Impella-Supported Optical Coherence Tomography-Guided Aggressive Rotational Atherectomy for Heavily Calcified Lesions in Left Main Trunk Bifurcation in a Patient with Severe Left Ventricular Systolic Dysfunction.

The Impella, a percutaneous left ventricular assist device, has been reported to minimize the risk of hemodynamic compromise and improve clinical outcomes during percutaneous coronary intervention (PCI) in complex high-risk indicated patients (CHIPs). Optical coherence tomography (OCT) provides information on calcified plaque thickness, which is helpful in determining the indication and endpoint of atherectomy during PCI for calcified lesions. However, there are few reports on OCT-guided aggressive rotational atherectomy with Impella assistance in CHIPs. A 71-year-old man on dialysis for end-stage renal failure was admitted for congestive heart failure. Transthoracic echocardiography revealed severe left ventricular systolic dysfunction, and coronary angiography performed after improvement of heart failure showed severe stenosis with heavily calcified lesions in the left main trunk (LMT) bifurcation and right coronary artery. The patient refused coronary artery bypass surgery and was revascularized using PCI. PCI was started with prophylactic Impella CP insertion because of the high risk of hemodynamic collapse. After OCT-guided rotational atherectomy with 1.5- and 2.0-mm burr toward the left anterior descending artery and left circumflex artery, respectively, double-kissing culotte stenting was performed in the LMT, and good dilation was obtained. Impella CP was removed immediately after PCI without hemodynamic compromise, and the procedure was completed.

Extraordinary Delayed-Onset Negative Pressure Pulmonary Hemorrhage Resulting in Cardiac Arrest after General Anesthesia for Vocal Cord Polypectomy.

Negative pressure pulmonary edema and hemorrhage are uncommon but potentially life-threatening complications associated with general anesthesia. Postoperative negative pressure pulmonary edema usually occurs immediately after surgery, and delayed-onset cases occurring more than 1 hour after surgery have rarely been reported. A 37-year-old woman with bronchial asthma underwent vocal cord polypectomy under general anesthesia in another hospital and experienced cardiac arrest due to a negative pressure pulmonary hemorrhage occurring 3 hours and 30 minutes after surgery. She was successfully treated with venoarterial extracorporeal membrane oxygenation and completely recovered without any complications. Extraordinary delayed-onset negative pressure pulmonary hemorrhage occurring more than three hours after surgery has rarely been reported. This case may indicate the need for more careful observation of patients following surgery.

In-Stent Restenosis with "Inflammatory" Neointima Following Everolimus-Eluting Stent Implantation.

A 53-year-old male presented with acute myocardial infarction and was subsequently implanted with a 4.0 × 28 mm everolimus-eluting platinum chromium stent in his proximal left anterior descending artery. Eight months after the implantation, he developed exertional angina and underwent coronary angiography, which revealed significant in-stent restenosis (ISR). Percutaneous coronary intervention was performed 1 month later, and the pre-procedural optical coherence tomography (OCT) revealed a diffusely bordered and rapidly attenuated signal-poor region with invisible stent struts at ISR site, potentially indicating a "lipid-laden" neointima. The ISR lesion was excised using a novel directional coronary atherectomy catheter. The histological analysis of the retrieved restenotic tissues revealed substantial inflammation characterized by abundant foamy macrophages and T-cell infiltration. This "inflammatory" neointimal tissue with numerous macrophages (without a necrotic core) detected on OCT was not expected owing to the absence of a known feature of macrophages on OCT (i.e., high backscattering with remarkable attenuation). The current histological confirmation of in vivo OCT findings of restenotic neointima indicated that a "lipid-laden" neointima on OCT may not necessarily reflect necrotic core accumulation, and this could be attributed to substantial inflammation with abundant macrophages.

Successful Complete Revascularization With PCI Using Super-Low Volume of Contrast Medium in a Patient With Three-Vessel Disease Including 2 Chronic Total Occlusions With Severe Renal Dysfunction.

The most important factor for preventing contrast-induced nephropathy (CIN) during percutaneous coronary intervention (PCI) in patients with severe renal dysfunction is to minimize the contrast volume. Herein, we report a successful case of complete revascularization after 3 separate PCI procedures using a super-low volume of contrast medium in a patient with 3-vessel disease, including two chronic total occlusions (CTOs). A 70-year-old man having exertional angina despite maximal medical therapy was referred to our hospital. He had severe renal dysfunction (estimated glomerular filtration rate 19 mL/minute/1.73 m2). Coronary angiography, in which a total volume of 15 mL (over 3 injections) of contrast medium was used after hydration with normal saline, demonstrated 2 CTOs in the proximal left circumflex artery (LCX) and the proximal right coronary artery (RCA) as well as focal stenosis in the mid left descending artery (LAD). Because the patient refused coronary artery bypass grafting, we opted for revascularization with PCI, divided into 3 procedures. We made full use of microcatheter tip injection and evaluation with intravascular ultrasound and achieved complete revascularization with a total of 31 mL of contrast medium: 9 mL for RCA, 6 mL for LAD, and 16 mL for LCX, without the occurrence of CIN. Additionally, we present tips for performing PCI using super-low contrast medium.

Optical coherence tomography findings after longitudinal ablation for an underexpanded stent in a heavily calcified lesion: a case report.

BACKGROUND: Heavy coronary artery calcification is responsible for stent underexpansion, which is associated with increased in-stent restenosis. Here we report a case in which optical coherence tomography (OCT) demonstrated that the metal component of an underexpanded stent previously implanted in a heavy calcified lesion had been completely removed after ablation with rotational atherectomy. CASE PRESENTATION: An 83-year-old man with exertional angina was referred to our hospital. Coronary angiography revealed severe stenosis in the proximal portion of the right coronary artery and left circumflex artery and chronic total occlusion (CTO) in the mid portion of the left anterior descending artery (LAD). We performed complete revascularization with percutaneous coronary intervention. Because the CTO lesion in LAD contained napkin-ring heavy calcifications, rotational atherectomy with a 1.75-mm burr was undergone, followed by the deployment of drug-eluting stents and postdilation with a high-pressure balloon. However, expansion of the stent was incomplete. To address the recurrence of in-stent restenosis and resistance to the dilation with the high-pressure balloon, we decided to simultaneously ablate both the heavy calcification and underexpanded stent. Longitudinal stent ablation with 1.75- and 2.0-mm burrs was successful, and OCT demonstrated that the metallic component of the underexpanded stent had been completely removed. CONCLUSION: If a stent fails to completely extend in heavy calcification, longitudinal stent ablation by rotational atherectomy could be an effective remedy.

Manipulation of cardiac phosphatidylinositol 3-kinase (PI3K)/Akt signaling by apoptosis regulator through modulating IAP expression (ARIA) regulates cardiomyocyte death during doxorubicin-induced cardiomyopathy.

PI3K/Akt signaling plays an important role in the regulation of cardiomyocyte death machinery, which can cause stress-induced cardiac dysfunction. Here, we report that apoptosis regulator through modulating IAP expression (ARIA), a recently identified transmembrane protein, regulates the cardiac PI3K/Akt signaling and thus modifies the progression of doxorubicin (DOX)-induced cardiomyopathy. ARIA is highly expressed in the mouse heart relative to other tissues, and it is also expressed in isolated rat cardiomyocytes. The stable expression of ARIA in H9c2 cardiac muscle cells increased the levels of membrane-associated PTEN and subsequently reduced the PI3K/Akt signaling and the downstream phosphorylation of Bad, a proapoptotic BH3-only protein. When challenged with DOX, ARIA-expressing H9c2 cells exhibited enhanced apoptosis, which was reversed by the siRNA-mediated silencing of Bad. ARIA-deficient mice exhibited normal heart morphology and function. However, DOX-induced cardiac dysfunction was significantly ameliorated in conjunction with reduced cardiomyocyte death and cardiac fibrosis in ARIA-deficient mice. Phosphorylation of Akt and Bad was substantially enhanced in the heart of ARIA-deficient mice even after treatment with DOX. Moreover, repressing the PI3K by cardiomyocyte-specific expression of dominant-negative PI3K (p110α) abolished the cardioprotective effects of ARIA deletion. Notably, targeted activation of ARIA in cardiomyocytes but not in endothelial cells reduced the cardiac PI3K/Akt signaling and exacerbated the DOX-induced cardiac dysfunction. These studies, therefore, revealed a previously undescribed mode of manipulating cardiac PI3K/Akt signaling by ARIA, thus identifying ARIA as an attractive new target for the prevention of stress-induced myocardial dysfunction.

Ecscr regulates insulin sensitivity and predisposition to obesity by modulating endothelial cell functions.

Insulin resistance is closely associated with obesity and is one of the earliest symptoms of type-2 diabetes. Endothelial cells are involved in the pathogenesis of insulin resistance through their role in insulin delivery and adipose tissue angiogenesis. Here we show that Ecscr (endothelial cell surface expressed chemotaxis and apoptosis regulator; also known as ARIA), the transmembrane protein that regulates endothelial cell signalling, is highly expressed in white and brown adipose tissues, and regulates energy metabolism and glucose homeostasis by modulating endothelial cell functions. Ecscr-deficient mice fed a normal chow show improved glucose tolerance and enhanced insulin sensitivity. We demonstrate that Ecscr deletion enhances the insulin-mediated Akt/endothelial nitric oxide synthase activation in endothelial cells, which increases insulin delivery into the skeletal muscle. Ecscr deletion also protects mice on a high-fat diet from obesity and obesity-related metabolic disorders by enhancing adipose tissue angiogenesis. Conversely, targeted activation of Ecscr in endothelial cells impairs glucose tolerance and predisposes mice to diet-induced obesity. Our results suggest that the inactivation of Ecscr enhances insulin sensitivity and may represent a new therapeutic strategy for treating metabolic syndrome.

Loss of bcl-2 during the senescence exacerbates the impaired angiogenic functions in endothelial cells by deteriorating the mitochondrial redox state.

Ageing is an important risk factor for ischemic cardiovascular diseases, although its underlying molecular mechanisms remain to be elucidated. Here, we report a crucial role of Bcl-2 in the impaired angiogenic functions in senescent endothelial cells (ECs) by modulating the mitochondrial redox state. Cellular senescence impaired angiogenic functions in ECs without attenuating the mitogen-activated protein kinase or Akt signaling, and vascular endothelial growth factor receptor 2 or Tie-2 expressions. We identified that Bcl-2 expression was markedly reduced in 3 independent models for senescent ECs, and pharmacological inhibition, as well as small interfering RNA-mediated gene silencing of Bcl-2, significantly impaired the angiogenic functions in young ECs. Bcl-2 has an antioxidative role by locating the glutathione at mitochondria, and we found that mitochondrial oxidative stress was significantly augmented in senescent ECs, in association with reduced mitochondria-associated glutathione. Transfection of Bcl-2 in senescent ECs significantly reduced the mitochondrial oxidative stress, restored the mitochondrial membrane potential, and improved the angiogenic capacity. Furthermore, gene transfer of Bcl-2 using adenovirus significantly improved the in vivo angiogenesis in the Matrigel plugs implanted into aged mice, whereas the Bcl-2 inhibitor reduced the angiogenesis in the Matrigel plugs implanted into young mice. Together, Bcl-2 plays a crucial role in the regulation of the mitochondrial redox state in ECs, and, thus, loss of Bcl-2 during the senescence exacerbates the impaired angiogenesis by augmenting the mitochondrial oxidative stress.

Apoptosis regulator through modulating IAP expression (ARIA) controls the PI3K/Akt pathway in endothelial and endothelial progenitor cells.

Endothelial and endothelial progenitor cells (ECs and EPCs) play a fundamental role in angiogenesis that is essential for numerous physiological and pathological processes. The phosphatase and tensin homolog (PTEN)/ phosphoinositide 3-kinase (PI3K) pathway has been implicated in angiogenesis, but the mechanism in the regulation of this pathway in ECs and EPCs is poorly understood. Here we show that ARIA (apoptosis regulator through modulating IAP expression), a transmembrane protein that we recently identified, regulates the PTEN/PI3K pathway in ECs and EPCs and controls developmental and postnatal angiogenesis in vivo. We found that ARIA is abundantly expressed in EPCs and regulates their angiogenic functions by modulating PI3K/Akt/endothelial nitric oxide synthase (eNOS) signaling. Genetic deletion of ARIA caused nonfatal bleeding during embryogenesis, in association with increased small vessel density and altered expression of various vascular growth factors including angiopoietins and VEGF receptors. Postnatal neovascularization induced by critical limb ischemia was substantially enhanced in ARIA-null mice, in conjunction with more bone marrow (BM)-derived ECs detected in ischemic muscles. Administration of PI3K or NO synthase inhibitor completely abolished the enhanced neovascularization in ARIA(-/-) mice. Mechanistically, we identified that ARIA interacts with PTEN at the intracellular domain independently of the PTEN phosphorylation in its C-terminal tail. Overexpressed ARIA increased PTEN in the membrane fraction, whereas ARIA-silencing reduced the membrane-associated PTEN, resulting in modified PI3K/Akt signaling. Taken together, our findings establish a previously undescribed mode of regulation of the PTEN/PI3K/Akt pathway by ARIA, and reveal a unique mechanism in the control of angiogenesis. These functions of ARIA might offer a unique therapeutic potential.

Paracrine osteogenic signals via bone morphogenetic protein-2 accelerate the atherosclerotic intimal calcification in vivo.

OBJECTIVE: Vascular calcification is an important risk factor for cardiovascular diseases. Here, we investigated a role of dedifferentiated vascular smooth muscle cells (VSMCs) in the atherosclerotic intimal calcification. METHODS AND RESULTS: We prepared human cultured VSMCs in either redifferentiatiated or dedifferentiated state and analyzed the gene expressions of bone-calcification regulatory factors. Expression of bone morphogenetic protein-2 (BMP-2), a potent initiator for osteoblast differentiation, was significantly enhanced in dedifferentiated VSMCs. Furthermore, endogenous BMP-2 antagonists, such as noggin, chordin, and matrix gamma-carboxyglutamic acid protein, were all downregulated in the dedifferentiated VSMCs. Conditioned medium from dedifferentiated VSMCs, but not from redifferentiated VSMCs, stimulated the osteoblastic differentiation of the mesenchymal progenitor C2C12 cells, which was abolished by BMP-2 knockdown. In atherosclerotic intima from apolipoprotein (apo)E-deficient mice, αSM-actin-positive cells, presumably dedifferentiated VSMCs, expressed BMP-2. We generated BMP-2-transgenic mice using αSM-actin promoter and crossed them with apoE-deficient mice (BMP-2-transgenic/apoE-knockout). Significantly accelerated atherosclerotic intimal calcification was detected in BMP-2-transgenic/apoE-knockout mice, although serum lipid concentration and atherosclerotic plaque size were not different from those in apoE-knockout mice. Enhanced calcification appeared to be associated with the frequent emergence of osteoblast-like cells in atherosclerotic intima in BMP-2-transgenic/apoE-knockout mice. CONCLUSIONS: Our findings collectively demonstrate an important role of dedifferentiated VSMCs in the pathophysiology of atherosclerotic calcification through activating paracrine BMP-2 osteogenic signals.

Prorenin induces ERK activation in endothelial cells to enhance neovascularization independently of the renin-angiotensin system.

Prorenin is an enzymatically inactive precursor of renin, and its biological function in endothelial cells (ECs) is unknown despite its relevance with the incidence of diabetic microvascular complications. Recently, (pro)renin receptor was identified, and the receptor-associated prorenin system has been discovered, whereas its expression as well as function in ECs remain unclear. In the present study, we found that ECs express the (pro)renin receptor, and that prorenin provoked ERK activation through (pro)renin receptor independently of the renin-angiotensin system (RAS). Prorenin stimulated the proliferation, migration and tube-formation of ECs, while it inhibited endothelial apoptosis induced by serum and growth factor depletion. MEK inhibitor abrogated these proangiogenic effects of prorenin, while AT1 receptor antagonist or angiotensin-converting enzyme inhibitor failed to block them. In vivo neovascularization in the Matrigel-plugs implanted into mouse flanks was significantly enhanced by prorenin, in which significant ERK activation was detected in ECs. Furthermore, tumor xenografts stably transfected with prorenin demonstrated the significantly accelerated growth rate concomitantly with enhanced intratumoral neovascularization. Our data demonstrated that the RAS-independent (pro)renin receptor-mediated signal transduction plays a pivotal role in the regulation of ECs function as well as in the neovascularization, and thus prorenin is potentially involved in the pathophysiology of diabetic microvascular complications as well as cancers.

Detection of hormone active chemicals using genetically engineered yeast cells and microfluidic devices with interdigitated array electrodes.

Endocrine disruptors that act like hormones in the endocrine system might have toxic effects. Therefore, it is important to develop a portable device that can detect hormone active chemicals in samples rapidly and easily. In this study, a microfluidic device was developed for the detection of hormone active chemicals using genetically engineered yeast cells. The yeast cells were used as biosensors since they were genetically engineered to respond to the presence of hormone active chemicals by synthesizing beta-galactosidase (beta-gal). For achieving further sensitivity, we incorporated interdigitated array (IDA) electrodes (width, 1.2 microm; gap, 0.8 microm) with 40 electrode fingers into the analytical chamber of the microfluidic device. The yeast cells precultured with a hormone active chemical, 17beta-estradiol (E2), were trapped from the main channel of the device to the analytical camber by electrophoresis. After trapping in the analytical chamber, we performed electrochemical detection of beta-gal induced in the yeast cells with the IDA electrodes. Actually, electrochemical detection was performed on p-aminophenol that was converted from p-aminophenyl-beta-D-galactopyranoside with beta-gal. The electrochemical signals from the yeast cells precultured with 17beta-estradiol were successfully detected with the device. Furthermore, the inhibitory effects of antagonists such as tamoxifen were also detected electrochemically by using the device. Thus, the present microfluidic device can be used for highly sensitive detection of hormone active chemicals.

Replicative senescence of vascular smooth muscle cells enhances the calcification through initiating the osteoblastic transition.

Medial artery calcification, which does not accompany lipid or cholesterol deposit, preferentially occurs in elderly population, but its underlying mechanisms remain unclear. In the present study, we investigated the potential role of senescent vascular smooth muscle cells (VSMCs) in the formation of senescence-associated medial calcification. Replicative senescence was induced by the extended passages (until passages 11-13) in human primary VSMCs, and cells in early passage (passage 6) were used as control young cells. VSMC calcification was markedly enhanced in the senescent cells compared with that in the control young cells. We identified that genes highly expressed in osteoblasts, such as alkaline phosphatase (ALP) and type I collagen, were significantly upregulated in the senescent VSMCs, suggesting their osteoblastic transition during the senescence. Knockdown of either ALP or type I collagen significantly reduced the calcification in the senescent VSMCs. Of note, runt-related transcription factor-2 (RUNX-2), a core transcriptional factor that initiates the osteoblastic differentiation, was also upregulated in the senescent VSMCs. Knockdown of RUNX-2 significantly reduced the ALP expression and calcification in the senescent VSMCs, suggesting that RUNX-2 is involved in the senescence-mediated osteoblastic transition. Furthermore, immunohistochemistry of aorta from the klotho(-/-) aging mouse model demonstrated in vivo emergence of osteoblast-like cells expressing RUNX-2 exclusively in the calcified media. We also found that statin and Rho-kinase inhibitor effectively reduced the VSMC calcification by inhibiting P(i)-induced apoptosis and potentially enhancing matrix Gla protein expression in the senescent VSMCs. These findings strongly suggest an important role of senescent VSMCs in the pathophysiology of senescence-associated medial calcification, and the inhibition of osteoblastic transition could be a new therapeutic approach for the prevention of senescence-associated medial calcification.

Identification of ARIA regulating endothelial apoptosis and angiogenesis by modulating proteasomal degradation of cIAP-1 and cIAP-2.

Endothelial apoptosis is a pivotal process for angiogenesis during embryogenesis as well as postnatal life. By using a retrovirus-mediated signal sequence trap method, we identified a previously undescribed gene, termed ARIA (apoptosis regulator through modulating IAP expression), which regulates endothelial apoptosis and angiogenesis. ARIA was expressed in blood vessels during mouse embryogenesis, as well as in endothelial cells both in vitro and in vivo. ARIA is a unique protein with no homology to previously reported conserved domain structures. Knockdown of ARIA in HUVECs by using small interfering RNA significantly reduced endothelial apoptosis without affecting either cell migration or proliferation. ARIA knockdown significantly increased inhibitor of apoptosis (cIAP)-1 and cIAP-2 protein expression, although their mRNA expression was not changed. Simultaneous knockdown of cIAP-1 and cIAP-2 abolished the antiapoptotic effect of ARIA knockdown. Using yeast 2-hybrid screening, we identified the interaction of ARIA with 20S proteasome subunit alpha-7. Thereafter, we found that cIAP-1 and cIAP-2 were degraded by proteasomes in endothelial cells under normal condition. Overexpression of ARIA significantly reduced cIAP-1 expression, and this reduction was abolished by proteasomal inhibition in BAECs. Also, knockdown of ARIA demonstrated an effect similar to proteasomal inhibition with respect to not only expression but also subcellular localization of cIAP-1 and cIAP-2. In vivo angiogenesis studied by Matrigel-plug assay, mouse ischemic retinopathy model, and tumor xenograft model was significantly enhanced by ARIA knockdown. Together, our data indicate that ARIA is a unique factor regulating endothelial apoptosis, as well as angiogenesis, presumably through modulating proteasomal degradation of cIAP-1 and cIAP-2 in endothelial cells.

Intracoronary transplantation of non-expanded peripheral blood-derived mononuclear cells promotes improvement of cardiac function in patients with acute myocardial infarction.

BACKGROUND: Transplantation of non-expanded peripheral blood mononuclear cells (PBMNCs) enhances neovessel formation in ischemic myocardium and limbs by releasing angiogenic factors. This study was designed to examine whether intracoronary transplantation of PBMNCs improves cardiac function after acute myocardial infarction (AMI). METHODS AND RESULTS: After successful percutaneous coronary intervention (PCI) for a ST-elevation AMI with occlusion of proximal left anterior descending coronary artery within 24 h, patients received an intracoronary infusion of PBMNCs within 5 days after PCI (PBMNC group). PBMNCs were obtained from patients by COBE spectra-apheresis and concentrated to 10 ml, 3.3 ml of which was infused via over-the-wire catheter. The global left ventricular ejection fraction (LVEF) change from baseline to 6 months followup in th ePBMNC group that underwent standard PCI for similar AMI [corrected]. The primary endpoint was the global left ventricular ejection fraction (LVEF) change from baseline to 6 months' follow-up. The data showed that the absolute increase in LVEF was 7.4% in the control group and 13.4% (p=0.037 vs control) in the PBMNC group. Cell therapy resulted in a greater tendency of DeltaRegional ejection fraction (EF) or significant improvement in the wall motion score index and Tc-99m-tetrofosmin perfusion defect score associated with the infarct area, compared with controls. Moreover, intracoronary administration of PBMNCs did not exacerbate either left ventricular (LV) end-diastolic and end-systolic volume expansion or high-risk arrhythmia, without any adverse clinical events. CONCLUSION: Intracoronary infusion of non-expanded PBMNCs promotes improvement of LV systolic function. This less invasive and more feasible approach to collecting endothelial progenitor cells may provide a novel therapeutic option for improving cardiac function after AMI.

[Clinical usefulness of 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT program using low-dose dobutamine loading in assessment of myocardial viability in patient with acute myocardial infarction--a case report].

An 86-year-old man with chest pain was admitted to our hospital. Coronary angiography revealed 99% stenosis of the mid segment of the left anterior descending coronary artery, therefore, a coronary stent was implanted. Immediately after the stent implantation, 99% stenosis occurred at the proximal site of the 1st diagonal artery because of stent jeal. On the 4th hospital day, ECG-gated 201TL/99mTc-PYP dual myocardial quantitative gated SPECT was performed at rest and during low-dose dobutamine loading. The 201Tl scintigraphy revealed moderately reduced uptake in the anterior, septal and apical walls, and 99mTc-PYP uptake was observed in the mid-anterior wall. A three-dimensional surface display of gated 201Tl SPECT images showed severe hypokinesis in the anterior, septal and apical walls at rest. On the other hand, during low-dose dobutamine loading, improved wall motion was observed in the basal anterior and septal walls, while no change was observed in the midanterior and apical wall movements. Three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed similar patterns of wall motion as those of gated 201Tl SPECT images at rest. During low-dose dobutamine loading, on the other hand, a three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed improved wall motion in the basal anterior, septal and apical walls, but worsened wall motion of the mid-anterior wall. After 6 months, a follow-up coronary angiography revealed no re-stenosis of the stent, but 99% stenosis at the proximal aspect of the 1st diagonal artery. Left ventriculography revealed improved wall motion in the apex and akinesis of the mid-anterior wall. These wall motion findings were similar to those visualized in the three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images during low-dose dobutamine loading in the acute phase. These results suggest that 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT using low-dose dobutamine loading could be useful for the assessment of myocardial viability after reperfusion therapy in patients with acute myocardial infarction.

[Assessment of microcirculation disturbance in patients with coronary ectasia by ATP-loading 99mTc-tetrofosmin myocardial SPECT].

UNLABELLED: Patients with coronary ectasia often develop chest pain and reveal ischemic changes on electrocardiograms and reduced left ventricular wall motion on left ventriculography, in the absence of epicardial coronary artery stenotic regions. We examined the disturbances in the coronary microcirculation in patients with coronary ectasia using left ventriculography and ATP loading 99mTc-tetrofosmin myocardial single photon emission computed tomography (SPECT) before and after administration of a coronary vasodilator and antiplatelet agents. METHODS: Twenty patients in whom coronary angiography revealed diffuse coronary artery ectasia but no stenotic regions were enrolled in this study. Left ventriculography and ATP loading 99mTc-tetrofosmin myocardial SPECT were performed before and after administration of the coronary vasodilator, nicorandil, as well as that of the antiplatelet agents, aspirin and ticlopidine. RESULTS: (1) The ejection fraction in left ventriculography was 48.3 +/- 17.4% before, and 56.6 +/- 18.3% after the drug administration, the ejection fraction was improved after the drug administration (p < 0.05). (2) Before the drug administration, the total defect scores on 99mTc-tetrofosmin myocardial SPECT were 5.9 +/- 3.1 and 8.8 +/- 2.7 in the ATP-loading and rest images, respectively (p < 0.05), and the corresponding scores after the drug administration were 4.1 +/- 3.0 and 5.4 +/- 3.1, respectively (N.S.). Thus, the total defect scores in the ATP-loading and rest images improved after the drug administration (p < 0.05). CONCLUSION: Myocardial damage in patients with coronary ectasia might be induced by microthrombotic embolism and microcirculation disturbance.