Tomoki Ohara

Plaque Gruel of Atheromatous Coronary Lesion May Contribute to the No-Reflow Phenomenon in Patients With Acute Coronary Syndrome

Background—No-reflow associated with direct angioplasty (PCI) of patients with acute coronary syndromes (ACS) is associated with unfavorable results. Methods and Results—We used a new thrombectomy device to treat 51 lesions in 48 consecutive ACS patients (40 male and 8 female; mean age 63 years) and conducted a microscopic analysis of aspirates and blood samples retrieved from the culprit coronary artery. The first aspirate was collected before PCI and the second was collected separately after percutaneous transluminal coronary angioplasty or stenting, including samples from the no-reflow lumen. Light microscopy showed that the materials obtained from the pre-PCI aspiration consisted of thrombus in 37.5%, thrombus and atheroma in 35.0%, and atheromatous plaque in 27.5%. The materials collected from the post-PCI aspiration were thrombus in 8.3%, thrombus and atheroma in 41.7%, and atheromatous plaque in 50.0%. We then compared the 9 lesions (19.1%) with no-reflow to those without no-reflow. There was no difference in the pre-PCI aspirates. However, after PCI, there was more atheromatous plaque retrieved from patients with no-reflow (P <0.001) as well as significantly more platelet and fibrin complex, macrophages, and cholesterol crystals in the blood aspirated from no-reflow cases. Aspiration of these elements improved the no-reflow in 7 of 9 lesions to TIMI-3 flow. Conclusions—No-reflow after angioplasty may be caused by gruel that formed from an atheroma attributable to mechanical plaque disruption during intervention.

Visceral abdominal fat accumulation predicts the progression of noncalcified coronary plaque.

BACKGROUND Excess visceral abdominal tissue (VAT) is more strongly associated with risk factors of coronary artery disease (CAD) than body mass index (BMI) or waist circumference. However, whether adding VAT measurements to CAD risk factors provides better risk assessment for CAD progression has not been fully evaluated. METHODS AND RESULTS This prospective cohort study comprised 553 CAD patients with coronary plaque with ≤50% coronary stenosis as assessed by computed tomography (CT) angiography. Quantification of VAT area was performed together with CT angiography using abdominal CT scanning. After a mean 38±8 months follow-up, 320 patients underwent repeated CT scans for worsening angina symptoms without findings of positive ischemia. Increased segments of noncalcified plaque were seen in 152 (48%) and an increased calcium score was seen in 261 (82%) patients. The risk for progression of noncalcified plaque increased steadily with higher VAT quartiles, independent of CAD risk factors. Patients in the higher quartiles were at increased risk of progression of noncalcified plaque (quartiles IV OR 4.7; 95% CI 2.3-9.4, p-value<0.001). In contrast, increases above the median calcium score showed no independent correlation to VAT. Compared to VAT, progression of noncalcified plaque showed no phased increase with higher waist circumference and weaker increase with higher BMI quartiles. CONCLUSION VAT accumulation was positively associated with progression of coronary noncalcified plaque, but not of calcified plaque. This suggests that risk assessment of progression of noncalcified plaque can be improved by combining VAT measurements and CAD risk factors.

Mechanism of Impaired Left Ventricular Wall Motion in the Diabetic Heart Without Coronary Artery Disease

OBJECTIVE To elucidate whether impairment of the myocardial free fatty acid (FFA)metabolism and small vessel abnormalities in the myocardium are etiologic or contributory factors of myocardial dysfunction in patients with NIDDM without any significant coronary artery disease RESEARCH DESIGN AND METHODS We performed myocardial imaging with 123I-labeled β-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a branched analog of FFA, and dipyridamole-infusion 201 thallium scintigraphy (Dip) in nine patients who demonstrated left ventricular wall motion abnormalities without any significant coronary artery disease and in fifteen control cases. As an index of myocardial FFA metabolism, the heart-to-mediastinum count ratio (H/M) of BMIPP was calculated from the mean count in the regions of interest at the heart and the upper mediastinum RESULTS Nine patients with reduced wall motion documented by left ventriculography (LVG) (hypokinetic group) demonstrated significantly lower BMIPP uptake (2.1 ± 0.2, mean ± SD) than fifteen patients with normal wall motion (normokinetic group) (2.3 ± 0.2, P <0.05). Regional ventricular wall motion observed by LVG, regional BMIPP uptake, and regional redistribution phenomenon (RD) were evaluated for five regions of the left ventricle: anterior, septal, apical, lateral, and inferoposterior regions. Wall motion was abnormal in 24 out of 120 regions. Regional BMIPP uptake was reduced in 47 regions. RD in Dip was observed in 23 regions. In regional analysis, the existence of defect in the BMIPP image showed significant correlation with wall motion abnormality (P <0.01), but there was no significant relationship between the RD in Dip and regional wall motion abnormality (P = 0.16). Myocardial biopsy specimens obtained from the right ventricle of 20 patients showed no pathologic changes, with the exception of two patients. CONCLUSIONS Our findings suggest that impairment of myocardial FFA metabolism rather than small vessel abnormalities in the myocardium is responsible for modest left ventricular dysfunction in patients with diabetes

Angiographic and clinical outcome of a new self‐expanding intracoronary stent (RADIUS): Results from multicenter experience in Japan

The RADIUS coronary stent featuring a multisegmented slotted tube design and self‐expanding nitinol delivery system has a high radial force and flexibility, uniform expansion, and contours to the shape of the vessel. Successful stent deployment was achieved in 104 stable angina patients (106 lesions; 44% LAD, 19% circumflex, and 37% RCA). Mean minimal lumen diameter (MLD) increased from 0.77 ± 0.46 mm to 2.88 ± 0.61 mm and mean percent diameter stenosis (% DS) decreased from 73 ± 14% to 6 ± 13% immediately after the procedure. At 6‐month follow‐up, two patients (2%) underwent urgent target revascularization, and cerebral bleeding occurred in one patient (1%). Angiographic follow‐up was performed in 94 lesions (89%) and mean MLD and mean % DS were 2.08 ± 0.92 mm and 30% ± 24%, respectively. Stent restenosis (>50% diameter stenosis at follow‐up) was observed in 16 (17%) of all lesions. The high success rate for stent deployment, low incidence of major adverse cardiac event, and lower restenosis rate after stent implantation indicate that the RADIUS stent is useful for coronary intervention. Cathet. Cardiovasc. Intervent. 49:401–407, 2000.

Metabolic changes in hibernating myocardium after percutaneous transluminal coronary angioplasty and the relation between recovery in left ventricular function and free fatty acid metabolism

To elucidate the changes in oxidative metabolism in hibernating myocardium after coronary revascularization, we performed myocardial single-photon emission computed tomography with a free fatty acid analog, I-123 beta-methyliodophenylpentadecanoic acid (BMIPP), and thallium-201 before and 1 month after percutaneous transluminal coronary angioplasty (PTCA) in 11 patients with angina pectoris caused by single artery stenosis. All patients had improvement in wall motion after PTCA at the region with coronary stenosis; the wall motion abnormality score evaluated by left ventriculography decreased from 5.5+/-0.8 (mean +/- SE) to 2.1+/-0.9, p <0.01) after PTCA. The defect score of I-123 BMIPP images was significantly larger than that of thallium-201 images either before (14+/-1.3 vs 8.9+/-1.1, p <0.01) or 1 month after (7.4+/-1.5 vs 3.7+/-0.8, p <0.01) PTCA. The decrease in the defect score of both images was significant (p <0.01). Changes in the wall motion abnormality score showed a significant correlation with both the change in the defect score of thallium-201 images (r = 0.58, p < 0.01) and that of I-123 BMIPP images (r = 0.75, p <0.01). These results indicate that the metabolism of free fatty acid is impaired in hibernating myocardium, and that improvement in left ventricular function after successful PTCA is strongly associated with the recovery of oxidative metabolism.

Zero flow pressure in human coronary circulation

Coronary pressure-flow (P/F) relationship has been investigated mainly from the viewpoint of coronary resistance. However, recent experimental evidence suggests that the zero flow pressure intercept (Pzf) provides important characteristics of coronary circulation. Although Pzf is likely to provide meaningful information about characteristics of coronary circulation, no data are available about Pzf in humans. The authors attempted to determine Pzf in humans by analyzing P/F relationship during long cardiac pause. This relationship, provoked by intracoronary adenosine triphosphate (ATP) infusion, was analyzed in 9 patients (8 men, 1 woman) with coronary heart disease (ages: fifty-six ±six years). After the diagnostic cardiac catheterization, ATP, 0.6 mg/3 mL, was administrated by bolus intracoronary injection during measurements of coronary blood flow velocity. Coronary blood flow velocity in the left anterior descending artery was measured with a 0.018-inch Doppler angioplasty guide wire (FloWire, Cariometrics, Inc., Mountain View, Calif.). The dynamic P/F relationship was obtained by correlation of the instantaneous aortic pressure and flow velocity with each other at constant intervals. The least square linear regression analysis was applied to the P/F data to yield the extrapolated Pzf axis. Immediately after intracoronary injection of ATP, long pause (5320 ±1498 msec) appeared and coronary blood flow velocity decreased to 11 ±8 cm/sec. Pzf calculated with P/F relationship was 14 ± 7 mmHg. Conclusions: Thus, the results clearly demonstrate that Pzf is higher than right atrial and left ventricular end-diastolic pressure in humans, indicating the complexity of the determinants of the Pzf.

Nonobstructive angioscopy in patient with atherosclerotic renal artery stenosis

Few applications of angioscopy for evaluating atherosclerosis of the abdominal aorta have been described. We report the demonstration of atherosclerotic yellow plaque by nonobstructive angioscopy in a patient with left renal artery stenosis. Computed tomography angiography showed stenosis in one of the left renal arteries in a 65-year-old man who presented with renal impairment and hypertension. Invasive selective renal angiography indicated severe stenosis in the proximal portion of the inferior left renal arteries. Intravascular ultrasound demonstrated eccentric plaque with predominant low-density plaque with calcification as the culprit. Percutaneous transluminal renal angioplasty with stent implantation of the left renal artery was performed. Nonobstructive angioscopy demonstrated a grade 3 yellow culprit plaque at the proximal end of the stent, and grade 2 and grade 1 yellow plaques as the culprit plaques at the middle and distal portions of the artery, respectively. <Learning objective: Atherosclerotic renal artery stenosis characterized by lipid-rich plaque and yellow plaque was diagnosed by intravascular imaging, such as intravascular ultrasound and angioscopy. As the stenosis was hemodynamically significant, percutaneous transluminal renal angioplasty was successfully performed. Nonobstructive angioscopy may be potentially applied for monitoring of transluminal ablation of the renal artery sympathetic nerves during drug-resistant hypertension.>.

Idiopathic pulmonary vein thrombosis complicated with old myocardial infarction detected by multidetector row computed tomography

Pulmonary vein thrombosis is rarely detected in patients with cancer, lung lobectomy, trauma and so on. We report the case of idiopathic pulmonary vein thrombosis complicated with coronary heart disease. A-57-year-old man with suspected coronary heart disease underwent computed tomography coronary angiography. He did not show any sign of malignancy in lung or other organs. Multi-detector row computed tomography demonstrated 3-dimensional images for the thrombi in bilateral lower pulmonary veins besides an old anterior myocardial infarction. Previously, few reports have described the detection of pulmonary vein thrombosis, however, multi-detector row computed tomography was thought to be useful for detecting and evaluating pulmonary vein thrombosis.

Improving the visual field in coronary artery by with non-obstructive angioscopy: dual infusion method

Non-obstructive angioscopy (NOA) is used to visualize the surface of the coronary artery, and a clear visual field is obtained by injecting transparent fluid into the gap between the probing catheter and the fiber. This study examines visual field expansion by a dual infusion method, which involves an infusion from the probing and guiding catheters, and the relationships between visual grade and vessel characteristics. Thirty-two patients and thirty patients performed coronary plaque analysis with NOA using the conventional method and the novel dual infusion method, respectively. Images were blindly analyzed retrospectively. Visual fields were assessed from image slices using a 5-point scale (0 = invisible, 1 = poor, 2 = adequate, 3 = good, 4 = excellent) at 5-s intervals. The relationships between visual grade and vessel characteristics were analyzed using multiple stepwise linear regression analysis. The mean visual grade, “excellent” ratio, and “adequate” ratio were significantly higher using the dual infusion method than those obtained using the conventional method (p = 0.003, p = 0.004, and p = 0.005 respectively). The “invisible” ratio was significantly lower using the dual infusion method than the conventional method (p = 0.027). The visual field was negatively associated with the conventional method (β  = −0.154, p < 0.001), large vessels (β = −0.004, p < 0.49), bifurcation (β  = −0.205, p < 0.001), vessels with a sharp angle (β  = −0.106, p < 0.001), in-stent (β = −0.180, p < 0.001), and distal border of stent (β  = −0.075, p < 0.001); and positively associated with significant stenosis (β  = 0.072, p < 0.001) and significantly covered stents (β  = 0.050, p = 0.018). The visual field with NOA can be effectively expanded by the dual infusion method.

A CT number-controlling system for reproducibility of intracoronary CT number on follow-up coronary CT angiography

BACKGROUND Coronary computed tomography angiography (CCTA) may be useful for noninvasive follow-up; however, evaluation of coronary stenosis and CT number of plaque may be inaccurate under different vessel enhancement of contrast media. We examined the reproducibility of the CT number of repeat CCTA using our original CT number-controlling system (CTN-CS), which selects contrast level by a multiple regression equation using body surface area and peak CT number and peak time on timing bolus and during CCTA. METHODS AND RESULTS One hundred seventy-two patients who underwent serial CCTA were prospectively and randomly assigned to 3 groups. In the first group, Group A, the amount of contrast for the second CCTA was determined by CTN-CS to match the intracoronary CT number of the first CCTA. In Group B, each patient received the same amount of intravenous contrast in both CCTA examinations. In Group C, 0.7 mL/mg body weight (BW) of contrast medium (350 mgI/mL) was used for baseline and follow-up CCTAs. The regression of repeated CCTAs was the best in Group A (r=0.85, p<0.001) vs. Group B (r=0.52, p<0.001), and Group C (r=0.61, p<0.001). The absolute difference between intracoronary CT numbers of the second and first CCTA was the lowest in Group A (24.8 ± 21.8HU), followed by Group B (37.6 ± 26.2 HU; p<0.05) and Group C (46.5 ± 34.4HU; p<0.001). CONCLUSIONS Using CTN-CS, the difference of intracoronary CT numbers of the second and first CCTA was the smallest when compared to CCTAs using the same contrast volumes or constant volumes per body weight.