Chest pain is a known symptom of blocked cardiac arteries, and urgent medical care is essential to improve health outcomes. However, patients often fail to seek help because they are hesitant to bother others and do not believe their symptoms are serious. A team of physicians led by Dr. Peter Gheeraert at Ghent University has developed an easy, reliable, handheld diagnostic device that can help patients determine the severity of their condition when they experience chest pain and discomfort. Such a self-administered test can remove doubt and shame and, ultimately, save lives as patients seek treatment when they need it.
In need of a better method
Patients with chest pains are examined using a conventional 12-lead electrocardiogram (ECG), during which 10 electrodes on the patient’s limbs and chest measure the magnitude of the heart’s electrical potential from 12 different angles over a period of time. This test must be performed and interpreted by trained medical personnel in a hospital, creating a significant threshold for patients who experience discomfort as they do not want to go to the hospital without just cause. Furthermore, the diagnostic accuracy of the 12-lead ECG is not great, and additional measurements or a reference ECG from the same patient are required for an adequate diagnosis.
Dr. Gheeraert and his team have developed an easier, more reliable method for detecting transmural ischemia in patients with blocked coronary arteries. Their RELF technique reduces the number of leads to three. It compares the right shoulder (R) to an exploratory electrode (E), the left shoulder (L), and the left iliac crest (F). Dr. Gheeraert and his team have also developed an algorithm to process these signals and increase their sensitivity and specificity.
Promising proof of concept
Due to the inclusion of a new lead that is not part of the 12-lead ECG, and the algorithm that processes the data, the RELF method clearly outperforms the traditional method. In the original publication, the RELF method was much more sensitive (95% vs 65%) and more specific (94% vs 85%) than a 12-lead ECG. Furthermore, the new method identified the occluded region of the vessel correctly in 26 of 27 cases. The measurements not only vastly improve the accuracy, but they are also much easier to perform.
In addition, the researchers have developed a Mini RELF device. It is a small, autonomic tool capable of capturing three-lead ECG signals and uploading them in real time via Bluetooth to a laptop, tablet, or smartphone. Such a device could be operated by patients after minimal training.
Combining these results with a questionnaire for life-threatening symptoms may allow the classification of patients into three levels of medical urgency: red, orange, or green. Patients who receive a red light should seek treatment immediately, patients in the orange category should follow up with repeated measurements and seek help within 2 hours, and patients with a green light should seek help within 12 hours.
Clinical validation is underway
The Mini RELF device is undergoing multi-center clinical validations, which are scheduled to end in 2018. This year, Ghent University led two phase II trials. The RELF IIa trial evaluated the accuracy of the device relative to the 12-lead ECG when the device was self-applied on a daily basis by patients with coronary artery disease. In the parallel RELF IIb study, investigators evaluated the specificity of the RELF method when self-applied by healthy subjects who represented future users of the device.
When the clinical validation is concluded successfully, the device can be implemented in medical practice. However, the design will be further refined. A single lead design that performs sequential measurements would be even easier to operate. Once this is achieved, one can envision doing the same with a smartphone instead of a dedicated device, making the RELF method available to anyone, which will save even more lives.
