Stress echo in chest pain unit: the SPEED trial

Background Emergency room (ER) evaluation of patients with acute chest pain and non-diagnostic electrocardiography (ECG) remains a frequent and difficult problem. Aim To assess safety and prognostic implications of pharmacological stress echocardiography in the ER chest pain unit (CPU). Methods A total of 552 patients (321 males, age 58±12.6 years) with acute chest pain, negative serial enzymes and/or troponin, and ECG recordings, and normal/unchanged resting left ventricular function were prospectively enrolled and underwent pharmacological (dipyridamole or dobutamine) stress echo. Six echo labs that had passed the preliminary quality control for stress echo reading entered the study. Follow-up was obtained in all patients after a median period of 13 months. Results No significant adverse events were observed during the test. Stress echocardiography was negative in 502 patients (91%) and positive in 50 (9%). The 502 patients with negative stress echocardiography were discharged with no or unchanged anti-ischemic medications. While the 50 patients with positive stress echo were admitted to the coronary care unit, 44 of these underwent coronary angiography with the result that 42 out of 44 showed significant coronary artery disease. There were 45 events in the follow-up: six in the 502 patients with negative and 39 in the 50 patients with positive stress echo (1.2% vs. 78%, p<0.001). The negative predictive value of stress echocardiography was 98.8% for all events and 99.6% for hard events. Conclusions Stress echocardiography is a feasible, safe, and effective tool for early stratification of patients admitted to the ER with acute chest pain and non-ischemic ECG and resting echo.