DOBUTAMINE STRESS ECHOCARDIOGRAPHY - PREVALENCE OF A NONISCHEMIC RESPONSE IN A LOW-RISK POPULATION

The problems of population referral bias in the calculation of specifi city in diagnostic testing for coronary artery disease have been previ ously described. Previous studies investigating the sensitivity and sp ecificity of dobutamine stress echocardiography (DSE) have been subjec t to pretest and posttest referral biases, largely as a result of the requirement for coronary arteriography. This study determines the norm alcy rate for DSE by examining a population at statistically low risk for coronary artery disease. The probability of significant coronary a rtery disease was determined for 828 consecutive patients referred for DSE at the University of Michigan, and groups were identified with <1 0% and <5% probability of disease. Four of 72 patients (5.6%) with a n ormal baseline echocardiogram and a probability of coronary artery dis ease of <10%, and three of 38 (7.9%) with a probability of <5% were fo und to have an abnormal DSE, yielding normalcy rates of 94.4% and 92.1 %, respectively. The area of abnormality involved the posterior circul ation in three of four patients (75%). This study demonstrates that DS E has a normalcy rate of 92% to 94% and is an accurate test for exclud ing the presence of significant coronary artery disease.