Effect of Luseogliflozin on Myocardial Flow Reserve in Patients with Type 2 Diabetes Mellitus (LUCENT-J Study)

INTRODUCTION

In patients with type 2 diabetes (T2D), treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitors has been shown to reduce hospital admission rates for heart failure (HF). However, the multiple mechanisms hypothesized and investigated to explain the cardioprotection of SGLT2 inhibitors are not fully understood.

OBJECTIVES

The effect of luseogliflozin on myocardial flow reserve (MFR) in patients with T2D (LUCENT-J) study aims to examine the effects of SGLT2 inhibitors on myocardial perfusion.

METHODS

The LUCENT-J study is a prospective, single-center, randomized, two-arm, parallel-group, open-label (i.e., the radiology readers are blinded), active-controlled study. A cohort of 40 patients with T2D with no or stable (with no history of myocardial infarction and with or without previous percutaneous coronary intervention) coronary artery disease will be included. Patients will be randomized in a 1:1 ratio to luseogliflozin or control and treated for 24 weeks. The primary outcome is the change in MFR, as measured by 13N-ammonia positron emission tomography/computed tomography, from baseline to 24 weeks after treatment initiation.

PLANNED OUTCOMES

The LUCENT-J study will elucidate the mechanisms of cardioprotection by SGLT2 inhibitors in patients with T2D.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (JRCTs051220016).

Lung-to-heart ratio analysis using virtual planar images obtained from myocardial perfusion SPECT data: A phantom and clinical studies

BACKGROUNDS

The lung-to-heart ratio (L/H ratio) in myocardial perfusion scintigraphy (MPS) is a useful marker that complements the sensitivity of ischemia detection. However, it requires planar imaging acquired following a separate protocol in addition to single-photon emission computed tomography (SPECT). We developed a novel method for constructing virtual planar image (VPI) from SPECT data.

METHODS

Myocardial phantoms using Tl-201 were built with different amounts of radioactivity in the lungs. SPECT data and conventional planar images of these phantoms were collected with an Anger-type gamma camera. VPIs were constructed by adding all coronal images reconstructed from SPECT data. The clinical utility of VPIs obtained from 52 patients who underwent MPS with Tc-99m sestamibi was evaluated.

RESULTS

The radioactivity linearity of VPIs was satisfactory, with a correlation coefficient of r ≥ .99 between the measured amounts of radioactivity and image counts. The L/H ratios obtained from VPI analysis were strongly correlated with those of conventional planar images with a correlation coefficient of r ≥ .99 in the phantom study and r = .929 in clinical application.

CONCLUSION

The accuracy of VPI-based L/H ratio analysis was comparable to that of conventional planar image-based analysis. VPIs could be used as an alternative method of obtaining planar images in clinical settings.

Transthyretin derived amyloid deposits in the atrium and the aortic valve: insights from multimodality evaluations and mid-term follow up

BACKGROUND

Recent studies have reported atrial involvement and coexistence of aortic stenosis in transthyretin (ATTR) cardiac amyloidosis (CA). However, pathological reports of extraventricular ATTR amyloid deposits in atrial structures or heart valves are limited, and the clinical implications of ATTR amyloid deposits outside the ventricles are not fully elucidated.

CASE PRESENTATION

We report 3 cases of extraventricular ATTR amyloid deposits confirmed in surgically resected aortic valves and left atrial structures, all of which were unlikely to have significant ATTR amyloidosis infiltrating the ventricles as determined by multimodality evaluation including ^99mtechnetium-pyrophosphate scintigraphy, cardiac magnetic resonance, endomyocardial biopsy and their mid-term clinical course up to 5 years. These findings suggested that these were extraventricular ATTR amyloid deposits localized in the aortic valve and the left atrium.

CONCLUSIONS

While long-term observation is required to fully clarify whether these extraventricular ATTR amyloid deposits are truly localized outside the ventricles or are early stages of ATTR-CA infiltrating the ventricles, our 3 cases with multimodality evaluations and mid-term follow up suggest the existence of extraventricular ATTR amyloid deposits localized in the aortic valve and left atrial structures.

Optimization of null point in Look-Locker images for myocardial late gadolinium enhancement imaging using deep learning and a smartphone

OBJECTIVES

To determine the optimal inversion time (TI) from Look-Locker scout images using a convolutional neural network (CNN) and to investigate the feasibility of correcting TI using a smartphone.

METHODS

In this retrospective study, TI-scout images were extracted using a Look-Locker approach from 1113 consecutive cardiac MR examinations performed between 2017 and 2020 with myocardial late gadolinium enhancement. Reference TI null points were independently determined visually by an experienced radiologist and an experienced cardiologist, and quantitatively measured. A CNN was developed to evaluate deviation of TI from the null point and then implemented in PC and smartphone applications. Images on 4 K or 3-megapixel monitors were captured by a smartphone, and CNN performance on each monitor was determined. Optimal, undercorrection, and overcorrection rates using deep learning on the PC and smartphone were calculated. For patient analysis, TI category differences in pre- and post-correction were evaluated using the TI null point used in late gadolinium enhancement imaging.

RESULTS

For PC, 96.4% (772/749) of images were classified as optimal, with under- and overcorrection rates of 1.2% (9/749) and 2.4% (18/749), respectively. For 4 K images, 93.5% (700/749) of images were classified as optimal, with under- and overcorrection rates of 3.9% (29/749) and 2.7% (20/749), respectively. For 3-megapixel images, 89.6% (671/749) of images were classified as optimal, with under- and overcorrection rates of 3.3% (25/749) and 7.0% (53/749), respectively. On patient-based evaluations, subjects classified as within optimal range increased from 72.0% (77/107) to 91.6% (98/107) using the CNN.

CONCLUSIONS

Optimizing TI on Look-Locker images was feasible using deep learning and a smartphone.

KEY POINTS

• A deep learning model corrected TI-scout images to within optimal null point for LGE imaging. • By capturing the TI-scout image on the monitor with a smartphone, the deviation of the TI from the null point can be immediately determined. • Using this model, TI null points can be set to the same degree as that by an experienced radiological technologist.

Clinical Outcomes of Radiologic Relapse in Patients With Cardiac Sarcoidosis Under Immunosuppressive Therapies

Although nuclear imaging can detect cardiac involvement of cardiac sarcoidosis (CS), including subclinical states, little is known about the prevalence and outcomes of radiologic relapse under prednisolone (PSL) therapy. This study aimed to investigate the clinical characteristics and outcomes in patients with radiologic relapse. A total of 80 consecutive patients with CS whose disease activity on nuclear imaging decreased at least once after initiation of immunosuppressive therapy were identified through a retrospective chart review. Radiologic relapse of CS was diagnosed using ¹⁸F-fluoro-2-deoxyglucose positron emission tomography or gallium-67 scintigraphy. Composite adverse events were defined as at least 1 of the following: all-cause death, hospitalization for heart failure, or lethal arrhythmia. During the follow-up period (median 2.9 years), radiologic relapse was observed in 31 patients (38.8% of overall patients) at 30 months (median) after immunosuppressive therapy initiation. After radiologic relapse was detected, all patients were treated with intensified immunosuppressive therapies (increasing PSL, n = 26 [83.9%], adding other immunosuppressive therapies to PSL, n = 5 [16.1%]). There were no differences in occurrences of composite adverse events in patients with and patients without radiologic relapse. Radiologic relapse under immunosuppressive therapy was observed in many patients with CS, but it was not associated with clinical outcomes under intensified immunosuppressive therapy.

Image Quality of Submillimeter High-Spatial-Resolution 2D Late Gadolinium-enhanced Images in Cardiac MRI: A Feasibility Study

Purpose

To evaluate the image quality of high-spatial-resolution two-dimensional (2D) late gadolinium enhancement (LGE) cardiac MRI compared with conventional normal-resolution LGE MRI.

Materials and Methods

This prospective study included participants suspected of having cardiomyopathy who underwent cardiac MRI between March 2021 and December 2021. Normal-resolution and high-resolution 2D LGE sequences (inversion recovery [IR] and phase-sensitive inversion recovery [PSIR]) were performed at 3 T. Resolution was compared between normal-resolution and high-resolution images obtained in a quality assurance phantom. In vivo image quality and resolution were evaluated qualitatively using a five-point scoring system. Receiver operating characteristic curve analysis was used for LGE detection performance. Border sharpness was assessed with profile curve measurement. The contrast-to-noise ratio (CNR) between hyperenhancement and remote myocardium and LGE detection performance were calculated using normal-resolution IR images as the reference.

Results

In total, 120 participants were evaluated (mean age, 56 years ± 17 [SD]; 72 men). Features smaller than 1 mm were detectable only on high-resolution images of the phantom. In vivo, the image resolution score with high-resolution LGE was 4.14-4.24, which was higher than the normal-resolution LGE reference score of 2.99 (P < .05). Border sharpness was higher in high-resolution images (P < .001). Receiver operating characteristic curve analysis revealed no evidence of a difference in LGE detection between normal-resolution and high-resolution images. There was also no evidence of a change in CNR of LGE in IR and PSIR magnitude compared with reference images.

Conclusion

Comparison of image quality in 2D high-resolution and normal-resolution LGE cardiac MRI demonstrated the highest resolution for high-resolution IR and high-resolution PSIR magnitude sequences.Keywords: Cartilage Imaging, MRI, Cardiac, Heart, Imaging Sequences, Comparative Studies Supplemental material is available for this article. © RSNA, 2022.

Multimodality assessments of wild‐type transthyretin cardiac amyloidosis with no ventricular hypertrophy

While patients with transthyretin cardiac amyloidosis (ATTR-CA) typically present with concentric or asymmetric hypertrophy, a small percentage of ATTR-CA is known to present with 'atypical' cardiac morphologies such as eccentric hypertrophy or even no hypertrophy. However, detailed report of multimodality assessments of ATTR-CA with no ventricular hypertrophy is lacking. Herein, we report detailed multimodality assessments of an 81-year-old Japanese woman with heart failure and history of carpal tunnel syndrome and lumbar canal stenosis, presenting no ventricular hypertrophy and negative ^99m technetium-pyrophosphate scintigraphy, who was eventually diagnosed as having wild-type ATTR-CA. Our case highlights the role of multimodality assessments for early diagnosis of ATTR-CA in patients with atypical cardiac morphologies and also emphasizes the limitations of bone scintigraphy and the importance of considering ATTR-CA in patients with non-cardiac manifestations of ATTR amyloidosis.

Extrapulmonary sarcoidosis involving only the heart and guts: a case report

Background

The respiratory tract is the most commonly affected organ system in sarcoidosis. Purely extrapulmonary sarcoidosis is rare. There have been no reports of extrapulmonary sarcoidosis with lesions only in the heart and guts.

Case summary

A 19-year-old male was admitted for chest symptoms accompanied by remarkably elevated troponin T and creatinine kinase levels. Electrocardiogram (ECG) showed sinus rhythm with a right bundle branch block, broad ST segment elevation, and abnormal Q waves. Endoscopic biopsy revealed granuloma formation in the transverse colon. Based on multimodal imaging, we made a clinical diagnosis of extrapulmonary sarcoidosis involving only the heart and guts. One year of immunosuppressive therapy with prednisolone resolved the inflammation in the guts but not in the heart. He experienced runs of sustained ventricular tachycardia with loss of consciousness and was admitted to our hospital again. The addition of methotrexate markedly reduced cardiac accumulation of fluorodeoxyglucose. No life-threatening ventricular arrhythmias have been recorded afterwards.

Discussion

This unusual case of cardiac sarcoidosis not only involved rare lesions only in the heart and guts but also presented with ST elevation on ECG. This case suggests that the gastrointestinal tract is a site of effective antigen capture outside of the respiratory tract that can affect the heart.

Crizotinib for ROS1‐rearranged Lung Cancer and Pulmonary Tumor Thrombotic Microangiopathy under Veno‐Arterial Extracorporeal Membrane Oxygenation

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rapidly progressive subtype of pulmonary hypertension (PH) associated with impaired right ventricular adaptation and very poor prognosis in cancer, and its rapid progression makes antemortem diagnosis and treatment extremely difficult. We describe the case of a 35‐year‐old woman who developed severe PH with subsequent circulatory collapse. The patient was clinically diagnosed with PTTM induced by lung adenocarcinoma harboring the c‐ros oncogene 1 (ROS1) rearrangement within 1–2 weeks, while hemodynamics were stabilized by rescue venoarterial extracorporeal membrane oxygenation support. Crizotinib, an oral tyrosine kinase inhibitor targeting anaplastic lymphoma kinase, MET, and ROS1 kinase domains dramatically resolved PH, resulting in more than 3 years of survival. Targeted gene‐tailored therapy with mechanical support can improve survival in PTTM.

Prognostic impact of multiple fragmented QRS on cardiac events in idiopathic dilated cardiomyopathy

AIMS

To evaluate the prognostic impact of fragmented QRS (fQRS) on idiopathic dilated cardiomyopathy (DCM).

METHODS AND RESULTS

We conducted a prospective observational study of 290 consecutive patients with DCM (left ventricular ejection fraction ≤ 40%) and narrow QRS who underwent cardiac magnetic resonance. We defined fQRS as the presence of various RSR' patterns in ≥2 contiguous leads representing the anterior (V1-V5), inferior (II, III, and aVF), or lateral (I, aVL, and V6) myocardial segments. Multiple fQRS was defined as the presence of fQRS in ≥2 myocardial segments. Patients were divided into three groups: no fQRS, single fQRS, or multiple fQRS. The primary endpoint was a composite of hard cardiac events consisting of heart failure death, sudden cardiac death (SCD), or aborted SCD. The secondary endpoints were all-cause death and arrhythmic event. During a median follow-up of 3.8 years (interquartile range, 1.8-6.2), 31 (11%) patients experienced hard cardiac events. Kaplan-Meier analysis showed that the rates of hard cardiac events and all-cause death were similar in the single-fQRS and no-fQRS groups and higher in the multiple-fQRS group (P = 0.004 and P = 0.017, respectively). Multivariable Cox regression identified that multiple fQRS is a significant predictor of hard cardiac events (hazard ratio, 2.23; 95% confidence interval, 1.07-4.62; P = 0.032). The multiple-fQRS group had the highest prevalence of a diffuse late gadolinium enhancement pattern (no fQRS, 21%; single fQRS, 22%; multiple fQRS, 39%; P < 0.001).

CONCLUSION

Multiple fQRS, but not single fQRS, is associated with future hard cardiac events in patients with DCM.

Unusual Overlapping Cardiac Sarcoidosis and Long-QT Type 3 Induced Ventricular Fibrillation

A 54-year-old woman had been resuscitated after ventricular fibrillation and her electrocardiogram showed a QT prolongation (QTc=510 ms), and genetic screening revealed a missense variant, R1644C, in the SCN5A gene. She was therefore diagnosed with congenital long-QT syndrome (LQTS) type 3. However, the patient had left ventricular dysfunction, and based on the findings of cardiac magnetic resonance imaging, positron emission tomography and pathological examinations, she was diagnosed with cardiac sarcoidosis. Although both are rare diseases, their overlapping presence in this case may have led to an increased cardiovascular risk compared with either alone. Thus, not only genetic but comprehensive clinical examinations are important for making a correct diagnosis.

Recurrences of disease activity in patients with cardiac sarcoidosis under corticosteroid therapy: prevalence, clinical background and prognosis

Background

Corticosteroid therapy (CTx) has been widely accepted as first-line therapy for cardiac sarcoidosis (CS), but there are very limited data regarding recurrence of disease activity of CS. We retrospectively investigated the prevalence, patient characteristics and prognostic significance in patients with recurrences of CS.

Methods

We identified 102 consecutive patients who were clinically diagnosed CS (admission: 2012 and 2019) and whose disease activity was diminished clinically at least once. Recurrence of CS was defined as detection of increased uptake of 18F-fluoro-2-deoxyglucose or gallium-67 in the follow-up examination. Composite adverse events (events) were defined as all-cause of death or hospitalization for heart failure. Echocardiographic and laboratory data before initiation of CTx were obtained.

Results

During the follow-up term (median: 4.9 years), the recurrences of CS occurred in 28 patients at 30 months (median) after the initiation of CTx. In patients with recurrence, left ventricular (LV) ejection fraction before initiation of CTx was lower than in those without recurrences (median: 31% vs. 39%, p&lt;0.05). After the detection of CS recurrences, 17 patients were treated with only increases of PSL and remaining 11 patients were treated with adding other immunosuppressive therapies to CTx. The univariate analysis demonstrated that there were no parameters in echocardiographic and laboratory examinations to predict the recurrences of CS. The results of univariate analysis for event occurrences (n=12) are shown in the Table. Additionally, the Kaplan-Meier analysis showed that there were no differences in event free survival rate in the patients with and without CS recurrences (Figure).

Conclusion

This study showed that the recurrences of disease activity were observed in a substantial number of patients with CS even under the CTx. All patients received intensification of CTx or additional immunosuppressive therapy, and LV systolic function, rather than the recurrence itself, was associated with clinical outcomes in this study.

Kaplan-Meier analysis for events

Funding Acknowledgement

Type of funding source: None

Prognosis and Clinical Characteristics of Dilated Cardiomyopathy With Family History via Pedigree Analysis

BACKGROUND

The clinical characteristics and prognostic outcomes of dilated cardiomyopathy (DCM) with a familial history (FHx) via pedigree analysis are unclear.Methods and Results:We conducted a prospective observational study of 514 consecutive Japanese patients with DCM. FHx was defined as the presence of DCM in ≥1 family member within 2-degrees relative based on pedigree analysis. The primary endpoint was a composite of major cardiac events (sudden cardiac death and pump failure death). The prevalence of FHx was 7.4% (n=38). During a median follow-up of 3.6 years, 77 (15%) patients experienced a major cardiac event. Multivariable Cox regression analysis identified FHx as independently associated with major cardiac events (hazard ratio [HR] 4.32; 95% confidence interval [CI], 2.04-9.19; P<0.001) compared with conventional risk factors such as age, QRS duration, and left ventricular volume. In the propensity score-matched cohort (n=38 each), the FHx group had a significantly higher incidence of major cardiac events (HR, 4.48; 95% CI, 1.25-16.13; P=0.022). In addition, the FHx group had a higher prevalence of a diffuse late gadolinium enhancement (LGE) pattern than the no-FHx group (32% vs. 17%, P=0.022).

CONCLUSIONS

DCM patients with FHx had a worse prognosis, which was associated with a higher prevalence of a diffuse LGE pattern, than patients without FHx.

Assessing the Clinical Value of Myocardial Perfusion SPECT in Cardiac Sarcoidosis with Diffuse Myocardial 18F-FDG Uptake

Background: Myocardial ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake is a sign of active inflammation in patients with cardiac sarcoidosis (CS) under the correct circumstance. However, even under the proper preparation, diffuse myocardial ¹⁸F-FDG uptake is frequently observed in the failing heart and misleads the CS disease activity. The aim of this study was to establish the diagnostic value of resting myocardial perfusion single photon emission computed tomography (SPECT) for assessing CS disease activity in patients with diffuse myocardial ¹⁸F-FDG uptake. Methods: We examined 39 patients with either histologically or clinically proven CS. All patients underwent ¹⁸F-FDG positron emission tomography (PET) and resting ^99mTc-SPECT. The presence of perfusion-metabolic mismatch was evaluated with generating polar maps of ¹⁸F-FDG PET and ^99mTc-SPECT images. Results: Increased myocardial ¹⁸F-FDG uptake was observed in 33 (85%) of 39 patients. Focal ¹⁸F-FDG uptake was detected in 16 patients and diffuse ¹⁸F-FDG uptake was seen in 17 patients. Brain natriuretic peptide (BNP) levels were significantly higher in patients with diffuse ¹⁸F-FDG uptake than those with focal ¹⁸F-FDG uptake (p=0.002). With comparing polar maps of ¹⁸F-FDG PET and ^99mTc-SPECT images, 8 of 16 patients with diffuse ¹⁸F-FDG uptake and myocardial perfusion defects demonstrated perfusion-metabolic mismatch which represented active inflammatory lesions in CS. Conclusions: Simultaneous evaluation of myocardial ¹⁸F-FDG PET and ^99mTc-SPECT by polar map analysis provides more relevant information for assessing disease activity in CS than ¹⁸F-FDG PET images alone. Perfusion-metabolic mismatch might indicate latent active inflammation in CS patients with diffuse myocardial ¹⁸F-FDG uptake, who had advanced heart failure.

Mortality and Sudden Cardiac Death Risk Stratification Using the Noninvasive Combination of Wide QRS Duration and Late Gadolinium Enhancement in Idiopathic Dilated Cardiomyopathy

BACKGROUND

The aim of this study was to investigate whether the combination of QRS duration ≥120 ms (wide QRS duration [wQRS]) and late gadolinium enhancement (LGE) is a precise prognostic indicator for dilated cardiomyopathy.

METHODS AND RESULTS

We investigated the association between the combination of LGE plus wQRS and the primary end point (all-cause death) and a composite of sudden cardiac death (SCD) or aborted SCD in 531 patients with dilated cardiomyopathy. We also analyzed the association between the combination of LGE and wQRS and these end points among patients with a class I indication for implantable cardioverter defibrillator implantation. We divided study patients into 3 groups according to LGE status and QRS duration: 2 negative indices (LGE negative and narrow QRS), 1 positive index (LGE positive or wQRS), or 2 positive indices (LGE positive and wQRS), and followed them for 3.8 years. Multivariable Cox regression analysis identified 2 positive indices as a significant predictor of all-cause death (hazard ratio, 4.29 [1.19-15.47]; P=0.026). Among 317 patients with a class I indication for implantable cardioverter defibrillator, the 5-year event rate of SCD or aborted SCD was the lowest in the 2 negative indices group (1.4%). With propensity score-matching cohorts, the 2 negative indices group had a significantly lower event rate of SCD or aborted SCD than the other 2 groups (hazard ratio, 0.12 [0.01-0.97]; P=0.046).

CONCLUSIONS

The combination of LGE and wQRS provides additional prognostic stratification compared with LGE status alone and might improve the appropriate use of implantable cardioverter defibrillator therapy in patients with dilated cardiomyopathy.

Clinical impact of native T1 mapping for detecting myocardial impairment in takotsubo cardiomyopathy

Aims

To investigate the clinical impact of T1 mapping for detecting myocardial impairment in takotsubo cardiomyopathy (TTC) over time.

Methods and results

In 23 patients with the apical ballooning type of TTC, the following 3T magnetic resonance (MR) examinations were performed at baseline and 3 months after TTC onset: T2-weighted imaging, T2 mapping, native T1 mapping, extracellular volume fraction (ECV), and late gadolinium enhancement. Eight healthy controls underwent the same MR examinations. Serial echocardiography was performed daily for ≥7 days and monthly until 3 months after onset. The median time from onset to MR examination was 7 days. During the acute phase, patients had, relative to controls, higher native T1 (1438 ± 162 vs. 1251 ± 90 ms, P < 0.001), ECV (35 ± 5% vs. 29 ± 4%, P < 0.001), and T2 (90 ± 34 vs. 68 ± 12 ms, P < 0.001) for the entire heart. Per-region analysis showed that higher native T1 and T2 in the basal region were correlated with lower left ventricular ejection fraction (r = −0.599, P = 0.004 and r = −0.598, P = 0.003, respectively). Receiver operator characteristic analysis showed that the area under the curve for native T1 (0.96) was significantly larger than that for T2 (0.86; P = 0.005) but similar to that for ECV (0.92; P = 0.104). At 3-month follow-up, native T1, ECV, and T2 in the apical region remained significantly elevated in all patients with TTC. The number of left ventricular (LV) segments with elevated native T1 (cut-off value 1339 ms) was significantly correlated with prolonged LV wall motion recovery time (r = 0.494, P = 0.027).

Conclusion

Characterization of myocardium with native T1 mapping is a promising method for predicting LV wall motion restoration in TTC.

Prognostic impact of blood pressure response plus gadolinium enhancement in dilated cardiomyopathy

Objective

Late gadolinium enhancement (LGE) is not necessarily ideal for detecting diffuse myocardial fibrosis in idiopathic dilated cardiomyopathy (DCM). Since systolic blood pressure response (SBPR) during exercise has been proposed to reflect cardiac pump reserve in patients with heart failure, we wished to determine whether LGE plus SBPR is a better prognostic factor in patients with DCM.

Methods

LGE and cardiopulmonary exercise testing results in consecutive 207 patients with DCM were examined. Patients were divided into four groups according to the presence or absence of LGE and the SBPR cut-off value of +40 mm Hg according to receiver operating characteristic curve analysis: LGE-positive+SBPR <40 mm Hg (n=65), LGE-positive+SBPR ≥40 mm Hg (n=40), LGE-negative+SBPR <40 mm Hg (n=33) and LGE-negative+SBPR ≥40 mm Hg (n=69). The composite end point was cardiac death, cardiac transplantation, LV assist device implantation, life-threatening arrhythmia or heart failure.

Results

Forty-two (20%) patients developed the composite end point, with rates of 35%, 20%, 21% and 6% in patients with LGE-positive+SBPR <40 mm Hg, LGE-positive+SBPR ≥40 mm Hg, LGE-negative+SBPR <40 mm Hg and LGE-negative+SBPR ≥40 mm Hg status, respectively. Multivariable Cox regression analysis identified LGE-positive and SBPR <40 mm Hg as a significant independent predictor of cardiac events (HR 2.08, 95% CI 1.06 to 4.11, p=0.034). Of note, there was no significant difference in the cardiac event-free survival rate between the LGE-positive+SBPR ≥40 mm Hg and LGE-negative+SBPR <40 mm Hg groups (p=0.736).

Conclusions

The combination of LGE and SBPR provides more clinically relevant information for assessing the risk of cardiac events in patients with DCM than LGE status alone.

Right ventricular reverse remodelling after balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has been reported to improve haemodynamics and functional capacity, with an acceptable risk, in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not candidates for pulmonary endarterectomy. However, right ventricular (RV) function, an important predictor in CTEPH, remains to be elucidated. We aimed to examine the impact of BPA on RV remodelling and dysfunction relative to haemodynamic improvements in patients with inoperable CTEPH. 20 consecutive patients with inoperable CTEPH who underwent BPA with cardiovascular magnetic resonance before and after BPA were retrospectively studied. BPA led to significant amelioration of the mean pulmonary arterial pressure, cardiac index and pulmonary vascular resistance (PVR), without death or major complications. Furthermore, BPA significantly ameliorated right-sided heart failure symptoms and signs, and exercise capacity. Cardiovascular magnetic resonance revealed a marked improvement in RV end-diastolic and end-systolic volume index, with concomitant improvements in RV ejection fraction, mass and interventricular septal bowing after BPA. Changes in RV volumes strongly correlated with changes in cardiac index and PVR. BPA induced RV reverse remodelling and improved systolic dysfunction safely by ameliorating haemodynamics in patients with inoperable CTEPH. Evaluating RV function with cardiovascular magnetic resonance may be effective for noninvasively monitoring BPA efficacy.

[Despite medication, overdrive pacing is required to stabilize the electrical storm associated with acute coronary syndrome: a case report]

A 75-year-old female complained of severe chest pain and was emergently admitted to our hospital because of anterior acute myocardial infarction. Emergent coronary angiography was performed and revealed occlusion in segment 7, so a stent was implanted. Lidocaine, carvedilol, amiodarone, magnesium, and nifekalant were administered successively because non-sustained ventricular tachycardia (NSVT) frequently appeared like an electrical storm. After nifekalant administration, QTc was significantly prolonged and torsades de pointes was induced. Overdrive pacing was performed and finally the NSVT was completely controlled. If fatal arrhythmias such as NSVT show resistance to medication, overdrive pacing should be considered to stabilize the arrhythmia associated with acute coronary syndrome.

Angiotensin II signaling and HB-EGF shedding via metalloproteinase in glomerular mesangial cells

BACKGROUND

Angiotensin II (Ang II) has been implicated in the development of glomerulosclerosis by stimulating fibronectin (FN) synthesis. The processing and release of heparin binding-endothelin growth factor (HB-EGF) are activated by protein kinase C (PKC) and Ca2+ signaling. We studied the roles of HB-EGF and endothelial growth factor (EGF) receptor (EGFR) in Ang II-induced FN expression using mesangial cells.

METHODS

Mesangial cells were prepared from mouse kidneys by the explant method and cells were used at passages 4 and 5.

RESULTS

Ang II stimulated FN mRNA levels dose-dependently with a maximal increase (3.4-fold) after 12 hours of incubation. This action was completely inhibited by PKC inhibitors and slightly blocked by Ca2+ chelating agents. FN mRNA accumulation by Ang II was abolished by tyrosine kinase inhibitors, a specific inhibitor for EGFR (AG1478) and extracellular signal-regulated kinase (ERK) inactivation. Addition of neutralizing anti-HB-EGF antibody, as well as pretreatment with heparin or the metalloproteinase inhibitor batimastat abolished induction of FN expression by Ang II. In mesangial cells stably transfected with a chimeric construct containing HB-EGF and alkaline phosphatase (ALP) genes, ALP activity in incubation medium was rapidly increased by Ang II (1.7-fold at 0.5 min) and reached a 4.1-fold increase at two minutes. Ang II phosphorylated EGFR (maximal at 2 min) and ERK (maximal at 8 min) in a PKC- and metalloproteinase-dependent manner. Ang II stimulated the expression and release of transforming growth factor-beta (TGF-beta) via EGFR-mediated signaling, and the released TGF-beta also contributed to Ang II-mediated FN expression via EGFR transactivation.

CONCLUSIONS

Ang II-mediated FN expression was regulated by autocrine effects of HB-EGF and TGF-beta, suggesting a novel paradigm for cross-talk between Ang II and growth factor receptor signaling pathways.

Angiotensin II type 2 receptor inhibits epidermal growth factor receptor transactivation by increasing association of SHP-1 tyrosine phosphatase

Angiotensin (Ang) II has 2 major receptor isoforms, Ang type 1 (AT(1)) and Ang type (AT(2)). AT(1) transphosphorylates epidermal growth factor receptor (EGFR) to activate extracellular signal-regulated kinase (ERK). Although AT(2) was shown to inactivate ERK, the action of AT(2) on EGFR activation remains undefined. Using AT(2)-overexpressing vascular smooth muscle cells from AT(2) transgenic mice, we studied these undefined actions of AT(2). Maximal ERK activity induced by Ang II was increased 1.9- and 2.2-fold by AT(2) inhibition, which was abolished by orthovanadate but not okadaic acid or pertussis toxin. AT(2) inhibited AT(1)-mediated EGFR tyrosine phosphorylation by 63%. The activity of SHP-1 tyrosine phosphatase was significantly upregulated 1 minute after AT(2) stimulation and association of SHP-1 with EGFR was increased, whereas AT(2) failed to tyrosine phosphorylate SHP-1. Stable overexpression of SHP-1-dominant negative mutant completely abolished AT(2)-mediated inhibition of EGFR and ERK activation. AT(1)-mediated c-fos mRNA accumulation was attenuated by 48% by AT(2) stimulation. Induction of fibronectin gene containing an AP-1 responsive element in its 5'-flanking region was decreased by 37% after AT(2) stimulation, corresponding to the results of gel mobility assay with the AP-1 sequence of fibronectin as a probe. These findings suggested that AT(2) inhibits ERK activity by inducing SHP-1 activity, leading to decreases in AP-1 activity and AP-1-regulated gene expression, in which EGFR dephosphorylation plays an important role via association of SHP-1.

Implantation of bone marrow mononuclear cells into ischemic myocardium enhances collateral perfusion and regional function via side supply of angioblasts, angiogenic ligands, and cytokines

BACKGROUND

Bone marrow implantation (BMI) was shown to enhance angiogenesis in a rat ischemic heart model. This preclinical study using a swine model was designed to test the safety and therapeutic effectiveness of BMI.

METHODS AND RESULTS

BM-derived mononuclear cells (BM-MNCs) were injected into a zone made ischemic by coronary artery ligation. Three weeks after BMI, regional blood flow and capillary densities were significantly higher (4.6- and 2.8-fold, respectively), and cardiac function was improved. Angiography revealed that there was a marked increase (5.7-fold) in number of visible collateral vessels. Implantation of porcine coronary microvascular endothelial cells (CMECs) did not cause any significant increase in capillary densities. Labeled BM-MNCs were incorporated into approximately 31% of neocapillaries and corresponded to approximately 8.7% of macrophages but did not actively survive as myoblasts or fibroblasts. There was no bone formation by osteoblasts or malignant ventricular arrhythmia. Time-dependent changes in plasma levels for cardiac enzymes (troponin I and creatine kinase-MB) did not differ between the BMI, CMEC, and medium-alone implantation groups. BM-MNCs contained 16% of endothelial-lineage cells and expressed basic fibroblast growth factor>>vascular endothelial growth factor>angiopoietin 1 mRNAs, and their cardiac levels were significantly upregulated by BMI. Cardiac interleukin-1beta and tumor necrosis factor-alpha mRNA expression were also induced by BMI but not by CMEC implantation. BM-MNCs were actively differentiated to endothelial cells in vitro and formed network structure with human umbilical vein endothelial cells.

CONCLUSIONS

BMI may constitute a novel safety strategy for achieving optimal therapeutic angiogenesis by the natural ability of the BM cells to secrete potent angiogenic ligands and cytokines as well as to be incorporated into foci of neovascularization.

Safety and availability of doxazosin in treating hypertensive patients with chronic renal failure

Hypertension accelerates the progression of renal disease in patients with chronic renal failure. Doxazosin, an alpha1-antagonist, is an antihypertensive agent with a long half-life. In this study, 15 patients with chronic renal failure were treated only with doxazosin and diuretics for 6 months and their blood pressure, renal parameters and lipid profile were measured. The initial dose of doxazosin was 2 mg/day and it was titrated until blood pressure was normalized. The average dose was 5.6 mg/day. As expected, systolic and diastolic blood pressure were decreased with treatment (165/91 mmHg to 135/73 mmHg). The drop in blood pressure was associated with an increase in glomerular filtration and a decrease in plasma BUN and creatinine levels. Reduction in mean blood pressure and decrease in proteinuria had a significant positive correlation (r=0.048, p=0.007). Proteinuria was decreased from 1.8 mg/day to 1.3 mg/day with doxazosin treatment and triglycerides also decreased, while HDL-cholesterol was increased. No side effects were observed. These results indicate that doxazosin is an efficient depressor agent with renal protective actions and that higher doses of doxazosin can be safely given to patients with chronic renal failure.

Effect of angiotensin II type 2 receptor on tyrosine kinase Pyk2 and c-Jun NH2-terminal kinase via SHP-1 tyrosine phosphatase activity: evidence from vascular-targeted transgenic mice of AT2 receptor

Angiotensin II (Ang II) has two major receptor isoforms, AT1 and AT2. AT1 transphosphorylates Ca(2+)-sensitive tyrosine kinase Pyk2 to activate c-Jun NH2-terminal kinase (JNK). Although AT2 inactivates extracellular signal-regulated kinase (ERK) via tyrosine phosphatases (PTP), the action of AT2 on Pyk2 and JNK remains undefined. Using AT2-overexpressing vascular smooth muscle cells (AT2-VSMC) from AT2-transgenic mice, we studied these undefined actions of AT2. AT1-mediated JNK activity was increased 2.2-fold by AT2 inhibition, which was abolished by orthovanadate. AT2 did not affect AT1-mediated Pyk2 phosphorylation, but attenuated c-Jun mRNA accumulation by 32%. The activity of src-homology 2 domain-containing PTP (SHP-1) was significantly upregulated 1 min after AT2 stimulation. Stable overexpression of SHP-1 dominant negative mutant in AT2-VSMC completely abolished AT2-mediated inhibition of JNK activation and c-Jun expression. These findings suggest that AT2 inhibits JNK activity by affecting the downstream signal of Pyk2 in a SHP-1-dependent manner, leading to a decrease in c-Jun expression.

Angiotensin AT(1) and AT(2) receptors differentially regulate angiopoietin-2 and vascular endothelial growth factor expression and angiogenesis by modulating heparin binding-epidermal growth factor (EGF)-mediated EGF receptor transactivation

Angiotensin II (Ang II)-mediated signals are transmitted via heparin binding epidermal growth factor (EGF)-like growth factor (HB-EGF) release followed by transactivation of EGF receptor (EGFR). Although Ang II and HB-EGF induce angiogenesis, their link to the angiopoietin (Ang)-Tie2 system remains undefined. We tested the effects of Ang II on Ang1, Ang2, or Tie2 expression in cardiac microvascular endothelial cells expressing the Ang II receptors AT(1) and AT(2). Ang II significantly induced Ang2 mRNA accumulations without affecting Ang1 or Tie2 expression, which was inhibited by protein kinase C inhibitors and by intracellular Ca(2+) chelating agents. Ang II transactivated EGFR via AT(1), and inhibition of EGFR abolished the induction of Ang2. Ang II caused processing of pro-HB-EGF in a metalloproteinase-dependent manner to stimulate maturation and release of HB-EGF. Neutralizing anti-HB-EGF antibody blocked EGFR phosphorylation by Ang II. Ang II also upregulated vascular endothelial growth factor (VEGF) expression in an HB-EGF/EGFR-dependent manner. AT(2) inhibited AT(1)-mediated Ang2 expression and phosphorylation of EGFR. In an in vivo corneal assay, AT(1) induced angiogenesis in an HB-EGF-dependent manner and enhanced the angiogenic activity of VEGF. Although neither Ang2 nor Ang1 alone induced angiogenesis, soluble Tie2-Fc that binds to angiopoietins attenuated AT(1)-mediated angiogenesis. These findings suggested that (1) Ang II induces Ang2 and VEGF expression without affecting Ang1 or Tie2 and (2) AT(1) stimulates processing of pro-HB-EGF by metalloproteinases, and the released HB-EGF transactivates EGFR to induce angiogenesis via the combined effect of Ang2 and VEGF, whereas AT(2) attenuates them by blocking EGFR phosphorylation. Thus, Ang II is involved in the VEGF-Ang-Tie2 system via HB-EGF-mediated EGFR transactivation, and this link should be considerable in pathological conditions in which collateral blood flow is required.

[Gene-therapy for peripheral vascular diseases]

The prognosis for patients with chronic critical leg ischemic is often poor. The treatment of peripheral vascular disease, although greatly improved over recent decades by drug medication, surgical and minimally-invasive techniques, remains limited by vascular proliferative lesions and by our inability to modulate the progression of native disease. The therapeutic angiogenesis is now the most expected therapy for peripheral vascular diseases. This review explores some of concepts and methods of therapeutic angiogenesis including gene therapy using angiogenic growth factor such as VEGF and basic FGF and an implantation of bone marrow derived endothelial progenitor cells.

Transactivation of EGF receptor induced by angiotensin II regulates fibronectin and TGF-beta gene expression via transcriptional and post-transcriptional mechanisms

The signaling cascade elicited by angiotensin II (Ang II) resembles that characteristic of growth factor, and recent evidence indicates transactivation of epidermal growth factor receptor (EGF-R) by G protein-coupled receptors. Here, we report the involvement of EGF-R in Ang II-induced synthesis of fibronectin and TGF-beta in cardiac fibroblasts. Ang II stimulated fibronectin mRNA levels dose-dependently with a maximal increase (approximately 5-fold) observed after 12 h of incubation. Ang II-, or calcium ionophore-induced fibronectin synthesis was completely abolished by tyrosine kinase inhibitors and intracellular Ca2+ chelating agents. Ang II-induced fibronectin mRNA was not affected by PKC inhibitors or PKC depletion, whereas specific inhibition of EGF-R function by a dominant negative EGF-R mutant and tyrphostin AG1478 abolished induction of fibronectin mRNA. We isolated the rat fibronectin gene including the 5'-flanking region and found that the AP-1 binding site present in the promoter region was responsible for the Ang II responsiveness of this gene. Gel retardation assay revealed the binding of nuclear protein to the AP-1 site, which was supershifted with anti-c-fos and anti-c-jun but not anti-ATF-2 antibodies. Conditioned medium from Ang II-treated cells contained TGF-beta bioactivity and addition of neutralizing TGF-beta antibody modestly (46%) inhibited induction of fibronectin. Ang II-induced synthesis of TGF-beta was also abolished by inhibition of EGF-R function. The effect of TGF-beta was exerted by stabilizing fibronectin mRNA without affecting the promoter activity and required de novo protein synthesis. We concluded that Ang II-induced expression of fibronectin and TGF-beta is mediated by downstream signaling of EGF-R transactivated by Ca2+-dependent tyrosine kinase, and that Ang II-induced fibronectin mRNA expression is regulated by two different mechanisms; transcriptional control by binding of c-fos/c-jun complex to the AP-1 site, and post-transcriptional control by mRNA stabilization due to autocrine and/or paracrine effects of TGF-beta. Thus, this study suggested that the action of Ang II on extracellular matrix formation should be interpreted in association with the EGF-R signaling cascade.

A greedy strategy for finding motifs from yes-no examples

We define a motif as an expression Z1.Z2...Zn with sets Z1, Z2,..., Zn of strings in a specified family omega called the type. This notion can capture the most of the motifs in PROSITE as well as regular pattern languages. A greedy strategy is developed for finding such motifs with ambiguity just from positive and negative examples by exploiting the probabilistic argument. This paper concentrates on describing the idea of the greedy algorithm with its underlying theory. Its experimental results on splicing sites and E. coli promoters are also presented.