Background: Patients undergoing major vascular surgery are at a relatively high risk of cardiac events, and pharmacological stress echocardiography is increasingly used for perioperative risk stratification. The aim of the current study was to evaluate the value of dipyridamole echocardiography test (up to 0.84 mg/kg over 10 minutes) in predicting cardiac events in a large-scale, multicenter, prospective, observational study design.
Methods and results: Five hundred nine patients (mean age 66+/-10 years) were studied before vascular surgery by dipyridamole stress echocardiography in 11 different centers. All patients underwent preoperative clinical risk assessment according to the American Heart Association guidelines. No major complications occurred during dipyridamole stress echocardiography. Technically adequate images were obtained in all patients; however, in 4 patients only the low dipyridamole dose (0.56 mg/kg over 4 minutes) was given for limiting side effects. Eighty-eight (17.3%) had a positive test. Perioperative events occurred in 31 (6.1%) patients: 6 deaths, 11 myocardial infarctions, and 14 episodes of unstable angina. Sensitivity and specificity of dipyridamole stress echocardiography for predicting spontaneous cardiac events were 81% and 87%, respectively, with a positive predictive value of 28% and negative predictive value of 99%. By multivariate analysis, the difference between wall motion score index at rest and peak stress (Deltawall motion score index), test positivity, and ST-segment depression during dipyridamole infusion were independent predictors of any perioperative cardiac event.
Conclusions: Dipyridamole stress echocardiography is safe and well tolerated in patients undergoing major vascular surgery and provides an effective preoperative screening test for the risk stratification of these patients, mainly because of the extremely high negative predictive value, which is a potent predictor of complication-free procedure.