Usefulness of an accelerated transoesophageal stress echocardiography in the preoperative evaluation of high risk severely obese subjects awaiting bariatric surgery

Abstract

BACKGROUND: Severe obesity is associated with an increased risk of coronary artery disease (CAD). Bariatric surgery is an effective procedure for long term weight management as well as reduction of comorbidities. Preoperative evaluation of cardiac operative risk may often be necessary but unfortunately standard imaging techniques are often suboptimal in these subjects. The purpose of this study was to demonstrate the feasibility, safety and utility of transesophageal dobutamine stress echocardiography (TE-DSE) using an adapted accelerated dobutamine infusion protocol in severely obese subjects with comorbidities being evaluated for bariatric surgery for assessing the presence of myocardial ischemia. METHODS: Subjects with severe obesity [body mass index (BMI) >40 kg/m2] with known or suspected CAD and being evaluated for bariatric surgery were recruited. RESULTS: Twenty subjects (9M/11F), aged 50 +/- 8 years (mean +/- SD), weighing 141 +/- 21 kg and with a BMI of 50 +/- 5 kg/m2 were enrolled in the study and underwent a TE-DSE. The accelerated dobutamine infusion protocol used was well tolerated. Eighteen (90%) subjects reached their target heart rate with a mean intubation time of 13 +/- 4 minutes. Mean dobutamine dose was 31.5 +/- 9.9 ug/kg/min while mean atropine dose was 0.5 +/- 0.3 mg. TE-DSE was well tolerated by all subjects without complications including no significant arrhythmia, hypotension or reduction in blood arterial saturation. Two subjects had abnormal TE-DSE suggestive of myocardial ischemia. All patients underwent bariatric surgery with no documented cardiovascular complications. CONCLUSIONS: TE-DSE using an accelerated infusion protocol is a safe and well tolerated imaging technique for the evaluation of suspected myocardial ischemia and cardiac operative risk in severely obese patients awaiting bariatric surgery. Moreover, the absence of myocardial ischemia on TE-DSE correlates well with a low operative risk of cardiac event.