Dual-source computed tomography coronary angiography in patients with high heart rate

Area of Science:

• Cardiovascular Imaging
• Radiology
• Medical Diagnostics

Background:

• Single-source CT coronary angiography (SSCTA) requires heart rate (HR) reduction for optimal image quality.
• Dual-source CT coronary angiography (DSCTA) offers potential advantages in patients with tachycardia.
• Comparing the diagnostic accuracy of DSCTA during tachycardia versus SSCTA with reduced HR is crucial.

Purpose of the Study:

• To compare the diagnostic accuracy of DSCTA in patients with HR >65 bpm against SSCTA in patients with HR <65 bpm.
• To evaluate the feasibility of image reconstruction during isovolumic relaxation time (IRT) in DSCTA.
• To assess the impact of HR on diastasis time (DT) and IRT.

Main Methods:

• Retrospective analysis of patients undergoing invasive coronary angiography and either SSCTA or DSCTA.
• SSCTA group (n=27) received HR reduction (<65 bpm) with beta-blockers.
• DSCTA group (n=27) included patients with HR >65 bpm.
• Diagnostic accuracy for coronary stenosis was compared to invasive angiography.
• Dual-Doppler echocardiography assessed isovolumic relaxation time (IRT) and diastasis time (DT).

Main Results:

• SSCTA: Sensitivity 89%, Specificity 99%, PPV 94%, NPV 98%.
• DSCTA: Sensitivity 96%, Specificity 99%, PPV 91%, NPV 99% (all non-significant differences compared to SSCTA).
• HR >75 bpm significantly shortened DT (<83 ms) but maintained IRT (>85 ms).
• Image reconstruction at IRT phase is feasible in DSCTA due to its 83 ms temporal resolution.

Conclusions:

• DSCTA demonstrates equivalent accuracy to SSCTA for detecting coronary stenosis, even without HR reduction.
• DSCTA's high temporal resolution allows for reliable image acquisition and reconstruction during IRT, even in tachycardic patients.
• This eliminates the need for beta-blockers in many patients undergoing CT coronary angiography.