Cardiac diagnostics – prompt and personalized

If physicians suspect an acute myocardial infarction, they first order an ECG. This test is very established and allows cardiologists to quickly diagnose acute heart attacks – though the test does not detect less common heart attack symptoms. So far, those patients had to wait up to twelve hours before a heart attack could be accurately diagnosed or ruled out. But things are about the change.

In this MEDICA-tradefair.com interview, Dr. Johannes Neumann talks about the black and white thinking when it comes to the diagnosis of heart attacks, explains how a new approach can enable a faster, personalized risk assessment and reveals what the Australian outback has to do with it.

Dr. Neumann, why is it so difficult to diagnose a heart attack?

Dr. Johannes Neumann: Things get difficult when the ECG results in a suspected heart attack are unclear, because an infarction might still have occurred. Biomarkers – primarily troponin- help us in this case. Troponin is a complex of proteins, which is predominantly found in the heart and released into the blood during a heart attack or when there is damage to the heart muscle. The level of cardiac-specific troponin in the blood can be measured. Guidelines provide recommendations on how and when to measure this biomarker. Generally, it should be measured as soon as the patient has been admitted to the hospital. The test should be repeated after three to six hours to reevaluate. This allows us to determine whether there is a dynamic change and specifically an increase in troponin levels. The problem is that the guidelines state very clear set values to determine whether this is a heart attack or not. However, this splitting – this black and white thinking – makes things difficult in practical application because some countries and even individual hospitals have different needs and circumstances.

How so?

Neumann: Let me explain this with an example: If a patient lives in the Australian Outback and is taken to the hospital, you want to be certain that there is absolutely no residual risk before he/she is being released again. That's because medical care options in this remote area are very limited. The situation is very different in a big city, where patients have better access to high-quality health care and physicians. In this setting, it's perfectly reasonable to send a patient who didn't have an acute heart attack but is at an increased risk home and release him or her into the care of a cardiologist's office the next day. These are two contrary situations that show the importance of assessments that take personal risk factors into consideration. This was ultimately the decisive factor for our study.

You developed a way to create a personalized algorithm. How did you do that?

Neumann: That was the point of our study. We collected data from patients all over the world. The level of the biomarker troponin was measured at two different times in 22,000 patients who came to an emergency room with suspicion of a heart attack. We studied the concentration of biomarkers in the blood, assessed the changes, and ultimately developed a tool that allowed us to develop an algorithm that's specific to individual hospitals. Emergency room physicians can then choose which algorithm they prefer to use to diagnose or rule out a heart attack.

In what way is the algorithm personalized or customizable?

Neumann: It is important to point out that the algorithm is not personalized for each patient, but customizable for a hospital. Every hospital or department can choose the level of accuracy.

What does this ultimately mean for the physician and the patient?

Neumann:  It affords physicians a better way to meet the individual needs of patients. The physician is able to make a better assessment of the risk of an acute heart attack in individual patients. What's more, it also allows doctors to partially predict future heart attacks. Colleague feedback has been very positive so far. The algorithm simply allows them to be more flexible in their response.

Patients benefit from a more accurate knowledge of whether or not they have suffered a heart attack. Another advantage is that the algorithm can be used earlier for the second measurement, foregoing the previously recommended three-hour interval. We already get accurate results after one hour. Needless to say, that's a big time advantage for the patient.

What is the development potential for this approach? What future developments do you envision?

Neumann: Basically, the next step would be to develop a fully personalized algorithm that incorporates other risk factors for a heart attack. The big potential here is that an assessment of risk can then be made for each individual patient.

These types of tests will rapidly improve in the future. We will develop high-sensitivity tests that yield better and faster results. Within the next years, we will certainly also see tests that don't have to be performed at large laboratories, but are available as point-of-care tests. They will significantly expand the scope of application and will be used outside of the emergency room – at a doctor's office, for example, where a cardiologist or general practitioner will be able to make an on-site diagnosis and determine whether or not the patient has a severe heart attack.