Osamu Katoh

Coronary angioplasty of chronic total occlusions with bridging collateral vessels: immediate and follow-up outcome from a large single-center experience.

OBJECTIVESnThe purpose of the present study was to assess the effect of bridging collateral vessels on the success of coronary angioplasty of chronic total occlusions in the context of state of the art technology and operator skill.nnnBACKGROUNDnCoronary angioplasty of chronic total occlusions has been associated with relatively low success rates. Because the presence of bridging collateral vessels in chronic total occlusion has been reported to be the major predictive factor in procedural failure, angioplasty is often not recommended in patients with such vessels.nnnMETHODSnThree hundred ninety-seven consecutive patients undergoing coronary angioplasty for chronic total occlusion were classified into two groups. Patients in group I had chronic total occlusion with bridging collateral vessels (97 patients, 109 total occlusions), and patients in group II had chronic total occlusion without such vessels (300 patients, 324 total occlusions).nnnRESULTSnThe mean +/- SD duration of occlusion was 46 +/- 66 months (range 2 to 170) in group I and 27 +/- 39 months (range 2 to 112) in group II (p < 0.05, high power value 0.83, group I vs. group II). Angioplasty for single-vessel disease was performed in a smaller proportion of patients in group I than in group II (22% vs. 36%, p < 0.05; power value 0.77). Procedural success was achieved in 82 chronic total occlusions in group I and 270 chronic total occlusions in group II (75% vs. 83%, p = 0.07; power value 0.53). The rates of restenosis and reocclusion were 54% and 16%, respectively, for group I and 56% and 13%, respectively, for group II (p = 0.76, 0.46; power value 0.51, 0.47). Complications were minor with no Q wave infarction or requirement for urgent bypass surgery in either group. Of 81 patients with unsuccessful coronary angioplasty, 1 patient from group I (1%) and 3 patients from group II (1%) required pericardiocentesis because of cardiac tamponade. Guide wire manipulation did not impair the flow of bridging collateral channels in group I.nnnCONCLUSIONSnCoronary angioplasty can open chronic total occlusions, with or without bridging collateral channels, for safe and effective recanalization without major complications.

Time course of functional improvement in stunned myocardium in risk area in patients with reperfused anterior infarction.

BackgroundThe beneficial effect of coronary reflow on myocardial salvage may be assessed more accurately than in previous studies if the size of risk area is taken into account, particularly because the size of risk area varies significantly among patients. In this study, the risk area was determined with myocardial contrast echocardiography to investigate the time course of functional recovery of postischemic myocardium within the risk area in patients with reperfused anterior myocardial infarction. Methods and ResultsThe study population consisted of 21 patients with anterior myocardial infarction who achieved coronary reflow within 6 hours of onset by means of thrombolysis or coronary angioplasty. Myocardial contrast echocardiography was performed with the injection of hand-agitated Haemaccel (5 ml) into the right and left coronary arteries before coronary reflow, and the risk area was defined as the area of contrast perfusion defect in the apical long-axis view. The ratio of the endocardial length of abnormal contraction (dyskinesis/akinesis) segment to that of contrast defect segment (AS/CD) was determined at days 1, 2, 3, 7, 14, and 28 of reflow. Before reflow, the length of contrast defect correlated well with the segment length of dyskinesis/akinesis. The values for AS/CD in patients with successful reperfusion significantly and progressively decreased until day 14; 1.00±0.02 at day 1, 0.93±0.11 at day 2 (p<0.05 versus day 1), 0.84±0.16 at day 3 (p<0.05 versus day 2), 0.80±0.13 at day 7 (p<0.01 versus day 2), 0.73±0.10 at day 14, and 0.72±0.10 at day 28. Greater improvement in function was obtained in patients reperfused within 4 hours than in those reperfused at 24 hours (AS/CD at day 28, 0.64±0.12 versus 0.75±0.09, p<0.05). ConclusionThus, a significant amount of myocardium, an average of 28%o in segment length of the risk area, is salvaged in patients with reperfused anterior myocardial infarction. Major functional improvement seems to be achieved within 14 days of reflow.

The efficacy of a bilateral approach for treating lesions with chronic total occlusions the CART (controlled antegrade and retrograde subintimal tracking) registry.

OBJECTIVESnThe aim of this study was to evaluate the safety and feasibility of a new concept for chronic total occlusion (CTO) recanalization-using a bilateral approach that utilizes a Controlled Antegrade and Retrograde subintimal Tracking (CART) technique.nnnBACKGROUNDnSuccessful percutaneous recanalization of coronary CTOs results in improved long-term outcomes. The recanalization of CTOs in native coronary arteries no doubt represents one of the most technically challenging of interventional procedures.nnnMETHODSnA total of 224 consecutive patients (mean age 61 +/- 9 years; 86.2% men) were enrolled in this prospective multicenter registry. This technique combines the simultaneous use of antegrade and retrograde approaches. A subintimal dissection is created in both antegrade and retrograde fashion, thereby limiting the extension of the subintimal dissection within the CTO portion.nnnRESULTSnOf 224 CTO lesions (>3 months in duration) undergoing attempted recanalization using the CART technique, 145 cases (64.7%) had undergone previous CTO recanalization attempts. The success rates of crossing in a retrograde fashion with a wire and a balloon were 87.9% and 79.9%, respectively. The overall technical and procedural success rates achieved in this registry were 92.4% and 90.6%, respectively.nnnCONCLUSIONSnA bilateral approach for CTO lesions using the CART technique is feasible, safe, and has a higher success rate than previous approaches. These results indicate that a bilateral technique can solve a major dilemma that commonly affects CTO procedures.

Effect of fluvastatin on progression of coronary atherosclerotic plaque evaluated by virtual histology intravascular ultrasound.

OBJECTIVESnThe aim of this study was to evaluate the effect of treatment with statins on the progression of coronary atherosclerotic plaques of a nonculprit vessel by serial volumetric virtual histology (VH) intravascular ultrasound (IVUS).nnnBACKGROUNDnRecent clinical trials have demonstrated a reduction of atherosclerotic plaque, yet whether statin therapy affects the change in components of plaque remains unknown.nnnMETHODSnThis study was a nonrandomized and nonblinded design. Eighty patients with stable angina pectoris were divided into either the fluvastatin group (n = 40) or the control group (n = 40) according to their total or low-density lipoprotein (LDL) cholesterol level. The volume of each plaque component (dense calcium, fibrous tissue, fibro-fatty, or necrotic core) was evaluated at baseline and at 12-month follow-up.nnnRESULTSnThe LDL cholesterol and high-sensitivity C-reactive protein (hsCRP) levels in the fluvastatin group were significantly decreased at time of follow-up. In VH IVUS findings, fibro-fatty volume was significantly decreased (baseline 80.1 +/- 57.9 mm(3) vs. follow-up 32.5 +/- 27.7 mm(3), p < 0.0001) and fibrous tissue volume was increased (baseline 146.5 +/- 85.6 mm(3) vs. follow-up 163.3 +/- 94.5 mm(3), p < 0.0001) in the fluvastatin group. In the control group, the volumes of all plaque components without fibrous tissue were significantly increased. Change in fibro-fatty volume has a significant correlation with a change in LDL cholesterol level (R = 0.703, p < 0.0001) and change in hsCRP level (R = 0.357, p = 0.006).nnnCONCLUSIONSnOne-year lipid-lowering therapy by fluvastatin showed significant regression of plaque volume and alterations in atherosclerotic plaque composition with a significant reduction of fibro-fatty volume.

Plaque characterisation by Virtual Histology intravascular ultrasound analysis in patients with type 2 diabetes

Objectives: To evaluate the in-vivo plaque composition and characteristics in patients with type 2 diabetes mellitus (DM) using Virtual Histology intravascular ultrasound (VH IVUS). Methods: In 90 patients with stable angina pectoris, de novo target vessels were studied and plaque components were analysed. Patients were divided into two groups: a diabetic group (36 vessels) and a non-diabetic group (54 vessels). Results: The percentage area of necrotic core and dense calcium were significantly larger in the DM group than the non-DM group (necrotic core: 11.0% (interquartile range (IQR): 7.2–15.2%) vs 7.6% (IQR 5.6–13.2%), pu200a=u200a0.03; dense calcium: 5.6% (IQR: 2.3–7.3%) vs 2.9% (IQR: 1.7–4.9%), pu200a=u200a0.01). The DM group presented with a significantly higher presence of at least one VH IVUS-derived thin-cap fibroatheroma (VHD-TCFA) (75% vs 41%, pu200a=u200a0.001) and VH IVUS-derived fibrocalcific atheroma (VHD-FCA) (75% vs 40%, pu200a=u200a0.001). In the DM group, 53% of the vessels had both VHD-TCFA and VHD-FCA, which was significantly higher than non-DM group (17%, pu200a=u200a0.0004). Conclusions: Coronary plaque characteristics in DM patients showed an increased amount of dense calcium and necrotic core, as well as a higher frequency of VHD-TCFA and VHD-FCA. Atherosclerosis of the target vessel was more advanced in diabetic patients.

Impact of Intramural Thrombus in Coronary Arteries on the Accuracy of Tissue Characterization by In Vivo Intravascular Ultrasound Radiofrequency Data Analysis

Virtual Histology (VH) intravascular ultrasound (IVUS) allows differentiation between 4 different tissue phenotypes. However, the current classification tree for analysis cannot differentiate the presence of intramural thrombus. The aim of this study was to evaluate the impact of intramural thrombus for correlative accuracy between in vitro histopathology of coronary atherosclerotic plaque obtained by directional coronary atherectomy and corresponding in vivo tissue characterization obtained by VH IVUS. Coronary IVUS imaging of 30 coronary artery lesions was obtained using a 20-MHz phased-array IVUS catheter with a motorized pull-back system at set 0.5 mm/s. The debulking region of the in vivo histologic image was predicted from comparison between pre- and post-first debulking VH IVUS images. Cross-sectional histologic slices were cut every 0.5 mm starting from the most proximal part of the formalin-fixed debulking tissue. Histologic slices were divided into 2 groups by the presence or absence of pathologic thrombus. A total of 259 in vitro histologic slices were obtained, and pathologic thrombus was detected in 81 slices. Correlation was favorable, with high sensitivity for all plaque components, but specificities for fibrous (thrombus slices vs nonthrombus slices 36% vs 94%) and fibrofatty (9% vs 60%) tissue were lower in thrombus slices. Therefore, predictive accuracies for the 2 plaque components were lower in thrombus slices (fibrous tissue 78% vs 99%, fibrofatty tissue 68% vs 83%, respectively). In conclusion, intramural thrombus was colored as fibrous or fibrofatty by VH IVUS, reducing VH accuracy in these kinds of lesions.

Impact of cilostazol on intimal proliferation after directional coronary atherectomy

Cilostazol, a novel platelet aggregation inhibitor, inhibits intimal proliferation in animal models. We randomly assigned 41 patients with lesions suitable for directional coronary atherectomy to the cilostazol group (200 mg/day) or the aspirin (250 mg/day) group. Medication was started before directional coronary atherectomy and was continued to a 6-month follow-up. Serial quantitative coronary angiography and intravascular ultrasound study were performed. Baseline characteristics were not different between the two groups. However, the minimal lumen diameter at follow-up was larger (2.33 +/- 0.60 mm vs 1.81 +/- 0.68 mm, p = 0.016) and the percent diameter stenosis (24.5% +/- 16.6% vs 40.9% +/- 21.0%, p = 0.010) was smaller in the cilostazol group. The change in vessel area was not different, but the percent plaque area at follow-up was smaller in the cilostazol group (55.7% +/- 11.2% vs 64.5% +/- 14.5%, p = 0.044). The restenosis rate was significantly lower in the cilostazol group (0% vs 26%, p = 0.020). We conclude that cilostazol appears to have an inhibitory effect on intimal proliferation after directional coronary atherectomy and may reduce restenosis.

Appropriateness of percutaneous revascularization of coronary chronic total occlusions: an overview.

Coronary chronic total occlusions (CTOs) are commonly encountered in patients undergoing coronary angiography. Several observational studies have demonstrated that successful CTO revascularization is associated with better cardiovascular outcomes and enhanced quality of life (QOL). However, in the absence of randomized trials, its prognostic benefit for patients remains debated. Over the past decade, the interest of the interventional community in CTO percutaneous coronary intervention (PCI) has exponentially grown due to important developments in dedicated equipment and techniques, resulting in high success and low complication rates. Both European and American guidelines have assigned a class IIa (level of evidence B) recommendation for CTO PCI. In the current review, we focus on the impact of CTO revascularization on clinical outcomes and QOL and on appropriate patient selection, and we provide a critical assessment of the current guidelines and recommendations on CTO PCI.

New double wire technique to stent ostial lesions

We describe a new fast technique to precisely deploy J&J Stents in ostial lesions using two guide wires. The second guide wire is inserted through the proximal stent strut and simultaneously advanced together with the stent on the balloon serving as a position marker that guides stent placement. This technique has been applied in 10 cases with 100% success and with no major complications.

In-vivo detection of the frequency and distribution of thin-cap fibroatheroma and ruptured plaques in patients with coronary artery disease: an optical coherence tomographic study.

ObjectivesThe purpose of this study was to assess the prevalence and to quantify the thin-cap fibroatheroma (TCFA) and ruptured plaques in patients with coronary artery disease using optical coherence tomography (OCT). BackgroundTCFA lesions are the most prevalent precursors of plaque rupture, and are responsible for acute coronary syndromes (ACS). There are limited data regarding the frequency and distribution of TCFA in diseased coronary arteries. MethodsCoronary artery OCT was performed in 78 vessels in 47 patients, with stable angina (SA) or ACS. OCT plaque characteristics were derived using criteria that had been validated earlier. TCFA was defined as rich in lipid (two or more quadrants) with thin fibrous cap (<65 &mgr;m). Comparison was made between SA and unstable angina, and culprit and nonculprit vessels. ResultsThere was a higher incidence of TCFA and plaque rupture (65 vs. 24%, P=0.003, and 40 vs. 15%, P=0.04) in ACS patients. This was reflected in a higher lipid pool (2.66 vs. 2.26 quadrants, P=0.04) and minimum fibrous cap thickness (52 vs. 74 &mgr;m, P=0.001) in ACS patients. The mean numbers of TCFA (2.5) were similar in patients with SA and ACS. However, the maximal length of TCFA (2.63 vs. 5.54 mm, P=0.026) and plaque rupture sites (P=0.046) were higher in ACS vessels. No relationship was found between baseline characteristics and TCFA incidence and plaque rupture. We identified ACS (P=0.002), higher mean lipid pool (P=0.002), longer TCFA length (P=0.007) and higher number of TCFA (P=0.02) as predictors of plaque rupture sites. ConclusionIn this in-vivo study, we identified a higher incidence of longer TCFAs and plaque rupture sites associated with ACS.