Lung comets predict cardiovascular events

The ultrasound signs known as lung comets predict cardiovascular events better than other ultrasound predictors in patients with chest pain and shortness of breath.

Lung comets are seen on ultrasound lung exams where several comet tails extend from water-thickened interlobular septa. They indicate an increase in extravascular lung water that often indicates heart problems.

Dr. Francesca Frassi and colleagues at the Consiglio Nazionale delle Ricerche at the Institute of Clinical Physiology in Pisa and the Clinica Cardiologica "Montevergine" in Mercogliano, Italy, published their study in the Journal of Cardiac Failure, which made it available online Dec. 7.

They examined 290 consecutive in-patients with a mean age of 68, all admitted for chest pain and shortness of breath. The exam included both 2D and Doppler echocardiography, including an assessment of lung comets. Each patient was given a score by adding the number of comets from the anterior right and left hemithoraces between the second and fifth intercostal spaces.

The investigators then tracked the patients for a median of 16 months, following up on cardiac events. A total of 62 events occurred, including three nonfatal myocardial infarctions, 20 acute heart failures requiring hospitalization, 19 cardiac deaths, and 20 noncardiac deaths.

They found patients with no ultrasound lung comets had the best chances of an event-free follow-up period, at 70%. Patients with more than 30 lung comets had the worst chances, at 19%. Univariate analysis showed ultrasound lung comets were better at predicting events, with a hazard ratio of 2.349, than other ultrasound predictors, including ejection fraction, with a hazard ratio of .0974, and wall motion score index, with a hazard ratio of 1.628. Lung comets also showed prognostic value for diabetes, with a hazard ratio of 2.05.

The researchers concluded that ultrasound lung comets provide useful prognostic information for the evaluation of patients with chest pain and shortness of breath, with the advantage of being simple, user-friendly, and radiation-free. In addition, the signs can be evaluated at bedside.