Sniffing Out Heart Failure
Dogs can potentially smell cancer in people with asymptomatic disease. Now an experimental, noninvasive device that is briefly attached to a person’s arm may be able to “smell” heart failure.
In a small pilot study of 27 adults with decompensated heart failure, 25 with compensated (or moderate) heart failure, and 28 with no chronic heart failure symptoms, measurements taken with this unnamed smell-o-meter differentiated between those with or without heart failure with an 89% sensitivity and an 84% specificity, Dr. Vasileios Kechagias and his associates reported at the annual congress of the European Society of Cardiology in Paris.
The device also detected differences between participants with decompensated or compensated heart failure with an 89% sensitivity and an 88% specificity, said Dr. Kechagias of University Hospital, Jena, Germany.
How does it work, if it does work? The “electronic nose” randomly took 10 cycles of 3-minute measures of gases emitted from participants’ skin, using a gas chromatographer and data analysis to look for patterns.
Or, as Dr. Kechagias put it: The system contains an array of three thick-film, oxide-based gas sensors with heater elements. Each of the sensors has a slightly different sensitivity to various odorant molecular types. Interactions between molecules and the sensor are caused by reactions with oxygen on the heated sensor surface, causing a change of the free charge carrier concentrations and, as a result, a change in conductivity in the metal oxide layer. A statistical analysis then divides odor components into two principal components.
Before this study, Dr. Kechagias and his associates found that the device could detect garlic or onions, perfume or alcohol. My nose can detect those, but heart failure?
“When we want to come up with some new strategies, some crazy people have to come up with some crazy ideas. They sometimes work, they sometimes don’t,” said Dr. Frank Ruschitzka of University Hospital, Zurich, who co-moderated a press briefing that included the study.
Dr. Martin Cowie of Imperial College, London, told me, “It’s just so difficult to know what to make of that. ... People have proposed vague things like sniffing out bladder cancer, but I’ve never seen it for heart failure before. I think it’s a curiosity which will peak cardiologists’ interests, but it’s far too early to say whether that’s going to come to anything or not.” Until more research is done, he thinks of the study simply as, “Quite fun.”
It’s unclear exactly which components detected by the system allow people with heart failure to be differentiated from those without. More work on that is underway.
“Our primary objective is to create a minimally invasive method, which will help to rapidly screen, diagnose, group, and monitor chronic heart failure,” Dr. Kechagias said. If he succeeds, the smell-o-meter may reduce the need for blood tests or echocardiograms in some patients, he suggested.
Dr. Kechagias’ institution has filed a patent on the system.
--Sherry Boschert (@sherryboschert on Twitter)