Clinical usefulness of the 16-slice computed tomography coronary angiography for evaluation of early phase intracoronary stent patency
Antoniucci, D., Valenti, R., Santoro, G.M., Bolognese, L., Trapani, M., Cerisano, G., Boddi, V., Fazzini, P.F., 1998. Restenosis after coronary stenting in current clinical practice. Am. Heart J. 135, 510-518.
Babapulle, M.N., Joseph, L., Bélisle, P., Brophy, J.M., Eisenberg, M.J., 2004. A hierarchical Bayesian meta-analysis of randomised clinical trials of drug-eluting stents. Lancet. 364, 583-591.
Buecker, A., Spuentrup, E., Ruebben, A., Günther, R.W., 2002. Artifact-free in-stent lumen visualization by standard magnetic resonance angiography using a new metallic magnetic resonance imaging stent. Circulation. 105, 1772-1775.
Garzon, P.P., Eisenberg, M.J., 2001. Functional testing for the detection of restenosis after percutaneous transluminal coronary angioplasty: A meta-analysis. Can J. Cardiol. 1, 41-48.
Gilardi, M., Cornily, J.C., Pennec, P.Y., Le Gal, G., Nonent, M., Mansourati, J., Blanc, J.J., Boschat, J., 2006. Assessment of coronary artery stents by 16 slice computed tomography. Heart. 92, 58-61.
Hamon, M., Champ-Rigot, L., Morello, R., Riddell, J.W., Hamon, M., 2008. Diagnostic accuracy of in-stent coronary restenosis detection with multislice spiral computed tomography: A meta-analysis. Eur. Radiol. 18, 217-225.
Hug, J., Nagel, E., Bornstedt, A., Schnackenburg, B., Oswald, H., Fleck, E., 2000. Coronary arterial stents: Safety and artifacts during MR imaging. Radiology. 216, 781-787. this purpose; eligible patients premedicated with beta-blocker drugs. Motion artifacts are even bigger problem in patients with arrhythmias and contraindications to beta-blockers. The stents implanted to Cx artery and RCA are more vulnerable to motion artifacts. By the development of new generation CT scanners (particularly 64-slices and more) with higher temporal resolution, this effect is dramatically reduced (Sun et al., 2012).
In our study, 23 patients (64%) with heart rates higher than 70 beats/min received the intravenous premedication. However, unlike many other studies, there was no upper heart rate limit established as a criterion for exclusion. In our study, the mean heart rate at the beginning of the scan was 73 ± 9 beats / minute. This heart rate is quite high compared to the other studies. Nowadays, more and more widely used 64 and higher slice CT scanners with high gantry rotation speeds and capacity of taking more slice allow to obtain higher quality images in patients with high heart rates. In a meta-analysis of 15 studies, 1175 intracoronary stent were assessed with the 16 and 64-slice CT scanners, and the average sensitivity and specificity were reported as 84% and 91%, respectively (Hamon et al., 2008). In our study, 33% sensitivity of 16-slice CT angiography is below the sensitivities of other studies but 95% specificity level is comparable to other studies. However, only nine restenotic stents were assessed within 30 stents. The evaluation of 16-slice CT angiography in intracoronary stent restenosis detection with only 9 stents is not reliable enough to draw conclusions. For this reason, the low number of the total and restenotic stents assessed is one of the limitations of our study.
The patients included in this study underwent 16-slice CT angiography and conventional coronary angiography with the clinical indications. This study was not planned in randomized, prospective design. The potential bias caused by results of 16-slice CT and conventional coronary angiography performed with clinical indications are another limitation of the study. In conclusion; the 16-slice CT angiography seems unlikely to take place of conventional coronary angiography in the evaluation of stent restenosis in clinical practice according to the data obtained from this study. It is difficult to reach a reliable conclusion about performance of 16-slice CT angiography in assessment of stent restenosis because of the low number of stents and low restenosis rate. More comprehensive studies including higher number of stents and high restenosis rate are needed.