Shinichi Arima

Serum levels of cardiac troponin I and troponin T in estimating myocardial infarct size soon after reperfusion.

Background Cardiac troponin I (Tnl) and troponin T (TnT) are highly specific myocardial markers.Objective To determine whether their serum levels can be used to estimate myocardial infarct size soon after reperfusion.Methods We measured the serum levels of Tnl, TnT, and creatine kinase every 3 h, and the serum cardiac myosin light chain I (MLCI) every 24 h, in 42 patients with acute myocardial infarction in whom reperfusion therapy had successfully been performed. We calculated the severity of regional hypokmesis by analyzing the follow-up ventriculograms with the centerline method.Results The time from reperfusion to the peak level for Tnl was 6.1 ± 3.5 h, significantly shorter than those for creatine kinase (7.5 ± 4.1 h) and MLCI (55 ± 28 h). The time to peak level for TnT (6.8 ± 4.0 h) differed significantly from that for MLCI but not from that for creatine kinase. There was a significant correlation between the peak levels of Tnl and TnT (r = 0.86). The peak Tnl and TnT levels were correlated well to the peak creatine kinase level (r = 0.67 and 0.69, respectively), total creatine kinase release (r = 0.66 and 0.66), and the peak MLCI level (r = 0.71 and 0.80). We observed excellent correlations between the peak levels of Tnl and TnT, and regional hypokinesis (r = −0.84 and −0.85, respectively). These were comparable to the correlations between regional hypokinesis and the peak creatine kinase level (r = −0.75), total creatine kinase release (r = −0.72), and the peak MLCI level (r = −0.76).Conclusions These results suggest that the peak serum levels of Tnl and TnT in patients with successful reperfusion are accurate and early indices of infarct size.

Early assessment of reperfusion therapy using cardiac troponin T

OBJECTIVES The purpose of this study was to investigate the utility of cardiac troponin T for early assessment of reperfusion therapy. BACKGROUND Several biochemical markers are used for early noninvasive detection of reperfusion during intravenous thrombolytic therapy. However, cardiac troponin T, a new myocardial-specific marker, has not been used previously for this purpose. METHODS We measured troponin T and creatine kinase, MB isoenzyme (CK-MB) levels in 38 patients with acute myocardial infarction whose infarct-related artery was totally occluded before reperfusion therapy. Subjects comprised 14 patients with successful angioplasty (group 1), 12 patients with successful thrombolytic therapy (group 2) and 12 patients with unsuccessful attempted reperfusion (group 3). Blood samples were taken every 15 min, and coronary angiography was performed every 5 to 8 min until 60 min after reperfusion (groups 1 and 2) or after the initiation of treatment (group 3). We calculated the increase in troponin T (delta troponin T) and CK-MB (delta CK-MB) 60 min after treatment was initiated and 60 min after reperfusion in groups 1 and 2. RESULTS Mean (+/- SD) delta troponin T and delta CK-MB levels were 9.35 +/- 7.83 ng/ml and 125 +/- 83 mU/ml in group 1 and 3.23 +/- 3.08 ng/ml and 130 +/- 137 mU/ml in group 2, respectively, 60 min after treatment and were 10.1 +/- 8.35 ng/ml and 131 +/- 84 mU/ml in group 1 and 6.84 +/- 8.30 ng/ml and 158 +/- 146 mU/ml in group 2, respectively, 60 min after reperfusion. These values were significantly higher than those 60 min after treatment in group 3: 0.16 +/- 0.19 ng/ml and 10 +/- 9 mU/ml, respectively. The predictive accuracy for detecting reperfusion using a threshold value of 0.50 ng/ml of delta troponin T and 25 mU/ml of delta CK-MB was 100% in group 1 and 92% in group 2 60 min after treatment, respectively. There was significant correlation between delta troponin T and delta CK-MB. CONCLUSIONS Serial measurements of cardiac troponin T as well as of CK-MB are useful for early assessment of reperfusion therapy.

Rapid diagnosis of coronary reperfusion by measurement of myoglobin level every 15 min in acute myocardial infarction

OBJECTIVES The purpose of this study was to examine whether coronary reperfusion can be diagnosed rapidly and accurately by myoglobin measurements. BACKGROUND When intravenous thrombolysis is used for acute myocardial infarction, it is important to determine coronary reperfusion rapidly and noninvasively so that further treatment can be initiated. METHODS We determined myoglobin, creatine kinase (CK) and creatine kinase, MB fraction (CK-MB) isoenzyme levels in 63 patients with acute myocardial infarction with total occlusion of the infarct-related artery that was confirmed by coronary angiography. Myoglobin was measured by turbidimetric latex agglutination, which has an assay time of 10 min. We measured myoglobin, CK and CK-MB every 15 min in 45 patients with and 18 patients without reperfusion. The condition of the infarct-related artery was confirmed every 5 to 8 min by coronary angiography. RESULTS The rate of increase in myoglobin, CK, and CK-MB at 15, 30, 45 and 60 min after treatment and reperfusion was significantly higher in the reperfused than in the nonreperfused group. In the reperfused group, the rate of increase in myoglobin was significantly higher than the corresponding rate of increase in CK and CK-MB at 15, 30 and 45 min after reperfusion. When reperfusion was evaluated on the basis of a cutoff level (myoglobin > or = 2.0, CK > or = 1.8, CK-MB > or = 1.5), the predictive accuracy of myoglobin (95%) was significantly higher than that of CK (68%) and CK-MB (73%) at 15 min after reperfusion. CONCLUSIONS Coronary reperfusion can be rapidly and accurately detected by measurement of the plasma myoglobin every 15 min.

High serum concentration of lipoprotein(a) is a risk factor for restenosis after percutaneous transluminal coronary angioplasty in Japanese patients with single-vessel disease

To determine the relation between the concentration of lipoprotein(a) [Lp(a)] and restenosis after percutaneous transluminal coronary angioplasty (PTCA) in Japan, we studied 80 consecutive patients with single-vessel disease who successfully underwent PTCA. All were evaluated by follow-up angiography a mean of 6.9 months after PTCA and were divided into the restenosis (30 patients) and the non-restenosis (50 patients) groups. The serum Lp(a) concentration of 29 +/- 17 mg/dl in the restenosis group was significantly higher than that of 17 +/- 14 mg/dl in the nonrestenosis group (p < 0.01). Multiple logistic regression analysis for risk factors revealed a significant correlation between restenosis and Lp(a) (p < 0.003). The serum Lp(a) concentration was positively correlated with the coronary artery percent stenosis at the time of follow-up angiography (r = 0.32, p < 0.01). High serum concentration of Lp(a) is therefore a risk factor for restenosis after PTCA in Japan.

A New Predictor of Restenosis After Successful Percutaneous Transluminal Coronary Angioplasty in Patients With Multivessel Coronary Artery Disease

With the goal of improving prediction of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for multivessel coronary artery disease (CAD), we evaluated the usefulness of serial exercise treadmill tests. We previously reported that an increase in the deltaST/delta heart rate (HR) index at follow-up over the value obtained several days after PTCA was useful for detecting restenosis following PTCA for 1-vessel CAD. In that report, comparison of the deltaST/deltaHR index was made based on measurements from the lead disclosing the greatest ST displacement before PTCA. This method was not applicable to patients with multivessel CAD. Seventy-eight patients with multivessel CAD before and several days after PTCA and just before follow-up performed exercise treadmill tests. Simple HR-adjusted indexes of ST-segment depression during exercise (deltaST/deltaHR index) and the sum of the deltaST/deltaHR index in leads II, III, aVF, V4, V5, and V6 (sigma deltaST/deltaHR index) were determined. We compared the predictive power of an increase in sigma deltaST/deltaHR index at follow-up with that of a positive exercise treadmill test and a positive thallium scintigram for restenosis. At follow-up, 37 of the 78 patients showed restenosis. The sigma deltaST/deltaHR index had increased in 30 of these 37 patients (81%), and in 12 of the 41 patients (29%) without restenosis. An increase in sigma deltaST/deltaHR index had a significantly higher sensitivity than the other methods and a significantly higher specificity than a positive exercise treadmill test.

A New Criterion Combining ST/HR Slope and ΔST/ΔHR Index for Detection of Coronary Artery Disease in Patients on Digoxin Therapy

Abstract We evaluated the clinical value of a new index combining ΔST/Δheart rate (HR) index and ST/HR slope for diagnosing coronary artery disease (CAD) in patients on digoxin therapy. Exercise treadmill tests were performed by 72 patients on digoxin therapy. Simple HR–adjusted indexes of ST-segment depression during exercise (ΔST/ΔHR index) and the decline calculated from the final 12 data points relating ST-segment depression to HR (ST/HR slope) were determined. A new index was obtained by subtracting the ΔST/ΔHR index from the ST/HR slope. On thallium scintigraphy, 37 of the 72 patients showed reversible perfusion defects related to the diseased coronary artery. The new index derived from this ST-HR relation was 4.1 ± 3.6 μV/beats/min in the ischemic group and 1.3 ± 1.0 μV/beats/min in the group of patients without ischemia (p

Transesophageal doppler echocardiographic assessment of left coronary blood flow velocity in chronic aortic regurgitation

Assessment of systolic and diastolic coronary blood flow velocities (FVs) in patients with aortic regurgitation (AR) has remained a clinical challenge. We recorded left anterior descending coronary blood FV in 21 patients with chronic AR an in 6 control subjects using transesophageal pulsed Doppler echocardiography. In 7 patients FV was measured 4.0 +/- 5.2 months after aortic valve replacement. Peak and mean FVs during systole and diastole and systolic/diastolic ratios of these FVs were determined. Left ventricular (LV) mass index was calculated by means of standard M-mode echocardiography. In patients with severe AR, peak and mean systolic FVs were significantly increased (34 +/- 8 cm/sec and 21 +/- 6 cm/sec, respectively) compared with FVs in the control group (15 +/- 4 and 12 +/- 3 cm/sec, respectively) and in patients with mild AR (17 +/- 3 cm/sec and 13 +/- 2 cm/sec, respectively). Peak and mean systolic FVs were also significantly increased in severe AR (54 +/- 13 cm/sec and 33 +/- 9 cm/sec, respectively) compared with FVs in the control (30 +/- 8 cm/sec and 21 +/- 5 cm/sec, respectively) and mild AR groups (30 +/- 5 cm/sec and 21 +/- 4 cm/sec, respectively). Peak systolic and diastolic FVs were correlated significantly with LV mass index (r = 0.72 and r = 0.73, respectively). Systolic and diastolic FVs and LV mass index were significantly decreased, normalized or both after aortic valve surgery. In conclusion, LV mass seems to have an effect on the significantly increased systolic and diastolic left coronary blood FV pattern in patients with chronic, severe AR. Increased systolic and diastolic FV appears to be normalized in the late period after surgery.

Marked alternans of the elevated ST segment during occlusion of the left anterior descending coronary artery in percutaneous transluminal coronary angioplasty: clinical background and electrocardiographic features.

To investigate the clinical background and the electrocardiographic features of marked alternans of the elevated ST segment during coronary angioplasty, we examined 12-lead electrocardiograms recorded continuously during occlusion of the left anterior descending coronary artery by balloon inflation in 41 patients. The incidence of marked ST alternans was 27% of 41 patients and 15% of 117 balloon occlusions. The incidence decreased progressively from the first to the third occlusion. The time course of ST alternans was determined. Compared with patients without ST alternans, patients with ST alternans had a shorter history of angina, less severe stenosis of the target lesion before coronary angioplasty, more leads showing ST elevation during occlusion, higher ST elevation during occlusion and lower incidence of previous myocardial infarction in the left anterior descending coronary arterial area. ST alternans recorded on the surface electrocardiogram may thus be considered a marker of acute severe and extensive myocardial ischemia.

Use of the QRS scoring system in the early estimation of myocardial infarct size following reperfusion

While the QRS scoring system has been established as a convenient tool for estimating infarct size in nonreperfused patients during the chronic stage of myocardial infarction, its applicability to reperfused patients in the acute stage has not been established. To investigate whether infarct size could be estimated by the QRS scoring system soon after reperfusion, we evaluated QRS scores obtained serially 6 hours to 1 month after reperfusion, total creatine kinase release, and left ventricular ejection fraction in 126 patients with acute myocardial infarction who underwent successful reperfusion therapy. A significant correlation was observed between the QRS score obtained after 6 hours and that obtained after 1 month (r = .89). The QRS scores obtained after 6 hours and 1 month were significantly correlated with total creatine kinase release (r = -.65 and r = -.75, respectively) and left ventricular ejection fraction (r = .62 and r = .76, respectively). Thus, the QRS scoring system can be used as a simple and economical method for estimation of infarct size soon after reperfusion.

Detection of reperfusion 30 and 60 minutes after coronary recanalization by a rapid new assay of creatine kinase isoforms in acute myocardial infarction.

We measured creatine kinase (CK) isoforms by a new immunoinhibition method to evaluate their usefulness in detecting early coronary reperfusion. Blood samples were collected at 15-minute intervals from 50 patients with acute myocardial infarction. CK isoforms were determined by a 10-minute immunoinhibition method with an autoanalyzer. Values for inhibited isoforms (MM3, MM2/2, and MB2/2) were divided by those of noninhibited isoforms (MM1, MM2/2, MB1, MB2/2, and BB) to calculate the isoform ratio. In the reperfused group the increase in the isoform ratio was 2.69 +/- 1.80 (SD) 30 minutes after reperfusion and 2.41 +/- 2.01 at 60 minutes, which was significantly higher than the corresponding values in the nonreperfused group (0.17 +/- 0.16 and 0.32 +/- 0.26, respectively). When an increase of 0.70 or more in the isoform ratio was used as the criterion for reperfusion, the sensitivity and specificity were 92% and 100% at 30 minutes and 100% and 100% at 60 minutes after recanalization, respectively. We conclude that the isoform ratio obtained by the new 10-minute assay of CK isoforms is useful for the noninvasive detection of reperfusion 30 and 60 minutes after recanalization in acute myocardial infarction.