Introduction: The aim of this prospective study was to evaluate the diagnostic accuracy of dual-source computed tomography coronary angiography (CTCA) compared to intravascular ultrasound (IVUS) for the detection of restenosis in patients who underwent coronary stenting for bifurcation left main (LM) stenosis.
Material and methods: Twenty-four patients underwent percutaneous intervention of the LM and were subsequently examined (median 9.2 months after procedure) using IVUS and CTCA for the detection of restenosis.
Results: Significant restenosis was detected according to IVUS examination in 6 patients (25%) and 8 segments (13%). Based on segment analysis, sensitivity, specificity, positive and negative predictive values of CTCA for the detection of restenosis were 89%, 68%, 32%, 97%, respectively. There was moderate to good correlation between the minimal luminal area (MLA), measured by CTCA and IVUS for LM, the left anterior descending artery (LAD) and the left circumflex artery (LCx) (r=0.64, p<0.01; r=0.49, p=0.03; r=0.76, p<0.01, respectively). A Bland-Altman analysis showed that the MLAs measured by CTCA were underestimated in all segments (mean difference 1.67 ±2.2 mm(2) for LM; 2.0 ±2.0 mm(2) for LAD; 1.79 ±1.79 mm(2) for LCx). An ROC analysis of the MLAs derived by CTCA for detecting significant stenosis was performed. The area under the curve for all analysed segments was 0.73.
Conclusions: The present study demonstrates that in patients after LM bifurcation stenting CTCA performs well in the exclusion of in-segment restenosis. However, due to the low positive predictive value of CTCA, the finding of any restenosis should be confirmed by invasive examination.
Keywords: computed tomography; intervention; left main stenosis; stent.