Eighty-two studies (n=7,935) were included in the review.
Twenty-nine studies were considered to be of 'high' quality, 32 were considered 'medium' quality and 20 were considered 'low' quality.
Vasodilators.
Dipyridamole SPECT imaging had a higher sensitivity but lower specificity than dipyridamole echocardiography. The sensitivity and specificity were 89% (95% CI: 84, 93) and 65% (95% CI: 54, 74), respectively, for dipyridamole SPECT (21 studies, 1,464 participants) and 70% (95% CI: 66, 74) and 93% (95% CI: 90, 95) for dipyridamole echocardiography (20 studies, 1,835 participants).
Similarly, adenosine SPECT had a higher sensitivity but lower specificity than adenosine echocardiography. The sensitivity and specificity were 90% (95% CI: 89, 92) and 75% (95% CI: 70, 79), respectively, for adenosine SPECT (9 studies, 1,207 participants) and 72% (95% CI: 62, 79) and specificity 91% (95% CI: 88, 93) for adenosine echocardiography (6 studies, 516 participants).
Inotropic agent.
Dobutamine SPECT imaging had a similar sensitivity but lower specificity than dobutamine echocardiography. The sensitivity and specificity were 82% (95% CI: 77, 87) and 75% (95% CI: 70, 79), respectively, for dobutamine SPECT (14 studies, 1,066 participants) and (sensitivity 80% (95% CI: 77, 83) and 84% (95% CI: 80, 86) for dobutamine echocardiography (40 studies, 4,097 participants).
The investigations into differences between the studies showed that the detection of 50% stenosis for disease definition significantly reduced diagnostic performance, while the proportion of patients with CAD significantly improved diagnostic performance. All other variables in the meta-regression failed to demonstrate significant association with diagnostic performance.
Subgroup analyses according to gender found that dobutamine echocardiography had similar sensitivity and specificity in women and men. No statistically significant difference was found between gender-specific results and results from all included participants.
Analyses of diagnostic performance in multi-vessel disease found that dipyridamole and dobutamine imaging had higher specificities and lower sensitivities for the detection of multi-vessel CAD compared with CAD in general.
There was no statistically significant difference in diagnostic performance between those studies that controlled for verification bias and those that did not.