our ability to detect heart attacks early.

“There’s still work to be done, but this device could reduce the time to treatment – emergency responders could plan how to treat a patient before they even get to the hospital.”

But Francisco Leyva-Leon, a professor of cardiology at Aston University in Birmingham, said he believes the technology is best for reading patients’ troponin levels when they are already in the hospital awaiting diagnosis.

“That would eliminate the need for a blood test, which would be fantastic,” he said.

“But this device needs to be properly validated, and while it looks great, there is still a long way to go before it can be used routinely.”

Researchers have yet to determine how well the device works with different skin tones and wrist sizes, but the current prototype has been approved for use in trials by the US Food and Drug Administration.

Prof Sengupta added: “With this level of accuracy, you can be fairly confident that if a patient tests positive with this device, they can be brought to treatment quickly.”