Ichizo Tsujino

Intravascular Ultrasound Results From the ENDEAVOR IV Trial Randomized Comparison Between Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease

OBJECTIVESnThe aim of this study was to compare the vessel response between zotarolimus-eluting stents (ZES) and paclitaxel-eluting stents (PES) using intravascular ultrasound.nnnBACKGROUNDnThe ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial was a randomized controlled study of zotarolimus-eluting, phosphorylcholine-coated, cobalt-alloy stents for the treatment of de novo coronary lesions compared with using PES for the same treatment.nnnMETHODSnData were obtained from patients with serial (baseline and 8-months follow-up) intravascular ultrasound analysis available (n = 198). Volumetric analysis was performed for vessel, lumen, plaque, stent, and neointima. Cross-sectional narrowing (given as percentage) was defined as neointimal area divided by stent area. Neointima-free frame ratio was calculated as the number of frames without intravascular ultrasound-detectable neointima divided by the total number of frames within the stent. Subsegment analysis was performed at every matched 1-mm subsegment throughout the stent.nnnRESULTSnAt follow-up, the ZES group showed significantly greater percentage of neointimal obstruction (16.6 +/- 12.0% vs. 9.9 +/- 8.9%, p < 0.01) and maximum cross-sectional narrowing (31.8 +/- 16.1% vs. 25.2 +/- 14.9%, p < 0.01) with smaller minimum lumen area than the PES group did. However, the incidence of maximum cross-sectional narrowing >50% was similar in the 2 groups. Neointima-free frame ratio was significantly lower in the ZES group. In overall analysis, whereas the PES group showed positive remodeling during follow-up (13.7 +/- 4.2 mm(3)/mm to 14.3 +/- 4.3 mm(3)/mm), the ZES group showed no significant difference (12.7 +/- 3.6 mm(3)/mm to 12.9 +/- 3.5 mm(3)/mm). In subsegment analysis, significant focal positive vessel remodeling was observed in 5% of ZES and 25% of PES cases (p < 0.05).nnnCONCLUSIONSnThere were different global and focal vessel responses for ZES and PES. Both drug-eluting stents showed a similar incidence of lesions with severe narrowing despite ZES having a moderate increase in neointimal hyperplasia compared with neointimal hyperplasia in PES. There was a relatively lower neointima-free frame ratio in ZES, suggesting a greater extent of neointimal coverage. (The ENDEAVOR IV Clinical Trial: A Trial of a Coronary Stent System in Coronary Artery Lesions; NCT00217269).

Drug delivery via nano-, micro and macroporous coronary stent surfaces

Drug-eluting stents (DESs) have revolutionized the treatment of occlusive coronary artery disease via marked reduction of in-stent restenosis. One critical feature for successful DESs is the sustained release of drugs, which is achieved using a polymer coating in the present generation of DESs. However, recent studies have raised a concern that polymers may trigger allergic reactions and/or prolonged inflammation in some patients. These untoward reactions may eventually lead to undesirable clinical events, including stent thrombosis and sudden cardiac death. A new drug delivery technology, using a porous stent surface, may offer desirable drug elution properties without the use of polymers, and may translate into an improved safety profile for the next-generation DESs.

SPIRIT III JAPAN Versus SPIRIT III USA: A Comparative Intravascular Ultrasound Analysis of the Everolimus-Eluting Stent

The aim of this study was to evaluate the vascular response after everolimus-eluting stent (EES) implantation in the SPIRIT III Japan Registry (JAPAN) compared to EES implantation in the SPIRIT III United States (USA) trial using serial intravascular ultrasound (IVUS) analysis. Data were obtained from the JAPAN and the randomized EES arm of the USA trial. Serial (postprocedure and 8-month follow-up) IVUS analysis was available in 199 lesions (JAPAN 82, USA 117) of 183 patients (JAPAN 73, USA 110). Although no difference was observed in vessel size in the reference segment between the 2 groups, postprocedure minimum lumen area and stent volume index were significantly greater in the JAPAN arm (minimum lumen area 5.8 +/- 2.2 vs 5.1 +/- 1.5 mm(2), p = 0.03; stent volume index 7.0 +/- 2.4 vs 6.3 +/- 1.7 mm(3)/mm, p = 0.03). Postprocedure incomplete stent apposition (ISA) was less frequently observed in the JAPAN arm (15.9% vs 33.3%, p = 0.006), possibly related to higher maximum balloon pressure and/or more postdilatation without excess tissue prolapse or edge dissection. In the JAPAN arm, percent neointimal obstruction and maximum percent cross-sectional narrowing were significantly lower at 8-month follow-up (percent neointimal obstruction 3.5 +/- 4.2% vs 6.8 +/- 6.4%, p = 0.0004). Late acquired ISA was infrequent in the 2 arms. In conclusion, comparative IVUS analysis between the JAPAN and USA arms showed more optimal stent deployment in the JAPAN arm as evidenced by the lower incidence of postprocedure ISA and larger minimum lumen area after the procedure. Moreover, there was less neointimal hyperplasia in patients with EES implants from the JAPAN arm compared to the USA arm.

Incidence of diffuse and focal chronic stent recoil after implantation of current generation bare-metal and drug-eluting stents

Abstract Background The incidence of chronic stent recoil of currently available stents is not well known. Methods The incidence and degree of both diffuse and focal stent recoil during 6xa0months follow-up were evaluated in 52 Cypher, 64 Taxus, 61 Endeavor and 50 Driver stents using 3 dimensional intravascular ultrasound (IVUS) data. Results The overall incidence of diffuse and focal stent recoil was 3.5% and 1.8%, respectively. No difference was found in the incidence of stent recoil among all stents evaluated. The degree of recoil was not correlated with the amount of neointima. Conclusions Analysis of serial IVUS volumetric data revealed a low incidence of chronic stent recoil among current generation stents.

Comparison of everolimus- versus paclitaxel-eluting stents implanted in patients with diabetes mellitus as evaluated by three-dimensional intravascular ultrasound analysis.

Previous reports have shown the advantage of paclitaxel compared to limus-derivative drugs for the treatment of diabetics. A total of 109 diabetics (115 lesions) treated with everolimus-eluting stents (EESs, n = 58) or paclitaxel-eluting stents (PESs, n = 55) undergoing 8 to 9 months of follow-up 3-dimensional intravascular ultrasound examinations were enrolled. In addition to the standard intravascular ultrasound parameters, the percentage of neointimal volume (neointimal volume/stent volume) and maximum percentage of cross-sectional narrowing (neointimal area/stent area) was calculated. EESs showed a lower percentage of neointimal volume (7.2 +/- 7.1% vs 11.7 +/- 11.0%; p = 0.01) and maximum percentage of cross-sectional narrowing (22.5 +/- 16.3% vs 29.4 +/- 19.2%; p = 0.04) than PESs. One case of severe narrowing (lesions with maximum percentage of cross-sectional narrowing >60%) in the EES group developed and 6 cases in the PESs group (p = 0.05). The EESs showed no serial changes for vessel or peri-stent plaque during the follow-up period, and PESs showed significant increases in vessel and peri-stent plaque. PESs showed significantly greater peri-stent plaque increase, with a tendency toward greater vessel enlargement than EESs. Late acquired incomplete stent apposition was observed in 2 PES cases. The major adverse cardiac event rate was comparable < or =2 years. In conclusion, EESs showed greater neointimal suppression without significant vessel expansion than PESs in diabetic patients. In this small cohort, no significant differences were observed in the major adverse cardiac event rate < or =2 years.

Comparison of vascular response to the everolimus-eluting stent versus the paclitaxel-eluting stent: intravascular ultrasound results from the SPIRIT III trial.

AIMSnThe purpose of this study was to investigate the vascular response of the everolimus-eluting stent (EES) compared with the paclitaxel-eluting stent (PES) using serial intravascular ultrasound (IVUS).nnnMETHODS AND RESULTSnData were obtained from the SPIRIT III trial, a multicentre, 2:1 randomised, controlled study comparing EES and PES in de novo native coronary artery lesions. IVUS images were eligible for volumetric analysis at eight-month follow-up in 158 lesions (EES: 113, PES: 45). At eight months, EES had a smaller neointimal volume index (VI: mm3/mm) (EES: 0.4±0.4 vs. PES: 0.8±0.8 mm3/mm, p=0.002) and also a smaller % neointimal obstruction (EES: 7.1±6.7% vs. PES: 11.1±10.5%, p=0.005) compared with PES. While there was no significant change in vessel VI with EES, there was a significant increase in vessel VI in PES during eight-month follow-up (EES: 0.1±1.2 vs. PES: 1.2±0.8 mm3/mm, p=0.001). There were no statistical differences in the frequency of edge dissection or incomplete stent apposition between the two groups.nnnCONCLUSIONSnDetailed IVUS analysis confirmed significantly less neointimal hyperplasia with EES compared with PES. While there was no increase in vessel volume with EES during the eight-month follow-up period, vessel enlargement was seen at the stented segment in PES.

Intravascular ultrasound insights from the Cobalt Chromium Stent With Antiproliferative for Restenosis II (COSTAR II) trial comparing CoStar and Taxus paclitaxel-eluting stents

BACKGROUNDnDedicated IVUS analyses of the second CObalt chromium STent with Antiproliferative for Restenosis (COSTAR II) trial have not been documented. We aim to compare IVUS findings between CoStar paclitaxel-eluting stent (PES) and Taxus PES in patients enrolled in the COSTAR II trial. We also attempted to examine the possible regional impact of multiple stenting.nnnMETHODS AND MATERIALSnAmong the 1700 patients enrolled, 238 were assigned to an IVUS cohort including 168 patients treated by provisional multiple stenting. At 9 months, qualitative and quantitative IVUS observations including incomplete stent apposition (ISA) and neointimal proliferation (neointimal obstruction: neointimal volume/stent volume ×100) were compared between CoStar and Taxus PESs.nnnRESULTSnIn qualitative analysis, late-acquired ISA was observed in 1 patient treated by Taxus PES. Impaired strut continuity suggestive of stent fracture was observed in 2 out of 33 patients treated by multiple CoStar, and 4 out of 21 patients treated by multiple Taxus (P=.14). No such findings were found in single-stented patients in either stent subset. Quantitative analysis showed greater neointimal obstruction in CoStar (19.7%±13.4%, n=52) than in Taxus (10.7%±9.9%, n=38), whereas no significant difference in neointimal obstruction was found between single and multiple stenting in either CoStar or Taxus PES.nnnCONCLUSIONSnThe CoStar PES exhibits greater neointimal proliferation compared with Taxus PES at 9 months but with similar qualitative outcomes including late-acquired ISA. IVUS findings suggestive of stent fracture were found only in multiple-stenting cases irrespective of the stent used.