Stenosis Of Major Coronary Artery Research Articles

Small LDL症例における抗動脈硬化作用を有するHDLサブクラスの検討

HDL consists of heterogeneous lipoproteins and plays an important role for antiatherogenic function. HDL can be clarified either by its apolipoprotein composition: Lp A-I containing apo A-I but no apo A-II and Lp A-I/A-II containing both apo A-I and apo A-II, or by its particle size:large sized HDL2 and small sized HDL3. Recent studies have indicated that specific HDL subclasses may be responsible for antiatherogenic properties.To confirm antiatherogenic HDL subclasses independendent of HDL cholesterol levels, we investigated the relationship between HDL subclasses and angiographically documented coronary artery disease (CAD) in 125 patients with a predominance of small LDL, which has been recognized as atherogenic state with dyslipidemia of low HDL cholesterol and high triglycerides.Patients with diabetes mellitus or who were taking lipid-lowering drugs were excluded. CAD(+) was defined as ≥50% stenosis in major coronary arteries. Lp A-I particles was quantified as the concentration of apo A-I in these particles by using a differential electroimmunoassay with hydrated agarose gels containing monospecific antibodies against apo A-I and apo A-II.HDL2 were examined by 4∼30% nondenaturing polyacrylamide gradient gel electrophoresis and the percentage of HDL2 protein (%HDL2) of the total HDL protein on densitometric scan area were determined.The CAD(+) group (n=82) had older patients (p=0.02) and higher proportion of male (p=0.01) compared with CAD(-) group (n=43). Although both groups had high levels of triglycerides and low levels of HDL cholesterol and apo A-I, there were no significant differences between the two groups.Analysis of HDL subclasses revealed that Lp A-I levels were significant lower in CAD(+) than in CAD(-) (37.5±11.4mg/dl vs. 54.2±13.4mg/dl, p<0.0001) and %HDL2 were also lower in CAD(+) than in CAD(-) (17%vs. 26%, p=0.08).CAD(+) frequency was lowest in highest quartiles of Lp A-I levels (23%) and it was inversely associated with Lp A-I levels (p<0.001).HDL cholesterol and Lp A-I were not associated with triglycerides, however, %HDL2 exhibited a significant correlation with triglycerides (r=0.56, p=0.046).These findings indicate that Lp A-I and HDL2 levels represent a protective effect of HDL subclasses independent of HDL cholesterol levels in individuals with a predominance of small LDL.We conclude that HDL metabolism producing largesized HDL containing only apo A-I may be important for antiatherogenic function.

Flow cytometric analysis of platelet activation markers CD62P and CD63 in patients with coronary artery disease.

We investigated whether platelet activation could be quantitatively detected in patients with coronary artery disease using flow cytometric analysis of the expression of CD62P and CD63, which are activation-specific antigens on the platelet surface. Platelet samples were obtained from 16 healthy control subjects and 65 patients, of whom 25 had angiographically normal coronary arteries and 40 had at least one major coronary artery stenosis (> or = 50% narrowing). In both patient groups, CD62P expression was significantly higher than in the control group, but the difference between the two patient groups was not significant. In contrast, CD63 expression did not differ among the three groups. We also compared expression of these antigens after stratifying the patients according to the number of significant coronary artery stenoses. Patients with three-vessel disease had significantly increased CD62P and CD63 expression compared with the other subgroups. Our findings indicate that platelet activation occurs in patients with severe coronary artery stenosis.

Hybrid intelligence system for diagnosing coronary stenosis. Combining fuzzy generalized operators with decision rules generated by machine learning algorithms

The authors' approach involved taking a set of "crisp" decision rules generated by a machine learning algorithm and converting them into fuzzy rules. These fuzzy rules utilized the previously specified 30 fuzzy sets. Then, fuzzy sets were derived to represent major coronary artery stenosis, using generalized fuzzy operators. Four such fuzzy sets were obtained, to represent obstructions in the three main coronary arteries, LAD, RCA, and CCX, and to represent normal patients. The authors employed the generalized aggregation operations, which are generalized intersection, union and mean. For union and intersection, they used a special class of generalized operators defined by Dombi (1982). Each fuzzy set, representing one of the 30 regions, was defined using a logarithmic scale dividing a range of possible value of a perfusion defect (0-100) into 8 intervals.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Placing patients in the queue for coronary revascularization: evidence for practice variations from an expert panel process.

A panel of 16 cardiologists and cardiac surgeons rated 438 case scenarios for the maximum acceptable delay prior to revascularization, using a scale with seven interventional time frames and two nodes for designating dubious or inappropriate cases. If consensus was defined as agreement by 12 or more panelists, only 1.4 percent of the case scenarios showed consensus on a single rating. Dividing the scale into three broad clinical categories (revascularize promptly, place on a waiting list, or no intervention), 11.4 percent of scenarios showed all 16 panelists agreeing on a single category, rising to 59.4 percent of scenarios if agreement by 12 panelists was accepted as a consensus. The mean difference between the panelists' highest and lowest urgency ratings yielded waiting time differences of two weeks for scenarios of very unstable angina, and more than three months for those with stable angina. However, in a regression model, individual panelist factors on average had less effect than clinical features such as severity and stability of angina, or stenosis of major coronary arteries. These findings strongly support the need for consensus criteria to ensure that triage practices are consistent and fair, and also suggest that widespread adoption of a standardized approach to revascularization priorities may be feasible.

Effects of major coronary artery stenosis on the pressure-flow relationship of an adjacent intact coronary artery branch in isolated supported canine left ventricle.

We investigated whether the relationship between the mean left anterior descending and septal coronary blood flow and the mean perfusion pressure varies with left circumflex coronary stenosis. We used excised, perfused canine heart preparations (n = 10), in which variables to influence the myocardial oxygen demand and supply relation can be fairly well controlled. The results showed that coronary blood flow in the adjacent, non-stenosed coronary artery increased significantly following LCX stenosis; this increased flow was found at the same values of heart rate, left ventricular end-diastolic pressure and perfusion pressure, as those in the preischemic state. Moreover, this increased flow was also observed when the values of peak left ventricular pressure and pressure-length loop area were similar between the pre-ischemic and ischemic states. Thus, contributions of neurohumoral factors or alterations in mechanical factors determining the myocardial oxygen demand and supply relation are negligible. This increased flow may be important in maintaining overall cardiac function in cases of acute coronary stenosis or coronary occlusion.

Nocturnal Angina Pectoris

To the Editor:— I would suggest that myocardial glycopenia due to hypoglycemic attacks be seriously entertained. In studying scores of comparable challenging cases, I have demonstrated the presence of diabetogenic hyperinsulinism in the vast majority (Clin Res13:28, 1965). Occasionally, it could be convincingly documented only by the method of afternoon glucosetolerance testing (J Amer Geriatric Soc12:423, 1964) because of the cyclic intensification of insulinogenesis as the day advances. Major coronary artery stenosis or occlusion was not found in several such patients who experienced nocturnal exacerbations of typical angina pectoris, either by careful angiographic studies or direct examination at the time of surgery. The institution of a corrective diet aimed at preventing severe reactive hypoglycemia day and night promptly ameliorated and indefinitely prevented or minimized both nocturnal angina pectoris and associated abdominal or leg cramps in most of these patients, notwithstanding previous refractoriness to divers therapeutic measures.