Which chest pain patients potentially benefit from continuous 12-lead ST-segment monitoring with automated serial ECG?

A prospective observational study was performed in 678 chest pain patients with suspected acute coronary ischemic syndrome (ACS) and absence of clinical and ECG criteria for emergent reperfusion therapy on presentation to determine how often continuous 12-lead ST-segment monitoring with automated serial ECG (SECG) results in a significant change in therapy during the initial emergency department (ED) evaluation in typical high- and low-risk chest pain patients. After initial history, physical, and ECG were obtained, patients were grouped into high and low risk subgroups based on ED physician's assessment of likelihood of ACS. Significant change in therapy was defined as thrombolytic drug administration, emergent percutaneous coronary angioplasty (PTCA), and intensive anti-ischemic therapy with intravenous heparin and/or intravenous nitroglycerin. SECG monitoring was continued until either the patient was taken for emergent PTCA or until 2-hour serum markers measurements were obtained. A total of 26 patients therapy was changed secondary to SECG monitoring which represented 14.6% of high-risk patients and 1.1% of low-risk patients. New injury (21 patients) and new ischemia (4 patients) were the only SECG findings that led to a change in therapy. SECG monitoring had a 15.2 times increased odds of changing therapy in the high risk patients as compared with the low risk patients (P < .0001; 95% CI 6.1 to 38.2). Chest pain evaluation protocols that exclude these high risk ED patients from SECG monitoring should be reevaluated. Our data also suggests that researchers designing randomized studies to show utility of SECG monitoring should focus on the high-risk patients.