Jun Tanigawa

The influence of strut thickness and cell design on immediate apposition of drug-eluting stents assessed by optical coherence tomography

BACKGROUND Stent strut malapposition correlates with poor intimal coverage and this may increase the risk of late stent thrombosis. At present, there is limited data on whether stent strut thickness and stent design impact on acute apposition. We aimed to investigate the influence of stent strut thickness and design on acute stent strut apposition (SSA) immediately following drug-eluting stent (DES) implantation using optical coherence tomography (OCT), a technique with higher resolution and fewer artefacts than intravascular ultrasound. METHODS Thirty-six DES in 23 patients (25 lesions) were studied by OCT. SSA was defined as embedded when a strut was buried in the intima for more than half its thickness, protruding when apposed to the intima but not embedded and malapposed when there was no intimal contact. RESULTS Cypher Select stents were implanted in 52%, Taxus Liberte in 32%, Costar in 12% and Endeavour in 4%. A total of 6402 struts were evaluated. Despite stent optimisation using balloons with a final balloon/artery ratio of 1.26+/-0.19 at a maximum inflation pressure of 17.5+/-3.0 atm, only 57.1+/-20.7% of struts were embedded, whereas 33.8+/-18.4% were protruding and 9.1+/-7.4% were malapposed. Stent type was a strong predictor of malapposition on logistic multilevel analysis (OR 3.95, 95%CI: 1.27-12.23, p=0.017). At 12 months follow-up, there were no adverse clinical events. CONCLUSION Despite angiographic optimisation with high pressures and adequately sized balloons, malapposed stent struts are frequently found in complex coronary lesions and more often following the implantation of Cypher Select stents which have a thicker stent strut and closed cell design. With no adverse clinical events at 12 months follow-up, this likely represents a benign phenomenon at least as long as combined anti-platelet therapy is maintained.

Effect of recanalization of chronic total occlusions on global and regional left ventricular function in patients with or without previous myocardial infarction

Previous studies have demonstrated improvement of regional wall motion and global left ventricular function after successful recanalization of chronic total occlusion in coronary artery. However, the difference of benefits of recanalization between infarct site and noninfarct site is unknown. This study assessed the changes in left ventricular ejection fraction, regional wall motion after successful angioplasty of chronic total occlusions with or without previous myocardial infarction. This study also evaluated the factors that influenced the outcome of left ventricular function. We retrospectively studied 75 patients with a successfully recanalized chronic total occlusion in native coronary artery. Left ventriculograms were obtained at baseline and after 6 months. Global and regional left ventricular function were determined. The patients were divided into two groups. Group 1 comprised patients without previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Group 2 comprised patients with previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Left ventricular ejection fraction increased from 53.2% ± 16.3% at baseline to 57.3% ± 20.1% at 6‐month follow‐up in the whole group (P = 0.001). In group 1 patients, the evolution of left ventricular (LV) ejection fraction increased from 59.5% ± 13.7% to 67.3% ± 14.6% (P < 0.001). In group 2 patients, the evolution of LV ejection fraction increased, but not significantly, from 48.9% ± 16.2% to 50.5% ± 16.9% (P = NS). The evolution of LV ejection fraction increased from 47.6% ± 17.4% to 50.8% ± 17.5% (P < 0.05) in the subgroup of recanalization in infarct‐related vessel that had rich collateral circulation and had long‐term patency. The regional wall motion all significantly improved in group 1 patients (P < 0.05). The regional wall motion did not change in group 2 patients (P = NS). The influence of recanalization of chronic coronary occlusions on the improvement of left ventricular global function was different between myocardial infarction and nonmyocardial infarction patients. The left ventricular function did not improve in myocardial infarction patient. Regional wall motion improved in patients without previous myocardial infarction. For reliable improvement of left ventricular function after recanalization of chronic total occlusions, evidence (not only by symptom or treadmill test) of viable myocardium in recanalized vessel is important. It is also important to keep patency of infarct‐related vessel that has good collateral circulation for improving the left ventricular function. Catheter Cardiovasc Interv 2003;60:368–374.

Optical coherence tomography to assess malapposition in overlapping drug-eluting stents.

AIMS Overlapping drug-eluting stents (DES) are frequently implanted to cover long segments of diseased and injured vessel, or as a bailout technique for edge dissection or incomplete lesion coverage. DES overlap is, nevertheless, associated with strut malapposition and poor intimal coverage, which may increase the risk of stent thrombosis. The aim of this study is to evaluate stent strut apposition in overlapping DES. METHODS AND RESULTS We assessed strut apposition in 10 overlapped segments (20 DES, 10 patients, 661 struts) immediately after implantation, using optical coherence tomography (OCT). Struts were defined as malapposed when no contact with the intima was detected by OCT, taking into consideration the strut thickness of each stent type. Despite aggressive stent optimisation using balloons with a final balloon/artery ratio of 1.26+/-0.18 at a maximum inflation pressure of 18.0+/-1.9atm, 41.8+/-21.5% of struts were malapposed in the overlapping segment, compared to 20.1+/-17.6% in the proximal and 9.7+/-10.6% in the distal segment (p </=0.05 for both). CONCLUSIONS OCT revealed that 40% of struts within an overlapped DES segment were malapposed, and this may explain the reported delay in endothelialisation in such segments.

A new quantitative analysis system for the evaluation of coronary bifurcation lesions: Comparison with current conventional methods

Objective conventional quantitative angiographic systems are designed to automatically follow the contours of straight vascular segments and not of bifurcations. Recently a new analysis method was specifically developed for bifurcation lesions, able to automatically divide the lesion into three separate segments. In this study, we aimed to assess whether the smaller interaction required by the analyst could reduce the analysis time and inter and intra observer variability when compared with a conventional analysis.

Immunoglobulin G4―related coronary periarteritis in a patient presenting with myocardial ischemia

Recent studies suggest that the cardiovascular system might be a possible target of immunoglobulin G4-related disease. Here we present a 66-year-old man who was admitted to our hospital because of chest symptoms suggestive of acute coronary syndrome. Besides luminal narrowing of the coronary arteries, marked periarterial thickening around the coronary artery was observed by computed tomography coronary angiography. Serum immunoglobulin G4 levels of this patient were elevated (564 mg/dL). The patient underwent coronary bypass surgery. After incision of the pericardium, a glittery white-yellowish, elastic-hard periarterial mass surrounding the left circumflex artery could be seen. Histologic analysis of the biopsy specimen showed the formation of lymphoid follicles and the presence of immunoglobulin G4-positive plasma cells; therefore, the diagnosis was immunoglobulin G4-related coronary periarteritis accompanied by physiologically significant myocardial ischemia.

Evaluation of the percusurge guardwire plus temporary occlusion and aspiration system during primary angioplasty in acute myocardial infarction

Thirty patients with acute myocardial infarction (AMI) underwent primary angioplasty under distal protection of PercuSurge GuardWire Plus Temporary Occlusion and Aspiration System. Before angioplasty, protection of the distal circulation was achieved with the system, followed by balloon angioplasty and/or stenting and debris aspiration. Technical device success was 100%. Distal occlusion was well tolerated in all patients. Mean total distal occlusion time was 7.3 ± 5.4 min. Macroscopically visible debris was aspirated from 29 cases (96.7%). Postprocedural Thrombolysis in Myocardial Infarction flow grade 3 was achieved in all cases (100%, vs. 16.7% at baseline). Myocardial blush flow grade 3 was achieved in 26 cases (86.7%). Regression of ST segment elevation ≥ 50% was shown in 23 cases (76.7%). No patient developed angiographic evidence of no‐reflow or distal embolization. Both angiographic and procedural success were 100%. The system is feasible, safe, and effective for distal protection against embolism during primary angioplasty in AMI. Catheter Cardiovasc Interv 2003;60:443–451.

An indeterminate occlusion duration predicts procedural failure in the recanalization of coronary chronic total occlusions.

To identify the impact of occlusion duration (OD) and, in particular, an indeterminate occlusion duration (IOD) on immediate angiographic success and long‐term clinical outcomes in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

A case of IgG4-related lymphadenopathy, pericarditis, coronary artery periarteritis and luminal stenosis

Immunoglobulin G4 (IgG4)-related disease is an emerging new clinicopathological disorder that is characterized by elevation of serum IgG4 levels and histological findings of IgG4-positive plasmacytic infiltration. IgG4-related disease may appear synchronously or metachronously in a wide variety of organs. The current patient was found to have pericardial effusion and retroperitoneal fibrosis. He was subsequently diagnosed with coronary artery stenosis. 18F-FDG positron emission tomography showed enhanced FDG uptake in lymph nodes as well as pericardial and peri-aortic tissue. Histopathology of the mediastinal lymph node showed the infiltration of numerous IgG4-positive cells, leading to the diagnosis of IgG4-related lymphadenopathy with pericardial and periarterial involvement.

Stenting alone versus debulking and debulking plus stent in branch ostial lesions of native coronary arteries

Angioplasty of branch ostial stenosis is associated with a high complication and restenosis rate. Previous investigations have demonstrated various treatments. However, the ideal strategy for treating branch ostial lesion remains uncertain. This investigation attempted to compare the acute, late results of stenting alone and debulking-based strategies in branch ostial lesions of native coronary arteries. Notably, various debulking strategies exist. This investigation also analyzed the acute and long-term results of the different treatments. In this study, we examined 86 patients with angina pectoris or exercise-induced ischemia and successful angioplasty of branch ostial lesions in native coronary arteries. The lesions were divided into two groups based on the angioplasty device used: group I (debulking devices, n = 44) and group II (stenting alone, n = 42). Procedural success and in-hospital complications were similar in both groups (P not significant). Following intervention, group I patients tended to show a smaller area of stenosis (42.3% ± 9.9% vs 48.2% ± 6.2%, P = 0.05) and a smaller plaque-media cross-sectional area (6.05 ± 1.87 vs 7.07 ± 1.79 mm2, P = 0.01) than group II. Furthermore, at 3 months’ follow-up, group I exhibited a larger minimal lumen diameter (MLD) (2.30 ± 0.91 vs 1.86 ± 0.80 mm, P = 0.03) than group II. Regarding the angiographic and clinical outcomes, group I displayed a restenosis rate of 32% (14/44), compared with 41% (17/42) in group II (P = 0.40). Even during the 6-month follow-up, group I had a lower cumulative restenosis rate of 40% (17/43), compared with 60% (22/37) in group II (P = 0.04). The minimal luminal diameter of the ostium had not changed after directional coronary atherectomy or at follow-up. In contrast, MLD of another ostium was significantly reduced during stenting alone and at follow-up (P < 0.01). When subgroups were studied, a debulking followed by stent group achieved a larger acute lumen gain than a debulking alone group (2.57 ± 0.59 vs 2.32 ± 0.55 mm, P = 0.04). The optimal debulking plus stent subgroup had a restenosis rate of 9% (1/11) compared with 33% (6/18) in the optimal debulking alone group (P = 0.05). The optimal debulking plus stent group also had a lower cumulative restenosis rate at 6 months than the optimal debulking alone group (9% vs 44%, P = 0.04). Guided by intravascular ultrasound, atherectomy-based intervention appears superior to stenting alone for treating branch ostial lesions. Directional coronary atherectomy did not cause the narrowing of another ostium. However, optimal debulking followed by stenting minimized the restenosis and target lesion revascularization rates.

Plasma Pentraxin3 Level Is Associated With Plaque Vulnerability Assessed by Optical Coherence Tomography in Patients With Coronary Artery Disease

The role of pentraxin 3 (PTX3) has been implicated in the process of plaque vulnerability. However, few studies have addressed the direct relationship between plaque morphology and plasma PTX3. We evaluated the relationship between coronary vulnerable plaque, assessed by optical coherence tomography (OCT), and plasma PTX3 in patients with coronary artery disease (CAD).OCT was used to determine plaque vulnerability in 51 patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS; n = 17) and stable angina (SA; n = 34). Both highly-sensitive C-reactive protein and systemic plasma PTX3 were measured.Based on the OCT findings, patients were divided into 3 groups; a fibrous plaque (n = 18), thick-cap fibroatheroma (ThCFA) (n = 19), and thin-cap fibroatheroma (TCFA) (n = 14) groups. ThCFA was defined as a lipid-rich plaque (lipid content in ≥ 2 quadrant) covered with ≥ 65 μm thick fibrous cap, and TCFA was that with < 65 μm. There were no differences in patient characteristics between the 3 groups except for the presence of ACS and eicosapentaenoic acid levels. TCFA was more frequently observed with plaque rupture and intraluminal thrombus compared with the other 2 groups. Plasma PTX3 levels were higher in the TCFA group compared with the fibrous plaque and ThCFA groups, and showed weak correlation with cap thickness.Plasma PTX3 level was associated with plaque vulnerability assessed by OCT in patients with CAD.