The Usefulness of a Predictive Instrument to Reduce Inappropriate Admissions to the Coronary Care Unit

Abstract

A mathematical instrument was developed to supplement the diagnostic information available to physicians in the emergency room to improve physicians' diagnostic accuracy in managing patients with acute ischemic heart disease and thereby reduce inappropriate coronary care unit admissions. The instrument was empirically derived and is based on nine clinical, historical, and electrocardiographic predictive variables. Probabilities of acute ischemic heart disease generated by the instrument were given to the house staff in an emergency room during alternate months. Comparison of the control months (455 patients) with the experimental months (401 patients) showed the following: The overall diagnostic accuracy increased from 83% to 91% (P less than 0.005), the overdiagnostic accuracy increased from 51% to 33% (P less than 0.01), and the admission rate to the coronary care unit fell from 26% to 14% (P less than 0.001), while the inappropriate discharge rate from the emergency room did not change, 3% versus 3% (not significant).

Chest pain in the emergency room. Importance of a systematic approach

“…Because the majority of these patients (60-80%) not have acute myocardial infarction or unstable angina 1,4,5,6,15 and the cost to eliminate these diagnoses is very high, a change in this policy has been recommended by various authors and several medical institutions in the last few years 1,[16][17][18] .…”

“…In the same way, algorithms or clinical decision trees and probability evaluations of the disease have been created by several authors to help in this task, besides identifying those who need to or need not to be transferred to a coronary unit or to undergo expensive examinations 5,6,17,[22][23][24][25] . Consequently, this has resulted in the evaluation and treatment of many coronary patients changed from being in the coronary units to intermediate units or to the emergency rooms.…”

“…The systematic diagnostic investigation model was obtained through a consensus of a group of researchers after extensive revision and discussion of same models already proposed in the medical literature 5,6,10,13 . When creating this model, not only the functional characteristics of our institution were taken into consideration, but also the necessity for a diagnosis as accurate as possible, and time cost efficiency.…”

“…This is explained by the greater mortality risk and the need for hospitalization. However, only 10-15% of the patients who go to the emergency room with chest pain have acute myocardial infarction, and less than 1% have pulmonary embolia or aortic dissection 4,5 , but more than 50% are hospitalized for diagnostic investigation (to exclude acute myocardial infarction) 1,4,6,7 . The cost of hospitalization varies in the United States from U$2000 to U$5000 per patient 8,9 , thus, equaling a total annual cost of approximately U$6-8 billions just to exclude the diagnosis of acute myocardial infarction 10 .…”

Efficacy of a diagnostic strategy for patients with chest pain and no ST-segment elevation in the emergency room

“…A systematic model was developed by consensus of a group of investigators after thorough review and discussion of the medical literature 2,3,7,8 . By taking into account the type of chest pain and the electrocardiographic changes present on admission, patients were triaged to diagnostic pathways -called routes -in which the need for further investigation and its duration in searching for a possible ischemic cause was decided according to the estimated probability of coronary artery disease.…”