Impact of heart rate frequency and variability on radiation exposure, image quality, and diagnostic performance in dual-source spiral CT coronary angiography.
OBJECTIVE
To investigate the effect of heart rate frequency (HRF) and heart rate variability (HRV) on radiation exposure, image quality, and diagnostic performance to help detect significant stenosis (> or =50% lumen diameter reduction) by using adaptive electrocardiographic (ECG) pulsing at dual-source (DS) spiral computed tomographic (CT) coronary angiography.


METHODS
Institutional review committee approval and informed consent were obtained. No prescan beta-blockers were applied. Unenhanced CT and CT coronary angiography with adaptive ECG pulsing were performed in 927 consecutive patients (600 men, 327 women; mean age, 60.3 years +/- 11.0 [standard deviation]) divided in three HRF groups: low, intermediate, and high (< or =65, 66-79, and > or =80 beats/min, respectively), and four HRV groups given mean interbeat difference (IBD) during CT coronary angiography: normal, minor, moderate, and severe (IBDs of 0-1, 2-3, 4-10, and >10, respectively). Radiation exposure and image quality were also evaluated. In 444 of these, diagnostic performance was presented as sensitivity, specificity, positive predictive values (PPVs), and negative predictive values and likelihood ratios with corresponding 95% confidence intervals by using quantitative coronary angiography as the reference standard.


RESULTS
CT coronary angiography yielded good image quality in 98% of patients and no significant differences in image quality were found among HRF and HRV groups. Radiation exposure was significantly higher in patients with low versus high HRF and in patients with severe versus normal HRV. No significant differences among HRF and HRV groups in image quality and diagnostic performance were found. A nonsignificant trend was found toward a lower specificity and PPV in patients with a high HRF or severe HRV when compared with low HRF or normal HRV in patients with a low calcium score (Agatston score <100).


CONCLUSIONS
DS spiral CT coronary angiography performed with adaptive ECG pulsing results in preserved diagnostic image quality and performance independent of HRF or HRV at the cost of limited dose reduction in arrhythmic patients.
Weustink
Annick C
AC
Department of Radiology, Erasmus Medical Center, Dr Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. a.weustink@erasmusmc.nl
Neefjes
Lisanne A
LA
Kyrzopoulos
Stamatis
S
van Straten
Marcel
M
Neoh Eu
Rick
R
Meijboom
Willem B
WB
van Mieghem
Carlos A
CA
Capuano
Ermanno
E
Dijkshoorn
Marcel L
ML
Cademartiri
Filippo
F
Boersma
Eric
E
de Feyter
Pim J
PJ
Krestin
Gabriel P
GP
Mollet
Nico R
NR
D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed
D003287:Contrast Media; D007472:Iohexol; C038192:iopromide