Abstract 19234: Exercise Echocardiography is Efficacious With Superior Cost Profile Compared to Exercise ECG as First Line Test in Patients With no History of Coronary Artery Disease and New Suspected Stable Angina; A Randomized Prospective Study

Abstract

Introduction: Exercise ECG (ExECG) is the initial investigation of choice according to AHA/ACC guidelines in patients with suspected stable angina, normal ECG and able to exercise.We hypothesized that Exercise Stress Echo (ESE), given its high feasibility (with contrast use) and superior diagnostic accuracy would confer a cost advantage over ExECG. Methods: Consecutive consenting patients with no previous history of coronary artery disease (CAD) and a calculated pre-test CAD risk of >10%, seen in our Rapid Access Clinic and able to exercise on the treadmill, were randomized into same day ExECG or ESE.Tests were classified as positive, negative or inconclusive for ischemia. Patients with negative tests were discharged from the clinic, with inconclusive tests were offered additional tests and with positive tests were offered Coronary Angiography (CA). Cost to diagnosis was calculated using the NHS tariff by adding the cost of all requested investigations up to an including CA on an intention to treat basis. Follow-up data on Death, Myocardial Infarction and Unplanned Revascularization were collected for a period of at least 1 year after the enrollment of the last study patient. Results: A total of 194 patients underwent ExECG (mean age 53, 66% male) and 191 patients ESE(mean age 55, 70% male).There were no significant differences in age, gender and in prevalence of diabetes mellitus, smoking and hyperlipidemia. Pre-test probability of CAD was also similar(39% vs. 40% p=0.6). Results of ExECG were:108(55.7% Negative), 14 (7.2%) Positive, 72(37.1%) Inconclusive and of ESE:191(94.8%) Negative, 9 (4.7%) Positive, 1(0.5%) Inconclusive. The positive predictive value for patients undergoing CA after a positive ESE was higher than that for positive ExECG (9/9 vs 9/14 p=0.04). Average cost to diagnosis was significantly lower for ESE vs Ex ECG ( £ 265 vs £ 331p=0.02). Over a mean follow-up period of 21±5 months there was no significant difference in cardiac event rates (1% vs. 0% p=0.1) in the ESE vs. ExECG groups. Conclusion: In this first randomized study, same day ESE was shown to be feasible, efficacious conferring superior cost advantage when compared to ExECG. This study suggests that ESE could be used as first line investigation in patients with suspected stable angina.