Correlation between myocardial scintigraphy and CT angiography in the evaluation of coronary disease

Coronary multidetector CT angiography (CTA) has shown good accuracy for detection of coronary stenosis. Although this is a promising technique for the evaluation of CAD, its correlation with the functional expression of the disease is not yet well established.

To evaluate whether the presence of CAD and the degree of coronary stenosis assessed by CT angiography are associated with changes in the Myocardial Perfusion Scintigraphy (MPS).

This is a retrospective observational study, which included 99 consecutive patients with known or suspected CAD. MPS and CTA were conducted. We compared the presence of perfusion defects by MPS with the presence of CAD and the degree of luminal obstruction by CTA. For statistical analysis, Student's t-test, ANOVA, and Chi-square (or Fisher's exact test for n <5) tests were used. Multivariate analysis was performed using logistic regression: the level of significance was 5%.

Mean age was 62 ± 11.4 years, with 46 (71.7%) men. The variable analysis was performed per patient (n = 99) and per coronary irrigation territory (n = 297). Of the 67 territories that had significant CAD by CTA, 44.8% had abnormal MPS. Considering the degree of stenosis, abnormal MPS was present in 18.7% of the territories with no significant stenosis, 45.28% of the territories with moderate stenosis, and 42.8% of the territories with severe injuries.

CTA is a good method for exclusion of CAD. However, its use to evaluate the severity of stenosis and its functional impact has not shown good correlation.