Comparison of the echo-dobutamine-atropine test and ergometric test in the diagnosis of coronary disease
Sarullo, F.M.; Schicchi, R.; Schirò, M.; Schillaci, A.M.; Ascione, A.; Bonnì, G.; Americo, L.; Orlando, G.; Andolina, S.; Adamo, M.; Castello, A.
Giornale Italiano di Cardiologia 26(11): 1279-1290
1996
ISSN/ISBN: 0046-5968 PMID: 9036023 Document Number: 459523
Echocardiography is the cardiological diagnostic test the use of which has increased most in recent years. However, despite the popularity and the massive use of the technique, there is little information regarding the usefulness and management impact of echocardiography as routinely ordered in current medical practice. Furthermore, clinical indications and expectations of physicians who ordered an echocardiogram (echo) have never been systematically evaluated in our country. During the last two weeks of September 1994, a prospective, observational study was carried out at echocardiographic laboratories in 9 hospitals. By means of a questionnaire completed by the physician who ordered the test prior to its performance, we surveyed: characteristics of the ordering physician, reasons for ordering the test, physicians' expectations regarding the test, and pre-echo clinical diagnosis as well as clinical evaluation of presence or absence and severity of specific cardiac abnormalities. In addition, pre-echo clinical and instrumental assessment of specific cardiac abnormalities was compared with echocardiographic findings. Three hundred and forty-eight questionnaires were successfully completed: 42% by cardiologists (C), 30% by general practitioners (GP), 18% by internists (I), and 10% by other specialists (Sp). Forty percent of the echoes were ordered to "Reevaluate a known cardiac disease" (62% C, 19% GP, 14% I and 5% Sp; p = 0.0001), 39% to "Confirm or exclude a clinical suspicion" (40% C, 24% GP, 24% I, and 12% Sp; p = 0.03), and 21% because of "Screening" purposes (40% GP; 32% C, 15% Sp, and 13% I; p = 0.0017). In the patients who had had a previous echo, the expectation of a significant change with respect to the previous one was "Low" for 48% (57% C, 28% GP, 12% I, and 3% Sp; p = NS), "Moderate" for 42% (44% C, 38% GP, 12% I, and 6% Sp; p = NS), and "High" for only 10% of physicians (58% C, 17% GP; 17% I, and 8% Sp; p = NS). Physicians reported that their expectations from the result of the test on patients' management were: "Modifying therapy or clinical management of the patients" for 66% (45% C, 24% GP, 20% I, and 11% Sp; p < 0.0001), "Objective documentations of presence/absence of cardiac disease" for 21% (40% GP, 35% C, 15% I, and 10% Sp; p = NS), and "Patient's reassurement" for 13% (62% GP, 30% C, 6% I, and 2% Sp; p < 0.0001). The expectation that the result of the echo would influence therapeutic and/or clinical management of the patient was "Moderate" for 44% (42% C, 29% GP, 20% I, and 9% Sp; p = NS), "Low" for 36% (43% C, 34% GP, 15% I, and 8% Sp; p = NS), and "High" for only 20% of the physicians (50% C, 23% GP, 17% I and 10% Sp; p = NS). The echo report was judged in agreement with pre-echo clinical assessment in 40% of cases, in disagreement in 32% and compatible in 28%. At the echo examination, clinical left ventricular (LV) enlargement was not confirmed in 45% of cases and was clinically unsuspected in 13%; clinical LV systolic dysfunction was not confirmed in 53% of cases and was clinically unsuspected in 6%; clinical LV hypertrophy was not confirmed in 43% of cases and was clinically unsuspected in 14%; clinical moderate or severe mitral regurgitation was not confirmed in 32% of cases and was clinically unsuspected in 9%; clinical left atrial enlargement was not confirmed in 27% of cases and was clinically unsuspected in 12%. GPs ordered echoes mainly for screening or to evaluate suspected cardiac abnormalities for the purpose of reassuring their patients or documenting the presence or absence of a cardiac disease. C ordered echoes to evaluate clinically suspected cardiac abnormalities or to reassess known cardiac diseases with the purpose of modifying patients' therapy or clinical management. One echo out of 3 gave clinically unsuspected results. In 1 echo out of 2 clinical assessment of the severity of the most common morpho-functional cardiac abnormalities was cha A prospective study has been done on 46 patients with suspected coronary artery disease (CAD). They had no history of myocardial infarction (MI) and a normal basal kinetic echocardiography. This was done in order to evaluate the overall accuracy of dobutamine-atropine stress echocardiography (DAS) compare to exercise stress test (ET) for the diagnosis of CAD. All the patients after suspension of coronary therapy, performed a casual sequence with both maximal or symptom limited exercise testing (treadmill-Bruce protocol) and DAS. The dobutamine has been given while monitoring systemic blood pressure, electrocardiography and echocardiography in steps of 10 mcg/kg/min' per 3 min' up to a maximum of 40 mcg/kg/min'. Atropine has been added (0.25-1 mg) in patients who did not reach the theoretical maximal cardiac frequency. The test is considered positive when kinetic segmen tal left ventricular dysfunction appeared. CAD was defined as 50% luminal area stenosis in at least 1 coronary artery at coronary angiography. Significant CAD was present in 27/46 patients (59%). Compared with ET, DAS had significantly higher sensitivity (59% vs 92%, p = 0.01). The different sensibility between the two tests was higher on these patients with a 1 vessel disease (40% vs 86%, p = 0.02). There were no significant differences in specificity among the two tests (79% vs 84%, respectively). Differences in overall accuracy between ET and DAS were significant (67% vs 89%, p = 0.02). The results of our study show that the DAS is a safe and feasible technique with high sensibility (especially in patients with single CAD) and specificity. This is a valid alternative to the traditional ET, especially for these patients unable to exercise or these who are poorly motivated to achieve a work load sufficient to make the test interpretable.