ABSTRACT
The addition of atropine during dobutamine stress echocardiography (DSE) is increasingly used for detecting coronary artery disease (CAD), but its safety and whether it has added diagnostic accuracy have not been well defined. The aim of this study was to retrospectively compare the complication rate and diagnostic accuracy of three different protocols in the same laboratory. DSE was performed in 1090 patients over a 5-year period. The protocol had included (1) 5' stages up to 30 µg/kg/min of dobutamine in the first 184 patients, (2) 3' stages up to 40 µg/kg/min in the next 274 patients, and (3) 3' stages up to 40 µg/kg/min with atropine, when required in the last 632 patients. A large number of patients (n = 938) underwent coronary angiography within 2 weeks, and 524 patients had a significant coronary stenosis (> 50%). In the whole group of 1090 patients, serious complications developed in 5 patients (one acute myocardial infarction, one sustained ventricular tachycardia, and three prolonged ischemia). Although the incidence was low, there were no detectable differences between protocols. Hypotension, which was defined as a >/= 20 mmHg decrease in systolic blood pressure from the baseline, was observed in 68 patients. Premature ventricular contraction was the most common arrhythmia. The complication rate was similar among three protocols. The diagnostic accuracy for detecting CAD was nearly the same among three protocols (30 µg, 86%; 40 µg, 84%; and 40 µg with atropine, 84%), but the prevalence of CAD was higher with the 30-µg protocol (65%) than the 40-µg protocol (55%) or 40-µg-with-atropine protocol (53%, P < 0.01). In 469 patients without a previous myocardial infarction, the prevalence of CAD was the same (38-42%). Sensitivity increased with more aggressive protocols (71%, 76%, and 84%). However, it was associated with the loss of specificity (92%, 92%, and 85%). Thus, the diagnostic accuracy was similar among groups (84%, 85%, and 84%). In conclusion, the addition of atropine during DSE does not increase the rate of complication compared with previous conservative protocols and shows the same diagnostic accuracy with a small increase in sensitivity at the cost of a small and matched decrease in specificity.
