Masahiko Ochiai

Predicting Successful Guidewire Crossing Through Chronic Total Occlusion of Native Coronary Lesions Within 30 Minutes : The J-CTO (Multicenter CTO Registry in Japan) Score as a Difficulty Grading and Time Assessment Tool

OBJECTIVESnThis study sought to establish a model for grading lesion difficulty in interventional chronic total occlusion (CTO) treatment.nnnBACKGROUNDnOwing to uncertainty of success of the procedure and difficulties in selecting suitable cases for treatment, performance of interventional CTO remains infrequent.nnnMETHODSnData from 494 native CTO lesions were analyzed. To eliminate operator bias, the objective parameter of successful guidewire crossing within 30 min was set as an end point, instead of actual procedural success. All observations were randomly assigned to a derivation set and a validation set at a 2:1 ratio. The J-CTO (Multicenter CTO Registry of Japan) score was determined by assigning 1 point for each independent predictor of this end point and summing all points accrued. This value was then used to develop a model stratifying all lesions into 4 difficulty groups: easy (J-CTO score of 0), intermediate (score of 1), difficult (score of 2), and very difficult (score of ≥ 3).nnnRESULTSnThe set end point was achieved in 48.2% of lesions. Independent predictors included calcification, bending, blunt stump, occlusion length >20 mm, and previously failed lesion. Easy, intermediate, difficult, and very difficult groups, stratified by J-CTO score, demonstrated stepwise, proportioned, and highly reproducible differences in probability of successful guidewire crossing within 30 min (87.7%, 67.1%, 42.4%, and 10.0% in the derivation set and 92.3%, 58.3%, 34.8%, and 22.2% in the validation set, respectively). Areas under receiver-operator characteristic curves were comparable (derivation: 0.82 vs. validation: 0.76).nnnCONCLUSIONSnThis model predicted the probability of successful guidewire crossing within 30 min very well and can be applied for difficulty grading.

In-Hospital Outcomes of Contemporary Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion: Insights From the J-CTO Registry (Multicenter CTO Registry in Japan)

OBJECTIVESnOur aim was to investigate in-hospital outcomes of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) using contemporary techniques.nnnBACKGROUNDnDespite its increasing popularity and technical complexity, clinical outcomes of PCI for CTO using contemporary techniques have not been adequately evaluated.nnnMETHODSnThe J-CTO registry (multicenter CTO registry in Japan) is a large scale, multicenter registry enrolling consecutive patients undergoing PCI for CTO from 12 Japanese centers. In-hospital clinical outcomes were evaluated in 498 patients with 528 CTO lesions.nnnRESULTSnMultiple wiring strategies were frequently attempted (parallel wiring 31% and retrograde approach 25%) with relatively long guidewire manipulation time (median 30 min). Utilizing these complex strategies, high procedural success rates (88.6% in the first attempt cases and 68.5% in the retry cases) were accomplished. In-hospital adverse event rates were strikingly low (cardiac death 0.2%, Q-wave myocardial infarction 0.2%, and stroke 0%). Potential disadvantages of these procedures, including a large amount of contrast volume (median 293 ml) and long fluoroscopic time (median 45 min), were not associated with serious clinical sequelae (contrast induced nephropathy 1.2% and radiation dermatitis 0%). Although coronary perforations were documented frequently by angiography (antegrade 7.2% and retrograde 13.6%), clinically significant perforation resulting in cardiac tamponade was rare (0.4%).nnnCONCLUSIONSnMost CTO lesions can be safely and successfully treated with PCI utilizing contemporary advanced techniques. Invasiveness and potential risks of these strategies, which have been the greatest concerns of CTO treatment, may be acceptable in the majority of cases considering the actual incidences of related adverse events and the procedural success rates.

Fundamental Wire Technique and Current Standard Strategy of Percutaneous Intervention for Chronic Total Occlusion With Histopathological Insights

Currently, successful treatment of chronic total occlusion (CTO) seems markedly improved, due to several new techniques and dedicated device developments. However, this improved success rate is often limited to procedures performed by skilled, highly experienced operators. To improve the overall success rate of percutaneous coronary intervention of CTO from a worldwide perspective, a deeper understanding of CTO histopathology might offer insights into the development of new techniques and procedural strategies. In this review, CTO histopathology and wire techniques are discussed on the basis of the fundamental concepts of antegrade and retrograde approaches. Although details pertaining to wire manipulation are very difficult to explain objectively, we tried to describe this as best as possible in this article. Finally, a systematic review of the current standard CTO strategy is provided. Hopefully, this article will enhance the understanding of this complex procedure and, consequently, promote safe and effective CTO-percutaneous coronary intervention for patients who present with this challenging lesion subset.

Intravascular Ultrasound Classification of Plaque Distribution in Left Main Coronary Artery Bifurcations Where Is the Plaque Really Located

Background—Angiographic classifications of the location and severity of disease in the main vessel and side branch of coronary artery bifurcations have been proposed and applied to distal left main coronary artery (LMCA) bifurcation. Methods and Results—We reviewed 140 angiograms of distal LMCA and ostial left anterior descending (LAD) and left circumflex (LCX) artery lesions with preintervention intravascular ultrasound (IVUS) of both the LAD and LCX arteries as well as the LMCA. Of 140 patients, 92.9% had at least 1 cross section with ≥40% IVUS plaque burden versus 57.2% of patients with an angiographic diameter stenosis ≥50%. Contrary to angiographic classifications, IVUS showed that bifurcation disease was rarely focal and that both sides of the flow divider were always disease-free. Continuous plaque from the LMCA into the proximal LAD artery was seen in 90%, from the LMCA into the LCX artery in 66.4%, and from the LMCA into both the LAD and LCX arteries in 62%. Plaque localized to either the LAD or LCX ostium and not involving the distal LMCA was seen in only 9.3% of LAD arteries and 17.1% of LCX arteries. Plaque distribution was not influenced by the LAD/LCX angiographic angle, lesion severity, LMCA length, or remodeling. We proposed an IVUS classification for bifurcation lesions illustrating longitudinal and circumferential spatial plaque distribution. Conclusions—Angiographic classification of LMCA bifurcation lesions is rarely accurate. IVUS shows that the carina is always spared and that the disease is diffuse rather than focal. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180466.

Intravascular Ultrasound Classification of Plaque Distribution in Left Main Coronary Artery Bifurcations

Background—Angiographic classifications of the location and severity of disease in the main vessel and side branch of coronary artery bifurcations have been proposed and applied to distal left main coronary artery (LMCA) bifurcation. Methods and Results—We reviewed 140 angiograms of distal LMCA and ostial left anterior descending (LAD) and left circumflex (LCX) artery lesions with preintervention intravascular ultrasound (IVUS) of both the LAD and LCX arteries as well as the LMCA. Of 140 patients, 92.9% had at least 1 cross section with ≥40% IVUS plaque burden versus 57.2% of patients with an angiographic diameter stenosis ≥50%. Contrary to angiographic classifications, IVUS showed that bifurcation disease was rarely focal and that both sides of the flow divider were always disease-free. Continuous plaque from the LMCA into the proximal LAD artery was seen in 90%, from the LMCA into the LCX artery in 66.4%, and from the LMCA into both the LAD and LCX arteries in 62%. Plaque localized to either the LAD or LCX ostium and not involving the distal LMCA was seen in only 9.3% of LAD arteries and 17.1% of LCX arteries. Plaque distribution was not influenced by the LAD/LCX angiographic angle, lesion severity, LMCA length, or remodeling. We proposed an IVUS classification for bifurcation lesions illustrating longitudinal and circumferential spatial plaque distribution. Conclusions—Angiographic classification of LMCA bifurcation lesions is rarely accurate. IVUS shows that the carina is always spared and that the disease is diffuse rather than focal. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180466.

Intravascular Ultrasound Comparison of the Retrograde Versus Antegrade Approach to Percutaneous Intervention for Chronic Total Coronary Occlusions

OBJECTIVESnWe sought to evaluate the results of the antegrade versus retrograde chronic total occlusion (CTO) technique with intravascular ultrasound (IVUS) imaging.nnnBACKGROUNDnThe most common failure mode of CTO interventions remains the inability to successfully cross the occlusion with a guidewire. Recently, the retrograde approach through collateral channels has been introduced to cross complex CTOs.nnnMETHODSnBetween October 2002 and April 2008, IVUS was performed in 48 de novo CTO lesions after guidewire crossing +/- pre-dilation with a 1.5- to 2.0-mm balloon. Twenty-three lesions were treated via the antegrade approach (Ante), and 25 lesions were treated via the retrograde approach (Retro).nnnRESULTSnRight coronary artery (RCA) CTOs were treated more frequently via the Retro technique. Although the CTO length was much longer in the Retro group (45 +/- 26 mm vs. 18 +/- 9 mm, p < 0.0001), at the end of the procedure Thrombolysis In Myocardial Infarction flow grade 3 was obtained in all patients. There were no significant differences between the 2 groups in minimum stent area and stent expansion. However, the incidence of the composite end point-subintimal wiring, angiographic extravasation, coronary hematoma, or IVUS-detected coronary perforation-was higher in the Retro group (68% vs. 30%, p = 0.01); and the guidewire was more often subintimal in the Retro group (40% vs. 9%, p = 0.02).nnnCONCLUSIONSnThe retrograde approach is a promising option for complex CTO segments, especially long RCA CTOs. Intravascular ultrasound can be a useful tool for the detection of procedure-related vessel damage and subintimal wire tracking.

Patients' skin dose during percutaneous coronary intervention for chronic total occlusion

The purpose of this research is to assess the patients entrance skin dose (ESD) during percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) in six institutions.

Is Accurate Intravascular Ultrasound Evaluation of the Left Circumflex Ostium from a Left Anterior Descending to Left Main Pullback Possible

Treatment of left main coronary artery bifurcation lesions might depend on the ostial left circumflex (LC) or ostial left anterior descending (LAD) disease severity. We sought to evaluate whether intravascular ultrasound assessment of the side branch ostium requires direct imaging or is accurate from the main vessel. Our retrospective analysis included 126 patients with left main coronary artery bifurcation disease (plaque burden > or =40% by intravascular ultrasound scanning). We analyzed pullbacks from the LAD and the LC. First, during the main vessel pullback (ie, from the LAD), we evaluated the side branch ostium (ie, of the LC). Second, we compared this oblique view with the direct ostial measurements during LC pullback. Finally, we repeated this process, imaging the ostial LAD from the LC. From the LAD, the oblique LC ostial lumen diameter was 3.0 +/- 0.8 mm compared to the directly measured lumen diameter of 2.9 +/- 0.6 mm. From the LC, the oblique LAD ostial lumen diameter was 2.9 +/- 1.1 mm compared to the directly measured lumen diameter of 2.8 +/- 0.5 mm. However, Bland-Altman plots showed significant variation in the oblique versus direct comparisons. The 95% limits of agreement ranged from -1.84 to 1.14 mm (mean difference -0.35, SD 0.75) for the LAD and -1.69 to 1.22 mm (mean difference -0.23, SD 0.73) for the LC. The oblique view detection of any plaque in the side branch predicted 40% or 70% plaque burden with good sensitivity but poor specificity. In conclusion, intravascular ultrasound evaluation of a side branch ostium from the main vessel is only moderately reliable, especially for distal left main coronary artery lesions. For an accurate assessment of the side branch ostium, direct imaging is necessary.

Association between increased epicardial adipose tissue volume and coronary plaque composition

To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or calcified tissue, based on the radiofrequency spectrum. Epicardial adipose tissue was measured as the tissue ranging from −190 to −30 Hounsfield units. EATV, calculated as the sum of the fat areas on short-axis images, was 85.0 ± 34.0 cm3. There was a positive correlation between EATV and the percentage of necrotic plaque tissue (R2 = 0.34, P < 0.01), while there was a negative correlation between EATV and the percentage of fibrous tissue (R2 = 0.24, P < 0.01). Multivariate analysis revealed that an increased low-density lipoprotein cholesterol level (β = 0.15, P = 0.03) and EATV (β = 0.14, P = 0.02) were independently associated with the percentage of necrotic plaque tissue. An increase in EATV was associated with the development of coronary atherosclerosis and, potentially, with the most dangerous type of plaque.

Cross-sectional and longitudinal positive remodeling after subintimal drug-eluting stent implantation: multiple late coronary aneurysms, stent fractures, and a newly formed stent gap between previously overlapped stents.

A 50-year-old man with a history of smoking and hyperlipidemia, but no chest pain, was admitted because of an abnormal electrocardiogram and regional wall motion abnormality on echocardiography (mild inferior hypokinesis). Coronary angiography revealed 2 chronic total occlusions (CTOs): ostial right