Huang Pj

Assessment of coronary artery disease in women by dobutamine stress echocardiography: Comparison with stress thallium-201 single-photon emission computed tomography and exercise electrocardiography

BACKGROUND Dobutamine stress echocardiography (DSE) is sensitive and specific in detecting myocardial ischemia of male patients. However, there have been few reports about the use of DSE for the detection of coronary artery disease (CAD) in women. METHODS DSE was evaluated in 51 consecutive women who underwent concomitant quantitative coronary angiography. Forty-four of the 51 patients received stress thallium-201 single-photon emission computed tomography (SPECT), and 30 of the 51 patients had interpretable results (exercise level > or = 85% of age-predicted maximal heart rate) of treadmill exercise. Twenty-nine patients had angiographically documented CAD defined as > or = 50% diameter stenosis. RESULTS The overall sensitivity of DSE and stress 201Tl SPECT in detecting CAD was 93% and 79% (p = nonsignificant), and the specificity was 82% and 75% (p = nonsignificant), respectively. A combination of both tests increased the sensitivity (96%) at the expense of some decrease in specificity (60%). The agreement of DSE and 201Tl SPECT was 68% (30 of 44; kappa statistic = 0.35; p < 0.0001). The overall sensitivity, specificity, and accuracy in detecting CAD by treadmill exercise test and DSE were 71% vs 93% (p = nonsignificant), 44% vs 82% (p = 0.036), and 57% vs 88% (p = 0.003). In patients with abnormal results of treadmill exercise testing, the false-positive rate in detecting CAD was 2 (18%) of 11 in patients with abnormal results of DSE and 7 (88%) of 8 in those with normal results of DSE (p = 0.005). In patients with normal results of treadmill exercise testing, the false-negative rate in detecting CAD was 4 (100%) of 4 in patients with abnormal results of DSE and 0 (0%) of 7 in those with normal results of DSE (p = 0.003). CONCLUSION The diagnostic accuracy of DSE was similar to that of stress 201Tl SPECT in women. DSE was able to stratify female patients with either abnormal or normal results of treadmill exercise testing and to avoid unnecessary cardiac catheterization.

Tl-201 myocardial SPECT in differentiation of ischemic from nonischemic dilated cardiomyopathy in patients with left ventricular dysfunction

BackgroundThe differentiation between ischemic and nonischemic cardiomyopathy by noninvasive modalities is of clinical importance. Whether thallium 201 single photon emission computed tomography (SPECT) could accurately distinguish the two groups remains unclear.Methods and ResultsTwenty-nine patients with chronic heart failure (left ventricular ejection fraction ≤40%), including fourteen patients with ischemic cardiomyopathy and fifteen patients with nonischemic dilated cardiomyopathy, underwent Tl-201 SPECT. The stress protocols included treadmill exercise in 8 patients, dipyridamole in 6 patients, and dobutamine infusion in 15 patients. Myocardial SPECT was interpreted with the use of a 17-segment model and 0- to 4-point scale system. Patients with ischemic cardiomyopathy had higher summed stress defect scores (27.9 ± 9.4 vs 20.6 ± 8.9, P = .04), more fixed defect segments (5.9 ± 2.9 vs 3.8 ± 2.9, P = .05), and more moderate or severe perfusion defect segments on stress scan (7.2 ± 2.0 vs 4.5 ± 2.6, P = .004) than did those with nonischemic dilated cardiomyopathy. However, considerable overlap of the scan patterns between the two groups existed. Moderate or severe perfusion defects on stress scan in at least 7 segments were noted in 71% of patients (10/14) with ischemic cardiomyopathy, as compared with 20% of patients (3/15) with nonischemic cardiomyopathy (P = .016).ConclusionsAssessment of Tl-201 myocardial SPECT yields only modest value to distinguish nonischemic dilated cardiomyopathy from ischemic cardiomyopathy in patients with chronic heart failure. This technique cannot clearly differentiate individual patients. (J Nucl Cardiol 2003;10:369-74.)

ASSESSMENT OF ZEBRAFISH CARDIAC PERFORMANCE USING DOPPLER ECHOCARDIOGRAPHY AND POWER ANGIOGRAPHY

The zebrafish (Danio rerio) has become a new animal model for cardiac researches. Although it is equipped with a prototypical vertebrate heart, the zebrafish studies for cardiac mutations and genetic control of development can reveal some hints for solving human problems. Despite the simplicity of the zebrafish heart, the objective parameters of cardiac performance are not easily available, except for the morphological description, due to its small size. Because the four components (sinus venosus, atrium, ventricle and bulbus arteriosus) of the zebrafish heart are connected in series, we studied it by applying ultrasonic imaging methods for the vascular system. A total of 20 fishes that were ages of 3 to 4 months were studied. Their mean body weight and height were 562 +/- 173 mg and 4.6 +/- 0.7 cm, respectively. Power angiography and routine Doppler echocardiography were used to evaluate the cardiac performance of zebrafish at 25 degrees C and 15 degrees C. The zebrafish hearts could be easily identified with color Doppler (8.5 MHz) or power angiography (7 MHz). The ventricular filling flow contained two components (E and A-flow). The E-flow velocities were lower than the A-flow velocities at both 25 and 15 degrees C. The cycle length was prolonged (p < 0.05) and the velocities of ventricular filling and bulbus arteriosus decreased significantly at 15 degrees C (p < 0.05). A significant decrease in early diastolic deceleration slope and significant prolongation in early diastolic and late-diastolic deceleration times were found at a lower temperature (15 degrees C). The acceleration:deceleration ratio for early and late diastole also showed a significant difference at 15 degrees C. In conclusion, the cardiac performance of the zebrafish could be approached using commercially available clinical instruments equipped with Doppler echocardiography and power angiography.

Simultaneous dobutamine stress echocardiography and thallium-201 perfusion imaging for the detection of coronary artery disease

To compare the diagnostic value of dobutamine stress echocardiography with dobutamine thallium-201 single-photon-emission computed tomography (SPECT) in detecting coronary artery disease, we performed both tests simultaneously on 93 patients who also underwent coronary arteriography. Dobutamine was infused at rates of 5, 10, 20, 30 and 40 microns/kg/min in 3-min stages. The left ventricle was divided into anteroseptal, posterolateral and inferior regions. Within each region, wall motion or perfusion abnormalities were classified as normal, ischemia or fixed defect. The response to stress was concordantly classified by both tests in 67 patients (72%, kappa = 0.48). Regional agreement for abnormalities was observed in 79% (kappa = 0.56) of the 279 regions analyzed. Dobutamine echocardiography detected 62 (93%) and thallium SPECT 60 (90%, p = NS) of the 67 patients with significant coronary artery disease (> or = 50% diameter stenosis). The specificity was 77 (20 of 26) and 81% (21 of 26), respectively. The accuracy was 88 and 87%, respectively. Combined the two tests gave a sensitivity of 97%, a specificity of 65% and an accuracy of 88%. The accuracy for detecting individual coronary stenosis with echocardiography was 83% for the left anterior descending artery, 84% for the right coronary artery and 73% for the left circumflex artery. With SPECT, it was 83, 87 and and 76%, respectively. In conclusion, dobutamine stress echocardiography and thallium SPECT provide a comparable accuracy for detection and localization of coronary artery disease, and for identification of regional myocardial abnormalities. Performing the two tests simultaneous is feasible but it adds limited value in detecting coronary artery disease.

Effect of acupuncture at nei-kuan on left ventricular function in patients with coronary artery disease.

Effect of acupuncture at Nei-Kuan (EH-6) on left ventricular ejection fraction (LVEF) was examined in 22 patients with angiographically proved coronary artery disease (CAD) and 22 normal subjects. Serial equilibrium radionuclide angiography was done to measure LVEF at 4 different times (at baseline, at 1 to 15 minutes, and 16 to 30 minutes during acupuncture, and immediately after acupuncture). One week later, each patient had an identical imaging protocol with acupuncture performed at a dummy point. Our results showed that in normal subjects, the mean values of LVEF did not change significantly during or after acupuncture. In contrast, in patients with CAD, the mean values of LVEF in the initial 15 minutes of acupuncture significantly increased from baseline (42.5 +/- 15.6% vs. 40.6 +/- 15.4%, p < 0.05). The increase persisted through the next 15 minutes of acupuncture and 15 minutes after acupuncture, but became insignificant at one week. Thus, acupuncture at Nei-Kuan can temporarily improve LV function in patients with CAD.

Do β-blockers affect the diagnostic sensitivity of dobutamine stress thallium-201 single photon emission computed tomographic imaging?

BackgroundThe effects of β-blockers on dobutamine stress 201Tl tomographic imaging are not known. This study was undertaken to examine whether β-blockers affect the sensitivity of dobutamine stress 201Tl imaging.Methods and ResultsOne hundred ten patients without previous myocardial infarction underwent dobutamine stress 201Tl single photon emission computed tomography (SPECT) and coronary arteriography, both studies within a 1-week period. Dobutamine was infused at rates of 5, 10, 20, 30, and 40 μg/kg/min in 3-minute stages. Atropine (as much as 1 mg) was injected intravenously when the patient’s heart rate was <100 beats/min. Patients in group 1 (n=72) were receiving β-blockers and patients in group 2 (n=38) were not. The SPECT images in group 1 showed perfusion abnormalities in 62%, 87%, and 94% of patients with one-, two-, and three-vessel coronary artery disease (≥50% diameter stenosis), respectively, compared with 75%, 71% and 100% in group 2 (p not significant). The overall sensitivities were 82% (37 of 45) in group 1 and 80% (16 of 20) in group 2 (p not significant). The specificities were 81% (22 of 27) in group 1 and 83% (15 of 18) in group 2 (p not significant). The overall accuracies were the same for both groups (82%). Atropine was added more often in group 1 than in group 2 (37/72 vs 5/38, p<0.001).ConclusionsOur results suggest that β-blockers do not affect the sensitivity, specificity, and accuracy of dobutamine stress 201Tl SPECT imaging for detecting coronary artery disease if atropine is given when the chronotropic response is inadequate. In patients receiving β-blockers, however, the addition of atropine to dobutamine stress is more frequently required.

Significance of Dobutamine-Induced ST-Segment Elevation and T-Wave Pseudonormalization in Patients With Q-Wave Myocardial Infarction: Simultaneous Evaluation by Dobutamine Stress Echocardiography and Thallium-201 SPECT

The clinical significance of stress-induced ST-segment elevation and T-wave pseudonormalization in infarct-related leads is still controversial. Therefore, we conducted the present study to assess this issue using simultaneous dobutamine stress echocardiography (DSE) and thallium-201 single-photon emission computed tomography. A total of 119 patients with Q-wave myocardial infarction were enrolled in this study. There were 58 patients with (group I) and 61 patients without (group II) dobutamine-induced ST-T changes. Left ventricular ejection fraction was 43 +/- 13% in group I and 49 +/- 14% in group II (p <0.05). The baseline, low-, and peak-dose global wall motion scores were similar between these 2 groups (26.2 +/- 6.1 vs 26.2 +/- 6.3 [p = NS]; 24.1 +/- 5.3 vs 23.5 +/- 5.7 [p = NS]; 26.4 +/- 5.7 vs 26.7 +/- 6.1 [p = NS]). The sensitivity, specificity, and accuracy of these ST-T changes for detecting residual myocardial viability and ischemia documented by DSE in all patients were 50%, 53%, and 51% (for viability), and 47%, 48%, and 47% (for ischemia), respectively. The sensitivity, specificity, and accuracy of these ST-T changes for detecting a reversible perfusion defect documented by thallium-201 single-photon emission computed tomography were 51%, 54%, and 52%, respectively. In conclusion, dobutamine-induced ST elevation and/or T-wave pseudonormalization is associated with poor resting left ventricular function. These ST-T changes are not associated with residual myocardial ischemia and viability in the infarct area. Therefore, these electrocardiographic changes alone cannot be reliably considered as distinctive markers in formulating the therapeutic strategy of coronary intervention.

Low-serum, high-density lipoprotein cholesterol concentration is an important coronary risk factor in Chinese patients with low serum levels of total cholesterol and triglyceride.

The significance of low-serum high-density lipoprotein concentrations (<35 mg/dl) with respect to coronary atherogenesis in Chinese patients with low levels of total serum cholesterol (<200 mg/dl) and triglycerides (<250 mg/dl) was assessed. Persons with such a lipid profile pattern were still at high risk, and high-density lipoprotein. like smoking, appeared to be the most predictive independent coronary risk factor.

Association of circulating matrix metalloproteinase-1, but not adiponectin, with advanced coronary artery disease

OBJECTIVE Recent evidence suggests that high tissue matrix metalloproteinase-1 (MMP-1) and low adiponectin may serve as biomarkers of atherosclerosis. Results on the associations of circulating MMP-1 and adiponectin concentrations are scarce. We hypothesized that patients with multivessel coronary artery disease (CAD) have elevated high-sensitivity C-reactive protein (hs-CRP), MMP-1 but low adiponectin levels, and concomitant measurements of these biomarkers could improve predictive strength for advanced CAD. RESEARCH DESIGN AND METHODS We analyzed concentrations of MMP-1, hs-CRP and adiponectin in 217 subjects with angiographically documented multivessel CAD (two-, or three-vessel disease by luminal stenosis >or=50%) and 81 controls. MMP-1 and hs-CRP were notably higher in patients with CAD; while adiponectin was not significantly different between two groups. Levels of hs-CRP positively correlated with body mass index and left ventricular dysfunction (R(2)=0.16, P<0.0001); while adiponectin was significantly associated with age, gender, and levels of cholesterol and triglyceride (R(2)=0.09, P<0.0001). On the contrary, MMP-1 was not associated with any clinical cardiovascular risk factors, and still an independent predictor (OR=1.49, P<0.0001) of multivessel CAD after the adjustment of clinical risk factors and hs-CRP. CONCLUSION Elevated MMP-1 and hs-CRP, but not low adiponectin concentrations, could predict the presence of advanced coronary atherosclerosis. In addition, MMP-1 may serve as a more specific marker for significant CAD independent of hs-CRP.

Value of circulating adhesion molecules in assessing cardiac allograft vasculopathy.

Circulating adhesion molecules have been implicated in the development of spontaneous and transplant coronary artery disease. We analyzed soluble (s) intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1 (sVCAM-1), and sE-selectin levels from the coronary sinuses of 25 cardiac allograft recipients, and we correlated these molecules with the degree of acute rejection detected in endomyocardial biopsy specimens and the presence of transplant vasculopathy assessed with coronary angiography. We found that sVCAM-1 significantly increased in patients with transplant vasculopathy compared with those without transplant vasculopathy, whereas sE-selectin and sICAM-1 did not. Therefore, increased coronary sinus levels of sVCAM-1 is a reliable marker in assessing cardiac transplant vasculopathy.