OBJECTIVES: To evaluate the diagnostic accuracy of Mehranâ€™s in-stent restenosis (ISR) classification by coronary computed angiography (CCTA), with reference to invasive coronary angiography (ICA).
METHODS: Consecutive symptomatic patients, who had clinically suspected ISR and implanted stent diameter â‰¥ 3 mm, were prospectively enrolled in our study. Mehranâ€™s classification was employed by CCTA and ICA to classify ISR lesions into four subtypes: focal, diffuse intrastent, diffuse proliferative and total occlusion. CCTA and ICA measurement of lesion length was further compared.
RESULTS: Sixty-one patients with 101 implanted stents were included in our study. The overall sensitivity, specificity, PPV and NPV of CCTA diagnosis of binary ISR, as shown by patient-based analysis (nâ€‰=â€‰61), were 100 % (49/49), 75 % (8/12), 92.45 % (49/53) and 100 % (8/8) respectively. Mehranâ€™s classification of CCTA correlated well with ICA findings. The diagnostic accuracy of CCTA for class I, class II, class III and class IV lesions was 92.5 %, 91.67 %, 100 % and 100 % respectively. Lesion length was assessed to be significantly longer with CCTA than with ICA (11.03â€‰Â±â€‰5.89 mm versus 8.56â€‰Â±â€‰4.99 mm, Pâ€‰<â€‰0.001).
CONCLUSIONS: Angiographic patterns of in-stent restenosis can be accurately classified by coronary computed angiography. The lesion length measured by CCTA is longer than that assessed by invasive coronary angiography.