Early experience with a novel plaque excision system for the treatment of complex coronary lesions.

The use of directional coronary atherectomy (DCA) in current practice has been limited. The SilverHawk System is a newly developed plaque excision device that aims to overcome the drawbacks of prior DCA platforms. The device was evaluated in a porcine coronary model and in a series of patients. Procedural variables along with outcomes were reviewed. Quantitative angiography (QCA) was performed and excised tissue fragments were weighed and examined histologically. In porcine cases, pretreatment MLD increased from 0.51 +/- 0.26 to 2.36 +/- 0.59 mm postdebulking and 19.9 +/- 7.6 mg of tissue was retrieved. In human cases, pretreatment MLD increased from 0.8 +/- 0.4 to 2.2 +/- 0.5 mm postdebulking and 15.2 +/- 7.8 mg of tissue was retrieved without complications. These data show that the SilverHawk System may offer significant utility in treating a wide variety of complex coronary lesions.     

Angiogenesis in human coronary atherosclerotic plaques.

Neovascularization in the walls of coronary arteries is associated with the presence of atherosclerotic plaque. The mechanisms responsible for the formation of these intraplaque microvessels are not understood. The purpose of this study is to examine the prevalence of endothelial cell replication in plaque microvessels. Two hundred and one primary and restenotic coronary atherectomy specimens were analyzed for the presence of microvessels and proliferation as reflected by positive immunolabeling for Ulex agglutinin and the proliferating cell nuclear antigen, respectively. In primary but not restenotic specimens, proliferation of any cell type was associated with the detection of microvessels on the same slide. However, intraplaque microvessels were more commonly found in restenotic compared to primary specimens (P = 0.004). Twelve highly vascularized specimens with evidence of replication were subjected to detailed histomorphological and quantitative image analyses. At 200 x, the most vascular optical field of each slide was identified and consistently included plaque macrophages. Total slide endothelial cell replication indices for these specimens varied, but in some instances were remarkably elevated (eg, 43.5%). The role of intraplaque angiogenesis may be analogous to that of tumor or wound angiogenesis and be important in development and progression of coronary artery lesions and restenosis.     

Feeding suppression induced by intra-ventricle III infusion of 1,5-anhydroglucitol

1,5-Anhydroglucitol (1-DG) has been known as an antimetabolic glucose analogue. Using gas chromatography, 1-DG was found to be physiologically present in rat serum. In order to investigate its direct and long-term effects on feeding, 1-DG was infused during the light period into the rat third ventricle in doses of 3.0, 6.0 and 12.0 mumol/rat. Its effects were then compared to those of similarly applied 2-deoxy-D-glucose (2-DG). Following initial hyperphagia, both of these glucose-analogues produced suppressive effects on feeding during the subsequent day throughout the light and dark periods. On the third day after 2-DG injection reduction of feeding did not recover completely to the pretreatment baseline levels, but it did recover after 1-DG. Both 1-DG and 2-DG caused linear dose-related hypophagia, with the slope for 1-DG being about half of that for 2-DG. It is suggested that the delayed hypophagia which followed the initial hyperphagia produced by deoxyglucose was a result of sustained inactivation of the Na-pump due to intracellular ATP deficiency caused by accumulation of deoxy-glucose-6-phosphate.     

Analysis of the p16INK4, p14ARF, p15, TP53, and MDM2 genes and their prognostic implications in osteosarcoma and Ewing sarcoma

We examined alterations of the p16INK4, p14ARF, p15, TP53, and MDM2 genes in 30 osteosarcomas and 24 Ewing sarcomas. Among 21 osteosarcomas and 24 Ewing sarcomas, p16INK4, p14ARF, and p15 abnormalities were found in 4 (19%), 2 (9%), and 3 (14%) osteosarcomas, respectively, and in 4 (17%), 3 (13%), and 4 (17%) Ewing sarcomas, respectively. The alterations of p16INK4, p14ARF, and p15 included homozygous deletions spanning all 3 genes, methylation of p16INK4 or p15, and a nonsense mutation of p16INK4, which simultaneously caused a missense mutation of p14ARF. Alterations of TP53 were found in 15 (50%) of 30 osteosarcomas and 1 (3%) of 24 Ewing sarcomas. None of the sarcomas showed MDM2 amplification. While TP53 abnormalities were far more frequent in osteosarcoma than in Ewing sarcoma, alterations of p16INK4, p14ARF, and p15 were present at similar frequencies in the two types of sarcoma. The event-free survival (EFS) was worse in Ewing sarcoma patients with p16INK4 and p14ARF mutation/deletion than in those without the mutation/deletion (P = 0.019), and EFS was worse in osteosarcoma patients with TP53 alterations than in those without TP53 alterations (P = 0.048). The different incidence of TP53 abnormalities in the 2 types of sarcoma may reflect differences of the molecular processes through which the 2 types of tumor develop.     

Repeat percutaneous transluminal coronary angioplasty and predictors of recurrent restenosis

One hundred seventeen consecutive patients undergoing repeat percutaneous transluminal coronary angioplasty (PTCA) were studied to assess procedural success and recurrent restenosis rates. Clinical, anatomic and procedural variables were examined as predictors of recurrent restenosis using stepwise logistic regression analysis. Primary success was achieved in 114 patients (97.5%). One patient (0.8%) died after acute occlusion. No other in-hospital complications were encountered. After a mean follow-up interval of 218 +/- 160 days, 72 of 114 successfully dilated patients (63%) remained angina free. There were no late deaths. Three patients (2.6%) experienced a late myocardial infarction. Follow-up arteriography was performed in 100 patients (88%), of whom 32% had recurrent restenosis (greater than 50% luminal diameter narrowing). On univariate analysis, the presence of 3 clinical variables at repeat PTCA was associated with significantly higher recurrent restenosis rates compared with their absence, that is, unstable angina (48 vs 20%, p = 0.003), diabetes (61 vs 26%, p = 0.003) and hypertension (46 vs 18%, p = 0.003). Patients with recurrent restenosis had a shorter interval between first and second PTCA compared with those who remained patent (136 +/- 116 vs 214 +/- 163 days, p = 0.018). Multivariate analysis confirmed unstable angina, diabetes and hypertension as independent predictors of recurrent restenosis. Repeat PTCA may be performed for restenosis with a high likelihood of success and low incidence of complications. The rate of recurrent restenosis is similar to that reported for initial angioplasty. Patients with unstable angina, diabetes and hypertension appear to be at higher risk for recurrent restenosis.     

Abrupt vessel closure after directional coronary atherectomy. The U.S. Directional Atherectomy Investigator Group.

From October 1, 1986 to December 31, 1989 directional coronary atherectomy was performed during 1,020 procedures (1,140 lesions) at 14 clinical centers. Abrupt vessel closure, defined as a total coronary occlusion or subtotal occlusion associated with clinical evidence of myocardial ischemia, occurred in 43 procedures (4.2%). It developed in the catheterization laboratory in 34 patients, but was delayed 1 to 96 h after directional atherectomy in 9 patients. By univariate analysis the incidence of abrupt closure was higher in directional atherectomy of de novo lesions (p less than 0.001), lesions in the right coronary artery (p = 0.001) and diffuse lesions (p = 0.04). The incidence of abrupt closure tended to be lower in directional atherectomy of saphenous vein grafts as opposed to native coronary arteries (1.6% vs. 4.4%; p = 0.08). Clinical findings during abrupt closure included severe angina in 26 patients, myocardial infarction in 17 patients, hypotension in 5 patients and death in 2 patients. Balloon angioplasty was attempted in 32 patients after abrupt vessel closure. In 16 patients balloon angioplasty resulted in initial resolution of the closure episode, although 1 patient died 96 h after the procedure. Fifteen of 16 patients without initial improvement after balloon angioplasty underwent coronary bypass operation; 9 additional patients with abrupt closure were referred directly for bypass operation. It is concluded that abrupt vessel closure develops relatively infrequently after directional coronary atherectomy. In the absence of severe coronary dissection, abrupt closure after directional atherectomy may be effectively managed with balloon angioplasty in some cases, although coronary bypass operation is often required.     

Cancer screening with PET: advantages and limitations

Warburg first reported that tumours are characterized by abnormally increased glucose metabolism accompanied by increase production of lactate. This is a basic principle underlying cancer detection by the glucose analogue 18-F-fluoro-2-deoxy-D-glucose (FDG). FDG positron emission tomography (PET) is currently used widely to examine virtually any part of the body in order to detect tumours, e.g., lung, breast, colorectal, pancreatic and head and neck cancers, malignant lymphoma and malignant melanoma. The advantage of whole-body FDG-PET in comparison with the other imaging modalities is that it allows the entire body to be surveyed seamlessly within a reasonably short period. Furthermore, the staging of most cancers can be determined. The characteristics of whole-body FDG-PET seem to satisfy the requirements for cancer screening. PET used simultaneously with conventional tests can prevent the overlooking of cancer, reduce false-positive results and assist in the interpretation of CT and MRI images. Thus, PET can play a supportive role when used with conventional screening tests. In 1994, PET was applied to cancer screening for the first time at our Imaging Center at Lake Yamanaka in Japan. Within 12 years after starting, a total of 10,292 asymptomatic individuals (6,227 men and 4,065 women; mean age, 52.2 and 52.9 years) participated in 29,090 screening sessions. As a result, malignant tumours were demonstrated in 355 of the 10,292 participants (2.61%). PET findings were true-positive in 175 of the 355 cancers (49.3%).     

The rs1333049 polymorphism on locus 9p21.3 and extreme longevity in Spanish and Japanese cohorts

GeroScience - The rs1333049 (G/C) polymorphism located on chromosome 9p21.3 is a candidate to influence extreme longevity owing to its association with age-related diseases, notably coronary artery...     

Late restenosis after emergent coronary angioplasty for acute myocardial infarction: comparison with elective coronary angioplasty

The late restenosis rate after emergent percutaneous transluminal coronary angioplasty for acute myocardial infarction was assessed by performing outpatient follow-up cardiac catheterization in 79 (87%) of 91 consecutive patients who had been discharged from the hospital with a successful coronary angioplasty. The majority of patients (90%) received high dose intravenous thrombolytic therapy with streptokinase in addition to angioplasty. Similar follow-up data were obtained in 206 (90%) of 228 consecutive patients who had successful elective angioplasty during the same period. The interval from angioplasty to follow-up was 28 +/- 9 weeks for the myocardial infarction group and 30 +/- 11 weeks for the elective group. Baseline clinical variables were similar for both the myocardial infarction and elective groups except for a higher percentage of men in the infarction group (81 versus 63%, p = 0.001). The number of coronary lesions undergoing angioplasty and the incidence of intimal dissection were similar, but multivessel angioplasty was more common in the elective group (13 versus 4%, p = 0.02). The rate of in-hospital reocclusion was higher in the patients receiving angioplasty for myocardial infarction (13 versus 2%, p = 0.0001). At the time of late follow-up after hospital discharge, the patients with myocardial infarction were more often asymptomatic (79 versus 55%, p = 0.0001), and the rate of angiographic coronary restenosis was lower for the infarction group both overall (19 versus 35%, p = 0.006) and when multivessel angioplasty patients were excluded (19 versus 33%, p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)