A novel quantitative method for evaluating diffuse in-stent narrowing at follow-up angiography.
A new quantitative parameter, diffuse index (DI), was proposed to evaluate objectively whether in-stent restenosis is diffuse or focal in nature. A total of 343 patients (346 lesions) with Wiktor-GX, AVE MS-II, or JOMED stents were evaluated at follow-up angiography. According to the QCA-CMS definition, lesion length is derived from the 100% reference diameter function (RDF). By moving the RDF downward, the lesion length, LL(x), at each percentage x of the RDF can be calculated. We have defined the DI by the ratio of this calculated length LL(x) and the total stent length, SL, in other words, DI = [LL(x)/SL]. The percentage plaque area (% PA) was calculated by dividing the plaque area by the sum of the plaque area and luminal area within the stent. An excellent correlation was found between the DI at 88% RDF and the % PA in all three stents (r > 0.88). The individual correlation curves were nearly identical, independent of the type of stent. Furthermore, based on the overall data, the combination of a DI > 0.8 and % PA > 30% correlated with a high incidence of subsequent major adverse cardiac events (13/25 = 52%). From these data, it can be concluded that the diffuse index is a new objective quantitative parameter to describe whether in-stent restenosis is of focal or diffuse nature.
Ishii
Y
Y
Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
van Weert
A W
AW
Hekking
E
E
de Marie
K
K
ter Horst
J
J
Oemrawsingh
P V
PV
Reiber
J H
JH
D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000150:complications / Q000601:surgery; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D009426:Netherlands / Q000453:epidemiology; D011182:Postoperative Care; D011300:Preoperative Care; D013223:Statistics as Topic; D015607:Stents; D014654:Vascular Patency