Sunnyside Biomedical :: Products and Services

EXTRA takes a unique approach to the interpretation of exercise test results, using a combination of scores rather than a single score. Using simple clinical and exercise test variables and scores improves the predictive accuracy of detecting the presence and severity of coronary artery disease far beyond the use of standard ECG criteria. In addition, the unique approach appears to be unaffected by disease prevalence, missing data, definition variances and even by angiographic criterion.

The outcomes are then stratified into low, intermediate and high risk for any coronary artery disease. Given that the patients in the intermediate group would be sent for further testing and would eventually be correctly classified, this approach has a sensitivity and specificity for any CAD of 85% and 92%, respectively, and a sensitivity and specificity for predicting severe CAD of 81% and 91%, respectively. Overall, a predictive accuracy of 88% is obtained by using EXTRA and this scoring strategy. These are results typically seen only with more expensive imaging modalities such as Stress Echo, Thallium/SPECT testing and Electron-Beam CT.

Test Modality	Any CAD Sensitivity	Any CAD Specificity	Predictive Accuracy
Standard Exercise ECG	68%	77%	73%
Thallium Scintillography	85%	85%	85%
SPECT	88%	72%	80%
Adenosine SPECT	89%	80%	85%
Exercise ECHO	84%	75%	80%
Dobutamine ECHO	88%	84%	86%
Dobutamine Scintillography	88%	74%	81%
EBCT	60%	70%	65%
EXTRA + Score Strategy	85%	92%	88%

This approach effectively limits the usage of these more expensive imaging modalities to one-third of patients and excludes the need for cardiac catheterization in another one-third of the patients. Also, these results could frequently prevent the need for cardiac catheterization.