Head-to-head comparison of dipyridamole echocardiography and stress perfusion scintigraphy for the detection of coronary artery disease:: a meta-analysis -: Comparison between stress echo and scintigraphy

Objectives: This meta-analysis was performed to assess and compare the diagnostic accuracy of dipyridamole echocardiography test (DET) vs. stress perfusion scintigraphy (SPS) for the diagnosis of coronary artery disease (CAD). Methods: We performed a meta-analysis of peer reviewed articles published in English language reporting head-to-head comparison of DET vs. SPS for the diagnosis of CAD. Data of 10 studies comprising 651 patients from 10 different institutions were analyzed. DET dose was 0.56 mg/kg (low dose) in two studies, 0.75 mg/kg in 10 min or 0.84 mg/kg in 10 min (high dose) in six studies, and 0.84 mg/kg in 6 min (accelerated high dose) in one study and 0.84 mg/kg in 10 min + 1 mg atropine co-administration (augmented dose) in one study. SPS was performed with dipyridamole in six studies, with exercise in three studies and with dobutamine in one study. Results: The overall diagnostic accuracy of the two tests was almost similar, 77% (95% CI = 74-81) for DET vs. 81% (95% CI = 78-84) for SPS (p = ns). SPS gave higher sensitivity, 88% (95% CI = 85-89) than DET 70% (95% CI = 66-75) in cumulative data (p < 0.0001) while DET gave higher specificity, 90% (95% CI = 86-94) vs. 67% (95% CI = 60-73) (p < 0.0001). With state of the art protocols, i.e. accelerated dose and atropine augmented high dose, sensitivity of DET improved and overall accuracy was better than SPS (p < 0.05). Conclusion: DET and SPS have a similar diagnostic accuracy. DET has a markedly higher specificity regardless of the dose employed. SPS shows a superior sensitivity, however this sensitivity gap diminishes when more aggressive dipyridamole dosage is used for the stress echocardiography.