Diagnostic Performance Of320-detector CT Coronary Angiography: A Comparison With Invasive Angiography

Objective To evaluate the diagnostic accuracy of320-detector row computedtomography to detect≥50%and≥70%luminal stenosis was compared to ICA asthe reference standard，and the diagnostic accuracy in subjects with heart rate＜65bpm compared with heart rate≥65bpm.Methods Between March2011and September2011,82consecutive patients(58male，24female) of Changhai hospital were in our study who underwent320-detector row computed tomography and invasive coronary angiography withintwo weeks. One hour before computed tomography, patients with heart rate＞65bpmreceived a single dose of metoprolol25or50mg, respectively. Patients with severeheart failure or unstable hemodynamic, severe impaired renal or liver function,previous allergic reaction to contrast or metoprolol, previous coronary artery bypasssurgey were excluded. Image quality was evaluated on a per-patient basis andclassified as a4-point scale according to Frank J. The coronaries were divided into15segements according to the American Heart Association model, and the intermediaryartery was regarded as the16th segment. Quantitative analysis was performed on allavailable CT coronary segments (diameter≥1.5mm) with an automated edgedetection system, and the similar to ICA. Diagnostic accuracy of320-detector rowCTA to detect≥50%and≥70%luminal stenosis was compared to ICA as thereference standard and presented as sensitivity, specificity, positive predictive value(PPV), negative predictive value (NPV).82cases were divided into two groups withheart rate＜65bpm and heart rate≥65bpm. The diagnostic accuracy was evaluatedand compared in two groups.Results71(86.6%) cases had excellent images at average heart rate of67bpm.10(12.2%) cases had good images at average heart rate of74bpm.1(1.2%) cases hadacceptable images at heart rate of83bpm. In a total of1139segments available forICA,1130segments could be evaluated by CTA, evaluable rate was99.2%. Overallsensitivity, specificity, positive and negative predictive value of320-detector rowcomputed tomography for detecting≥50%luminal stenosis were93.1%、96.0%、 77.0%and99.0%, by segment (n=1139), while for detecting≥70%luminal stenosiswere100%、95.9%、50.0%and100%. There was no significant difference ofdiagnostic accuracy in group of heart rate＜65bpm and heart rate≥65bpm.Conclusion Noninvasive320-detector row computed tomography coronaryangiography provides high image quality and high diagnostic accuracy across allcoronary segments, and the diagnostic accuracy was not influenced by heart rate.320-detector row computed tomography will be the first choice of noninvasivemethod for detecting coronary artery stenosis.