Is the standard weight-based dosing of dobutamine for stress testing appropriate for patients of widely varying body mass index?

Although a gradual increase in heart rate (HR) during dobutamine stress testing (DST) is desired, few data exists regarding whether this is similarly achieved in patients of widely varying body mass index (BMI). Whether difference in BMI contributes to variation in the hemodynamic and symptomatic response to dobutamine is also unknown

Relation of dyspnea in patients unable to perform exercise stress testing to outcome and myocardial ischemia

Limited information exists regarding the significance of dyspnea in patients who are unable to exercise and the contribution of myocardial ischemia to this symptom. To assess this, we evaluated results of dobutamine stress echocardiography (DSE) and long-term outcome of patients with dyspnea referred for DSE. We studied 6,376 consecutive patients who were unable to perform an exercise test and were referred for DSE. Patients were classified according to presenting symptoms and followed for 5.5 +/- 2.8 years. End points were cardiac ischemic events (myocardial infarction or revascularization), hospitalization for heart failure (HF), and death. Dobutamine stress echocardiogram was positive for ischemia in 19% of patients with dyspnea versus 24% (p = 0.002) of those with typical angina and 17% (p = 0.2) of asymptomatic patients. In multivariate analysis, risk of death was increased in dyspneic patients versus asymptomatic patients (hazard ratio [HR] 1.14, p = 0.02) and patients with chest pain (HR 1.20, p >0.001). Hospitalization for HF occurred more often in patients with dyspnea (HR 1.26, p = 0.05 vs asymptomatic; HR 1.24, p = 0.06 vs chest pain), especially in the subset without previous HF (HR 1.45, p = 0.006 vs chest pain). Risk of cardiac ischemic events in patients with dyspnea was similar versus asymptomatic patients (HR 0.92, p = 0.39) and decreased versus patients with chest pain (HR 0.70, p >0.001). In conclusion, in patients referred for DSE, dyspnea was associated with a poor outcome. This increased hazard seems not to be linked to myocardial ischemia, but instead to HF and death

Does the prognostic value of dobutamine stress echocardiography differ among different age groups?

Age is associated with reduced exercise capacity and greater prevalence of coronary artery disease. Whether the prognostic information obtained from dobutamine stress echocardiography (DSE), a stress test commonly used for patients unable to perform an exercise test, provides differential information based on age is not well known