Masahiro Karakawa

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 (≥ 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.

Evaluation of Factor XIa–α1-Antitrypsin in Plasma, a Contact Phase–Activated Coagulation Factor–Inhibitor Complex, in Patients With Coronary Artery Disease

Excess activated factor XI (FXIa) in plasma indicates increased activation during the contact phase of blood coagulation. To investigate the relationship between such elevations and coronary atherosclerosis, we examined FXIa values in patients with coronary artery disease (CAD) by an enzyme-linked immunosorbent assay method that we developed that detects FXIa in plasma samples as an FXIa-alpha 1-antitrypsin complex (FXIa-alpha 1AT). The presence and extent of CAD were documented by coronary angiography and assessed by a recently developed scoring system for semiquantitative estimation of coronary atherosclerosis. Plasma FXIa-alpha 1AT levels were significantly increased in patients with angiographically proven CAD (13.9 +/- 3.0 micrograms/L, n = 42) compared with age-matched, healthy control subjects (11.9 +/- 1.7 micrograms/L, n = 20) as well as patients with angiographically normal coronary arteries (12.0 +/- 2.3 micrograms/L, n = 25). Moreover, in the total patient population, the FXIa-alpha 1AT level was related to the number of significant coronary artery stenoses as well as to the total coronary score. FXIa-alpha 1AT showed a positive correlation with thrombin-antithrombin III complex, fibrinogen, and Lp(a) and an inverse correlation with apo A-I, as determined by multi-variate analysis. Our studies provide evidence that increased activation of the contact pathway occurs in patients with CAD and is related to the severity of the disease. Although it is unknown whether this abnormality is the cause or the result of the vascular lesion, it may be important for progression of the underlying atherosclerosis or for propagation of the atherosclerotic process itself.

Prevalence, resolution, and determinants of late potentials in patients with unstable angina and left ventricular wall motion abnormalities.

Although transient myocardial ischemia such as exercise-induced ischemia has not been reported to be associated with the occurrence of late potentials, the association of late potentials with more profound ischemic damage, which is represented by reversible but prolonged left ventricular wall motion abnormalities, has not been demonstrated. We prospectively evaluated 37 unstable angina patients who had reversible but prolonged wall motion abnormalities after resolution of chest pain and electrocardiogram (ECG) changes. Signal-averaged ECG (SAECG) and echocardiogram were recorded during the acute phase and before hospital discharge. Late potentials were present in 6 (16 percent) patients on the initial SAECG recording and resolved in all 6 patients on the second recording before hospital discharge. Normalization of inferior left ventricular wall motion abnormality and multivessel disease were observed more frequently in patients with late potentials on the initial recording than in patients without (p < 0.05 and p < 0.05, respectively). In conclusion, late potentials were observed in patients who had reversible but prolonged wall motion abnormalities; these late potentials were resolved with improvement of left ventricular wall motion abnormalities. These results suggest that myocardial ischemia with prolonged wall motion abnormalities is a possible mechanism of the occurrence of late potentials.

Clinical Significance of S-T Segment Elevation in Lead aVR in Anterior Myocardial Infarction

The significance of exercise-induced S-T elevation in aVR was studied in 57 patients with recent anterior infarction and single-vessel disease. S-T elevation in aVR was found at peak exercise in 24 patients. Although the initial defect area was similar in the groups with and without S-T elevation in aVR, the redistribution area was larger in the former group (p < 0.01). When three electrocardiographic criteria were used in the multivariate analysis, S-T elevation in aVR was the significant variable related to redistribution in the anterior wall. Thus, S-T elevation in aVR may indicate ischemia of the anterior wall.

Late potentials during left ventricular healing of acute myocardial infarction.

BackgroundLate potentials and left ventricular remodeling are important factors in the prognosis of acute myocardial infarction. However, the relationship between late potentials and ventricular remodeling has not been fully evaluated. MethodsWe evaluated clinical characteristics, coronary angiographie findings and radionucltde angiographie measures about 1 month after an acute myocardial infarction in patients with and without late potentials. ResultsAlthough the left ventricular ejection fraction of patients with late potentials was not different from that of patients without late potentials, the left ventricular end-diastolic volume of patients with late potentials was larger than that of patients without late potentials (P<0.05). There was a significant positive correlation between the left ventricular end-diastolic volume and the filtered QRS duration (r = 0.53, P< 0.001). The root mean square of the voltage in the terminal 40ms and the low-amplitude signal duration of 7lt;40 μV in the terminal QRS sequence were also correlated with the left ventricular end-diastolic volume (r = 0.40, P<0.02, and r = 0.39, P<0.02, respectively). Patency of the infarct-related vessel in the late phase of an acute myocardial infarction was an important factor associated with the occurrence of late potentials (P<0.01). ConclusionA larger left ventricular end-diastolic volume in patients with late potentials might be associated with left ventricular remodeling during the first month after an acute myocardial infarction.

Residual left ventricular pump function following acute myocardial infarction in postmenopausal diabetic women

BackgroundThe Framingham Study indicated that women with diabetes mellitus developed cardiac failure four times more often than those without diabetes mellitus after acute myocardial infarction. However, there is little information on residual left ventricular pump function after myocardial infarction in female diabetic patients. MethodsTo evaluate the difference between postmenopausal women and age-matched men in the impact of diabetes mellitus on left ventricular pump function during the first year after myocardial infarction, radionuclide angiography was performed during the third week after acute myocardial infarction and again 1 year later in 50 patients (21 women, 29 men) with diabetes mellitus and 62 patients (25 women, 37 men) without diabetes mellitus. ResultsAlthough the radionuclide angiographie indices did not change during the first year after myocardial infarction in non-diabetic patients, left ventricular end-diastolic volume increased, and the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the ratio of arterial systolic blood pressure to left ventncular end-systolic volume (pressure:volume ratio) decreased in the diabetic patients. Furthermore, the degree of change in the left ventricular end-diastolic volume, the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the pressure: volume ratio in diabetic women was larger than that in diabetic men. ConclusionThe increase in the left ventricular end-diastolic volume and the decrease in the regional ejection fraction of the non-infarcted area during the first year after myocardial infarction in postmenopausal women with diabetes mellitus indicate that female sex associated with diabetes mellitus may be important factors in left ventricular remodeling in postmenopausal women.

Effect of Body Characteristics on the Variables of Signal-Averaged Electrocardiogram in Healthy Teenage Subjects

Ventricular late potentials are obtained by signal-averaged surface electrocardiography. Late potentials have been reported to be affected by body characteristics or left ventricular mass. To evaluate late potentials in relation to body characteristics, 52 healthy Japanese young volunteers (21 girls, 31 boys) aged 15-16 years were studied. QRS duration in men was significantly longer than in women. There were no significant differences in low-amplitude signal and root mean square voltage between women and men. When relations between signal-averaged electrocardiographic parameters and body characteristics were examined, QRS duration had positive linear correlations with weight and body mass index. The slope of QRS duration and weight relation, and QRS duration and body mass index relation was significantly steeper in men compared to those in women; a prolongation of QRS duration in men compared to women as weight and body mass index increased. Our results indicated that QRS duration in teenage healthy subjects should be used with caution because it is affected by gender.

Scintigraphic predictor of left ventricular size after acute myocardial infarction.

The aim of this study was to evaluate the relation between thallium-201 scintigraphic indices and left ventricular size after acute myocardial infarction. Forty-seven patients with acute myocardial infarction underwent rest-redistribution thallium-201 scintigraphy at 2 weeks and left ventriculography at 4 weeks, after the onset of myocardial infarction. Percent (%) fixed defect, %redistribution and %reverse redistribution, calculated as a percentage of whole left ventricular area, were quantified with computer-generated unfolded map method of the myocardial radioactivity. Despite no significant difference in peak plasma creatine phosphokinase between the two groups, patients with anterior myocardial infarction (28 patients) had larger %fixed defect (p < 0.01), which was associated with higher end-diastolic pressure (p < 0.05) and larger end-diastolic volume index (p < 0.01) than those with inferior myocardial infarction (19 patients). End-diastolic volume index was not related to %redistribution and %reverse redistribution, but there was a good relation between end-diastolic volume index and %fixed defect in anterior (r = 0.79, p < 0.001) and in inferior (r = 0.73, p < 0.001) myocardial infarction. However, left ventricular end-diastolic volume index in anterior myocardial infarction was larger than that of inferior myocardial infarction at any given %fixed defect. Thus, site as well as size of fixed defect at 2 weeks after the onset of acute myocardial infarction was related to left ventricular end-diastolic volume at chronic phase.

Frequency of pericardial friction rub ("pericarditis") after direct percutaneous transluminal coronary angioplasty in Q-wave acute myocardial infarction.

The clinical significance of infarct-associated pericarditis was examined in 201 consecutive patients with acute Q-wave myocardial infarction with successful direct percutaneous transluminal angioplasty. A pericardial rub was a reliable clinical sign of extensive myocardial damage in patients with direct angioplasty.

The effectiveness of super-selective injection with anchor balloon technique for collateral channel assessment

The careful assessment of collateral channels is important for a retrograde approach for a chronic total coronary occlusion (CTO). This case report describes a percutaneous coronary intervention for CTO of the distal right coronary artery with good collateral circulation. All visible collateral channels failed by the retrograde approach; however, the procedure was successful using the distal atrial circumflex (AC) channel. Although this distal channel was poorly visualized on standard coronary angiography, it was clearly contrasted retrogradely from the CTO exit using a super-selective injection through the proximal AC channel as the antegrade flow was obstructed by the anchor balloon. This case highlights a unique super-selective injection with anchor balloon technique for collateral channel assessment.