Akiyoshi Miyazawa

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

OBJECTIVES The aim of this study was to compare the vessel response between zotarolimus-eluting stents (ZES) and paclitaxel-eluting stents (PES) using intravascular ultrasound. BACKGROUND The 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. METHODS Data 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. RESULTS At 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). CONCLUSIONS There 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).

Analysis of left main coronary artery bifurcation lesions treated with biolimus‐eluting DEVAX AXXESS plus nitinol self‐expanding stent: Intravascular ultrasound results of the AXXENT trial

Objective: To assess the efficacy of the AXXESS stent on the treatment of left main coronary artery (LMCA) bifurcation lesions using IVUS. Background: The treatment of LMCA bifurcation lesions remains challenging even with the use of drug‐eluting stents. The AXXESS system is a biolimus A9‐eluting self‐expanding stent, dedicated to the treatment of bifurcation lesions. Methods: Data were obtained from the AXXENT trial, a prospective, single‐arm, multicenter study designed to evaluate the efficacy of the AXXESS stent on the treatment of LMCA bifurcation lesions. IVUS was available in 26 cases at 6‐months follow‐up. Volumetric and cross‐sectional analyses within the AXXESS stent, and cross‐sectional analyses at the ostia of left anterior descending (LAD) and left circumflex coronary arteries (LCX) were performed. Results: Within the AXXESS stent, percent neointimal volume obstruction was (3.0 ± 4.1)% with a minimal lumen area of 10.3 ± 2.6 mm2. AXXESS stent volume showed an 12.4% increase at follow‐up compared with postprocedure (P = 0.04). Lumen area was significantly smaller in the LCX ostium compared with the LAD ostium at follow‐up (3.6 ± 1.3 mm2 vs. 5.5 ± 2.0 mm2, P = 0.0112). There was greater neointimal formation in the LCX ostium compared with the LAD ostium (1.37 ± 1.20 mm2 vs. 0.30 ± 0.36 mm2, P = 0.0003). Conclusions: The AXXESS stent in the LMCA showed enlargement through 6‐months follow‐up and significant neointimal suppression. Greater neointimal formation and relatively inadequate stent expansion may contribute to luminal narrowing in the LCX ostium.

Analysis of bifurcation lesions treated with novel drug-eluting dedicated bifurcation stent system: intravascular ultrasound results of the AXXESS PLUS trial.

The aim of this intravascular ultrasound (IVUS) study was to assess the efficacy of the AXXESS Plus stent system for the treatment of bifurcation coronary lesions.

Outcomes of everolimus-eluting stent incomplete stent apposition: a serial optical coherence tomography analysis.

AIM The aim of the present study was to evaluate the natural course of acute incomplete stent apposition (ISA) after second-generation everolimus-eluting stent (EES) when compared with first-generation sirolimus-eluting stent (SES) by using optical coherence tomography (OCT). METHODS AND RESULTS From the OCT substudy of the RESET trial, we identified 77 patients (EES = 38 and SES = 39) who successfully underwent serial OCT examination at post-stenting and 8-12-month follow-up. The presence of ISA was assessed in the OCT images, and ISA distance was measured from the centre of the strut blooming to the adjacent lumen border. Incomplete stent apposition was observed in all EES and SES at post-stenting, and it was persistent in 26% of EES and 38% of SES at 8-12-month follow-up. Maximum ISA distance was significantly decreased during the follow-up period in both EES (315 ± 94-110 ± 165 μm, P < 0.001) and SES (308 ± 119-143 ± 195 μm, P < 0.001). Receiver-operating curve analysis identified that the best cut-off value of OCT-estimated ISA distance at post-stenting for predicting late-persistent ISA at 8-12-month follow-up in EES and SES was >355 and >285 μm, respectively. CONCLUSIONS The second-generation EES showed better healing of acute ISA in comparison with the first-generation SES. Optical coherence tomography can predict late-persistent ISA after DES implantation and provide useful information to optimize PCI.

Sex differences in neointimal hyperplasia following endeavor zotarolimus-eluting stent implantation.

Inconsistent results in outcomes have been observed between the genders after drug-eluting stent implantation. The aim of this study was to investigate gender differences in neointimal proliferation for the Endeavor zotarolimus-eluting stent (ZES) and the Driver bare-metal stent (BMS). A total of 476 (n = 391 ZES, n = 85 BMS) patients whose volumetric intravascular ultrasound analyses were available at 8-month follow-up were studied. At 8 months, neointimal obstruction and maximum cross-sectional narrowing (CSN) were significantly lower in women than in men receiving ZES (neointimal obstruction 15.5 ± 9.5% vs 18.2 ± 10.9%, p = 0.025; maximum CSN 30.3 ± 13.2% vs 34.8 ± 15.0%, p = 0.007). Conversely, these parameters tended to be higher in women than in men receiving BMS (neointimal obstruction 36.3 ± 15.9% vs 27.5 ± 17.2%, p = 0.053; maximum CSN 54.3 ± 18.6% vs 45.6 ± 18.3%, p = 0.080). There was a significant interaction between stent type and gender regarding neointimal obstruction (p = 0.001) and maximum CSN (p = 0.003). Multivariate linear regression analysis revealed that female gender was independently associated with lower neointimal obstruction (p = 0.027) and maximum CSN (p = 0.004) for ZES but not for BMS. Compared to BMS, ZES were independently associated with a reduced risk for binary restenosis in both genders (odds ratio for women 0.003, p = 0.001; odds ratio for men 0.191, p <0.001), but the magnitude of this risk reduction with ZES was significantly greater in women than men (p = 0.015). In conclusion, female gender is independently associated with decreased neointimal hyperplasia in patients treated with ZES. The magnitude of risk reduction for binary restenosis with ZES is significantly greater in women than in men.

Peri-stent contrast staining and very late stent thrombosis after sirolimus-eluting stent implantation: an observation from the RESTART (REgistry of Stent Thrombosis for review And Re-evaluaTion) angiographic substudy.

AIMS The aim of the study was to clarify the angiographic characteristics of stent thrombosis (ST) in relation to sirolimus-eluting stents (SES). METHODS AND RESULTS RESTART is a Japanese registry of SES-associated ST. As an angiographic substudy, coronary angiograms at baseline, at six to 12 months and at the time of ST were analysed. Angiograms of 313 patients (early ST [EST] 169 patients, late ST [LST] 59 patients, and very late ST [VLST] 85 patients) were investigated. Residual dissection post procedure was more frequently seen in the EST group. Stent fracture was more frequently seen in the VLST group than in the EST and LST groups (16.5%, 3.0%, and 3.4%, respectively; p<0.001). Peri-stent contrast staining (PSS), defined as contrast staining outside the stent contour extending to ≥20% of the stent diameter, was remarkably more prevalent in the VLST group than in the EST and LST groups (34.1%, 4.7%, and 6.8%, respectively; p<0.001). CONCLUSIONS Abnormal angiographic findings such as PSS and stent fracture were found significantly more frequently in lesions with VLST than in lesions with EST and LST.

Predominant microvessel proliferation in coronary stent restenotic tissue in patients with diabetes: insights from optical coherence tomography image analysis.

BACKGROUND Coronary optical coherence tomography (OCT) enables virtual depiction of histological findings of in-stent restenotic tissue. The aim of this study was to investigate the microvessel proliferation within in-stent restenotic tissue and the influence of diabetes mellitus (DM). METHODS We examined 54 in-stent restenotic coronary artery lesions (stenotic area>50%) from 50 consecutive patients including 28 with DM (56%) and 9 insulin-treated DM patients (18%); who underwent coronary time-domain OCT imaging with automatic pull back (1mm/s, 20 frames/s). Microvessels were defined as low-signal cavities with a diameter of 50-150 microns and a trajectory parallel to the lumen recognized on 3 consecutive cross-sectional OCT image frames. The microvessel index was calculated as the number of frames with microvessel/total number of frames × 100. Patients were stratified into 3 groups: 1) without microvessels, 2) with a low (< median value) microvessel index, 3) with a high microvessel index. RESULTS Microvessels were detected in 566 frames (3.1%) from 26 lesions (48%) in 24 patients (48%). A greater incidence of DM and higher serum glucose levels were observed in the high microvessel index group (DM: 42% vs 58% vs 83%, p=0.049; serum glucose level: 118.2 ± 44.6 vs 122.6 ± 31.0 vs 172.8 ± 63.1mg/dL, p=0.03 between low and high microvessel index group, p=0.005 between no microvessel and high microvessel index group). CONCLUSIONS Microvessel formation may be a unique pathophysiological factor of in-stent restenoses in patients with DM.

Quantitative coronary optical coherence tomography image analysis for the signal attenuation observed in-stent restenotic tissue

primary pulmonary hypertension has been published by Rothman et al. [21]. Thus, a review of the epidemiological literature supports the assertion that phentermine has not been implicated in producing primary pulmonary hypertension. The same considerations discussed above apply to the statement in the PDR that “the possibility of an association between valvular heart disease and the use of phentermine alone cannot be ruled out”. At the time the labelwaswritten, thatwas an appropriately cautious statement. However, as we discussed in our reply to Yosefys original letter, further researchhas failed tofindanassociationof phenterminewithVHD[5], an assessment that is shared with by The American College of Cardiology/ American Heart Association Task Force on Practice Guidelines [6]. In our opinion, although the PDR is a valuable resource for information on medications, the PDR entry for phentermine is overly cautiouswhen considered in the context of published reports. In viewof the worsening worldwide obesity epidemic and of the known cardiac risks obesity imposes, it is fortunate that physicians have available to them a medication such as phentermine, which, in fifty years of widespread use, has proven to be remarkably safe. The drug is effective and inexpensive, costing far less thanmore recentlyapproveddrugs [13]. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology [22].

Novel stent system for bifurcation lesions: examination by intravascular ultrasound.

Bifurcation disease represents a mechanical and biological challenge for definitive interventional treatment. This case report discusses an experience with a novel stent system designed for the treatment of bifurcation lesions.

Coronary Artery Stent Evaluation Using a Vascular Model at 64-Detector Row CT: Comparison between Prospective and Retrospective ECG-Gated Axial Scans

Objective We wanted to evaluate the performance of prospective electrocardiogram (ECG)-gated axial scans for assessing coronary stents as compared with retrospective ECG-gated helical scans. Materials and Methods As for a vascular model of the coronary artery, a tube of approximately 2.5-mm inner diameter was adopted and as for stents, three (Bx-Velocity, Express2, and Micro Driver) different kinds of stents were inserted into the tube. Both patent and stenotic models of coronary artery were made by instillating different attenuation (396 vs. 79 Hounsfield unit [HU]) of contrast medium within the tube in tube model. The models were scanned with two types of scan methods with a simulated ECG of 60 beats per minute and using display field of views (FOVs) of 9 and 18 cm. We evaluated the in-stent stenosis visually, and we measured the attenuation values and the diameter of the patent stent lumen. Results The visualization of the stent lumen of the vascular models was improved with using the prospective ECG-gated axial scans and a 9-cm FOV. The inner diameters of the vascular models were underestimated with mean measurement errors of -1.10 to -1.36 mm. The measurement errors were smaller with using the prospective ECG-gated axial scans (Bx-Velocity and Express2, p < 0.0001; Micro Driver, p = 0.0004) and a 9-cm FOV (all stents: p < 0.0001), as compared with the other conditions, respectively. The luminal attenuation value was overestimated in each condition. For the luminal attenuation measurement, the use of prospective ECG-gated axial scans provided less measurement error compared with the retrospective ECG-gated helical scans (all stents: p < 0.0001), and the use of a 9-cm FOV tended to decrease the measurement error. Conclusion The visualization of coronary stents is improved by the use of prospective ECG-gated axial scans and using a small FOV with reduced blooming artifacts and increased spatial resolution.