Prognostic value of coronary computed tomography in patients with non-significant perfusion defects by myocardial perfusion SPECT.

AIMS: Myocardial perfusion scintigraphy (MPS) is an important diagnostic tool in the management of patients with suspected coronary artery disease (CAD). However, the presence of mild-moderate perfusion defects can be challenging and may lead to unnecessary cardiac catheterization. Coronary computed tomography angiography (CCTA) is a method with excellent accuracy in the evaluation of CAD, but its role in this setting of patients has not been fully defined. This study aims to assess the potential of CCTA in the prediction of cardiac adverse events in patients with suspected CAD with non-significant perfusion defects by MPS.

METHODS AND RESULTS: We conducted a cohort study in 292 patients presenting with non-significant perfusion defects by MPS undergoing a CCTA. The patients were followed for a mean of 34 months for occurrence of major cardiac adverse events - MACE. The majority of the patients (64.7%) were male, with a mean age of 57.9 ± 12.6 years. During the follow-up there were 37 MACE. In multivariate Cox proportional hazards model, hypertension and CCTA were independent predictors of MACE. The patients who presented a significant coronary obstruction by CCTA had a high risk of MACE (HR 15.3; 95% CI 4.06 to 57.90; P < 0.001). Kaplan-Meier curve showed a significant difference (log-rank χ²; P < 0.001) using CCTA in predicting MACE.

CONCLUSION: CCTA carries a powerful prognostic value in predicting adverse events in patients with suspected CAD and MPS with mild-moderate perfusion defects and may be useful in risk stratification of these patients.