UCLA

Background

Although several studies have shown promise for noninvasive angiography by coronary computed tomographic angiography (CCTA), few prospective multicenter trials have been conducted. This study evaluated the diagnostic accuracy of Visipaque enhanced CCTA to detect obstructive coronary stenosis compared with quantitative coronary angiography (QCA).

Patients and methods

Three sites prospectively enrolled 77 patients (58.1% men, 54 years) with chest pain referred for invasive coronary angiography (ICA). Patients underwent CCTA (Lightspeed VCT/Visipaque 320) before ICA. CCTAs were graded on a 15-segment American Heart Association model by a CCTA core lab with blinded readers for the presence of obstructive stenosis (>50% or >70%); ICAs were independently graded for %stenosis by QCA, considered the reference standard. The efficacy of CCTA was assessed including all vessel segments for per-patient and per-vessel analyses.

Results

A total of 46 more than 50% stenoses in 27 (35%) patients, and 31 more than 70% stenoses in 20 (26%) patients, were identified by QCA. Per-patient and per-vessel efficacy of CCTA compared with QCA yielded sensitivities of 85% and specificities of 90 and 95%, respectively.

Conclusion

This study shows the high accuracy of CCTA to reliably detect more than 50% and more than 70% stenoses in low-probability to intermediate-probability chest pain patients being referred for ICA. The high negative predictive values observed (92-100%) indicate that CCTA is also an effective noninvasive alternative to exclude obstructive coronary stenosis.