DSCT accurately detects coronary artery disease in general, but regular sinus rhythm has been considered a prerequisite for an adequate examination, the researchers note.

For the current study, Dr. Mohamed Marwan and colleagues from University of Erlangen tested DSCT in 60 patients with atrial fibrillation referred for invasive coronary angiography.

All 60 were in atrial fibrillation at the time of the scan, and their mean heart rate was 70 beats per minute (range, 32-107).

Coronary angiography identified 14 patients (22 arteries) as having at least one significant stenosis.

DSCT accurately detected (or ruled out) significant stenoses in 88% (53/60) of patients and provided 100% sensitivity, 85% specificity, 100% negative predictive value, and 67% positive predictive value on a per-patient basis.

In per-artery analysis, DSCT had 95% sensitivity, 94% specificity, 99% negative predictive value, and 60% positive predictive value for identifying significant stenoses.

DSCT failed to identify only one significant stenosis in the heavily calcified left circumflex artery of one patient, and it overestimated the extent of stenosis in eight patients (11 lesions).

The mean effective radiation dose was 16 mSv overall, but it was lower (11 mSv) with a tube voltage of 100 kV than with a tube voltage of 120 kV (16 mSv).

"Mean effective radiation dose in our cohort is relatively high ... due to absent tube current modulation to allow for flexible reconstructions at every point of the cardiac cycle," the authors note.

"The results of our study represent a single center experience and can therefore be generalized only with limitations," they add.

"In patients with controlled atrial fibrillation (heart rate below 100 beats per minute), with carefully performed reconstructions using absolute delay algorithms and meticulous ECG editing, DSCT angiography may be an alternative to invasive coronary angiography in ruling out coronary artery disease," the investigators conclude.