The prognostic value of contrast stress echocardiography in a real-world population of symptomatic patients without known coronary artery disease

Abstract Background Coronary artery disease (CAD) is the leading cause of mortality and morbidity worldwide. In addition to diagnosis, non-invasive tests may also provide prognostic information useful in the risk stratification and management of CAD patients. Stress echocardiography (SE) is an accurate, non-invasive method for the detection of obstructive CAD. However, in real-world clinical practice the test performance may vary among different centres, depending on availability, local protocols, and operator expertise. Purpose To evaluate the prognostic value of contrast SE in a real-world population of symptomatic patients without known CAD. Methods This was a cohort follow-up study of patients without known CAD and symptoms of atypical chest pain, unexplained dyspnoea or palpitations who were referred to the echocardiography lab of a tertiary hospital for SE between January 2020 and December 2021. Patients with resting regional wall motion abnormalities were excluded. All patients underwent treadmill exercise stress echocardiography (ESE) or dobutamine stress echocardiography (DSE) if unable to exercise. Contrast agents were used in almost all patients (99%). The study population was followed-up for at least 2 years after SE by phone and/or electronic hospital records. Cardiac outcome was defined as anatomically or functionally significant stenosis on angiography, revascularization, acute coronary syndrome (ACS), or cardiac-related death. Results The study comprised 266 patients (mean age 58±12 years, 63% male) who underwent either ESE (58%) or DSE (42%). The patients' details are reported in Table 1. The most common indication for the exam was atypical chest pain, with a prevalence of 73%. SE exams were positive for inducible ischaemia in 14 (5%) patients. Symptoms during the exam were present in 3 (21%) patients with positive SE and 4 patients (2%) with negative SE (p=0.004). No serious complications (sustained ventricular tachycardia, myocardial infarction, or death) were recorded. During the follow-up (median 30, IQR 23–38 months), 264 patients (99%) were successfully contacted. Cardiac outcome occurred in 10 patients. Among 14 patients with positive SE, 8 underwent revascularization due to significant coronary artery stenosis. Among 250 patients with negative SE, 1 underwent revascularization due to significant coronary artery stenosis and 1 presented with ACS 13 months after the test (both patients underwent DSE). Negative predictive value was 99% over a median follow-up of 30 months, corresponding to an annualized event rate of 0.32% per year. A positive SE was significantly associated with cardiac outcome (log-rank test p<0.0001, Figure 1). Conclusion Contrast SE carries significant prognostic implications in symptomatic patients without known CAD. A positive test is strongly associated with the need for revascularization, while a normal test result has an excellent negative predictive value regarding cardiovascular morbidity and mortality.Figure 1