Revolutionary Breakthrough: A Simple Saliva Test Could Detect Heart Failure

Medicine relentlessly seeks to diagnose diseases before they take hold. Heart failure, often silent at first, still too often escapes the clinical radar. What if a few drops of saliva were enough to change things? This is what seems to indicate a series of studies which rely on a trio of proteins to spot the early signs of a weakening heart.

A weakened heart that is often noticed too late

Despite its alarming name, heart failure does not mean a stopping of the heart, but a gradual loss of its ability to pump blood effectively. The heart muscle becomes unable to oxygenate the tissues properly, causing fatigue, shortness of breath or edema. However, these symptoms can take years to appear, because the body compensates for the first failures for a long time.

In France, this pathology affects more than a million people and remains a major cause of hospitalization after the age of 65. The problem is not so much the lack of treatment (medications and lifestyle changes can stabilize the disease) as the delay in diagnosis. According to the American Heart Association, the majority of cases are detected at an advanced stage, when the body's compensation mechanisms are overwhelmed and the patient becomes out of breath with the slightest effort.

The available tests, based on blood analysis or cardiac imaging, remain cumbersome and poorly suited to mass screening. It is precisely to fill this void that Australian researchers have explored a hitherto neglected avenue: saliva.

From saliva to biomarkers, the detection of heart failure is changing scale

The idea seems obvious at first glance. Rather than blood, why not analyze saliva? It is collected painlessly, without risk, and remains much simpler to collect. In addition, it contains approximately a third of the biomolecules found in plasma. The real challenge, however, was to identify the right indicators. We had to find those that could reliably detect heart failure.

A team from the Queensland University of Technology, led by researcher Chamindie Punyadeera, developed a panel of three salivary proteins: KLK1, S100A7 and CAMP. In a study published in the journal Biomolecules, they analyzed samples from 100 patients with systolic heart failure and 88 healthy individuals. As a result, the levels of S100A7 and KLK1 were significantly higher in the patients.

Using a classic immunological test (ELISA), the combined panel made it possible to distinguish sick people from healthy people with an overall accuracy of 81.6%. This performance increases to 89% when an algorithm machine learning also includes age and gender. A rate higher than that of standard laboratory tests on blood, according to the first results published in ScienceAlert.

The S100A7 protein, in particular, attracts attention. Already involved in certain inflammatory diseases, it is strongly linked to the exacerbated immune responses observed in systolic forms of heart failure. It is also the subject of a second article published in Biosensors and Bioelectronics:

Towards portable tools that spot disease before symptoms

The challenge now is to transform these laboratory discoveries into devices accessible to all. A saliva test could be used routinely, in general practices or even at home. This rapid screening method would facilitate the monitoring of populations at risk. Particularly in rural areas, where access to specialized care remains limited.

Another advantage is repeatability. It becomes possible to follow the progress of a patient with a series of samples without venipuncture, which opens the way to continuous monitoring. By integrating this data into automated analysis systems, professionals could detect weak signals well before the first visible symptoms.

Of course, these avenues must still pass the test of large-scale clinical validations. But the accessibility, speed and precision of the saliva panel make it a serious candidate for early detection. While heart failure remains a chronic pathology with no definitive cure, it is better to act before the heart tires silently.