OBJECTIVES: This study was undertaken to examine the influence of plasma lipoprotein(a) [Lp(a)] levels on coronary endothelial vasomotor function. BACKGROUND: Epidemiologic studies have demonstrated a direct relation between elevated plasma levels of Lp(a) and increased risk of coronary artery disease. Well recognized coronary risk factors are known to affect endothelium-dependent vasomotion; however, the influence of Lp(a) on coronary vasomotor function has not been determined. METHODS: We used quantitative coronary angiography to measure left anterior descending coronary artery diameter changes produced by intracoronary acetylcholine and isosorbide dinitrate in 30 patients with angiographically normal coronary arteries. Plasma Lp(a) levels were determined with enzyme-linked immunosorbent assay. RESULTS: Vasomotor response to acetylcholine ranged from +13% to -47% in the proximal, from +23% to -53% in the middle and from +13% to -56% in the distal segment of the left anterior descending coronary artery. According to univariate linear regression analysis, Lp(a) had a significant inverse correlation with vasomotor response to acetylcholine: r = 0.47, p < 0.01 in the proximal; r = -0.61, p < 0.001 in the middle; and r = -0.52, p < 0.01 in the distal segment of the left anterior descending coronary artery. By multiple stepwise regression analysis, plasma Lp(a) was the significant predictor of vasomotion in response to acetylcholine in all tested segments (p < 0.01). CONCLUSIONS: Elevated Lp(a) levels were associated with impairment of endothelium-dependent vasodilation even when atherosclerotic lesions were not recognizable by angiography. This finding suggests that elevated plasma levels of Lp(a) cause endothelial dysfunction and may contribute in part to later development of atherosclerosis, as shown in epidemiologic studies.

Acetylcholine↗

PubMed1995

Pravastatin (mevalotin) restenosis trial after percutaneous transluminal coronary angioplasty. Cholesterol reduction rate determines the restenosis rate.

There is no consensus on lipids and restenosis after percutaneous transluminal coronary angioplasty (PTCA). We evaluated whether prevastatin could prevent restenosis after PTCA. In this study, pravastatin therapy was started one month before PTCA. The follow-up angiography was done three months later. Total cholesterol reduction rates [one index of reduction rate is calculated between 1 M (month) before PTCA and at PTCA, and another done between 1 M before PTCA and at follow-up angiography] proved to be good predictors of restenosis rate after PTCA; The greater the cholesterol reduction rate, the lower the rate of restenosis. The residual stenosis after PTCA correlated with the restenosis rate. The restenosis rate in the pravastatin group was lower than that in the control group, but the difference was not statistically significant. However, in the subgroup with pre-PTCA restenosis of 99% or more, the restenosis rate in the pravastatin group was significantly lower than that of the control group. Pravastatin seems to prevent intimal hyperplasia through the reduction of cholesterol level and to reduce restenosis. Many macrophages are present in the highly stenosed or occluded coronary arteries, and the reduction of the number and the activity of macrophages may prevent the restenosis. Pravastatin also has an antithrombotic action. In such regions, the occlusion by the thrombus formation is also considered to play a key role in restenosis in addition to the intimal hyperplasia. Thus, pravastatin may be useful especially for PTCA against highly stenosed or occluded coronary arteries.

Aged↗

PubMed1995

Complement component C3 production and its cytokine regulation by gastrointestinal epithelial cells.

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Adenocarcinoma↗

PubMed1995

The role of cardiac mitochondria in the regulation of intracellular calcium during ischemia and reperfusion: X-ray microanalysis using freeze-dried sections.

The calcium concentration in papillary muscles was measured by X-ray microanalysis in order to clarify the role played by mitochondria in intracellular calcium regulation during ischemia and reperfusion. Rat hearts perfused by the Langendorff method were rapidly frozen prior to and during ischemia, as well as following reperfusion. Sections prepared by cryoultramicrotomy were freeze-dried, carbon-coated, and analyzed in an electron microscope. A new freeze-drying procedure was developed, in which the ultrastructure was well-preserved, with sarcomeres, triads, and mitochondria easily recognized. Calcium accumulation into the mitochondria occurred during 30-min ischemia (29.7 +/- 17.0 mmol/kg dry weight) and increased further after 15-min reperfusion (157.1 +/- 104.5), the calcium concentration decreased after 60-min reperfusion (58.1 +/- 29.0). However, the calcium concentration in the cytosol did not change significantly. It is thought that mitochondrial calcium accumulation is reversible, to a certain degree, and that the mitochondria play a part in intracellular calcium regulation in pathological states.

Animals↗

PubMed1995

Chloride conductance in human atrial cells.

Many types of chloride current have been reported in the hearts of various species; however, the nature of chloride conductance in the human heart is still unclear. We investigated cyclic AMP-dependent chloride current and swelling-induced chloride current in isolated human atrial cells using the whole-cell voltage-clamp method. External application of 1 microM isoprenaline increased calcium current by 391.9 +/- 48.6% (mean +/- S.D., n = 8); however, there was no activation of cyclic AMP-dependent chloride current at steady-state membrane potentials between -80 and +50 mV. Neither external application of 10 microM forskolin nor internal application of 50 microM cyclic AMP activated a cyclic AMP-dependent chloride current. On the other hand, when the same cell was superfused with a 50% hypotonic solution, it exhibited osmotic swelling and an outward rectifying current (6.59 +/- 0.96 pA/pF at +30 mV, n = 10). This swelling-induced current reversed at -26.5 +/- 3.1 mV (n = 10), close to the calculated equilibrium potential for chloride, and it was sensitive to the stilbene-derivative chloride channel blocker. In conclusion, no activation of cyclic AMP-dependent chloride current was observed in human atrial cells. On the other hand, a swelling-induced chloride current was consistently demonstrated and its kinetic properties were similar to those reported in other cardiac myocytes.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗

PubMed1995

Follow-up of 2,733 Japanese patients with myocardial infarction.

Two thousand, seven hundred and thirty-three patients with acute myocardial infarction (AMI) who were admitted to our 11 institutions between 1983 and 1988, examined by coronary arteriography and discharged alive, were followed for an average of 2.9 years. During the follow-up period, 212 patients (7.6%) died. The factors that governed the prognosis of myocardial infarction after discharge were advanced age, female gender, obesity, previous infarction, angina pectoris more than 1 month before the onset of AMI, post-infarction angina, multiple-vessel diseases, advanced stage by Killip's and/or Forrester's classification on admission, elevated pulmonary capillary arterial pressure, decreased cardiac index, decreased left ventricular ejection fraction, increased left ventricular end-diastolic volume and left ventricular aneurysm before hospital discharge. Patients with ventricular tachycardia or ventricular fibrillation during hospitalization showed a poor prognosis. In contrast, patients who received intracoronary thrombolysis, or emergent and/or elective percutaneous transluminal coronary angioplasty showed a favorable prognosis.

Adult↗

PubMed1995

Factors governing re-infarction in patients with myocardial infarction in Japan.

The subjects consisted of 2,733 patients with acute myocardial infarction (AMI) who were admitted to our 11 institutions between 1983 and 1988, examined by coronary arteriography, and discharged alive. The patients were followed for an average of 2.9 years after discharge. During the follow-up period, re-infarction occurred in 172 patients (6.3%). The factors associated with re-infarction were total cholesterol of more than 250 mg/dl, HDL-cholesterol of less than 35 mg/dl and diabetes mellitus. The rate of re-infarction was also high in patients who had had a previous infarction before admission, angina pectoris before or after the onset of AMI or multiple-vessel disease. In contrast, intracoronary thrombolysis reduced the rate of re-infarction.

Angina Pectoris↗

PubMed1995

[Clinical characteristics of pancreatitis after cardiovascular surgery].

Increases in pancreatic enzyme levels after cardiovascular surgery were studied, and their clinical characteristics evaluated. The subjects were 128 patients who had undergone cardiovascular surgery (65 patients after valve replacement, 32 after coronary bypass surgery and 31 after aortic artificial graft replacement). The pancreatic enzyme (serum amylase and lypase) levels were monitored serially before and after operation, and amylase fractions were measured at their peaks. The relationships of the peak lypase level with underlying cardiac diseases, background factors, factors related to surgery, factors related to the extracorporeal circulation, presence or absence of symptoms, and treatments were examined. The amylase level exhibited biphasic changes consisting of a peak in which salivary glands amylase (S type) was dominant and a peak in which pancreatic amylase (P type) was dominant. The second peak coincided with the peak lypase and occurred mostly 3 to 10 days after operation. The peak lypase level exceeded the normal range in 78% of all the patients. It exceeded 564 U/l, 4 times the normal value in 28% of the patients, many of whom were symptomatic. So, we recommended that these cases should be treated as "postoperative pancreatitis". A high peak lypase level showed a significant correlation with the history of gallbladder and pancreatic diseases and diabetes mellitus among the background factors and emergency operation and the use of IABP among the surgery-related factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

[The characteristics of 123I-MIBG myocardial scintigraphy in patients with left ventricular pressure-overload diseases].

The purpose of this study was to clarify the clinical significance of 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in patients with left ventricular pressure-overload diseases. MIBG scintigraphy was applied to 10 pts with aortic valve stenosis (AS group), 11 pts with hypertrophic obstructive cardiomyopathy (HOCM group), 17 pts with hypertrophic non-obstructive cardiomyopathy (HCM group) and 6 control cases (C group). Mean pressure gradient in AS and HOCM groups was 62 +/- 21 mmHg and 38 +/- 18 mmHg, respectively. Initial myocardial uptake of MIBG (MU) was higher in the AS (1.92 +/- 0.46%) and HOCM (2.27 +/- 0.47%) groups than those in the HCM (1.61 +/- 0.29%) and C (1.50 +/- 0.23) groups. Myocardial clearance of MIBG (MC) was higher in the AS (39 +/- 11%), HOCM (37 +/- 19%) and HCM (28 +/- 17%) groups than that in the C (14 +/- 6%) groups. Heart/mediastinum count ratio (H/M) of AS, HOCM, HCM and C groups was 1.87 +/- 0.29, 2.09 +/- 0.19, 1.98 +/- 0.26, and 2.20 +/- 0.10, respectively. In the cases of AS, positive correlation was observed between mean pressure gradient and MU (r = 0.618, p < 0.05). In conclusion, MU was increased in the case of left ventricular pressure-overload state (AS and HOCM).

3-Iodobenzylguanidine↗

PubMed1995

[Usefulness of 123I-BMIPP myocardial imaging in patients with stable effort angina and unstable angina].

We evaluated the clinical significance of myocardial imaging using 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) scintigraphy in patients with stable effort angina pectoris (SAP) and unstable angina pectoris (UAP). Thirty-three patients with SAP were studied using rest BMIPP and stress 201TlCl (Tl) myocardial scintigraphy, and 13 patients with worsening effort type of UAP were also examined using both rest BMIPP and Tl scintigraphy. We compared those BMIPP findings with myocardial perfusion images obtained with Tl and the regional wall motion determined by left ventriculography. In 45% of 282 segments of myocardial ischemia of SAP, the degree of myocardial uptake of BMIPP was concordant with that of stress Tl and the defect score of Tl was higher than that of BMIPP. On the other hand, in 32% of 62 segments of ischemia of UAP, the degree of myocardial BMIPP and Tl uptake was concordant and BMIPP defect score was higher than Tl score. In SAP, the decrease in regional wall motion agreed better with the decrease in myocardial uptake of BMIPP than that of Tl. These results suggest that myocardial ischemic regions decreased BMIPP uptake show the disturbance of fatty acid metabolism and lead to abnormal wall motions. Such ischemic regions may be clinically severe state in patients with angina pectoris.

Aged↗

PubMed1995

[Detection for the prediction of sustained ventricular tachycardia and sudden cardiac death using late potentials in patients with hypertrophic cardiomyopathy].

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Adult↗

PubMed1995

[Detection and significance of late potential in patients with cardiac sarcoidosis].

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Adult↗

PubMed1995

[Comparison of inferior myocardial defect between planar and SPECT image of 123I-metaiodobenzylguanidine cardiac scintigraphy].

Discordant findings of inferior MIBG defect between SPECT and planar images were sometimes observed in the clinical studies. In this study, we compared inferior myocardial findings between planar and SPECT image of 123I-metaiodobenzyl-guanidine (MIBG) cardiac scintigraphy in 29 patients. All patients were estimated as normal in anterior accumulation of MIBG. The patients were divided into 3 groups according to the visual finding of inferior defect in the planar and SPECT image; normal group (normal inferior accumulation of MIBG both in the planar and SPECT image, N = 10), discordance group (inferior MIBG defect was only observed in the SPECT image, but was not observed in the planar image, N = 7), inferior defect group (inferior MIBG defect was observed both in the planar and SPECT image, N = 12). Inferior/anterior count ratio of SPECT and planar image were 0.96 +/- 0.11 vs. 0.97 +/- 0.05 in normal group, 0.59 +/- 0.21 vs. 0.99 +/- 0.13 in discordance group, 0.46 +/- 0.13 vs. 0.82 +/- 0.04 in inferior defect group. Liver/heart count ratio was significantly higher in the discordance group (2.07 +/- 0.49) than that in the normal (1.14 +/- 0.15) and inferior defect group (1.45 +/- 0.39). In phantom study, it has been reported that increased liver accumulation of MIBG causes artifactual inferior defect adjacent to the liver. These data indicate that increased liver/heart count ratio may cause artifactual inferior defect on MIBG SPECT image in the clinical studies. Planar image evaluation may be helpful to distinct the artifactual inferior defect on SPECT image.

3-Iodobenzylguanidine↗

PubMed1995

[Clinical significance of transesophageal echocardiography for evaluation of patients after Bentall's operation: detection of graft failure].

Leakage from the composite graft at the site of coronary anastomosis into the perigraftal space (pseudoaneurysm) is an important complication of Bentall's operation. The clinical value of transesophageal echocardiography (TEE) for detecting this graft failure was evaluated in 30 patients who underwent Bentall's operation or Piehler's modification. Three patients (10%) had perigraftal leakage (pseudoaneurysm). TEE demonstrated the leakage site which was not clearly showed by computed tomography (CT) scan and aortography. The detection rate of the anastomosed native coronary artery was 89% (left: 100%, right: 67%). Interposition graft by Pichler's modification method was detected in 96% (left: 100%, right: 92%) of cases by TEE, but only in 43% (left: 57%, right: 29%) by CT scan (left: p < 0.005, right: p < 0.0001). The detection rate of the right coronary artery, interposition graft to right coronary artery, and their color signals were lower than those of the left coronary artery. TEE has considerable diagnostic value in evaluating patients after Bentall's operation.

Adult↗