Gender Differences in the Circadian and Seasonal Variations in Patients with Takotsubo Syndrome: A Multicenter Registry at Eight University Hospitals in East Japan

Objective The aim of this study was to clarify the circadian and seasonal variations in addition to identify sex-based differences in Japanese patients with Takotsubo syndrome (TTS). Methods The authors conducted a retrospective observational study to analyse the differences between the groups based on sex. Patients The patients were registered out of each institute registry of the acute coronary syndrome (ACS) which contains a total of 10,622 cases in eight academic hospitals in east Japan. Results Data for 344 consecutive TTS (73 male and 271 female) were extracted from each hospital registry. In-hospital mortality was higher in the male group than in the female group (18% vs. 7%; p=0.005). With regard to the circadian variations in all study patients, TTS events occurred most often in the afternoon and least often during the night. Moreover, the patterns of circadian variations in the female and male groups were the same as that of all study patients. TTS events occurred most frequently in the autumn and least often in the spring in the whole study cohort. Moreover, the seasonal variation in the female group showed the same pattern as that of the whole cohort. However, there were no significant seasonal differences in the incidence of TTS in the male group. Conclusion In a multicenter study in Japan, seasonal variation was observed in the female group but not in the male group. Circadian variation was observed in both groups. These results suggested that the pathogenesis and clinical features of TTS might therefore differ according to sex.

Online three-dimensional OFDI-guided versus angiography-guided PCI in bifurcation lesions: design and rationale of the randomised OPTIMUM trial

AIMS

The feasibility of offline optical coherence tomography (OCT) guidance in bifurcation (with either two-dimensional or three-dimensional images) and its potential benefits have been demonstrated in retrospective studies; however, these have not yet been investigated prospectively. The aim of this trial is to determine the superiority of online three-dimensional optical frequency domain imaging (3D-OFDI)-guided stenting to angiography-guided percutaneous coronary intervention (PCI) in terms of incomplete stent apposition (ISA) at the bifurcation segment.

METHODS AND RESULTS

The OPTIMUM trial is a randomised, superiority, multicentre clinical trial. The primary endpoint of this trial is the post-procedural percentage of malapposed struts assessed by OFDI in the main branch bifurcation region after final kissing balloon dilatation (FKBD). A total of 106 patients will be randomly allocated to either 3D-OFDI guidance or angiography guidance PCI. Bifurcation lesions will be treated with a provisional single-stent strategy using the Ultimaster sirolimus-eluting stent. Patients randomised to the 3D-OFDI guidance arm will undergo OFDI assessment in the main branch (MV) after rewiring into the jailed side branch following stent implantation, while in the angiography guidance arm re-crossing of a wire into the side branch will be performed using conventional fluoroscopic/angiographic guidance. In patients in the 3D-OFDI guidance arm, if the position of the wire is not located in the optimal cell, further attempts to redirect the wire to the optimal cell will be performed, with subsequent OFDI acquisitions to confirm the re-crossing position. The proximal optimisation technique and FKBD are mandatory in this trial. The study will provide a 90% power to show superiority of 3D-OFDI guidance PCI compared with angiography-guided PCI.

CONCLUSIONS

The OPTIMUM trial will be the first prospective, randomised trial to evaluate the efficacy and safety of online 3D-OFDI-guided PCI in bifurcation lesions. ClinicalTrials.gov Identifier: NCT02972489.

Sex differences in clinical outcomes after rotational atherectomy of calcified coronary stenoses: from multicenter registry

BACKGROUND

Recent improvements in devices and medications may diminish the risk of adverse events following percutaneous coronary intervention (PCI) in women. However, complex calcified coronary lesions are increasingly being encountered in clinical practice, which remain challenging for contemporary PCI. Rotational atherectomy (RA) of severely calcified lesions is an option that facilitates the technical success of PCI. We aimed to examine sex differences in long-term clinical prognoses after PCI with RA in the drug-eluting stent (DES) era.

METHODS AND RESULTS

We evaluated J2T ROTA registry data from 1,090 patients with severely calcified de novo coronary artery stenoses who underwent PCI using RA at 3 hospitals between 2004 and 2015. After excluding patients who received regular hemodialysis, 788 patients, including 570 men and 218 women, were ultimately analyzed. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), which included death, acute coronary syndrome (ACS), and stroke. The women were significantly older, and presented more frequently with chronic kidney disease, ACS, atrial fibrillation, lower body mass indexes, and worse lipid profiles than the men. During the observation period, MACCE occurred in 197 patients (25%) (118 deaths, 29 strokes, and 50 ACS). In the unmatched population, women had a higher MACCE rate than men (hazard ratio: 1.48, [95% confidence interval: 1.07-2.06]). However, sex was not associated with MACCE in the propensity score-matched population.

CONCLUSION

In the DES era, differences between sexes were not observed in relation to long-term MACCE in patients undergoing PCI with RA for severely calcified coronary artery stenoses.

Long-Term Clinical Outcomes After Filter Protection During Percutaneous Coronary Intervention in Patients With Attenuated Plaque - 1-Year Follow up of the VAMPIRE 3 (Vacuum Aspiration Thrombus Reemoval 3) Trial

BACKGROUND

Selective use of distal filter protection during percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) decreased the incidence of no-reflow phenomena and in-hospital serious adverse cardiac events compared with conventional PCI in patients with attenuated plaque ≥5 mm; however, its long-term clinical outcome remains unknown.Methods and Results:Patients who had ACS with attenuated plaque ≥5 mm were assigned to receive distal protection (DP) (n=98) or conventional treatment (CT) (n=96). The rate of major adverse cardiovascular events (MACE), a composite of death from any cause, non-fatal myocardial infarction, or target vessel revascularization (TVR) at 1 year, was the pre-specified secondary endpoint of the trial. MACE at 1 year occurred in 12 patients (12.2%) in the DP group and 3 patients (3.1%) in the CT group (P=0.029), which was driven by a higher risk of TVR (11 [11.2%] vs. 2 [2.1%], P=0.018). In patients treated with bare-metal stents (n=42), MACE occurred in 25.0% of the patients in the DP group and in none of the patients in the CT group (P=0.029), whereas in patients treated with drug-eluting stents (n=151), rates of MACE were similar in the groups (8.1% vs. 3.9%, P=0.32).

CONCLUSIONS

In ACS patients with attenuated plaque ≥5 mm, the 1-year rates of MACE were higher in the DP group than in the CT group. This effect might be mitigated by the use of drug-eluting stents.

A Randomized Trial Evaluating Online 3-Dimensional Optical Frequency Domain Imaging-Guided Percutaneous Coronary Intervention in Bifurcation Lesions

Supplemental Digital Content is available in the text.

Background:

Clinical implications of online 3-dimensional optical frequency domain imaging (3D-OFDI)-guided stenting for bifurcation lesions have not been investigated in the randomized controlled trials. The purpose of this study was to determine whether online 3D-OFDI-guided stenting is superior to angiography-guided percutaneous coronary intervention (PCI) in terms of incomplete stent apposition at the bifurcation segment.

Methods:

The OPTIMUM trial (Online 3-Dimensional Optical Frequency Domain Imaging to Optimize Bifurcation Stenting Using UltiMaster Stent) was a randomized, multicenter clinical trial. Eligible patients had an angiographically significant stenosis in the bifurcation lesion treated with a provisional single stent strategy using the Ultimaster sirolimus eluting stent. Patients were randomly allocated to either online 3D-OFDI-guided or angiography-guided PCI. Patients randomized to 3D-OFDI guidance underwent online 3D-OFDI assessment after rewiring into the jailed side branch after stenting and proximal optimization technique, while in the angiography guidance arm, rewiring was performed using conventional fluoroscopic/angiographic guidance. The primary end point of this trial was the postprocedural average percentage of malapposed struts per lesion assessed by OFDI in the confluence zone of the main and side branches.

Results:

Between June 8, 2017 and September 26, 2018, 110 patients with 111 bifurcation lesions were randomized at 4 Japanese centers. Of these, 56 patients with 57 lesions were treated with 3D-OFDI-guided PCI, whereas 54 patients with 54 lesions were treated with angiography-guided PCI. In the 3D-OFDI guidance arm, the feasibility of online 3D-OFDI was 98.2%. The average percentage of incomplete stent apposition per lesion at bifurcation was lower in the 3D-OFDI guidance arm than that in the angiography guidance arm (19.5±15.8% versus 27.5±14.2%, P=0.008). The superiority of the 3D-OFDI guidance arm was also confirmed in the strut level analysis (odds ratio: 0.54 [95% CI, 0.36–0.81]; P=0.003).

Conclusions:

Online 3D-OFDI-guided bifurcation PCI was superior to angiography-guided bifurcation PCI in terms of acute incomplete stent apposition at bifurcation.

Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02972489.

Long-Term Clinical and Angiographic Outcomes After Implantation of New-Generation Drug-Eluting Stents for Patients on Maintenance Hemodialysis

Prior research has revealed poorer clinical outcomes after drug-eluting stent (DES) implantation for hemodialysis patients. This study aims to investigate the long-term clinical and angiographic outcomes after new-generation DES implantation for hemodialysis patients.We retrospectively enrolled 91 consecutive patients (118 lesions) who underwent successful new-generation DES (everolimus-, zotarolimus-, and biolimus-eluting stents) implantation for the first time. We measured the serum calcium and phosphorus levels in the blood samples obtained just before hemodialysis. The follow-up period of clinical events was, at least, 1.5 years. In this study, major adverse cardiac and cerebrovascular events (MACCE) and clinically driven target lesion revascularization were reported in 36 (39.6%) and 11 (12.1%) patients, respectively. The prevalence of peripheral artery disease was significantly higher in the MACCE group (41.7% versus 14.5%, P = 0.006). The serum calcium level was significantly higher in the MACCE group (9.34 ± 0.92 mg/dL versus 8.77 ± 0.88 mg/dL; P = 0.004). The multivariate Cox proportional hazards model revealed that the serum calcium level (hazard ratio, 1.86; 95% confidence interval [CI]: 1.26-2.77; P = 0.002), suboptimal (over 55 mg²/dL²) calcium-phosphorus product (hazard ratio, 3.27; 95% CI: 1.41-7.61; P = 0.006) and the coexistence of peripheral artery disease (hazard ratio, 3.15; 95% CI: 1.49-6.65; P = 0.003) were independent predictors of MACCE.For hemodialysis patients, MACCE remains a frequent occurrence after new-generation DES implantation and is associated with calcium-phosphate metabolism and peripheral artery disease.

Prognostic Impact of Scoring Balloon Angioplasty After Rotational Atherectomy in Heavily Calcified Lesions Using Second-Generation Drug-Eluting Stents: A Multicenter Registry-Based Study

BACKGROUND

We aimed to assess the impact of scoring balloon angioplasty (SBA) after rotational atherectomy (RA) on long-term clinical outcomes in patients who underwent percutaneous coronary intervention (PCI) using second-generation drug-eluting stents (DES). The long-term outcomes associated with SBA after RA in severely calcified lesions is unknown.

METHODS

Using the J2T ROTA registry data, we evaluated the clinical events of patients who underwent PCI using RA for heavily calcified lesions from January 2004 to December 2015. A total of 307 patients who underwent PCI with second-generation DES were analyzed and divided into the SBA (n = 96) and conventional balloon angioplasty (CBA) groups (n = 211). Eighty-two and 189 patients comprised the "SBA after small burr (SBA-SB)" and "CBA after small burr (CBA-SB)" subgroups, respectively, for the subgroup analysis. Study endpoints were incidence of 3-year major adverse cardiac events (MACE), target vessel revascularization (TVR), and target lesion revascularization (TLR).

RESULTS

Kaplan-Meier analysis revealed that the incidence of 3-year cumulative MACE, TVR, and TLR were comparable between groups, and that the incidences of 3-year cumulative MACE, TVR, and TLR were significantly lower in the SBA-SB subgroup than in the CBA-SB subgroup (log-rank p = 0.008; log-rank p = 0.047; log-rank p = 0.045; respectively). Multivariate Cox regression model indicated that SBA after RA was an independent predictor of MACE (hazard ratio: 0.337; 95% confidence interval: 0.139 to 0.817; p = 0.016).

CONCLUSIONS

Additional SBA following RA was associated with lower MACE incidence in patients undergoing RA with a small-sized burr.

Quantified frequency-domain optical coherence tomography analysis for the thin-high signals on restenotic tissue after paclitaxel-coated balloon angioplasty

Thin-high signals (THS), detectable by optical coherence tomography (OCT), represent the paclitaxel coverage of in-stent restenotic tissue. This study was conducted to assess the relationship between THS and angiographic outcomes by means of quantified post-procedural frequency-domain OCT (FD-OCT) analysis. From January 2014 to July 2016, 41 patients underwent FD-OCT-guided percutaneous coronary intervention using paclitaxel-coated balloon (PCB) to prevent in-stent restenosis. Of these, we retrospectively enrolled 32 patients (38 lesions) who underwent a 6- to 9-month follow-up angiogram. THS were assessed quantitatively, as THS length and lumen perimeter length were measured using semi-automated software; %THS was calculated by the following formula; total THS area/lumen perimeter area × 100. THS were detected in all 38 lesions that had undergone PCB angioplasty. THS and %THS were significantly higher in lesions without binary restenosis (3.34 ± 2.11 vs. 11.48 ± 8.53 mm², p = 0.001 and 1.49 ± 0.73 vs. 4.42 ± 2.71%, p = 0.001, respectively). Values for THS, which indicates the paclitaxel coverage on restenotic tissue, are associated with reducing restenosis after PCB for in-stent restenosis.

Efficacy and safety of transcatheter aortic valve implantation with Edwards SAPIEN 3 and XT in smaller Asian anatomy

We aimed to compare the efficacy and safety of transcatheter aortic valve implantation (TAVI) using Edwards SAPIEN 3 (S3) valve and SAPIEN XT) in smaller anatomy. The new generation S3 TAVI device has been used worldwide; however, its efficacy and safety in smaller Asian anatomy remain unknown. Between February 2014 and March 2017, 166 consecutive patients (S3, 54; XT, 112) were treated with balloon-expandable TAVI in a single center and their outcomes were analyzed. Median patient age was 85 (range: 81-88) years and mean body surface area was 1.41 ± 0.15 m². A 23-mm size valve was used in S3 and XT groups (70 vs. 62%, p = 0.224). The transfemoral approach was more frequently used in the S3 than in the XT group (96 vs. 72%, p < 0.001). Although, the minimal luminal diameter of the femoral artery was smaller in the S3 group (5.9 vs. 6.4 mm, p = 0.001), the rates of major (2 vs. 11%, p = 0.226) and minor (11 vs. 5%, p = 0.107) vascular complications did not increase. The frequency of paravalvular leaks (PVL) ≥ 2 was significantly reduced in the S3 group (11 vs. 61%, p < 0.001); however, pre- (24 vs. 91%, p < 0.001) and post- (4 vs. 19%, p < 0.001) dilatations were less frequently performed. Pacemaker implantation incidence did not increase (4 vs. 5%, p = 1.0) and peak velocity of the transcatheter heart valve was significantly higher in the S3 group (2.3 vs. 2.2 m/s, p = 0.046). Device success was high (89 vs. 93%, p = 0.387) while the 30-day all-cause mortality was low (2 vs. 1%, p = 0.583) in both groups. TAVI with the S3 device was safe and effective, with low incidence of vascular complications and reduced PVL, in smaller body-sized Asians.

Clinical Characteristics and Long-Term Outcomes of Rotational Atherectomy - J2T Multicenter Registry

BACKGROUND

Rotational atherectomy (RA) is an adjunct tool for the management of heavily calcified coronary lesions during percutaneous coronary intervention (PCI), but the long-term clinical outcomes of RA use remain unclear in this drug-eluting stent era.Methods and Results:This multi-center registry assessed the characteristics and outcomes of patients treated by RA for calcified coronary lesions between 2004 and 2015. Among 1,090 registered patients, mean age was 70±10 years and 815 (75%) were male. Sixty percent of patients had diabetes mellitus and 27.7% were receiving hemodialysis. The procedure was successful in 96.2%. In-hospital death occurred in 33 patients (3.0%), and 14 patients (1.3%) developed definite/probable stent thrombosis. During the median follow-up period of 3.8 years, the incidence of major adverse cardiac events (MACE), defined as all-cause death, acute coronary syndrome, stent thrombosis, target vessel revascularization and stroke, was 46.7%. On multivariable Cox hazard analysis, hemodialysis (HR, 2.08; 95% CI: 1.53-2.86; P<0.0001) and age (HR, 1.03; 95% CI: 1.01-1.04; P<0.0001) were strong independent predictors of MACE. Conversely, statin treatment was associated with lower incidence of MACE (P=0.035).

CONCLUSIONS

This study has provided the largest Japanese dataset for long-term follow-up of RA. Although RA in calcified lesions appears feasible with a high rate of procedural success, a high incidence of MACE was observed.

Three-Year Clinical and Angiographic Outcomes After Everolimus-Eluting Stent Implantation in Patients With a History of Coronary Artery Bypass Grafting

The clinical and angiographic outcomes after percutaneous coronary intervention (PCI) with everolimus-eluting stent (EES) implantation in patients with a history of coronary artery bypass grafting (CABG) have yet to be fully investigated. The aim of the present study was to investigate 3-year clinical outcomes after EES implantation in patients with a history of CABG.We retrospectively enrolled 176 consecutive patients who had undergone EES implantation. Three-year clinical follow-up data were obtained from all patients. Follow-up angiograms and serial quantitative coronary angiography analysis (QCA) were performed for 139 (79.0%) patients. Patients from the prior CABG (+) group (n = 17; 9.7%) had higher incidences of target lesion revascularization (TLR; 41.2% versus 3.8%, P < 0.001) and major adverse cardiac events (47.1% versus 15.1%, P = 0.004). A landmark analysis conducted 1 year into our study showed a higher incidence of TLR in the prior CABG (+) group (20.0% versus 3.0%, P = 0.017).The reason for EES implantation in the prior CABG (+) group was saphenous vein graft (SVG) failure in 19 (79.2%) lesions, although the target vessel was the SVG in 8 (33.3%) lesions. There were no significant differences in clinical and follow-up QCA data between the native vessel and SVG PCI groups.This study revealed that a history of CABG was a risk factor for TLR after EES implantation. The major reason for PCI after CABG was SVG failure; both native vessel and SVG PCI showed poor outcomes. Further investigations may be warranted to determine which interventions are most effective in this high-risk subset.

Usefulness of Everolimus-Eluting Coronary Stent Implantation in Patients on Maintenance Hemodialysis

The outcomes of second-generation drug-eluting stent (DES) are unknown in patients on maintenance hemodialysis (HD) although HD has been reported as a strong predictor of adverse outcome after the first-generation DES implantation. The OUCH-PRO Study is a prospective multicenter single-arm registry design to study clinical and angiographic outcomes after everolimus-eluting stent (EES). Patients who underwent maintenance HD were prospectively enrolled at the time of elective coronary intervention using EES. Quantitative coronary angiography was performed in an independent core laboratory. The primary end point was the occurrence of target vessel failure (TVF) defined as cardiac death, myocardial infarction (MI), and target vessel revascularization at 1 year. A total of 123 patients were enrolled and 161 EES were implanted. The TVF rate at 1 year was 18% (4% cardiac death, 0% MI, 17% target vessel revascularization). No stent thrombosis was documented. Other clinical events at 1 year were 3% noncardiac death, 3% stroke, and 9% non-target-vessel revascularization. Late lumen loss in stent was 0.37 ± 0.63 mm at 8 months. In conclusion, EES had a high TVF rate and great late lumen loss in patients on HD compared with previous huge EES data in non-HD patients.

Clinical and angiographic outcomes of paclitaxel-eluting coronary stent implantation in hemodialysis patients: A prospective multicenter registry: The OUCH-TL study (outcome in hemodialysis of TAXUS Liberte)

BACKGROUND

The outcome of percutaneous coronary intervention (PCI) has been reported to be poor in hemodialysis (HD) patients even in the drug-eluting stent era. We have reported relatively poor outcomes after sirolimus-eluting stent implantation in the OUCH study.

METHODS

The OUCH-TL study is a prospective, non-randomized, single-arm registry designed to assess the results of paclitaxel-eluting stent (PES) in HD patients with follow-up quantitative coronary angiography analysis. The primary endpoint was the occurrence of target-vessel failure (TVF) defined as cardiac death, myocardial infarction (MI), and target-vessel revascularization (TVR) at 12 months.

RESULTS

A total of 119 patients with 154 lesions were enrolled (one withdrawal). Mean age was 65±10 years, male gender was 79%, 89% of cases had stable coronary disease. Diabetic nephropathy was diagnosed in 61% of the patients. American College of Cardiology/American Heart Association type B2/C accounted for 96% of lesions and 22.7% of lesions were treated with Rotablator (Boston Scientific Corporation, Natick, MA, USA). Rates of TVF, death, MI, stent thrombosis and TVR at 12 months were 20.2%, 5.9%, 5.0%, 1.4%, and 12.6%, respectively. TVR was performed in 8.4% of the patients up to 12 months. Late loss in-stent was 0.48±0.61mm, and late loss in-segment was 0.37±0.61mm at 9 months. Binary restenosis in-stent was 10.3% and in-segment was 14.5%.

CONCLUSIONS

Outcomes of PES implantation in hemodialysis patients appears comparable to those of non-hemodialysis patients.

Quantitative optical coherence tomography analysis for late in-stent restenotic lesions

Coronary optical coherence tomography (OCT) has the potential to identify in-stent neoatherosclerosis, which is a possible risk factor for late acute coronary events after drug-eluting stent implantation. The purpose of this study was to investigate differences between mid-term and late in-stent restenosis after stent implantation by quantitative and semiautomated tissue property analysis using OCT. In total, 1063 OCT image frames of 16 lesions in 15 patients were analyzed. This included 346 frames of 6 lesions in late in-stent restenosis, which was defined as restenosis that was not detected at 6 to 12 months but ≥ 12 months after follow-up coronary angiography. Signal attenuation was circumferentially analyzed using a dedicated semiautomated software. Attenuation was assessed along 200 lines delineated radially for analysis of the in-stent restenotic lesions (between the lumen and stent contours). All lines were anchored by the image wire to avoid artifacts resulting from wire location. Stronger signal attenuation at the frame level (2.46 ± 0.78 versus 1.47 ± 0.32, P < 0.001) and higher maximum signal intensity at the lesion level (9.19 ± 0.19 versus 8.84 ± 0.32, P = 0.018) were observed in late in-stent restenotic lesions than in mid-term in-stent restenotic lesions. OCT demonstrated stronger signal attenuation and higher maximum signal intensity in late in-stent restenotic lesions than in mid-term in-stent restenotic lesions, indicating the possibility of neoatherosclerosis.

Angiographic findings of everolimus-eluting as compared to sirolimus-eluting stents: angiographic sub-study from the Randomized Evaluation of Sirolimus-eluting versus Everolimus-eluting stent Trial (RESET)

Several recent randomized trials comparing everolimus-eluting stent (EES) and sirolimus-eluting stent (SES) reported similar clinical outcomes. This study was aimed to clarify the differences in the angiographic findings of EES as compared to SES. Randomized Evaluation of Sirolimus-eluting versus Everolimus-eluting stent Trial is a prospective multicenter randomized open-label trial comparing EES with SES in Japan. From February to July 2010, 3197 patients were randomly assigned to receive either EES or SES. Of these, angiographic sub-study enrolled 571 patients (EES 285 patients, SES 286 patients). Angiograms were assessed qualitatively and quantitatively at procedure and at 8-12 months in the independent core angiographic laboratory. Late loss of the proximal edges tended to be greater in the EES group than that in the SES group (0.12 ± 0.49 vs. 0.04 ± 0.43 mm, P = 0.05), although late loss in the other segments was similar between the 2 groups. Edge restenosis was mainly observed in EES group, whereas body restenosis was demonstrated in half of SES group. Stent fracture was observed only in the SES group (1.5 %), and peri-stent contrast staining (PSS) tended to be more frequently observed in the SES group than in the EES group (3.6 and 1.5 %, P = 0.18). Restenotic response in the proximal edge was more prominent in the EES group as compared to the SES group. Abnormal angiographic findings such as stent fracture and PSS tended to be more frequent in the SES group.

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies: a report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

OBJECTIVES

The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease.

BACKGROUND

Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ~10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results.

METHODS

The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings.

RESULTS

Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text.

CONCLUSIONS

This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data.

Impact of acute gain on clinical outcomes of patients treated with sirolimus-eluting stent. - A sub-analysis study from the STLLR trial-

BACKGROUND

Geographical miss (GM), representing suboptimal drug-eluting stent deployment, is associated with an increased risk of target lesion revascularization (TLR) and myocardial infarction. The impact of suboptimal stenting techniques on clinical outcomes in diabetics remains unknown.

METHODS AND RESULTS

Stent deployment Techniques on cLinicaL outcomes of patients treated with the cypheR(TM) stent (STLLR) is the first multicenter, large trial to prospectively evaluate outcomes associated with sirolimus-eluting stent (SES) deployment techniques. Axial GM and longitudinal GM (LGM), defined as a balloon injured segment or a diseased segment not covered by a SES, were assessed by an independent core laboratory. One-year outcomes between diabetics and non-diabetics and their relationship with GM were assessed. This substudy included 1,336 patients, 28.8% with diabetes. In non-LGM patients, TLR was similarly low in both diabetics and non-diabetics (2.0% vs. 2.0%, P=NS). However, TLR increased 4.1 times in diabetics (8.0%) and 1.9 times in non-diabetics (3.8%) in the presence of LGM (P=0.03). Axial GM had no impact on outcomes. By univariate analysis, stent length, acute gain, and LGM were the predictors of TLR in the total cohort. However, by multivariate analysis, acute gain was the only predictor of TLR (P=0.03), independently of LGM or diabetes.

CONCLUSIONS

Acute gain is the exclusive predictor of TLR after SES implantation. Particularly in diabetics, the negative impact of LGM on TLR seems to be amplified. Diligent SES deployment for larger acute gain is critical to improve clinical outcomes.

Assessment of coronary stent by optical coherence tomography, methodology and definitions

Optical coherence tomography has emerged as a powerful tool for stent assessment, and in a short time, has become the modality of choice for studying stent and vascular interactions in vivo. In this review, we discuss qualitative and quantitative parameters used for stent assessment by OCT. Various qualitative/quantitative variables of stent assessment are discussed in the perspective of the clinical and research values of each of them.

Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images

Coronary calcified plaque (CP) is both an important marker of atherosclerosis and major determinant of the success of coronary stenting. Intracoronary optical coherence tomography (OCT) with high spatial resolution can provide detailed volumetric characterization of CP. We present a semiautomatic method for segmentation and quantification of CP in OCT images. Following segmentation of the lumen, guide wire, and arterial wall, the CP was localized by edge detection and traced using a combined intensity and gradient-based level-set model. From the segmentation regions, quantification of the depth, area, angle fill fraction, and thickness of the CP was demonstrated. Validation by comparing the automatic results to expert manual segmentation of 106 in vivo images from eight patients showed an accuracy of 78±9%. For a variety of CP measurements, the bias was insignificant (except for depth measurement) and the agreement was adequate when the CP has a clear outer border and no guide-wire overlap. These results suggest that the proposed method can be used for automated CP analysis in OCT, thereby facilitating our understanding of coronary artery calcification in the process of atherosclerosis and helping guide complex interventional strategies in coronary arteries with superficial calcification.

Strut Coverage and Vessel Wall Response to a New-Generation Paclitaxel-Eluting Stent With an Ultrathin Biodegradable Abluminal Polymer

Background—

Polymer-coated drug-eluting stents are effective in preventing restenosis but have been associated with delayed healing and incomplete strut coverage. It is unknown whether paclitaxel-eluting stents (PES) with minimal biodegradable abluminal coating enhances strut coverage while preventing neointimal hyperplasia. Using optical coherence tomography (OCT) as a primary imaging modality, we assessed the proportion of uncovered struts at 6-month follow-up in PES coated with durable versus ultrathin (<1 μm) biodegradable abluminal polymers.

Methods and Results—

In this pilot trial, 60 patients with de novo lesions (≤25 mm) in native coronary vessels were randomly assigned to receive either TAXUS Liberté PES or JACTAX PES, a Liberté stent with polymer deposited abluminally as microdots (JACTAX HD: 9.2 μg each of polymer and paclitaxel per 16-mm stent; JACTAX LD: 5 μg each). OCT follow-up occurred at 6 months with clinical follow-up through 1 year. The primary end point was percent uncovered struts by OCT. An independent core laboratory blinded to stent assignment analyzed images. The 6-month rate of uncovered struts per patient was 5.3±14.7% for TAXUS Liberté, 7.0±12.2% for JACTAX HD, and 4.6±7.3% for JACTAX LD ( P =0.81); percent malapposed struts was 1.4±4.4%, 0.8±1.9%, and 1.1±2.8%, respectively ( P =0.86). Strut-level intimal thickness was 0.20±0.10, 0.22±0.15, and 0.24±0.15 mm ( P =0.64); percent volume obstruction by OCT was 22.2±12.8, 22.5±16.2, and 25.8±15.2 ( P =0.69). There were no deaths, Q-wave myocardial infarctions, or stent thromboses through 1 year.

Conclusions—

JACTAX PES with an ultrathin microdot biodegradable abluminal polymer did not result in improved strut coverage at 6 months compared with TAXUS Liberté.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00776204.

Initial clinical experience with distal embolic protection using "Filtrap", a novel filter device with a self-expandable spiral basket in patients undergoing percutaneous coronary intervention

We developed a new filter-type distal protection guide wire, Filtrap, that uses a polyurethane filter with 1834 100-μm micropores covering the distal half of a spindle-shaped spiral Ni-Ti basket. The basket is 5 mm in diameter, self-expandable, and is mounted at the distal end of the system. This study aimed to assess the usefulness and safety of Filtrap during percutaneous coronary intervention (PCI). Early angiographic and in-hospital outcomes were reviewed in 14 patients, including 9 acute coronary syndrome patients, treated with Filtrap during PCI. All lesions were located in native coronary arteries but one was located in a saphenous vein graft. The Filtrap was successfully delivered and deployed distal to the lesion in 13 of 14 patients (93%). All PCI procedures including stent implantation were successfully completed except for 2 AMI patients, who ended up with Thrombolysis in Myocardial Infarction (TIMI) 2 coronary flow. One of these 2 patients had a distal embolization which occurred after thrombectomy before Filtrap insertion. The mean time of device insertion was 9.4 ± 3.2 min. Five patients showed transient no-reflow that was completely restored immediately with removal of the device. Embolic debris was entrapped in 8 (62%) of these cases. All patients were free from in-hospital events except for one patient with a large anterior acute myocardial infarction who received an emergency surgery due to a free wall cardiac rupture. These results suggest that the Filtrap is a practical and safe device for embolic protection during PCI.

Angiographic impact of the GuardWire system on inflated coronary segments after six months: does the distal protection balloon of the GuardWire Plus lead to restenosis?

AIMS

To investigate the consequences of inflating low-pressure balloon occlusion devices in native coronary arteries.

METHODS AND RESULTS

One hundred eighteen segments of 118 patients who were enrolled in the ASPARAGUS study were analysed post-procedure and at six months by means of quantitative coronary angiography. ASPARAGUS was a randomised study to assess the efficacy of the PercuSurge GuardWire system in acute myocardial infarction. Patients were divided into two groups; protection group (group P, n=53) and control group (group C, n=65). Matched 15 mm segments were selected for quantitative coronary angiographies using anatomical landmarks post-procedure and at six months. There were 118 matched QCA analysis (Group P 53, Group C 65). Baseline characteristics were similar between groups. The mean minimal lumen diameter (MLD) post procedure was 1.94+/-0.57 mm in group P and 1.92+/-0.57 mm in group C. The MLD at six months was 1.98+/-0.54 mm in group P and 1.92+/-0.54 mm in group C. There was virtually no late loss in both group (P: -0.04+/-0.38 mm, C: 0.00+/-0.38 mm, p=0.561).

CONCLUSIONS

The inflation of the low-pressure PercuSurge balloon in native coronary arteries was not associated with angiographic vascular response during the 6-month follow-up. This finding may suggest the safety of using similar technology such as the low-pressure balloon system in human native coronary arteries.

Optical coherence tomography (OCT) strut-level analysis of drug-eluting stents (DES) in human coronary bifurcations

AIMS

We sought to evaluate the vascular response of stent struts deployed in bifurcation segments using optical coherence tomography (OCT).

METHODS AND RESULTS

This study is a sub-analysis of ODESSA, a prospective randomised trial designed to evaluate healing of overlapped drug-eluting stents (DES) vs. bare metal stents (BMS) (sirolimus SES: paclitaxel PES: zotarolimus ZES: Liberté BMS in a 2: 2: 2: 1 ratio) for de novo coronary artery stenosis. OCT was performed at 6-month follow-up. Bifurcation segments with side branch diameters larger than 1.5mm by angiography were analysed. The cross-sectional image at the bifurcation segment was divided into three regions: opposite to the ostium (OO), adjacent to the ostium (AO), or side-branch ostium (SO). Struts were classified in three categories: uncovered (U), covered (C), or proliferative (P). The incidence of each strut category was compared between regions and stent types. There were 12,656 struts in 61 bifurcation segments (PES: 16, SES: 14, ZES: 23, Liberté BMS: 8) from 46 patients obtained at six months. PES had the highest rate of U in SO region (PES 60.1, SES 17.0, ZES 13.2, BMS 12.3 (%), P<0.0001), whereas SES demonstrated the highest rate of U in OO (PES 3.8, SES 14.0, ZES 1.5, BMS 0.0 (%), P=0.0025).

CONCLUSIONS

This study demonstrates a variable pattern of strut coverage in the bifurcation among stent technologies, with a high percentage of PES floating struts remaining uncovered at 6-month follow-up.

Serial quantitative coronary analyses for the evaluation of one-year change in saphenous vein grafts

BACKGROUND

A paucity of data exists with respect to changes in whole saphenous vein grafts (SVGs) despite accelerated atherosclerosis within grafted saphenous vein conduits. In the present study, we evaluated the one-year change in SVGs by means of quantitative coronary analysis.

METHODS

This study enrolled consecutive 52 patients with 109 SVGs, who underwent coronary artery bypass graft surgery successfully. A follow-up study was performed in 33 patients with 65 SVGs after one year because 16 SVGs were obstructed (baseline, 8; follow-up period, 8), and 15 patients with 28 SVGs dropped out within one year.

RESULTS

Both minimal and mean lumen diameters decreased significantly (3.17 +/- 0.64 mm vs 2.41 +/- 0.57 mm, p < 0.001; 3.70 +/- 0.69 mm vs 2.92 +/- 0.70 mm, p < 0.001; respectively). Graft length also decreased significantly (107.1 +/- 25.8 vs 100.6 +/- 25.2 mm, p < 0.001). The graft shortening rate (graft shortening length/baseline graft length x 100) was greater than 5% in 33 vessels (51%) and greater than 10% in 23 vessels (35%). Coronary risk factors (smoking, diabetes mellitus, hypertension, dyslipidemia) did not reveal significant relationship with late loss of minimal and mean lumen diameters.

CONCLUSIONS

The present study showed a considerable and uniform lumen loss of SVGs after one year, irrespective of coronary risk factors. Graft length shortening was seen more than elongation.

The impact of metallic allergy on stent implantation

BACKGROUND

Relation between metallic allergy and in-stent restenosis (ISR) has been inconclusive. We hypothesized that mechanism of restenosis is different between initial stent implantation and dilatation for ISR. Thus, we studied metallic allergy and restenosis in these two different situations separately.

METHODS AND RESULTS

We performed follow-up angiography and patch test for metallic allergy in a total of 174 stented consecutive patients, 109 patients (63%) for restudy of initial stent implantation and 65 patients (37%) for restudy of treatment following ISR. The positive rate of patch test in initial stent implantation was not significantly different between with or without restenosis (10% vs. 9%; p=ns). Whereas, following dilatation of ISR, the incidence of positive patch test was significantly higher in patients with recurrence of restenosis than those without the recurrence (39% vs. 12%; p=0.02). Multivariate analysis revealed that the positive patch test (Odd Ratio 4.39, p=0.02) and diffuse typed ISR (Odd Ratio 3.68, p=0.03) were significant predictors of recurrent restenosis.

CONCLUSIONS

Metal allergy does not have any correlation with the restenosis after initial stent implantation. However, metal allergy is frequently observed in patients with recurrence of ISR. Metal allergy may contribute to a mechanism in the repeat recurrence of ISR, but not to restenosis after initial stent implantation.

Pulmonary clearance and lesions in rats after a single inhalation of ultrafine metallic nickel at dose levels comparable to the threshold limit value

This study aimed to (1) determine the deposition and clearance rates of ultrafine metallic nickel (Uf-Ni) in rats after a 5 hours single inhalation exposure, and (2) to histopathologically examine the pulmonary lesions induced at dose levels comparable to the Occupational Exposure Limit recommended in Japan (OEL). The exposure concentrations of Uf-Ni for the 3 groups were 0.15 (Low), 1.14 (Medium), and 2.54 (High) mg/m3. Five rats/group were sacrificed at 0 h and 1, 3, 7, 14, and 21 days post exposure. The amount of Ni in the lung accumulated dose-dependently. The half-times for Ni in the lung were estimated as 32 days on average, and were similar to each other regardless of the initial dosage. The histopathologically observed pulmonary lesions induced by a single inhalation of Uf-Ni were, (1) a significant increase in lung weight in the High and Medium groups with time, (2) accumulation of foamy alveolar macrophages (AM), (3) degenerated AM indicating alveolar lipoproteinosis which was aggravated for up to 4 weeks in the High group and (4) acute calcification of the degenerated AM was remarkable. The present results suggest that even a single inhalation of Uf-Ni induces potency of lung lesions at dose levels comparable to the OEL (1 mg/m3 as Ni), or the TWA of ACGIH (1.5 mg/m3 for elemental/metal).

Acute biological effects of intratracheally instilled titanium dioxide whiskers compared with nonfibrous titanium dioxide and amosite in rats

The dimensions of man-made mineral fiber whiskers are similar to those of some kinds of asbestos. Thus these mineral fibers raise the concern for potential health hazard for workers exposed in the occupational environments. This study was designed to define acute biological effects of intratracheally administered titanium dioxide whiskers (TO1) compared with nonfibrous titanium dioxide (TOP) and UICC amosite (Ams), and their relations to acute lung inflammation in rats. The observed geometric mean length (microm) and width (microm) and geometric standard deviation are: TO1(2.1[2.0], 0.14[1. 53]); Ams (4.3[3.3], 0.31[1.9]); and TOP (50 nm, 1-2 microm aggregates). Ten-week-old Wistar-Jcl male rats received a single tracheal injection of test materials at doses between 0.05 and 1.0 mg/rat. Control animals were injected with the same volume of saline. Lung tissue and bronchoalveolar lavage (BAL) fluid were collected from rats on days 1, 3, and 7 after administration. In the group injected with TO1, total protein, cytokine-induced neutrophil chemoattractant (CINC)/growth-regulated gene product (GRO), interleukin (IL) 1beta, and tumor necrosis factor (TNF) alpha increased on day 1. Subsequently, total elastolytic activity and fucose levels in BAL increased by day 3. All parameters, except for fucose in BAL, recovered to the normal levels. Animals in the Ams group showed increased total protein and CINC/GRO and decreased total elastolytic activity in a dose-dependent manner on day 1. The fucose level increased on day 3 in the Ams group. All parameters returned to their control levels on day 7. Animals in the TOP group did not show significant changes any of parameters during the experimental period. Gene expression of TNF-alpha and monocyte chemoattractant protein (MCP) 3 in the lung increased dose-dependently in the animals treated with the three materials. The mRNAs for eotaxin and MIP-1alpha were overexpressed in the lung of animals treated with Ams and TO1, while RANTES mRNA was overexpressed dose-dependently in the lung of animals treated with Ams on day 1. Onset of inflammatory response was more rapid in the Ams group than the TO1 group. Recovery of the fucose level in BAL was slower in the TO1 group than in the Ams group, though we observed similar histopathological changes in the lung of animals with TO1 or Ams. We conclude that whisker-induced acute biological effects in the lung may be related to the shape of the whiskers and not to their chemical composition or surface crystal structure, showing biological effects similar to those of UICC amosite.

Hexavalent chromium responsible for lung lesions induced by intratracheal instillation of chromium fumes in rats

Lung toxicity of chromium fumes (Cr fumes) was examined by a single intratracheal instillation into rats of 10.6 mg and 21.3 mg Cr fumes/kg body weight and by repeated (3 times) instillations of 10.8 mg and 21.7 mg Cr fumes/kg. The pathological changes were compared with those induced by single administrations of 3.2 mg and 19.2 mg Na2CO3 solution-insoluble fraction of Cr fumes (Cr-Fr)/kg and 20.8 mg commercially available chromium (III) oxide powder (Cr (III) oxide)/kg. Single and repeated administrations of Cr fumes suppressed growth rate in a dose-dependent manner, but administrations of Cr-Fr and Cr (III) oxide did not. A single administration of Cr fumes produced granulomas in the entire airways and alveoli with progressive fibrotic changes, as well as severe mobilization and destruction of macrophages and foamy cells. Those histopathological changes were aggravated by the repeated administration of Cr fumes. On the other hand, single administrations of Cr-Fr and Cr (III) oxide produced no remarkable histopathological changes. Cr fumes were found to be composed of 73.5% chromium (III) oxide and 26.5% chromium (VI) oxide. The primary particles of Cr fumes and Cr-Fr were similar, 0.02 micron in size (sigma g: 1.25), and Cr (III) oxide particles were 0.30 micron in size (sigma g: 1.53), measured by analytical electron microscopy (ATEM). Diffuse clusters of the primary particles in Cr fumes were identified as Cr (VI) oxide. The present results suggested that the lung toxicity of Cr fumes was mainly caused by these Cr (VI) oxide (CrO3) particles in Cr fumes.

A new model rat with acute bronchiolitis and its application to research on the toxicology of inhaled particulate matter

The aim of the present study was to establish a useful animal model that simulates humans sensitive to inhaled particulate matter (PM). We have developed a new rat model of acute bronchiolitis (Br) by exposing animals to NiCl2 (Ni) aerosols for five days. Three days following the Ni exposure, the animals developed signs of tachypnea, mucous hypersecretion, and bronchiolar inflammation which seemed to progress quickly during the fourth to fifth day. They recovered from lesions after four weeks in clean air. To assess the sensitivity of the Br rats to inhaled particles, two kinds of PM of respirable size were tested with doses similar to or a little higher to the recommended threshold limit values (TLVs) for the working environment in Japan. Titanium dioxide (TiO2 = Ti) was chosen as an inert and insoluble particles and vanadium pentoxide (V2O5 = V), as a representative soluble and toxic airborne material. The Br rats exposed to either Ti or V were compared the pathological changes in the lungs and the clearance of particles to those in normal control or Br rats kept in clean air. The following significant differences were observed in Br rats: 1. delayed recovery from pre-existing lesions or exacerbated inflammation, 2. reductions in deposition and clearance rate of inhaled particles with the progress of lesions. The present results suggest that Br rats are more susceptible to inhaled particles than control rats. Therefore, concentrations of particulate matter lower than the TLVs for Japan, which have no harmful effects on normal lungs, may not always be safe in the case of pre-existing lung inflammation.

Evaluation of low-level asbestos exposure by transbronchial lung biopsy with analytical electron microscopy

To improve diagnostic sensitivity for detecting low-level asbestos exposure (AEx) in patients, a new method was developed using an analytical transmission electron microscope (ATEM) for specimens of transbronchial lung biopsy (TBLB). The TBLB specimens from 28 patients were examined and the results were: 1) In cases with long-term AEx, the present method detected a large amount of asbestos fibers (AF) as well as asbestos bodies (AB) showing a good agreement with the results of light microscope (LM) which detected definite amounts of ferruginous bodies (FB). 2) In cases with short-term or suspected AEx, the LM failed to detect FB in some cases, but an appreciable amount of AF was detected using the present method, and AEx was disclosed through a second close interview. 3) Neither AB nor AF were detected in most of the cases without any dust exposure. Although small amounts of chrysotile fibers were observed in some cases, this might simply reflect the exposure level of urban dwellers. These results show that the ATEM applied to the TBLB specimens promises to confirm low-level AEx in such small specimens even if the patients were unaware of their past AEx.

Effects of arterial distensibility on left ventricular ejection in the depressed contractile state

OBJECTIVE

The aim was to evaluate the effects of arterial distensibility on ventricular ejection in various ventricular contractile states: (1) control; (2) a regionally depressed contractile state due to left circumflex coronary artery occlusion (ligation); (3) a globally depressed contractile state induced by lignocaine (lignocaine); and (4) a globally augmented contractile state due to dobutamine infusion (dobutamine).

METHODS

Arterial compliance was decreased from 2.3 x 10(-4) dyne-1.cm5 (C2.3) to 0.4 x 10(-4) dyne-1.cm5 (C0.4), maintaining other afterload components and left ventricular end diastolic pressure constant. Nine excised perfused and paced canine hearts, supported from donor dogs, were used.

RESULTS

In control, ligation, lignocaine, and dobutamine groups, the difference in cardiac output between the compliance values of C0.4 and C2.3 was 124(SEM 32), 204(36), 163(33), and 130(24) ml, respectively. Thus cardiac output at C0.4, as a percentage of that at C2.3, was 88(2.8)% (control), 75(2.9)% (ligation), 82(2.9)% (lignocaine), and 88(2.4)% (dobutamine), respectively: control v ligation, and lignocaine v ligation, p < 0.001; control v lignocaine, and dobutamine v ligation, p < 0.01. Stroke work at C0.4 decreased in the ligation group (63%, p < 0.001) and in the lignocaine group (70%, p < 0.001).

CONCLUSIONS

When cardiac dysfunction is already present, decreased arterial distensibility has a further deleterious effect on cardiac output. This may be due to the fact that the pressure at the end of ejection is higher and as a result the change in dimension during ejection is considerably reduced, especially in cases with depressed cardiac function caused by afterload dependency.