Heart Failure: Is There a Breath Test?

By Kathleen Struck, Senior Editor, MedPage Today

Published: March 25, 2013

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Action Points

• This was a prospective, single-center cohort study to assess the feasibility of exhaled breath analysis to identify patients admitted for acute decompensated heart failure.
• Investigators were able to identify five ion peaks that were incorporated into a canonical discriminant analysis model that successfully distinguished patients with acute decompensated heart failure from control patients.

Analyzing a single puff of exhaled air, or "breathprint," aids in speedy diagnosis of heart failure, according to research from Cleveland Clinic.

In a prospective study that tested the technique in 25 consecutive patients versus 16 controls, ion-flow tube mass-spectrometry (SIFT-MS) detected significantly higher levels of acetone in the exhaled breath of patients (811 parts per billion [ppb] versus 187 P=0.01), wrote Raed Dweik, MD, of Cleveland Clinic, and colleagues in a research letter published online in the Journal of the American College of Cardiology.
Likewise, there was significant difference in the median amount of detected pentane (40 ppb versus 22 ppb, P=0.03).

"Our findings demonstrate the feasibility of single exhaled-breath analysis in acute decompensated heart failure, and provided pilot evidence to support SIFT-MS technology," the authors wrote. "Exhaled breath constitutes a complex mixture of hundreds of volatile organic compounds (VOCs) that could potentially be used as a safe and noninvasive method of diagnostic and therapeutic monitoring."

While there were significant differences in baseline hypertension (54% versus 100%), and baseline estimated glomerular filtration rate was significantly worse in heart failure patients versus controls, there were no significant differences in age, body mass index, or comorbidities such as diabetes, chronic obstructive pulmonary disease, and active smoking that could compromise the exhaled metabolome, the authors said.
The patients tried to exert 15 millibars of exhaled pressure into a mouthpiece. The authors said all patients tolerated the "breathprint," even those in intensive care or being monitored invasively. All samples were analyzed within 2 hours of collection.

While heart failure is the most common hospital admission and readmission in the elderly, identifying decompensation by conventional techniques remains unreliable and time-consuming, the authors wrote.

"I think the exciting thing here is the fact that this is a breath test," said Dweik in an interview with MedpageToday. "I call it the new frontier of medical testing, and I think it's really the future of medicine where you can do something very easy and very simple and convenient for the patient and get a lot of information out of it.

"Our breath has lots of information that we are just beginning to scratch the surface of the benefit of understanding what is there and analyzing it. So I think this is very exciting that patients with heart failure can benefit from that."

The study compared 25 heart failure patients (mean left ventricular ejection fraction 27% +/-13%) with 16 control subjects with no heart failure. Hospitalization was warranted in the control group for unstable angina or non-ST-segment elevation myocardial infarction conduction disorders, hypertension, atrial tachyarrhythmia, or stable angina, the authors said.

The pilot study was limited by its size, the authors said, and they called for larger, prospective studies. They also said sample collection "is highly susceptible to the confounding effects of timing and context," and metabolomic data analysis will need to be more refined.

"Once a specific VOC or panel of VOCs is identified, highly sensitive and specific solid-state sensors can be integrated into portable devices," the authors said. "The promise of this technology lies in the potential for point-of-care and ambulatory monitoring and screening."