First Heart Patients Diagnosed Using Ultrathin Fiber Optic Sensor

Medical personnel have used a fiber optics sensors-based diagnostic technology to detect the causes of heart disease for the first time in patients. The device, developed by University College London (UCL), is called iKOr. It uses an ultrathin microcatheter integrated with fiber optic sensors to enable doctors to check both blood pressure and blood flow around the heart and look for signs of narrowing and thickening of the arteries — common signs of disease.

The iKOr device has a temperature and pressure sensor that is just 0.2 mm wide — or twice the thickness of a human hair — which is threaded through the patient’s blood vessels on an ultrathin catheter. It measures flow rate around the heart by flashing a short pulse of light upstream of the vessels under investigation, which warms the blood there by about one degree. The sensor detects the time taken for the temperature to change downstream, from which the sensor can tell whether the flow is obstructed by narrowing of the blood vessels.

The technology was developed with assistance from collaborators at Queen Mary University of London and has since been commercialized through UCL spinout company Echopoint. The technology is being trialed at Barts Health NHS Trust.

As of late February, three patients had undergone a test for heart disease using the iKOr device.

Lead iKOr developer Adrien Desjardins, a professor in UCL’s Medical Physics and Biomedical Engineering Department and a co-investigator at the Wellcome-EPSRC Centre for Interventional and Surgical Sciences, said that the iKOr device is responding to a clinical need — to significantly improve how blood flow in the heart is measured.

The slimline probe is particularly suited for detecting narrowing of the microvasculature. These tiny blood vessels don’t show up well in traditional x-rays (angiograms), which are typically used by cardiologists to image the heart’s larger arteries. The device provides simultaneous pressure and flow measurements, taken from inside the coronary arteries, a feature unique to the device that makes the tiny blood vessels more measurable as compared to traditional x-ray imaging, Desjardins said.

“This will help to significantly improve diagnosis and treatment for a large group of patients, those with obstructive coronary artery disease and coronary microvascular dysfunction,” Desjardins said. “An increasing body of evidence shows the importance of accurate assessments of the coronary microvasculature in targeting therapies, which has particular relevance to women and diabetic patients who are more likely to have microvascular dysfunction.”

Having access to more accurate information on the health of a person’s heart will allow doctors to better decide what course of treatment to prescribe: medication, surgery or no surgery, or cessation of medication.

“In current clinical practice there is a potential for overdiagnosis, resulting in invasive surgeries, such as stent insertion, that comes with risk and can take time to recover from,” Desjardins said. “Being able to more accurately diagnose heart disease, particularly microvascular disease, will mean more patients can be treated with specific tailored drugs that would not be prescribed without a diagnosis.”

Before iKOr can be widely used by doctors, researchers need to assess whether the device works safely and easily in patients. The first patient tests, carried out at St. Bartholomew’s Hospital, London, confirm all these qualities: It is safe for patients, it is easy to use, and it works.

The current clinical trial is designed as a proof-of-principle study and will see 10 patients diagnosed using iKOr. This will be followed by a larger clinical trial to further show the device’s safety, efficacy, and advantages over existing tests.