Shuzou Tanimoto

Comparison of in vivo acute stent recoil between the bioabsorbable everolimus‐eluting coronary stent and the everolimus‐eluting cobalt chromium coronary stent: Insights from the ABSORB and SPIRIT trials

Objectives: This study sought to evaluate and compare in vivo acute stent recoil of a novel bioabsorbable stent and a metallic stent. Background: The bioabsorbable everolimus‐eluting coronary stent (BVS) is composed of a poly‐L‐lactic acid backbone, coated with a bioabsorbable polymer containing the antiproliferative drug, everolimus, and expected to be totally metabolized and absorbed in the human body. Because the BVS is made from polymer, it may have more acute recoil than metallic stents in vivo. Methods: A total of 54 patients, who underwent elective stent implantation for single de novo native coronary artery lesions, were enrolled: 27 patients treated with the BVS and 27 patients treated with the everolimus‐eluting cobalt chromium stent (EES). Acute absolute recoil, assessed by quantitative coronary angiography, was defined as the difference between mean diameter of the last inflated balloon at the highest pressure (X) and mean lumen diameter of the stent immediately after the last balloon deflation (Y). Acute percent recoil was defined as (X − Y)/X and expressed as a percentage. Results: Acute absolute recoil of the BVS and EES was 0.20 ± 0.21 mm and 0.13 ± 0.21 mm, respectively (P = 0.32). Acute percent recoil was 6.9% ± 7.0% in the BVS group and 4.3% ± 7.1% in the EES group (P = 0.25). Conclusions: In vivo acute stent recoil of the BVS is slightly larger but insignificantly different from that of the EES, implying that the BVS may have good radial strength similar to the metallic stent.

Late Stent Recoil of the Bioabsorbable Everolimus-Eluting Coronary Stent and its Relationship With Plaque Morphology

OBJECTIVES This study sought to evaluate late recoil of a novel bioabsorbable everolimus-eluting coronary stent (BVS), which is composed of a poly-L-lactic acid backbone, coated with a bioabsorbable polymer containing everolimus. BACKGROUND Little is known about the mechanical behavior of bioabsorbable polymer stents after deployment in diseased human coronary arteries. METHODS The study population consisted of 16 patients, who were treated with elective BVS implantation for single de novo native coronary artery lesions and were followed at 6 months. All patients underwent an intravascular ultrasound examination at post-procedure and follow-up. A total of 484 paired cross-sectional areas (CSAs) were acquired and analyzed. Late absolute stent recoil was defined as stent area at post-procedure (X) - stent area at follow-up (Y). Late percent stent recoil was defined as (X - Y)/X x 100. In each CSA, plaque morphology was assessed qualitatively and classified as calcific, fibronecrotic, or fibrocellular plaque. RESULTS Late absolute and percent recoil of the BVS was 0.65 +/- 1.71 mm(2) (95% confidence interval [CI]: 0.49 to 0.80 mm(2)) and 7.60 +/- 23.3% (95% CI: 5.52% to 9.68%). Calcified plaques resulted in significantly less late recoil (0.20 +/- 1.54 mm(2) and 1.97 +/- 22.2%) than fibronecrotic plaques (1.03 +/- 2.12 mm(2) and 12.4 +/- 28.0%, p = 0.001 and p = 0.001, respectively) or fibrocellular plaque (0.74 +/- 1.48 mm(2) and 8.90 +/- 19.8%, p = 0.001 and p = 0.001, respectively). CONCLUSIONS The BVS shrank in size during the follow-up period. The lesion morphology of stented segments might affect the degree of late recoil of the BVS. (ABSORB Everolimus Eluting Coronary Stent System First in Man Clinical Investigation; NCT00300131).

Prevalence of Carotid Artery Stenosis in Patients With Coronary Artery Disease in Japanese Population

Background and Purpose— Prevalence of carotid artery stenosis in patients with coronary artery disease (CAD) is unknown in Japanese population. Methods— The study populations consisted of 632 consecutive patients who underwent coronary angiography because of suspicion of CAD. All patients underwent carotid ultrasonography to screen carotid artery stenosis before coronary angiography. We defined echographic carotid stenosis as area stenosis of >50% or peak systolic velocity of >200 cm/s. Results— Echographic carotid stenosis was observed in 124 patients (19.6%). Coronary angiography revealed 433 patients had CAD. Prevalence of echographic carotid artery stenosis was 14 of 199 (7.0%), 18 of 124 (14.5%), 28 of 131 (21.4%), and 64 of 178 (36.0%) in patients with 0-, 1-, 2-, and 3-vessel CAD, respectively (P<0.0001). The prevalence rate with carotid stenosis and CAD was 25.4%. Multivariate stepwise logistic regression analysis showed that age and the extent of CAD were independently related to the presence of carotid stenosis (P=0.0002 and <0.0001, respectively). Conclusions— Prevalence of carotid stenosis in patients with CAD is high in Japan as well as in Western countries. Screening of carotid artery stenosis is recommended especially in older patients with multivessel CAD.

A novel approach for quantitative analysis of intracoronary optical coherence tomography: High inter-observer agreement with computer-assisted contour detection

Objective: This study aims to examine observer‐related variability of quantitative optical coherence tomography (OCT) derived measurements from both in vitro and in vivo pullback data. Background: Intravascular OCT is a new imaging modality using infrared light and offering 10 times higher image resolution (15 μm) compared to intravascular ultrasound. The quantitative analysis of in vivo intracoronary OCT imaging is complicated by the presence of blood, motion artifacts and the large quantity of information that has to be processed. Methods: We developed a standardized, automated quantification process for intracoronary OCT pullback data with inter‐observer variability assessed both in vitro by using postmortem human coronary arteries and in vivo by studying simple and complex coronary pathology and outcomes following stent implantation. The consensus between measurements by two observers was analyzed using the intraclass and interclass correlation coefficient and the reliability coefficients. Bland–Altman plots were generated to assess the relationship between variability and absolute measurements. Results: In vitro OCT assessment was performed in nine postmortem coronary arteries. The time needed for semiautomated contour detection of a 15‐mm long coronary segment was ∼40 min. The absolute and relative difference between lumen area measurements derived from two observers was low [0.02 ± 0.10 mm2; (0.3 ± 0.5)% respectively] with excellent correlation confirmed by linear regression analysis (R2 = 0.99; P < 0.001). Similarly, in vivo measurements demonstrated a high correlation with the main source of inter‐observer variation occurring as a result of coronary dissection and motion artifact. The absolute and relative difference between measurements were 0.11 ± 0.33 mm2 (1.57 ± 0.05)% for lumen area (R2 = 0.98; P < 0.001), 0.17 ± 0.68 mm2 (1.44 ± 0.08)% for stent area (R2 = 0.94; P < 0.001), and 0.26 ± 0.72 mm2 (14.08 ± 0.37)% for neointimal area (R2 = 0.78; P < 0.001). Conclusions: Highly accurate computer‐assisted quantitative analysis ofintracoronary OCT pullbacks is feasible with low inter‐observer variability. The presented approach allows for observer independent analysis of detailed vessel structures, and may be a valuable tool for future longitudinal studies incorporating OCT.

Efficacy of everolimus eluting stent implantation in patients with calcified coronary culprit lesions: two-year angiographic and three-year clinical results from the SPIRIT II study

Background: Little is known about the impact of treatment with drug‐eluting stents (DES) on calcified coronary lesions. This analysis sought to assess the safety and efficacy of the XIENCE V everolimus‐eluting stent (EES) in patients with calcified or noncalcified culprit lesions. Methods: The study population consisted of 212 patients with 247 lesions, who were treated with EES alone. Target lesions were angiographically classified as none/mild, moderate, or severe grades of calcification. The population was divided into two groups: those with at least one target lesion moderately or severely calcified (the calcified group: 68 patients with 75 calcified lesions) and those with all target lesions having mild or no calcification (the noncalcified group: 144 patients). Six‐month and 2‐year angiographic follow‐up and clinical follow‐up up to 3 years were completed. Results: The baseline characteristics were not significantly different between both groups. When compared with the noncalcified group, the calcified group had significantly higher rates of 6‐month in‐stent angiographic binary restenosis (ABR, 4.3% vs. 0%, P = 0.03) and ischemia‐driven target lesion revascularization (ID‐TLR, 5.9% vs. 0%, P = 0.01), resulting in numerically higher major cardiac adverse events (MACE, 5.9% vs. 1.4%, P = 0.09). At 2 years, when compared with the noncalcified group, the calcified group presented higher in‐stent ABR (7.4% vs. 0%, P = 0.08) and ID‐TLR (7.8% vs. 1.5%, P = 0.03), resulting in numerically higher MACE (10.9% vs. 4.4%, P = 0.12). At 3 years, ID‐TLR tended to be higher in the calcified group than in the noncalcified group (8.6% vs. 2.4%, P = 0.11), resulting in numerically higher MACE (12.1% vs. 4.7%, P = 0.12). Conclusions: The MACE rates in patients treated with EES for calcified lesions were higher than in those for noncalcified lesions, but remained lower than the results of previously reported stent studies. EES implantation in patients with calcified culprit lesions was safe and associated with favorable reduction of restenosis and repeat revascularization.

Five-year clinical outcomes after coronary stenting of chronic total occlusion using sirolimus-eluting stents: Insights from the rapamycin-eluting stent evaluated at Rotterdam Cardiology Hospital—(Research) Registry†

Background: The use of drug eluting stents (DES) in patients with a successfully recanalized chronic total occlusion (CTO) has been associated with a significant decrease in the need for repeat revascularization, and a favorable short‐term clinical outcome when compared with the use of bare metal stents (BMS). Our group, however, has previously reported similar rates of target lesion revascularisation (TLR) and major adverse cardiovascular events (MACE) at 3 years follow‐up in patients with a successfully opened CTO who were treated with either a sirolimus eluting stent (SES) or a BMS. The objective of this report was to evaluate the outcomes of these patients at 5‐years clinical follow‐up. Methods and Results: A total of 140 (BMS 64, SES 76) patients with successfully opened CTOs were included. Seven patients died in the BMS group whilst nine patients died in the SES group (P = 0.90). Noncardiac death was the major component of all‐cause mortality (11 noncardiac deaths vs. 5 cardiac). There were two and three myocardial infarctions (MI) in the BMS and SES group, respectively (P = 1.0). The composite of death and MI occurred in seven (10.9%) and eleven (14.5%) patients in the BMS and SES group, respectively (P = 0.53). Clinically driven TLR was performed in eight patients (12.5%) in the BMS group, and five (6.6%) in the SES group (P = 0.26). Non‐TLR target vessel revascularization was performed in one patient in the BMS group, and four in the SES group (P = 0.37). The 5‐year device‐oriented cumulative MACE rate was 15.6% and 11.8% in the BMS and SES group, respectively (P = 0.56). Conclusion: In patients with a successfully treated CTO, clinical outcome after 5 years was similar between SES and BMS, however, clinically driven TLR was slightly higher in the BMS group.

Quantitative multi-modality imaging analysis of a bioabsorbable poly-L-lactic acid stent design in the acute phase: a comparison between 2- and 3D-QCA, QCU and QMSCT-CA

AIMS To investigate if three-dimensional (3D) based quantitative techniques are comparable to each other and to explore possible differences with respect to the reference method of 2D-QCA in the acute phase and to study whether non-invasive MSCT could potentially be applied to quantify luminal dimensions of a stented coronary segment with a novel bioabsorable drug-eluting stent made of poly-l-lactic-acid (PLLA). METHODS AND RESULTS Quantitative imaging data derived from 16 patients enrolled at our institution in a first-in-man trial (ABSORB) receiving a biodegradable stent and who were imaged with standard coronary angiography and intravascular ultrasound were compared. Shortly, after stenting the patients also underwent a MSCT procedure. Standard 2D-QCA showed significant smaller stent lengths (p < 0.01). Although, the absolute measured stent diameters and areas by 2D-QCA tend to be smaller, the differences failed to be statistically different when compared to the 3D based quantitative modalities. Measurements made by non-invasive QMSCT-CA of implanted PLLA stents appeared to be comparable to the other 3D modalities without significant differences. CONCLUSIONS Three-dimensional based quantitative analyses showed similar results quantifying luminal dimensions as compared to 2D-QCA during an evaluation of a new bioabsorbable coronary stent design in the acute phase. Furthermore, in biodegradable stents made of PLLA, non-invasive QMSCT-CA can be used to quantify luminal dimensions.

Two‐year clinical outcome after coronary stenting of small vessels using 2.25‐mm sirolimus‐ and paclitaxel‐eluting stents: Insight into the RESEARCH and T‐SEARCH registries

To evaluate long‐term outcomes after drug‐eluting stents (DES) implantation in small coronary vessels.

Clinical and Angiographic Outcomes Following Percutaneous Coronary Intervention With Sirolimus-Eluting Stents Versus Bare-Metal Stents in Hemodialysis Patients

BACKGROUND Percutaneous coronary intervention for hemodialysis patients has been hampered by the high rate of adverse cardiac events. Our aim was to investigate whether sirolimus-eluting stents (SESs) improve clinical outcomes of hemodialysis patients compared with bare-metal stents (BMSs). STUDY DESIGN Retrospective study. SETTING & PARTICIPANTS 123 consecutive patients on hemodialysis therapy treated with either an SES or BMS. There were 56 patients with 68 lesions treated with SESs between August 2004 and April 2006 (SES group) and 67 patients with 71 lesions treated with BMSs 4 years before approval of SESs in Japan (BMS group). PREDICTOR SES and BMS implantation for hemodialysis patients with coronary artery disease. OUTCOMES & MEASUREMENTS Follow-up angiography was performed at 6 to 8 months and clinical follow-up was obtained at 9 months after the procedure. Late lumen loss and major adverse cardiac events, including all-cause death, myocardial infarction, and target-lesion revascularization, were investigated. RESULTS Clinical follow-up was obtained in all patients. Angiographic follow-up was obtained in 50 patients (89.3%) in the SES group and 50 patients (74.6%) in the BMS group. The SES group had more complex lesions than the BMS group. Quantitative angiographic analysis showed a significant difference for in-stent late lumen loss (SES, 0.62 +/- 0.75 mm; BMS, 1.07 +/- 0.75 mm; P = 0.003). Of angiographic restenosis lesions analyzed, a focal restenotic pattern was observed more frequently in the SES group than the BMS group (SES, 87.5%; BMS, 23.8%; P < 0.001). The rate of major adverse cardiac events was significantly lower in the SES group (n = 14; 25.0%) than the BMS group (n = 26; 38.9%; log-rank P = 0.02). LIMITATIONS Retrospective study design, small sample size, and a single-center study. CONCLUSIONS Clinical and angiographic data in the present study suggest that SESs are more effective than BMSs in hemodialysis patients.

MAHOROBA, first-in-man study: 6-month results of a biodegradable polymer sustained release tacrolimus-eluting stent in de novo coronary stenoses

AIMS To report the 4-month angiographic and 6-month clinical follow-up in first-in-man study using the tacrolimus-eluting bioabsorbable polymer-coated cobalt-chromium MAHOROBA stent. METHODS AND RESULTS A total of 47 patients with either stable angina or unstable angina, or silent myocardial ischaemia, based on a de novo coronary stenosis that could be covered by a single 18 mm stent in a native coronary artery with a diameter between 3.0 and 3.5 mm were enrolled at three sites. The primary endpoint was in-stent late loss at 4 months. The secondary endpoints include %volume obstruction of the stents assessed by intravascular ultrasound (IVUS) at 4 months and major adverse cardiac events (MACE) at 6 months. Forty-seven patients were enrolled. Procedural success was achieved in 97.9%. At 4-month follow-up, in-stent late loss was 0.99 +/- 0.46 mm, whereas in-stent %volume obstruction in IVUS was 34.8 +/- 15.8%. At 6 months, there were no deaths, but 2 patients suffered from a myocardial infarction and 11 patients required ischaemia-driven repeat revascularization. The composite MACE rate was 23.4%. CONCLUSION This tacrolimus-eluting stent failed to prevent neointimal hyperplasia, despite the theoretical advantages of the tacrolimus, which has less inhibitory effects on endothelial cells than smooth muscle cells.