Abstract 2088: The Impact of Dyspnea in Patients Referred for Dobutamine Stress Echocardiography
Background: The presence of dyspnea has recently been shown to be associated with increased risk of cardiac events in patients referred for exercise echocardiography or nuclear perfusion stress testing. Patients undergoing dobutamine stress echocardiography (DSE) usually have comorbidities that make exercise testing impossible. The significance of dyspnea in this population is not known.
Methods: We studied 6659 consecutive patients referred for DSE. Patients were divided into five symptom groups (asymptomatic, non-anginal chest pain, atypical angina, typical angina, dyspnea without chest pain). End-points were all-cause mortality and cardiac events, including myocardial infarction and coronary revascularization.
Results: In patients with dyspnea, the rate of ischemia by DSE (19%) was lower than in patients with typical angina (25%, P<0.001) and similar compared to asymptomatic patients (17%, P=0.2). During follow-up of 5.5±2.8 years, 2634 (40%) patients died. Cardiac events occurred in 994 (15%) patients. In multivariate analysis, using the asymptomatic group as reference and adjusting for clinical and DSE parameters, the risk of death from any cause was increased in dyspneic patients (hazard ratio [HR] 1.17, P=0.004), whereas there was no association between dyspnea and cardiac events. In patients with dyspnea, ejection fraction (HR 0.84/10% increment, P<0.0001) and failure to achieve target heart rate (HR 1.42, P<0.001) were important DSE-derived predictors of death after adjustment for other variables. Among the clinical variables, age, male gender, diabetes mellitus, pulmonary disease, and preoperative risk assessment as an indication for testing were predictors of death, whereas increased body mass index showed an inverse association.
Conclusion: Patients with dyspnea who are unable to perform exercise testing are at increased risk of death. However, the impaired prognosis seems not to be linked to myocardial ischemia.