ORIGINAL ARTICLE Assessment of optimum stent deployment by stent boost imaging: comparison with intravascular ultrasound Nobuhiro Tanaka • Nico H. J. Pijls • Jacques J. Koolen • Kees-Joost Botman • Herman R. Michels • Bart R. G. Brueren • Kathinka Peels • Naohisa Shindo • Jun Yamashita • Akira Yamashina Received: 17 May 2011 / Accepted: 30 September 2011 / Published online: 29 October 2011 Ó Springer 2011 Abstract Stent boost (SB) imaging is an enhancement of the radiologic edge of the stent by digital management of regular X-ray images. The purpose of the present study was to validate SB imaging by comparison with the anatomical standard using intravascular ultrasound (IVUS). We investigated SB and IVUS after stent implantation in 68 arteries in 60 patients. Based on those findings, we added high-pressure dilatation in four patients and another stent implantation in four patients. We defined the SB criteria for adequate stent deployment as: complete stent expansion, stent minimum diameter C70% of reference diameter, and stent minimum diameter C2.0 mm; and IVUS criteria for adequate stent deployment as: minimal stent area C5.0 mm 2 . If the reference vessel was \ 2.8 mm, adequate stent deployment was defined as minimum stent area C4.5 mm 2 . IVUS findings indicated inadequate stent deployment in 21/72 observations (29%). Seven SB images showed inadequate stent expansion. SB predicted inade- quate findings of IVUS with 100% specificity, 33% sensi- tivity, and 81% agreement. Although the sensitivity of SB image for adequate stent deployment is low, the specificity is sufficiently high for it to be the first-line for monitoring just after stent implantation in centers where IVUS is not used routinely. Keywords Stent boost imaging Á Intravascular ultrasound Á Optimum stent deployment Introduction Coronary stent implantation has improved clinical outcome after percutaneous coronary intervention. However, early or late thrombotic complications after coronary stent implantation (acute/subacute/late stent thrombosis) remain a problem. These are associated with a high mortality or serious morbidity (myocardial infarction) [1, 2], and with both bare metal and drug-eluting stents. One of the major causes of stent thrombosis is insufficient stent deployment. This condition is often hard to recognize from regular coronary angiograms. The only reliable way to exclude insufficient stent deployment with certainty is intravascular ultrasound (IVUS) [3–6]. However, in every daily practice, this technique is not used routinely because it is expensive, time-consuming, and can only be used by interventionalists who are specifically trained in the interpretation of this technique [7]. Stent boost (SB) imaging has been developed by a Philips Medical Systems based upon techniques that enhance the radiologic edge of the stent, and can be obtained by digital management of regular coronary angi- ograms [8, 9]. The stent edges are generally only very faintly visible, but by using this method, a better contour of the stent is obtained. The promise of this methodology is that adequate deployment of the stent can be better judged, without additional steps or expensive equipment. The methodology is extremely safe, user-friendly, cheap, and requires only an extra cine-run of a few seconds. This is in sharp contrast to the present gold standard, i.e., IVUS, as mentioned above. The purpose of the present study was to N. Tanaka (&) Á N. Shindo Á J. Yamashita Á A. Yamashina Department of Internal Medicine, Tokyo Medical University, 6-7-1 Nishi-shinjuku, Shinjuku-ku, Tokyo 160-0023, Japan e-mail: n-tanaka@tokyo-med.ac.jp N. H. J. Pijls Á J. J. Koolen Á K.-J. Botman Á H. R. Michels Á B. R. G. Brueren Á K. Peels Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands 123 Heart Vessels (2013) 28:1–6 DOI 10.1007/s00380-011-0202-9