Coronary computed tomography angiography without ECG leads; A feasibility study.

Background: Modern CT scanners with wide coverage and high temporal resolution have enabled robust coronary CT angiography (CCTA) with automated phase selection and motion correction algorithms, even at high heart rates and arrhythmia. We hypothesized that these advanced technologies may make it feasible to perform a CCTA without triggering from a patient's ECG signal.

Methods: Forty-three subjects undergoing clinically indicated CCTA were prospectively enrolled. ECG-less CCTA data was acquired for approximately the whole cardiac cycle using a wide-coverage scanner with fast gantry rotation (Revolution Apex, GE HealthCare). Images were generated using seven sub-ranges of the acquired data and evaluated for motion artifact using a 6-point Likert scale by three experts.

Results: The mean age of the study population was 62.0 ± 12.0 years; 51.2 % were male. The mean heart rate (HR) was 65.3 ± 9.0 beats per minute (bpm). Overall image quality (IQ) was higher with motion correction vs standard reconstruction (4.6 ± 0.66 vs 4.0 ± 0.95, p < 0.01). At HR ≤ 60 bpm, 61-70 bpm, ≥ 71 bpm, IQ scores were 4.9 ± 0.31, 4.5 ± 0.66, 4.4 ± 0.78, respectively. IQ from sub-ranges was similar to the reference of the study, reconstructed images from full-phase data, except in the cases where 1/4 of the scanned data was considered in HR ≤ 60 bpm and ≥ 71 bpm (4.3 ± 0.83, 4.6 ± 0.67 and 4.1 ± 0.96 respectively).

Conclusion: CCTA without ECG leads on an advanced CT scanner is feasible. This approach could improve patient comfort, workflow efficiency, and access to CCTA.