Diagnostic performance of prospectively ECG triggered versus retrospectively ECG gated 64-slice computed tomography coronary angiography in a heterogeneous patient population

Objective

To compare diagnostic performance and applicability of prospectively versus retrospectively gated 64-slice computed tomography coronary angiography (pro-CTCA vs. retro-CTCA) in a heterogeneous patient population compared to invasive coronary angiography.

Methods

77 patients referred to an ECG-gated-CT of the chest were retrospectively included. Pro-CTCA was applied, whenever possible, alternatively retro-CTCA was performed. All coronary artery segments ≥1.5 mm were analysed and image quality was assessed.

Results

In 39 patients retro-CTCA and in 38 patients pro-CTCA was applied, mean heart rate (HR) was 69.5 ± 9.1 min⁻¹ and 62.8 ± 5.9, respectively. For a stenosis ≥50% segment-based (patient-based) analysis revealed a sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of 97%, 98%, 71%, 100% (91%, 82%, 67%, 96%) using retro-CTCA and 94%, 97%, 75%, 99% (93%, 96%, 93%, 96%) using pro-CTCA. Sensitivity and NPV increased in the pro-CTCA group in patients with a HR < 65. Vessel-based analysis showed lower diagnostic performance for the right coronary artery (RCA) using pro-CTCA, which increased when HR < 65. Image quality did not differ significantly in both groups.

Conclusions

Prospectively triggered CTCA in a heterogeneous patient group has a very high diagnostic accuracy and image quality, when used in HR ≤ 65. A low HR is of special importance for the evaluation of the RCA.