Prognostic Implication of Appropriateness Criteria for Pharmacologic Stress Echocardiography Performed in an Outpatient Clinic

Background— Although appropriateness criteria for stress echocardiography have been developed to deliver high-quality care, the prognostic impact of these criteria remains undefined. Therefore, we sought to assess the prognostic implication of the American College of Cardiology/American Society of Echocardiography appropriateness criteria for pharmacological stress echo in a cohort of ambulatory patients. Methods and Results— The study population consisted of 1552 ambulatory patients who underwent pharmacological (752 dobutamine, 800 dipyridamole) stress echo for the evaluation of known (n=549) or suspected (n=1003) coronary artery disease at a single cardiology center. Patients were followed up for a median of 36 months. Indications were determined for consecutive studies by 2 reviewers and categorized as follows: 984 (63%) patients had appropriate, 145 (9%) uncertain, and 423 (27%) inappropriate indication for stress echo. Ischemia was present in 15% of patients with appropriate, 8% of those with uncertain, and 5% of those with inappropriate indication ( P <0.0001). During follow-up, 146 events (89 deaths, 57 nonfatal infarctions) occurred. Annual event rate associated with appropriate, uncertain, and inappropriate study was 3.1%, 3.8%, and 1.3%, respectively. The abnormal test result in patients with appropriate, uncertain, and inappropriate study was associated with 5.0%, 5.6%, and 1.8% annual event rate, respectively, exerting an independent value only in the appropriate and uncertain subset. Conclusions— Inappropriate indication for pharmacological stress echo is common, being documented in about 1 of 4 patients evaluated in an ambulatory setting, and is associated with lower rate of positive results and better survival as compared with appropriate and uncertain indication.