NEW YORK (Reuters Health) – In patients with chest pain of uncertain origin, emergency department evaluation combining clinical history and N-terminal pro-B-type natriuretic peptide (NT-proBNP) level, without exercise testing, safely reduces hospitalizations compared with a conventional strategy.
That’s according to randomized trial results reported by Spanish researchers in the American Heart Journal for February.
The practice of using exercise testing to determine whether chest pain patients should be admitted is often limited by restricted availability and patients’ inability to exercise, said lead author Dr. Juan Sanchis, at the University of Valencia, and his associates.
“In this setting, a simpler alternative tool to exercise testing seems to be justified,” they suggest. Clinical history alone cannot predict short-term events — but NT-proBNP has been shown to provide additional prognostic information.
The research team compared two different strategies among 320 patients (160 in each study arm). Each patient had chest pain of possible coronary origin but with a nonischemic electrocardiogram and normal troponin levels.
The new strategy used a risk score accounting for pain, number of pain episodes in the previous 24 hours, age, insulin-treated diabetes, and prior percutaneous coronary intervention. Patients with a low clinical risk score and NT-proBNP < 110 ng/L (in a blood sample drawn 8 to 12 hours after pain onset) were directly discharged; otherwise they were admitted to the hospital.
In the usual care group, the decision to hospitalize was guided by the exercise test; patients with a contraindication to exercise were also hospitalized.
On the day of the index episode, the hospitalization rate was 56% with the new strategy and 69% with usual care (odds ratio 0.6, p = 0.03).
Usual care was also associated with more frequent revascularization at the index episode (18% vs 8%, p = 0.01), although the NT-proBNP-based strategy was associated with higher rates of planned postdischarge revascularizations (0.6% vs 5%, p = 0.04).
There were no significant differences between the usual care and new strategy groups, respectively, in rates of death (0.6% vs 1.3%), acute MI (6.9% vs 3.1%), or readmission for unstable angina (3.1% vs 3.8%) during 1-year follow-up.
Dr. Sanchis and his associates advise that “studies sized for clinical end points are needed to confirm the promising results of the present pilot study.”
Until then, they do not recommend the new strategy for routine clinical use.
Am Heart J 2010;159:176-182.