Yusuke Fujino

Optical coherence tomography versus intravascular ultrasound to evaluate coronary artery disease and percutaneous coronary intervention.

OBJECTIVES We compared intravascular ultrasound (IVUS) and 2 different generations of optical coherence tomography (OCT)-time-domain OCT (TD-OCT) and frequency-domain OCT (FD-OCT)-for the assessment of coronary disease and percutaneous coronary intervention (PCI) using stents. BACKGROUND OCT is a promising light-based intravascular imaging modality with higher resolution than IVUS. However, the paucity of data on OCT image quantification has limited its application in clinical practice. METHODS A total of 227 matched OCT and IVUS pull backs were studied. One hundred FD-OCT and IVUS pull backs in nonstented (n = 56) and stented (n = 44) vessels were compared. Additionally, 127 matched TD-OCT and IVUS images were compared in stented vessels. RESULTS FD-OCT depicted more severe native coronary disease than IVUS; minimal lumen area (MLA) was 2.33 ± 1.56 mm(2) versus 3.32 ± 1.92 mm(2), respectively (p < 0.001). Reference vessel dimensions were equivalent between FD-OCT and IVUS in both native and stented coronaries, but TD-OCT detected smaller reference lumen size compared with IVUS. Immediately post-PCI, in-stent MLAs were similar between FD-OCT and IVUS, but at follow-up, both FD-OCT and TD-OCT detected smaller MLAs than did IVUS, likely due to better detection of neointimal hyperplasia (NIH). Post-PCI malapposition and tissue prolapse were more frequently identified by FD-OCT. CONCLUSIONS FD-OCT generates similar reference lumen dimensions but higher degrees of disease severity and NIH, as well as better detection of malapposition and tissue prolapse compared with IVUS. First-generation TD-OCT was associated with smaller reference vessel dimensions compared with IVUS.

Frequency-domain optical coherence tomography assessment of unprotected left main coronary artery disease-a comparison with intravascular ultrasound.

To investigate safety and feasibility of imaging unprotected left main (ULM) using frequency‐domain optical coherence tomography (FD‐OCT) compared with intravascular ultrasound (IVUS).

Impact of residual chronic total occlusion of right coronary artery on the long-term outcome in patients treated for unprotected left main disease: the Milan and New-Tokyo registry.

Background—The presence of chronic total occlusion of the right coronary artery (CTO-RCA) in patients undergoing percutaneous interventions for unprotected left main (ULM) disease may affect the prognosis. In this study, we evaluated the immediate results and follow-up of patients with ULM-percutaneous interventions and with or without associated CTO-RCA. Methods and Results—Between March 2002 and December 2008, a total of 568 consecutive patients with ULM stenosis treated with drug-eluting stent were included in this analysis. The mean EuroScore and SYNTAX scores were 4.05±2.62 and 28.12±10.82, respectively. Of these, 522 had ULM lesions without residual CTO-RCA (493 ULM without CTO-RCA+29 ULM with treated CTO-RCA), and 46 patients had residual CTO-RCA. At 1466 days (interquartile range, 1150–1917) follow-up, the cardiac-death occurred in 41 patients (7.2%). Cardiac-death was more frequently observed in patients with ULM and residual CTO-RCA as compared with those without residual CTO-RCA (adjusted hazard ratios, 2.163 [95% confidence interval, 1.018–4.597]; P=0.045). However, target lesion revascularization occurred less frequently in patients with residual CTO-RCA (adjusted hazard ratios, 0.321 [95% confidence interval, 0.13–0.794]; P=0.014), resulting in the similar major adverse cardiovascular events rates between the 2 groups. When we analyzed patients with concomitant ULM and CTO-RCA, cardiac-death was significantly higher in patients with residual as compared with treated CTO-RCA (log-rank P=0.01) despite no difference in baseline characteristics. Conclusions—Cardiac-death occurred more frequently in patients with residual CTO-RCA as compared with those without residual CTO-RCA. These findings suggest that recanalization of CTO-RCA has significant impact on the long-term cardiac-mortality in patients undergoing ULM-percutaneous interventions probably by offering reserve coronary circulation, if in-stent restenosis were to occur in the treated left main.

Intravascular Frequency-Domain Optical Coherence Tomography Assessment of Carotid Artery Disease in Symptomatic and Asymptomatic Patients

OBJECTIVES The goal of this study was to investigate carotid plaque characteristics in symptomatic versus asymptomatic patients with the use of nonocclusive optical coherence tomography (OCT). BACKGROUND The identification of asymptomatic patients with carotid disease who are at risk of stroke remains a challenge. There is an increasing awareness that plaque characteristics may best risk-stratify this population. We hypothesized that OCT, a new high-resolution (∼ 10 μm) imaging modality, might be useful for the identification of low-risk versus high-risk carotid plaque features and help us to understand the relationship between carotid diameter stenosis and plaque morphology to ischemic stroke. METHODS Fifty-three patients undergoing diagnostic carotid angiography were studied with OCT. Data analysis was carried out by imaging experts who were unaware of the clinical characteristics of the study population. RESULTS Plaque with American Heart Association type VI complicated features was more common in symptomatic than asymptomatic patients (74.1% vs. 36.4%, p = 0.02). This was largely driven by differences in the incidence of thin-cap fibroatheroma with rupture (40.7% vs. 13.6%, p = 0.056) and thrombus (67.7% vs. 36.4%, p = 0.034). Conversely, non-type VI plaques were more common in asymptomatic than symptomatic patients (63.6% vs. 25.9%, p = 0.02). No association between the degree of stenosis and plaque morphology was identified. CONCLUSIONS This retrospective analysis of carotid OCT data supports the hypothesis that the evaluation of carotid plaque characteristics with this high-resolution imaging technique has the potential to alter the understanding and treatment of carotid artery disease.

Serial Assessment of Vessel Interactions After Drug-Eluting Stent Implantation in Unprotected Distal Left Main Coronary Artery Disease Using Frequency-Domain Optical Coherence Tomography

OBJECTIVES This study sought to assess stent-vessel interactions after drug-eluting stent (DES) implantation in unprotected left main coronary artery (ULM) by frequency-domain optical coherence tomography (FD-OCT). BACKGROUND Percutaneous coronary intervention using DES in ULM has been increasingly performed in routine practice. Recently, FD-OCT assessments of DES-vessel interactions have been used as surrogates for DES safety; however, there are no FD-OCT studies in ULM. METHODS We prospectively enrolled 33 consecutive patients with ULM disease treated with sirolimus- (n = 11) and everolimus-eluting stents (n = 22). FD-OCT assessments were performed post-percutaneous coronary intervention and at 9-month follow-up. Three different segments of ULM were compared: distal (DIS), bifurcation (BIF), and ostial-body (BODY). The primary endpoints were percentages of uncovered and malapposed struts at 9-month follow-up, and the secondary endpoint was neointimal hyperplasia area. RESULTS We analyzed 25,873 stent struts. Significant differences were demonstrated for percentage of uncovered struts (3.4%, 11.7%, and 18.7%, respectively for DIS, BIF, and BODY; p < 0.05 for all the comparisons). Malapposition was also more common in BODY (5.3%) than in DIS (0.6%) and BIF (2.0%) segments (p < 0.05 for BODY vs. DIS, and BODY vs. BIF). Equivalent neointimal hyperplasia areas were demonstrated in all segments. Acute malapposition rates led to different patterns of DES-vessel interactions at 9-month follow-up. CONCLUSIONS Distinct patterns of DES-vessel interactions were demonstrated in different segments of ULM. Acute stent strut malapposition affects these findings.

3-D Stent Detection in Intravascular OCT Using a Bayesian Network and Graph Search

Worldwide, many hundreds of thousands of stents are implanted each year to revascularize occlusions in coronary arteries. Intravascular optical coherence tomography is an important emerging imaging technique, which has the resolution and contrast necessary to quantitatively analyze stent deployment and tissue coverage following stent implantation. Automation is needed, as current, it takes up to 16 h to manually analyze hundreds of images and thousands of stent struts from a single pullback. For automated strut detection, we used image formation physics and machine learning via a Bayesian network, and 3-D knowledge of stent structure via graph search. Graph search was done on en face projections using minimum spanning tree algorithms. Depths of all struts in a pullback were simultaneously determined using graph cut. To assess the method, we employed the largest validation data set used so far, involving more than 8000 clinical images from 103 pullbacks from 72 patients. Automated strut detection achieved a 0.91±0.04 recall, and 0.84±0.08 precision. Performance was robust in images of varying quality. This method can improve the workflow for analysis of stent clinical trial data, and can potentially be used in the clinic to facilitate real-time stent analysis and visualization, aiding stent implantation.

The impact of main branch restenosis on long term mortality following drug-eluting stent implantation in patients with de novo unprotected distal left main bifurcation coronary lesions: the Milan and New-Tokyo (MITO) Registry.

In‐stent restenosis (ISR) remains one of the main limitations for percutaneous coronary intervention of unprotected distal left main (UDLM). This study aims to demonstrate the impact of main‐branch ISR (MB‐ISR) on mortality and to clarify the optimal strategy.

Frequency-Domain Optical Coherence Tomography Assessment of Unfavorable Kissing-Balloon Result in Unprotected Left Main Intervention

A 67-year-old man with a history of hypertension and dyslipidemia was admitted because of angina symptoms. Coronary angiography (CAG) showed an eccentric lesion of the distal unprotected left main coronary artery (ULMCA) involving the ostium of the left anterior descending coronary artery (LAD) ([

Bioresorbable Vascular Scaffolds for the Treatment of Chronic Total Occlusions: An International Multicenter Registry

Background— There are only limited studies reporting clinical outcomes after bioresorbable vascular scaffold (BVS; Absorb; Abbott Vascular, Santa Clara, CA) implantation for coronary chronic total occlusions (CTO). The aim of this study was to evaluate the real-world feasibility and safety of BVS implantation for the treatment of CTO. Methods and Results— We retrospectively evaluated CTO cases treated with BVS from a multicenter registry. The primary end point was target lesion failure defined as a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization. From September 2012 to November 2015, 65 patients with CTO were successfully treated with BVS. The mean age of patients was 60.8±11.0 years; 89.2% were male and 40.0% diabetic. The mean ejection fraction was 57.7±10.8%. The mean reference vessel diameter and CTO lesion length were 3.0±0.4 and 20.2±3.0 mm, respectively. The mean number of BVS deployed per patient was 1.8±0.7, of which mean diameter and total length were 3.0±0.4 and 47.6±19.9 mm, respectively. Postdilatation with noncompliant balloons (mean diameter 3.3±0.3 mm) was performed at high pressures (18.6±5.3 atm) in all cases. Intravascular ultrasound (n=34) or optical coherence tomography (n=31) was performed in all cases. During the follow-up period (median: 453 days, 25th and 75th percentiles: 230 and 703), there were no occurrences of target lesion failure or scaffold thrombosis. Conclusions— BVS implantation for the treatment of CTO seems feasible and safe. Appropriate lesion preparation, high-pressure postdilatation, and the use of intravascular imaging are recommended to obtain the best possible final result.

Comparison Between 1- and 2-Stent Strategies in Unprotected Distal Left Main Disease: The Milan and New-Tokyo Registry

Background—There are only little data available on the comparison of clinical outcomes between a 1-stent strategy (1-SS) and a 2-stent strategy (2-SS) for percutaneous coronary intervention in unprotected distal left main disease. Methods and Results—Between April 2005 and August 2011, we recruited 937 consecutive unprotected distal left main patients treated with drug-eluting stents (1-SS, 608 patients; 2-SS, 329 patients). Major adverse cardiovascular events were defined as all-cause death, myocardial infarction, or target lesion revascularization (TLR) during the median follow-up period of 1592 days. Furthermore, the individual components of major adverse cardiovascular events, cardiac death, and stent thrombosis were evaluated. More complex lesions were seen with 2-SS than with 1-SS. Cardiac death occurred more frequently with 1-SS than with 2-SS (propensity score–adjusted hazard ratio, 0.52; 95% confidence interval, 0.29–0.64; P=0.03), whereas TLR occurred more frequently with 2-SS than with 1-SS (propensity score–adjusted hazard ratio, 1.59; 95% confidence interval, 1.15–2.20; P=0.005). TLR was mainly driven by revascularizations after restenosis at the ostial left circumflex artery (propensity score–adjusted hazard ratio, 1.94; 95% confidence interval, 1.33–2.82; P=0.001). However, there were no differences in major adverse cardiovascular events, all-cause death, stent thrombosis, and myocardial infarction. Of the 139 pairs that were propensity score matched, only TLRs were significantly higher in the 2-SS group (hazard ratio, 1.59; 95% confidence interval, 1.00–2.53; P=0.05). Conclusions—The difference between 1-SS and 2-SS in percutaneous coronary intervention for unprotected distal left main disease may be summarized by the high incidence of TLR, mainly because of restenosis at the ostial left circumflex artery in the 2-SS group.