By Steven Reinberg
NEW YORK (Reuters Health) – For patients who present at the emergency department (ED) with dyspnea, measuring B-type natriuretic peptide (BNP) levels predicts the likelihood of cardiac events over the next 6 months, researchers report in the February issue of the Annals of Emergency Medicine.
"Not only are BNP levels diagnostically important for patients presenting at the ED with dyspnea, but they are also prognostically important," Dr. Alan S. Maisel from the Veterans Affairs Medical Center, La Jolla, California, told Reuters Health.
He and his colleagues previously showed the BNP can differentiate congestive heart failure from other causes of dyspnea (see Reuters Health report, "BNP testing can help in differential diagnosis of acute dyspnea," January 17, 2002.). Now they have shown that "patients who have very high BNP levels have markedly worse 6-month CHF outcomes compared with patients with low BNP levels, irrespective of the ED diagnosis," Dr. Maisel said.
The researchers measured BNP levels in 325 patients who presented to the ED with dyspnea. They found that for patients whose BNP levels were greater than 480 pg/mL there was a 51% probability that they would have a CHF event within 6 months, while patients whose BNP was below 230 pg/mL had only a 2.5% probability.
For BNP values of 480 pg/mL the sensitivity was 68% the specificity was 88% and the accuracy was 85% in predicting a CHF event, the investigators note.
"We now have a marker for CHF, so all patients with dyspnea should have their BNP measured," Dr. Maisel said. "This is a positive finding for ED doctors, because measuring BNP can really help to triage the sickest patients."