Heterogeneous myocardial distribution of iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in patients with hypertrophic cardiomyopathy.

IT has been proposed that iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) is an agent for myocardial fatty acid metabolism in animal models. The aim of the present study was to determine whether alterations in fatty acid uptake and/or utilization in patients with hypertrophic cardiomyopathy (HCM) could be detected by 123I-BMIPP. Myocardial imaging with 123I-BMIPP and thallium-201 (201Tl) was performed in 14 fasted patients. A dose of 111 MBq of 123I-BMIPP was administered intravenously at rest, and myocardial emission computed tomography was obtained 20 min and 3 h after injection. The 201Tl imaging was also performed within 1 week after the 123I-BMIPP study. The regional myocardial uptake and clearance of 123I-BMIPP and 201Tl were assessed quantitatively. The myocardial distribution of 123I-BMIPP was more heterogeneous than that of 201Tl in patients with HCM. The myocardial uptake of 123I-BMIPP was lower in the anteroseptal region of the left ventricle than in the posterolateral region (74% vs. 85%, P less than 0.001). The anteroseptal wall showed a faster clearance of 123I-BMIPP than the posterolateral wall (33% vs. 27%, P less than 0.01). Both a decreased uptake and rapid clearance of 123I-BMIPP were observed in the hypertrophied myocardium of the anteroseptal wall, where 201Tl uptake was normal or even increased. Myocardial segments with a markedly increased thickness showed a lower uptake and faster clearance of 123I-BMIPP than those with mild hypertrophy (uptake 73% vs. 82%, P less than 0.05; clearance 30% vs. 25%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

The characteristics of myocardial fatty acid metabolism in patients with left ventricular hypertrophy]

We evaluated the characteristics of myocardial fatty acid metabolism in patients with left ventricular hypertrophy (LVH). Myocardial imaging with 123I-beta-methyl iodophenyl pentadecanoic acid (BMIPP) was performed in 28 patients with hypertrophic cardiomyopathy (HCM), 15 patients with hypertensive heart disease (HHD), 13 patients with aortic stenosis (AS) and 8 normal controls (NC). The patients with HCM consisted of 13 patients of asymmetric septal hypertrophy (ASH), 7 patients of diffuse hypertrophy (Diffuse-HCM) and 8 patients of apical hypertrophy (APH). Planar and SPECT images of BMIPP were acquired 15 minutes and 4 hours after tracer injection. Resting 201Tl SPECT images and echocardiography were also performed on other days. We calculated heart/mediastinum count ratio and washout rate of BMIPP by using planar image. In patients with LVH, the incidence of reduced BMIPP uptake was more frequent than that of reduced 201Tl uptake. In delayed images, more than 60% of patients with LVH reduced BMIPP uptake, especially remarkable for patients with ASH and APH. The washout rate of all cardiac hypertrophic disorders was tended to be higher than that of normal subjects. Reduced BMIPP uptake was frequently found in septal portion of anterior and inferior wall in patients with ASH, in inferior wall in patients with Diffuse-HCM and HHD, in apex in patients with APH and AS. These results suggest that BMIPP scintigraphy can differentiate three types of cardiac hypertrophy.     

Heterogeneous myocardial distribution of iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in patients with hypertrophic cardiomyopathy

It has been proposed that iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (¹²³I-BMIPP) is an agent for myocardial fatty acid metabolism in animal models. The aim of the present study was to determine whether alterations in fatty acid uptake and/or utilization in patients with hypertrophic cardiomyopathy (HCM) could be detected by ¹²³I-BMIPP. Myocardial imaging with ¹²³I-BMIPP and thallium-201 (²⁰¹Tl) was performed in 14 fasted patients. A dose of 111 MBq of ¹²³I-BMIPP was administered intravenously at rest, and myocardial emission computed tomography was obtained 20 min and 3 h after injection. The ²⁰¹Tl imaging was also performed within 1 week after the ¹²³I-BMIPP study. The regional myocardial uptake and clearance of ¹²³I-BMIPP and ²⁰¹Tl were assessed quantitatively. The myocardial distribution of ¹²³I-BMIPP was more heterogeneous than that of ²⁰¹Tl in patients with HCM. The myocardial uptake of ¹²³I-BMIPP was lower in the anteroseptal region of the left ventricle than in the posterolateral region (74% vs. 85%, P < 0.001). The anteroseptal wall showed a faster clearance of ¹²³I-BMIPP than the posterolateral wall (33% vs. 27%, P < 0.01). Both a decreased uptake and rapid clearance of ¹²³I-BMIPP were observed in the hypertrophied myocardium of the anteroseptal wall, where ²⁰¹Tl uptake was normal or even increased. Myocardial segments with a markedly increased thickness showed a lower uptake and faster clearance of ¹²³I-BMIPP than those with mild hypertrophy (uptake 73% vs. 82%, P < 0.05; clearance 30% vs. 25%, P < 0.05). Myocardial imaging with ¹²³I-BMIPP was thus applicable to patients with HCM for detecting myocardial regions with altered fatty acid metabolism.Supported in part by Grants-in-Aid for Scientific Research (nos. 02454259, 03268224) from the Ministry of Education, Science and Culture, Japan, a grant for Research on Cardiovascular Disease (1S-1) from the Ministry of Health and Welfare, Japan, and a grant from Uehara, Memorial Foundation. Offprint requests to: Y Takeishi     

Clinical results with β-methyl-p-(<Superscript>123</Superscript>I)iodophenylpentadecanoic acid,single-photon emission computed tomography in cardiac disease

This study was undertaken to evaluate the relationships between myocardial perfusion and metabolism. Simultaneous β-methyl-p-(¹²³I)iodophenylpentadecanoic acid (¹²³I-BMIPP) and thallium 201 myocardial single-photon emission computed tomography (SPECT) were performed in 25 patients with myocardial infarction (group A) and 16 patients with hypertrophic cardiomyopathy (group B). The severity scores of¹²³I-BMIPP and²⁰¹Tl myocardial SPECT images were evaluated semiquantitatively by segmental analysis. In Group A, dissociations between thallium- and¹²³I-BMIPP-imaged defects were frequently observed in patients with successful reperfusion compared with those with no reperfusion and those with reinfarction. In four patients with successful reperfusion, repeated¹²³I-BMIPP and²⁰¹Tl myocardial SPECT showed gradual improvement of the¹²³I-BMIPP severity score compared with the thallium severity score. In group B, dissociations between thallium- and¹²³I-BMIPP-imaged defects were also demonstrated in hypertrophic myocardium. In addition, nonhypertrophic myocardium also had decreased¹²³I-BMIPP uptake. In groups A and B,¹²³I-BMIPP severity scores correlated well with left ventricular function compared with thallium severity scores. These findings indicate that¹²³I-BMIPP is a suitable agent for the assessment of functional integrity, because left ventricular wall motion is energy dependent and¹²³I-BMIPP may reflect an aspect of myocardial energy production. This agent may be useful for the early detection and patient management of various heart diseases as an alternative to positron emission tomographic study.     

Phase 2 study of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid, a myocardial imaging agent for evaluating myocardial fatty acid metabolism]

A phase 2 study of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), a myocardial imaging agent developed for evaluating myocardial fatty acid metabolism, was performed in 197 patients with various heart diseases. The myocardial distribution of 123I-BMIPP did not change from early to late images in 88% of 91 patients with ischemic heart disease (IHD), while washout and/or fill-in were observed in 45% of 55 patients with hypertrophic cardiomyopathy (HCM). In comparison with 201Tl in 165 patients with various heart diseases, the decrease in uptake was more profound with BMIPP in 56% and with 201Tl in only 4%. 123I-BMIPP showed more severely decreased uptake in 83% of the patients with subacute myocardial infarction (15 to 30 days after the onset) and in 73% of the patients with HCM. High-quality SPECT images were obtained with 123I-BMIPP in 93% of 194 patients analyzed. However, the image quality in cardiomyopathy was inferior to that in IHD. The optimal injection dose range and standard dose of 123I-BMIPP were considered to be 74-148 MBq and 111 MBq, respectively. These findings suggest that 123I-BMIPP myocardial imaging is safe and useful for evaluating myocardial fatty acid metabolism in various heart diseases.     

Phase 3 study of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid, a myocardial imaging agent for evaluating fatty acid metabolism--a multi-center trial]

A multi-center trial of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP) was performed to assess its clinical usefulness in the evaluation of myocardial fatty acid metabolism in 587 patients with various heart diseases. 123I-BMIPP showed relatively decreased uptake compared with 201Tl in the myocardial lesions of 62% of patients with ischemic heart disease (IHD), 39% of those with cardiomyopathy and 32% of those with other heart diseases. In case of myocardial infarction, less uptake of 123I-BMIPP (Type B) than 201Tl was more frequently seen in patients with successful recanalization than in those without recanalization. The patients with matched distribution of the two tracers (Type E) increased in the direct proportion to the interval between the onset of myocardial infarction and the radionuclide studies. The uptake of 123I-BMIPP correlated well with myocardial viability evaluated by 201Tl exercise-redistribution studies. Type B was frequently seen in the areas with 201Tl redistribution, while Type E was seen in the fixed defect areas. In the other heart diseases studied, Type E was observed in approximately 60% of patients with dilated or secondary cardiomyopathies. Type B was seen in about 45% of patients with valvular heart diseases and myocarditis. Various types of mismatch between the two tracers were demonstrated in hypertrophic cardiomyopathy and hypertensive heart disease. It is concluded that 123I-BMIPP is a safe and useful agent for the diagnosis of various heart diseases, since it reflects myocardial fatty acid metabolism.     

Influence of increased 201Tl lung uptake on the myocardial viability of the patients with dilated cardiomyopathy under congestive heart failure]

Influence of increased 201Tl lung uptake on the myocardial viability was studied in 15 patients with dilated cardiomyopathy under congestive heart failure. Rest and 4 hours delayed 201Tl SPECT were obtained. At the same time anterior planar images were collected. In 10 patients of 15 patients 201Tl lung heart ratio in SPECT (LHR) was larger than that in planar images. Maximal 201Tl lung uptake was noted at the lower left lung adjacent to the heart. In the delayed images 201Tl lung uptake diminished. In 10 patients the value of LHR in the delayed images was less than 0.5. By comparing initial images with delayed images it was proved to be difficult to determine the myocardial margin adjacent to the increased 201Tl lung uptake. In 2 patients lateral defects were concealed by the increased 201Tl lung uptake. In the remaining patients lateral wall was similar to the hypertrophic myocardium. The effect of scatter due to the increased 201Tl lung uptake was noted in the neighboring myocardium. In most cases %201Tl uptake in the septum was relatively depressed by increased %201Tl uptake in the lateral wall. In the delayed images pseudo-redistribution was noted in the septum. Mean value of differences in %201Tl uptake between initial and delayed images was 8 (2-15)%. It was concluded that in case of increased 201Tl lung uptake SPECT could not accurately estimate myocardial viability by initial images and delayed images were necessary for precise estimation.     

Clinical study on myocardial imaging with beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid in patients with mitochondrial myopathy]

Myocardial imaging with beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), a new radiopharmaceutical designed to evaluate myocardial fatty acid metabolism, was performed in 7 patients with mitochondrial myopathy to detect their myocardial damages in comparison with 201Tl myocardial imaging. These patients were divided into 4 chronic progressive external ophthalmoplegia (CPEO) cases, 2 mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) cases and 1 myoclonus epilepsy with ragged-red fibers (MERRF). In visual assessment, we observed more myocardial segments with decreased uptake of 123I-BMIPP compared to 201Tl in MELAS cases than in CPEO cases. The mean myocardial uptake of 123I-BMIPP was higher than that of 201Tl in CPEO cases. On the other hand, in MELAS and MERRF cases, the mean myocardial uptake of 123I-BMIPP was lower than that of 201Tl. Abnormal findings suggesting myocardial damages were observed in echocardiogram and/or in electrocardiogram in MELAS and MERRF cases, while no such abnormal findings were observed in CPEO cases. Along with the previously reported experimental result that the impairment of rat myocardial mitochondria decreased myocardial uptake of 125I-BMIPP, these results suggest that 123I-BMIPP may be useful to detect myocardial damages in patients with mitochondrial myopathy.     

Myocardial defect detected by123I-BMIPP scintigraphy and left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy

The present study examined the role of myocardial fatty acid in patients with idiopathic cardiomyopathy (DCM) by means of¹²³I-β-methyl-p-iodophenyl pentadecanoic acid (¹²³I-BMIPP) scintigraphy. Thirteen patients underwent¹²³I-BMIPP imaging,²⁰¹Tl imaging and echocardiography. All patients showed defective myocardial uptake of¹²³I-BMIPP and²⁰¹Tl. The left ventricular end-diastolic dimension (64.1 ± 7.3 mm vs. 55.6 ± 1.5 mm, p < 0.05) and end-systolic dimension (52.4 ± 8.0 mm vs. 40.6 ± 2.1 mm, p < 0.01) were significantly larger in the large defect group (¹²³I-BMIPP defect score (DS) > 8) than the small defect group (DS < 7). The % fractional shortening (%FS) was also significantly smaller (18.6 ± 3.8% vs. 27.0 ± 3.3%, p < 0.01) in the large defect group. The¹²³I-BMIPP DS correlated statistically with %FS (r = 0.75, p < 0.01), while the²⁰¹Tl DS did not (r = 0.41, ns). We conclude that the patients with DCM revealed a¹²³I-BMIPP uptake defect and the defect reflected the degree of left ventricular dysfunction.     

Sequential change of BMIPP uptake with age in spontaneously hypertensive rat model

Changes in myocardial perfusion and metabolism are often associated with myocardial hypertrophy, but there are few reports describing the serial assessment of fatty acid metabolism in hypertrophic myocardium. The aim of this study is to assess fatty acid metabolism serially in hypertrophic myocardium in spontaneously hypertensive rats (SHR) with¹²⁵I-BMIPP, a branched fatty acid analog.Methods: SHR and Wistar-Kyoto rats (WKY) as the control were divided into 4 groups (12, 15, 18 and 51 weeks after birth). The heart was extracted 10 minutes after intravenous injection of¹²⁵I-BMIPP and²⁰¹Tl at the same time. The accumulation of each radiotracer in the myocardium was counted with a well gamma counter. In addition,¹²⁵I-BMIPP uptake was corrected by²⁰¹Tl uptake (B/T).Results: The heart weight/body weight ratio was significantly higher in SHR than that in WKY (p < 0.001). In SHR, this ratio increased up to 18 weeks (12 weeks; 0.266 ± 0.005, 18 weeks; 0.281 ± 0.006: mean ± SE, p < 0.05). The¹²⁵I-BMIPP uptake tended to be significantly reduced in SHR (12 weeks; 2.373 ± 0.212, 18 weeks; 1.380 ± 0.047: mean ± SE, p < 0.05). Such a difference in BMIPP uptake was more evident when BMIPP uptake was corrected by Tl uptake (B/T), but no regional difference or heterogeneity of BMIPP distribution was observed in the hypertrophie myocardium in SHR.Conclusion: A change in fatty acid metabolism with age was observed in association with myocardial hypertrophy in this hypertensive rat model, which was well demonstrated with¹²⁵I-BMIPP and²⁰¹Tl.     

Clinical significance of reverse redistribution on resting thallium-301 imaging in patients with vasospastic angina

To evaluate the clinical significance of reverse redistribution (RR) of resting 201Tl single photon emission computed tomography (SPECT) in patients with vasospastic angina (VSA), we performed left ventriculography, coronary angiography and resting 201Tl-SPECT in 22 patients with VSA. Left ventriculography showed abnormal wall motion in 17 of 22 patients (77%) and 37 of 154 segments. Thirty-one of these 37 segments (84%) were within the area perfused by coronary arteries showing acetylcholine-induced vasospasm. On 201Tl images, abnormal findings were observed in 11 of 22 patients (50%), and among them, 7 patients (32%) had RR. Seven of 37 segments (19%) having abnormal regional wall motion had RR of 201TI, and in 6 of these 7 segments (86%), accumulation of 123I-BMIPP was found to be reduced. We conclude that repetitive brief myocardial ischemia may cause myocardial injuries in patients with VSA, and that the presence of RR of 201Tl indicates the presence of myocardial injury in these patients.     

多普勒超声心动图对肥厚型心肌病诊断及预后的评价

 目的评价多普勒超声心动图技术在肥厚型心肌病诊断与预后中的价值.方法对比分析1998年～2002年诊治的28例肥厚型心肌病患者的多普勒超声心动图、CT或核磁共振检查资料、动态心电图和临床表现.结果与CT或核磁共振检查相比较,多普勒超声心动图诊断肥厚型心肌病符合率89.3%,其中室间隔与左室后壁非对称性肥厚型心肌病诊断符合率100%,左室流出道梗阻诊断符合率100%,局限性肥厚型心肌病诊断符合率57.1%.结论多普勒超声心动图是无创诊断肥厚型心肌病和评价其预后的有效方法.     

The usefulness of 123I-BMIPP myocardial SPECT in diagnosis for silent myocardial ischemia induced by vasospasm

This study was designed to evaluate the clinical usefulness of 123I-BMIPP myocardial SPECT in patients with silent myocardial ischemia induced by vasospasm. Ultrasonic echocardiography (UCG), Holter electrocardiogram recording (Holter ECG), exercise 201Tl myocardial SPECT (EX-Tl) and rest 123I-BMIPP myocardial SPECT (BMIPP) were performed in 8 patients with asymptomatic vasospasm without history of myocardial infarction. The sensitivity of each modality in detecting coronary artery spasm was 37.5% (3 of 8 cases) for UCG, 37.5% (3 of 8 cases) in Holter ECG, 25.0% (2 of 8 cases) in Ex-Tl, 62.5% (5 of 8 cases) on initial BMIPP images and 75.0% (6 of 8 cases) on delayed BMIPP images. Severity of regional left ventricular wall motion abnormality in UCG correlated with the severity of regionally decreased tracer uptake in BMIPP. The washout rate of BMIPP was 18.7 +/- 2.4 in normal controls, 32.4 +/- 5.9 in asymptomatic vasospasm, and 38.2 +/- 4.0 in asymptomatic vasospasm with abnormal left ventricular wall motion. It was suggested that 123I-BMIPP myocardial SPECT might be useful for assessing asymptomatic vasospasm.     

Evaluation of myocardial function with the 201thallium scintimetry in various diseases of the heart. A correlative study based on 100 patients.

To assess the validity of the quantitative 201Tl scintimetry in various diseases of the heart (coronary heart disease with and without myocardial infarction, non-coronary cardiomyopathy, scleroderma heart disease and asymmetric septal hypertrophy with IHSS), the 201Tl myocardial uptake values for five standardized projections (a) were correlated with the grade of LAD stenosis, (b) the pattern of myocardial wall motion and (c) were compared with the 201Tl uptake values derived from normal patients. Significant reduction (c) of 201Tl myocardial uptake could in individual cases be evaluated in acute myocardial infarction (95%), in dys- and akinesia (90%), in hypokinesia (71%), in scleroderma heart disease (50%), in non-coronary cardiomyopathy (50%) as well as in normokinesia (28%) when associated with LAD stenosis. The mean values (b) of 201Tl uptake in normo- and hypokinesia significantly differed between these two groups and from those evaluated in dys- and akinesia. The latter group showed the lowest 201Tl uptake values computed which in some cases were very close to the mean mediastinal 201Tl uptake. The correlation (a) of individual 201Tl values demonstrated that 201Tl distribution in the myocardium is not only equivalent to myocardial "perfusion' but is corresponding with the myocardial function. In non-coronary cardiomyopathy reduced 201Tl values sometimes could not be separated from values in coronary heart disease (and myocardial infarction). A regional increase of myocardial mass as in septal hypertrophy correlated well with an augmented 201Tl uptake when referred to the 201Tl storage in the mediastinum.     

Prognosis of hypertrophic cardiomyopathy: Assessment by123I-BMIPP (β-methyl-p-(123I)iodophenyI pentadecanoic acid) myocardial single photon emission computed tomography

¹²³I-BMIPP (β-methyl-iodophenyl pentadecanoic acid) has shown unique properties for potential use in assessing myocardial metabolism. Previous basic and clinical studies demonstrated that the disturbances of myocardial metabolism precede the occurrence of myocardial perfusion abnormalities by using²⁰¹Tl in hypertrophic myocardium. The present study was therefore undertaken to determine whether or not¹²³I-BMIPP myocardial SPECT is useful in predicting the prognosis of hypertrophic cardiomyopathy (HCM) in 65 patients in 6 facilities. There were 33 patients with non-obstructive HCM, 12 with obstructive HCM, 12 with apical HCM and 8 with dilated-phase HCM. Fasted patients at rest received an intravenous injection of 111 MBq of¹²³I-BMIPP. Twenty to thirty minutes later, myocardial SPECT was carried out. The BMIPP severity score (BMIPP SS) was evaluated semiquantitatively by using representative short axial SPECT images. We followed up the incidence of cardiac events for a mean period of 3.0 ± 0.6 years. Cardiac events occurred in 13 patients. Of these, 11 developed heart failure and 6 died (4 from heart failure and 2 from sudden death). The BMIPP SS in the dilated-phase HCM was significantly higher than that in the remaining HCM patients. The BMIPP SS for the survivors was significantly lower than that for the non-survivors. The BMIPP SS was particularly high in patients with fatal heart failure. Furthermore, there was a close negative correlation between the BMIPP SS and percent fractional shortening measured by echocardiography (r = ?0.49). Finally, the mortality over the three years increased according to the extent of the BMIPP SS. In conclusion, these results indicate that the BMIPP SS is useful in evaluating the severity of HCM. We conclude that¹²³I-BMIPP is a valuable metabolic tracer in predicting the outcome of HCM.     

Comparison of myocardial thallium and beta-methyl iodophenyl pentadecanoic acid (BMIPP) distribution in the cardiomyopathic hamster

The usefulness of fatty acid imaging in the detection of cardiomyopathy was evaluated by comparing thallium and BMIPP myocardial distribution in Bio 14.6 Syrian Hamster (25 week ages). Autoradiography was performed in 3 using 3.7 MBq (100 microCi) of 125I-BMIPP and 37 MBq (1 mCi) of 201TlCl. In vivo pin-hole imaging was performed in 3 using 37 MBq (1 mCi) of 123I-BMIPP and 37 MBq (1 mCi) of 201TlCl. In all cardiomyopathic hamsters decreased uptake of BMIPP compared to that of thallium was demonstrated. These findings suggest dilated cardiomyopathy is associated with severe focal alteration in the substrate used for the performance of myocardial work. In conclusion, myocardial imaging using BMIPP may be useful for early detection of myocardial degeneration compared to thallium in patients with dilated cardiomyopathy.     

Incremental predictive value of myocardial scintigraphy with<Superscript> 123</Superscript>I-BMIPP in patients with acute myocardial infarction treated with primary percutaneous coronary intervention

Purpose It is unclear whether ¹²³I-labelled -methyl iodophenyl pentadecanoic acid (¹²³I-BMIPP) myocardial scintigraphy adds further predictive value for future cardiac events compared with the variables obtained during cardiac catheterisation in patients with acute myocardial infarction (AMI) treated with primary percutaneous coronary intervention (PCI). We therefore investigated whether ¹²³I-BMIPP imaging in patients with AMI treated by primary PCI was useful in predicting future cardiac events.Methods One hundred and fifty-nine patients with AMI who were treated with primary PCI and underwent left ventriculography (LVG) on admission underwent ²⁰¹Tl and ¹²³I-BMIPP myocardial scintigraphy. Scintigrams were visually classified, and the total defect score (TDS) was calculated. Major adverse cardiac events (MACE) were defined as cardiac death including sudden death, congestive heart failure and recurrence of acute coronary syndrome. Patients were followed up for a mean of 34.5 months (12–63 months).Results Twenty-six patients had MACE. Kaplan-Meier analysis indicated that patients with the top 50% of ¹²³I-BMIPP TDSs had a significantly higher rate of MACE (P=0.007). Patients with mismatch between ²⁰¹Tl and ¹²³I-BMIPP images also had significantly more MACE (P=0.02). In the prediction of MACE, the global chi-square value was 5.2 (P=0.001) based on LVEF (<45%) and the number of diseased vessels (two or three). Adding ¹²³I-BMIPP TDS and the mismatch improved the global chi-square value ( ²=7.2)Conclusion Myocardial scintigraphy using ²⁰¹Tl and ¹²³I-BMIPP predicts future cardiac events in patients with AMI treated with primary PCI, and provides additional predictive value compared with the variables obtained with cardiac catheterisation alone.     

Impairment of regional fatty acid uptake in relation to wall motion and thallium-201 uptake in ischaemic but viable myocardium: Assessment with iodine-123-labelled beta-methyl-branched fatty acid

In coronary artery disease, discrepancy in the uptake of thallium-201 and of methyl-branched fatty acid at rest has been described. The purpose of this study was to evaluate iodine-123 labelled beta-methylbranched fatty acid (BMIPP) myocardial uptake and wall motion at rest in segments with stress-induced ischaemia identified by stress²⁰¹Tl tomography in patients with chronic coronary artery disease.¹²³I-BMIPP myocardial tomography was performed at rest and was compared with the findings of exercise-reinjection²⁰¹Tl tomography in 45 patients with chronic coronary artery disease. Regional wall motion was evaluated by contrast left ventriculography in 36 patients. Among 237 segments with reversible²⁰¹Tl defects, equally decreased uptake on both reinjection²⁰¹Tl and BMIPP images was observed in 93 (39%), more severely decreased uptake of BMIPP in 118 (50%) and more severely decreased uptake of reinjection²⁰¹Tl in 26 (11%). On the other hand, among 90 segments with non-reversible²⁰¹Tl defects, each pattern was observed in 71 (79%), 6 (7%) and 13 (14%) segments, respectively. When comparing the ischaemic segments with and without more severely reduced uptake of BMIPP than of reinjection²⁰¹Tl, wall motion was impaired to a greater extent in the segments with more severely reduced uptake of BMIPP than of reinjection²⁰¹Tl [severe hypo- or dyskinesis was present in 64 (70%) of 91 segments and in 24 (22%) of 110 segments, respectively,P<0.005]. In patients with chronic coronary artery disease, resting fatty acid uptake was frequently more reduced than reinjection²⁰¹Tl in the segments with stress-induced ischaemia, while in most of the fixed perfusion defects BMIPP and reinjection²⁰¹Tl uptake decreased concordantly. In ischaemic myocardium, wall motion was impaired to a greater extent in those segments which showed more severely reduced uptake of BMIPP than of reinjection²⁰¹Tl. In ischaemic but viable myocardium, discordant BMIPP uptake less than reinjection²⁰¹Tl uptake may indicate metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities. In conclusion, the combination of resting BMIPP and stress-reinjection²⁰¹Tl imaging may provide information on metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities.     

Influence of hypertensive left ventricular hypertrophy on detection of ischemic area with exercise thallium-201 myocardial scintigraphy]

Sixty-four patients with single left anterior descending artery disease having effort angina (group A: 40 patients without hypertension, group B: 10 patients with hypertrophic hypertension, group C: 14 patients with non-hypertrophic hypertension) were assessed the influence of hypertensive left ventricular (LV) hypertrophy on detection of ischemic area. The criterion of hypertrophy by two-dimensional echocardiography was > 12 mm in the wall thickness of interventricular septal or posterior wall. Population in Group B might show low detectability in ischemic area by 201Tl myocardial scintigraphy (positive thallium rate 60%, defect score 2.7 +/- 3.6), and high lung thallium uptake and high frequence of ECG positive among three groups. In semiquantitative analysis, the washout rate of the posterolateral wall and %RD (delayed %uptake-initial %uptake) of the septal wall in patients with Group B were lowest among three groups. However, the washout rate in the septal wall against the posterior wall, and the initial %uptake and the delayed %uptake of the septal wall were not significantly different among three groups. We could conclude that the decreased washout rate in nonischemic area with hypertensive LV hypertrophy might make the ischemic area masked.     

Estimation of regional myocardial sympathetic neuronal function with I-123 metaiodobenzylguanidine (MIBG) myocardial images in patients with cardiomyopathy

I-123 Metaiodobenzylguanidine (MIBG) is taken up by myocardial sympathetic neuronal endings. Sympathetic neuronal function in 10 patients with cardiomyopathy under stable state were studied by using MIBG and Tl-201 (Tl) SPECT images with 50% cut off level. For myocardial imaging MIBG and Tl were simultaneously injected and collected (dual injection and dual collection mode; Dd mode). Four hours delayed images were also collected. Three types of abnormal findings were noted in MIBG images in combination with Tl images. 1) Enhancement of regional MIBG washout with otherwise normal MIBG and Tl uptake in infero-lateral wall were noted in 5 patients with history of congestive heart failure (Pathophysiologically acceleration of regional sympathetic neuronal function was suspected. Mean washout ratio is 63 +/- 7% vs. 45 +/- 10% in normal region). 2) In 3 patients with dilated cardiomyopathy increase of MIBG/Tl (M/T) ratio was noted in basal septal wall (Sympathetic neuronal function is abnormally accelerated in the region with depressed coronary perfusion. Exaltation of regional sympathetic neuronal function was suspected. Mean M/T ratio is 1.6. Tentative normal range is from 0.8 to 1.20). 3) In 2 patients with dilated cardiomyopathy under severe congestive heart failure defects of MIBG uptake with normal Tl uptake were noted (Sympathetic neuronal function was depleted in spite of normal coronary perfusion. Depletion of myocardial catecolamine was suspected. M/T ratio is 0.75 and 0.7 respectively). Heterogeneous abnormality of sympathetic neuronal function was noted in MIBG images. This findings corresponded to report about heterogeneous myocardial catecholamine concentrations in hearts of recipients of transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)