Head-to-head comparison of 18F-sodium fluoride coronary PET imaging between a silicon photomultiplier with digital photon counting and conventional scanners.

BACKGROUND: We compared silicone photomultipliers with digital photon counting (SiPM) and photomultiplier tubes (PMT) PET in imaging coronary plaque activity with 18F-sodium fluoride (18F-NaF) and evaluated comprehensively SiPM PET reconstruction settings. METHODS: In 25 cardiovascular disease patients (mean age 67±12 years), we conducted 18F-NaF PET on a SiPM (Biograph Vision) and conventional PET (Discovery 710) on the same day as part of a prospective clinical trial (NCT03689946). Following administration of 250 MBq of 18F-NaF, patients underwent a contrast-enhanced CT angiography and a 30-min PET acquisition in list mode on each PET consecutively. Image noise was defined as mean standard deviation of blood pool activity within the left atria. Target-to-background ratio (TBR) and signal-to-noise ratio (SNR) were measured within the whole-vessel tubular 3-dimensional volumes of interest on the cardiac motion and attenuation corrected 18F-NaF PET images using dedicated software. RESULTS: There were significant differences in image noise and background activity between the two PETs (Image noise (%), PMT: 7.6±3.7 vs. SiPM: 4.0±2.3, p<0.001; background activity, PMT: 1.4±0.4 vs. SiPM: 1.0±0.3, p<0.001). Similarly, the SNR and TBR were significantly higher in vessels scanned with the SiPM PET (SNR, PMT: 16.3±11.5 vs. SiPM: 32.7±29.8, p<0.001; TBR, PMT: 0.8±0.4 vs. SiPM: 1.1±0.6, p<0.001). SiPM PET image reconstruction with a 256 matrix, 1.4 mm pixel, and 2 mm Gaussian filter provided best tradeoff in terms of maximal SNR, TBR and clinically practical file size. CONCLUSIONS: In 18F-NaF coronary PET imaging, the SiPM PET showed superior image contrast and less image noise compared to PMT PET.

Evaluation of balloon pulmonary angioplasty using lung perfusion SPECT in patients with chronic thromboembolic pulmonary hypertension.

BACKGROUND: The aim of this study was to evaluate the effect of balloon pulmonary angioplasty (BPA) using lung perfusion single-photon emission computed tomography (SPECT) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). METHODS AND RESULTS: 20 consecutive patients (64 ± 15 years) who were diagnosed with CTEPH and underwent BPA were included in this study. All patients underwent lung perfusion SPECT before and after BPA. The relationship between functional %volume of the lung calculated from the lung perfusion SPECT (FVL-LPSPECT), and other clinical parameters before and after BPA was assessed using the Wilcoxon signed-rank test. The correlation between each parameter and mean pulmonary artery pressure (mPAP) using the Spearman's correlation was performed. To determine predictors of mPAP for evaluating treatment effectiveness, significant parameters were included in multiple regression analysis. After BPA, world health organization functional classification, six-minute walk distance (6MWD), mPAP, and FVL-LPSPECT significantly improved. FVL-LPSPECT (r = - 0.728, P < 0.001) and 6MWD (r = - 0.571, P = 0.009) were significant correlation of mPAP. In the multiple regression analysis, FVL-LPSPECT was the most significant predictor of improvement in mPAP after BPA (P < 0.001). CONCLUSIONS: This study demonstrated that the lung perfusion SPECT could be a potential measurement of the effectiveness of BPA in patients with CTEPH.

Association between coronary artery calcium score on non-contrast chest computed tomography and all-cause mortality among patients with congestive heart failure.

Coronary artery calcium (CAC) score is a robust prognostic tool to predict cardiac events. Although patients with congestive heart failure (CHF) occasionally undergo non-contrast computed tomography (NCCT), the prognostic utility of CAC by NCCT is not widely known. We aimed to determine if CAC measured on NCCT is associated with all-cause mortality (ACM) among patients with CHF. We identified 550 patients admitted due to CHF who underwent NCCT. Patients were categorized into three groups according to CAC scores 0, 1-999, and ≥ 1000. The multivariate Cox proportional hazards model was used to assess if CAC by NCCT was associated with ACM after adjusting for traditional coronary artery disease (CAD) risk factors, brain natriuretic peptide and left ventricular ejection fraction (LVEF). In a subset of 245 patients with invasive coronary angiography (ICA), the associations between CAC scores and ACM were assessed in the multivariate Cox proportional hazards model. Further, we assessed if CAC increased statin use at discharge. During a mean follow-up of 3.3 ± 3.1 years, ACM occurred in 168 patients (30.55%). Compared with patients with CAC 0, those with CAC ≥ 1000 (HR 1.564, 95% CI 0.969-2.524, P = 0.067) were more likely to experience ACM, while those with CAC score 1-999 (HR 0.971, 95% CI 0.673-1.399, P = 0.873) were not. Similarly, a trend toward significance was observed in patients with LVEF < 40% (HR 2.124, 95% CI 0.929-4.856, P = 0.074). In the sub-analysis, patients with CAC ≥ 1000 had increased ACM compared to those with CAC 0, only if ICA ≥ 50% (HR 3.668, 95% CI 1.141-11.797, P = 0.029). Multivariate logistic regression revealed that statin use at discharge was increased with ICA ≥ 50%, but not CAC. The CAC score measured by NCCT tended to be associated with ACM among CHF patients. Statin use was not increased by CAC on NCCT.

Appropriate Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension Improves Right Ventricular Ejection Fraction via Lung Perfusion Scan.

Balloon pulmonary angioplasty (BPA) is a robust treatment and has been performed among patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). A lung perfusion scan (LPS) is required for inspection in deciding the curative effect judgment and treatment lesion of BPA. Nevertheless, the impact of BPA in the improvement of right heart system function is not well known. We investigated whether BPA improves right heart function alongside other parameters.We studied 20 patients with CTEPH (mean age 63.6 ± 15.9 years, male 30.0%) who underwent BPA. All study sets including right heart catheter, pulmonary angiography, 6-minute walk test (6MWT), blood gas analysis, and LPS were performed before BPA treatment. All parameters using right heart catheter and oxygenation level were measured at room air temperature. Regarding LPS, right ventricular ejection fraction (RVEF) was calculated using the first-pass method. These parameters before BPA were compared with those after BPA.In total, 120 BPAs were performed (mean number of procedures/patient; 6.0 ± 2.4 sessions). Per BPA session, 6.0 ± 2.4 areas and 10.0 ± 4.3 lesions were treated with a volume of 181.3 ± 53.5 mL of contrast media. No complication required an invasive procedure. World Health Organization functional class, 6MWT, pulmonary artery pressure, pulmonary vascular resistance, and oxygenation level were significantly improved after BPA. RVEF via LPS was also significantly improved after BPA (45.0 ± 6.2% to 50.6 ± 2.9%, P < 0.001).In the present study, we found that RVEF via LPS was improved through appropriate BPA alongside the other parameters. It would be useful to be able to evaluate right heart function.

Prognostic values of 123I-MIBG myocardial scintigraphy and heart rate variability in patients with heart failure with preserved ejection fraction.

BACKGROUND: The aim of this study was to evaluate the prognostic values of sympathetic nerve system using 123I-MIBG myocardial scintigraphy and using Holter electrocardiogram (ECG) in patients with heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: Among 403 consecutive patients with stable HF who underwent 123I-MIBG myocardial scintigraphy and Holter ECG, we identified 133 patients (64 ± 16 years) who had preserved ejection fraction (≥ 50%) by echocardiography. Multivariate Cox model was used to assess if washout rate (WR) by 123I-MIBG scintigraphy and very low frequency power (VLFP) by Holter ECG was associated with major adverse cardiovascular events (MACE). During a mean follow-up of 5.4 ± 4.1 years, 39 MACE occurred. The lower nighttime VLFP (HR 3.29, 95% CI 1.56 to 6.92) and higher WR (HR 4.01, 95% CI 1.63 to 9.88) were the significant prognostic factors for MACE. As compared to high nighttime VLFP and low WR group, MACE risk was significantly the highest in the low nighttime VLFP and high WR group (HR 40.832; 95% CI 5.378 to 310.012, P < 0.001). CONCLUSION: This study demonstrated that the nighttime VLFP adding to WR could be a potential prognostic value among patients with HFpEF.

Myocardial T2 Mapping in Patients With Hypertrophic Cardiomyopathy.

OBJECTIVE: The aim of this study was to evaluate the usefulness of T2 mapping for detecting myocardial injuries in patients with hypertrophic cardiomyopathy (HCM). METHODS: Twenty-one HCM patients and 7 healthy volunteers were examined. The T2 values were measured at hyperintense areas (high-T2 areas) identified with T2 mapping, at late gadolinium enhancement (LGE) areas, and in nullified myocardium of the HCM patients. The associations between T2 values and laboratory data or LGE areas were assessed. RESULTS: High-T2 areas had significantly greater T2 values than LGE areas (P < 0.05) and nullified areas (P < 0.01) of HCM and normal myocardium (P < 0.01). The presence of high-T2 areas was associated with an increase in troponin T levels (P = 0.02), and T2 values correlated with the levels of brain natriuretic peptide (P = 0.036, r = 0.86). CONCLUSIONS: T2 mapping identified myocardial injuries suggested by the laboratory data in HCM.

Hemodynamic recognition of pure autonomic failure: A case report.

Neurogenic orthostatic hypotension (OH) causes severe orthostatic intolerance. We evaluated hemodynamic parameters in a patient with pure autonomic failure (PAF) using various unique approaches. A 60-year-old woman had worsening light-headedness, fatigue, and severe OH without compensatory tachycardia. PAF was diagnosed based on negative neurological findings, testing, and imaging results. The active standing test did not increase the heart rate (HR), and it decreased cardiac output, indicating impaired sympathetic control of cardiovascular activity. HR did not change during the supine bicycle exercise stress test, whereas blood pressure decreased. The patient had an accentuated reaction to isoproterenol but did not respond to atropine sulfate. Isoproterenol 0.01 µg/kg/min caused a 153 % increase in HR that required more than 30 min to return to its original value, suggesting hypersensitivity to catecholamines and decreased parasympathetic activity. As for why atropine sulfate (0.04 mg/kg) did not increase HR, we assumed that parasympathetic activity was already suppressed or the sympathetic effects were not predominant. Intravenous atropine sulfate may be useful in diagnosing PAF, which generally lacks specific neurological physical findings. A proper understanding of the hemodynamics involved in the management of PAF-associated OH is crucial. Learning objective: The autonomic control of cardiovascular function is impaired in pure autonomic failure, and neurogenic orthostatic hypotension can be diagnosed by evaluating changes in heart rate. Treatment should be based on the hemodynamic characteristics using non-invasive cardiac output monitoring, pharmacological approaches, and supine bicycle exercise stress tests.

Prognostic value of ECG monitor findings in COVID-19.

AIMS: COVID-19 can cause severe illness and multiorgan dysfunction. Acute myocardial damage has been detected in a significant portion of patients with COVID-19; therefore, several studies have reported that electrocardiographic findings could be used to evaluate the severalty of COVID-19. However, performing standard ECG for each patient hospitalised with COVID-19 can increase the level of exposure to COVID-19 among medical staff. Therefore, this study aimed to investigate the prognostic value of continuous electrocardiographic monitor findings in patients with COVID-19. METHODS: Among 1612 consecutive patients with COVID-19 who were admitted to our hospital between August 2021 and May 2022, we identified 96 (76±4 years) patients who underwent electrocardiographic monitor during hospitalisation. All electrocardiographic monitors were analysed by two independent cardiologists blinded to the clinical data of the patients. The endpoint was defined as the occurrence of all-cause mortality related to COVID-19. The event data were retrospectively gathered from the patients' medical records. A multivariate Cox model was used to assess whether these electrocardiographic monitor findings and clinical data were associated with in-hospital mortality. RESULTS: During a mean hospitalisation period of 22.8±3.2 days, in-hospital mortality occurred in 17 (18%) patients. Atrial fibrillation (HR: 3.95, 95% CI: 1.39 to 11.21) and lung disease complications (HR: 2.91, 95% CI: 1.06 to 7.98) were significant prognostic factors for death in multivariate analysis. Compared with the non-complicated lung disease and non-atrial fibrillation group, the risk of mortality was significantly higher in the lung disease complication and atrial fibrillation group in the multivariate Cox proportional model (HR: 8.37, 95% CI: 1.69 to 41.30, p=0.009). CONCLUSIONS: The simple method of ECG monitor could adequately detect atrial fibrillation. This study demonstrated that atrial fibrillation complicated with lung disease, could have potential prognostic value among patients with COVID-19.

Prediction of atrial fibrillation using a home blood pressure monitor with a high-resolution system.

OBJECTIVE: The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a high-resolution system (HiRS) for AF prediction and its usefulness when installed in home BP monitors. METHODS: In patients with paroxysmal, persistent or permanent AF, ECG recording and BP measurements were performed simultaneously. The relationship between ECG rhythm diagnosis and pulse irregularity recognition, using a home BP monitor with HiRS, was investigated. The severity of a pulse disturbance during BP measurement was displayed as an irregular pulse rhythm symbol (IPRS) in three instances. The IPRS was not displayed if the pulse was regular, turned on if there was a weak variation in the pulse, and blinked if there was a strong variation in the pulse. RESULTS: One hundred and seven patients (44 paroxysmal AF, 63 persistent or permanent AF) were enrolled, and a total of 333 recordings were analysed. The rhythms recorded by each ECG were 73 sinus regular rhythms, 35 extrasystoles, 222 AFs and 3 atrial flutters. Sensitivity and specificity for the prediction of any arrhythmia by the IPRS display of the BP monitor were 95.8% (95% CI 92.6% to 97.6%) and 96.8% (95% CI 92.6% to 100%), respectively. In addition, sensitivity and specificity for the prediction of AF were 100% (95% CI 97.5% to 100%) and 74.8% (95% CI 65.6% to 82.5%), respectively. Sensitivity and specificity for the prediction of AF by the IPRS blinking display were 88.3% (95% CI 83.3% to 92.2%) and 94.6% (95% CI 88.6% to 98.0%%), respectively. IPRS exhibited lighting or blinking during AF occurrence; however, during sinus rhythm, IPRS was not displayed in 72 out of 73 recordings. CONCLUSION: The IPRS device predicted AF with precision and may be particularly useful for predicting an arrhythmia attack in patients with paroxysmal AF.

Evaluation of lung perfusion by using lung perfusion SPECT and lung CT with breathing synchronization software.

BACKGROUND: Lung perfusion using 99mTc-macroaggregated albumin single-photon emission computed tomography (SPECT) and lung computed tomography (CT) is a useful modality for identifying patients with pulmonary artery embolism. However, conformity between SPECT and CT at the bottom of the lung is generally low. This study aims to investigate the progression of conformity between lung perfusion SPECT and lung CT using a breathing synchronization software. METHODS: Among 95 consecutive patients who underwent lung perfusion SPECT and lung CT within 14 days because of suspected pulmonary embolism between June 2019 and August 2020 in department of cardiovascular medicine, we identified 28 patients (73 ± 10 years) who had normal pulmonary artery on contrast lung CT. We compared lung volumes calculated using lung perfusion SPECT and lung CT as gold standard. Visual conformity between lung SPECT and lung CT was scored 0-4 (0: 0-25%, 1: 25-50%, 2: 50-75%, 3: 75-90%, 4: > 90%) by two specialists in nuclear medicine and assessed. RESULTS: The lung volume calculated from lung CT was 3749 ± 788 ml. The lung volume calculated from lung perfusion SPECT without using the breathing synchronization software was 3091 ± 610 ml. There was a significant difference between the lung volume calculated from CT and SPECT without using the breathing synchronization software (P < 0.01). The lung volume calculated from lung perfusion SPECT using the breathing synchronization software was 3435 ± 686 ml, and there was no significant difference between the lung volume calculated from CT and SPECT using the breathing synchronization software. The visual score improved with the use of breathing synchronization software (without software; 1.9 ± 0.6 vs. with software; 3.4 ± 0.7, P < 0.001). CONCLUSION: This study demonstrated that the breathing synchronization software could improve conformity between lung perfusion SPECT and lung CT.

Relationship Between 18F-fluorodeoxyglucose Uptake on Positron Emission Tomography and Aortic Calcification.

Introduction: Although 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been widely utilized to assess the extent of inflammation, the association between the extent and severity of atherosclerosis and 18F-FDG uptake on PET remains unexamined. The current study aimed to investigate whether aortic calcium (AC) scores were associated with increased aortic uptake of 18F-FDG on PET. Methods: A total of 167 consecutive patients with suspected lung cancer but unproven malignancy who underwent non-contrast-enhanced computed tomography (CT) and 18F-FDG PET/CT were enrolled. The average standardized uptake values in the ascending aorta were used to calculate the target-to-background ratio (Mean TBR). The total (thoracic and abdominal) AC scores were measured on non-contrast-enhanced chest and abdominal CT using the Agatston method, and were categorized into three groups (0, 1-399, and ≥400). The relationship between total AC scores and 18F-FDG uptake in the ascending aorta was assessed using multivariate linear regression analysis. Results: In total, 68.26% were male, and a mean age was 67.10±14.70 years. Mean TBR values increased progressively with total AC score 0, 1-399, and ≥400 (1.01±0.07, 1.08±0.09, and 1.11±0.11, respectively; p<0.00001). Multivariate linear regression analysis revealed that increased total AC scores of 1-399 (ß=0.06, 95% CI: 0.01-0.11, p=0.02) and ≥400 (ß=0.11, 95% CI: 0.06-0.16, p<0.001) were significantly associated with higher Mean TBR. Conclusions: The current study demonstrated that total AC scores were associated with Mean TBR. Patients with a greater extent and severity of aortic calcifications may possess increased atherosclerotic inflammatory activity as measured by 18F-FDG PET/CT.

Prognostic values of coronary artery calcium score and 123I-BMIPP SPECT in patients with non-ischemic heart failure with preserved ejection fraction.

This study aimed to determine whether coronary artery calcium score (CACS) can be a prognostic indicator for the development of major adverse cardiac events (MACEs) and compare the value of CACS with that of the 123I-betamethyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) defect score (BDS) in patients with non-ischemic heart failure with preserved ejection fraction (NIHFpEF). Among 643 consecutive patients hospitalized due to acute heart failure, 108 (74 ± 13y) were identified to have NIHFpEF on non-contrast regular chest computed tomography and 123I-BMIPP single-photon emission computed tomography (SPECT). We evaluated whether CACS and BDS were associated with MACEs using multivariate Cox models. Thirty-two MACEs developed at a mean follow-up period of 2.4 years. CACS > 0 (hazard ratio [HR] 2.38, 95% confidence interval [CI] 1.02-5.54) and higher BDS (HR 16.00, 95% CI 5.88-43.49) were significantly associated with the development of MACEs. The proportion of patients who experienced MACEs was significantly higher in the CACS > 0 and high BDS group than in the CACS = 0 and low BDS group (3% vs. 75%, p < 0.001). CACS, as well as BDS, could serve as potential prognostic indicators in patients with NIHFpEF.

Improving Quality of Clinical Diagnosis Report with Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging and Coronary Computed Tomography Angiography.

Non-invasive cardiac imaging modalities including single-photon emission computed tomography myocardial perfusion image (SPECT-MPI) and coronary computed tomography angiography (CTA) have been widely used for diagnosis of coronary artery disease (CAD). The American Society of Nuclear Cardiology and Society of Cardiovascular Computed Tomography have recently published the guidelines for the instrumentation, acquisition, processing, interpretation, as well as reporting of SPECT and coronary CTA. These guidelines have highlighted and well documented how the imaging reporting influences medical practice for physician and treatment care for patients, suggesting that cardiac imaging reports for interpretation for patient management. This review article here summarizes improving quality of cardiac imaging reports by SPECT-MPI and coronary CTA.

Prognostic value of 99mTc-ECD brain perfusion SPECT in patients with atrial fibrillation and dementia.

BACKGROUND: Patients with atrial fibrillation (AF) and dementia experience reduced quality of life and increased mortality. Technetium 99m ECD brain perfusion single-photon emission computed tomography (99mTc-ECD brain perfusion SPECT) is a beneficial modality for diagnosing dementia and identifying high-risk patients with mild cognitive impairment. The aim of this study was to evaluate the prognostic value of brain perfusion using 99mTc-ECD SPECT in patients with AF and dementia. METHODS: Of a total of 405 consecutive patients diagnosed with AF as cardiac outpatients with dementia using the Mini-Mental State Examination by neurologists or psychiatrists, we identified 170 patients (81 ± 10 years) who underwent 99mTc-ECD brain perfusion SPECT. Of them, 73, 73, and 24 were diagnosed with Alzheimer's dementia (AD), vascular dementia (VD), and non-specified dementia, respectively. A multivariable Cox model was used to assess if higher Z-score by 99mTc-ECD brain perfusion SPECT and clinical parameters were associated with major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, hospitalization for heart failure, and stroke. RESULTS: During a mean follow-up of 1258 ± 1044 days, 62 MACE occurred. There was no significant difference in MACE between AD and VD (33%, vs. 44%, p = 0.153). The multivariable Cox model confirmed that the higher Z-score of temporo-parieto-occipital lobe was associated with increased MACE compared to the lower group (HR 2.521, 95% CI 1.465-4.337, p < 0.001). CONCLUSION: This study demonstrated that decreased cerebral blood flow in the temporo-parieto-occipital lobe could be a potential prognostic value in patients with both AF and dementia.

The relationship between coronary artery calcium density and optical coherence tomography-derived plaque characteristics.

BACKGROUND AND AIMS: Although coronary artery calcium (CAC) density has been associated with plaque stability, pathological evidence is lacking. We investigated the relationship between coronary computed tomography (CCT)-derived CAC density and multiple calcified and high-risk plaque (HRP) characteristics using optical coherence tomography (OCT). METHODS: We analyzed 83 plaques from 33 stable angina patients who underwent both CCT and OCT. CAC density was measured at calcium plaques with ≥90 Hounsfield units (HU) and ≥130 HU using custom CT software. The correlation between median CAC density and OCT-derived calcium size (thickness and area) was assessed. To investigate whether median CAC densities measured at the 90 HU threshold were associated with plaque vulnerability, OCT-derived plaque characteristics and HRP characteristics were compared between the low (90-129 HU), intermediate (130-199 HU) and high (≥200 HU) CAC HU groups. RESULTS: Median CAC densities at 130 HU were moderately associated with calcium thickness (R = 0.573, p < 0.001) and area (R = 0.560, p < 0.001). Similar results were observed at 90 HU (thickness, R = 0.615, p < 0.001; area, R = 0.612, p < 0.001). Among groups with low, intermediate and high HU levels, calcium thickness (0.42 ± 0.14 mm, 0.60 ± 0.17 mm and 0.77 ± 0.19 mm, respectively; p < 0.001) and area (0.55 ± 0.29 mm2, 1.20 ± 0.58 mm2 and 1.78 ± 0.87 mm2, respectively; p < 0.001) were significantly greater in the high HU group. HRP characteristics, however, did not differ among the three groups. CONCLUSIONS: OCT-derived calcium size, but not HRP characteristics, were associated with CAC density, suggesting that CAC density is driven mainly by calcified plaque size but not local plaque vulnerability.

Feasibility of myocardial flow reserve prediction without the use of dynamic data from myocardial perfusion positron emission tomography.

Quantification of myocardial flow reserve (MFR) provides diagnostic value for detection of cardiovascular artery disease. However, the common calculation method for MFR requires dynamic acquisition and specific software. The study aimed to predict coronary artery disease by simpler calculation of myocardial count without the use of dynamic data from 13N-ammonia myocardial perfusion positron emission tomography (MP-PET). This study included 40 consecutive patients suspected of ischemic heart disease and 7 healthy controls (34 men and 13 women, 66 ± 12 years). All participants underwent adenosine stress and rest 13N-ammonia MP-PET. From the dynamic images, the MFR in the entire left ventricular myocardium (ELV) and the three-vessel area was calculated by dividing stress myocardial blood flow (MBF) by rest MBF. From the static images, the myocardium-to-background ratio (MBR) was calculated by dividing each area's counts/pixel by background counts in the upper thoracic aorta/pixel in both stress and rest images. The MBR-increasing rate (MBR-IR) was calculated by dividing stress MBR by rest MBR. The relationship between MFR and MBR-IR in each area was examined. The cutoff diagnostic value of MBR-IR corresponding to that of MFR for detection of cardiovascular artery disease was calculated. Each MBR-IR was closely correlated with each MFR (r = 0.830 in ELV, r = 0.864 in LAD, r = 0.829 in LCX, r = 0.757 in RCA). The cutoff values of MBR-IR were 1.45 in ELV, 1.46 in LAD, 1.41 in LCX, and 1.45 in RCA, respectively. This study demonstrated that quantification of MBR-IR may provide diagnostic value for detection of coronary artery disease as well as MFR.

Prognostic Value of 123I-BMIPP SPECT in Patients with Nonischemic Heart Failure with Preserved Ejection Fraction.

Imaging of myocardial fatty acid metabolism using 123I-betamethyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) SPECT is useful for identifying high-risk patients with known ischemic heart disease. However, its utility for patients who have nonischemic heart failure with preserved ejection fraction is not well known. This study aimed to evaluate the prognostic value of the 123I-BMIPP defect score in such patients. Methods: Of 804 consecutive patients who were admitted to the hospital because of acute heart failure and underwent 123I-BMIPP SPECT, we identified 133 (mean age ± SD, 73 ± 13 y) who had normal coronary arteries by invasive coronary angiography and preserved left ventricular ejection fraction (≥50%) by echocardiography. 123I-BMIPP defects were quantitatively scored to obtain summed defect scores in 17 segments of 123I-BMIPP SPECT images. The patients were divided into 2 groups based on their score. The multivariate Cox model was used to assess a possible correlation between a higher score (≥4, n = 46) and major adverse cardiac events, including cardiac death, cardiovascular events, and hospitalization for heart failure, compared with a lower score (<4, n = 87). Results: During a mean follow-up of 2.5 y, 35 major adverse cardiac events occurred. The median scores in the high-score and low-score groups were 7.13 ± 4.21 and 1.29 ± 0.80, respectively. By multivariate Cox analysis, a higher score was associated with increased major adverse cardiac events, compared with a lower score (hazard ratio, 11.04; 95% confidence interval, 4.93-24.74; P < 0.001). Conclusion: This study demonstrated that the defect score by 123I-BMIPP SPECT may have potential prognostic value in patients who have nonischemic heart failure with preserved ejection fraction.

Long-term use of ipragliflozin improved cardiac sympathetic nerve activity in a patient with heart failure: A case report.

Ipragliflozin is the first SGLT2 inhibitor approved in Japan. Reported here is a case where long-term administration of ipragliflozin decreased the rate of re-hospitalization due to heart failure (HF). An 83-year-old man with chronic HF and diabetes mellitus (DM) was hospitalized four times in the last five years. He was discharged six months after his last hospitalization, but he continued to have class III HF according to the New York Heart Association classification (NYHA), and his DM was also not properly managed. Therefore, he received ipragliflozin. One year after initiation of ipragliflozin, he lost weight (body weight (BW): 79.0 to 76.2 kg), his levels of brain natriuretic peptide (BNP) decreased (191.4 to 122.5 mg/dL), and the class of his HF improved (class III to class II). The management of DM also improved (fasting blood glucose: 100 to 110 mg/dL; hemoglobin A1C: 6.8 to 6.6%). In addition, cardiac sympathetic nerve function evaluated with 123I-metaiodobenzylguanidine cardiac-scintigraphy (123I-MIBG) also improved (the average of the heart-to-mediastinum ratio in early and delayed phases; 1.44 to 2.17 in the early phase, 1.41 to 1.92 in the delayed phase, washout rate; 43.3 to 35.6). The patient was not re-hospitalized due to HF two years after administration of ipragliflozin started. A reduction in cardiac sympathetic nerve hyperactivity by an SGLT2 inhibitor might be one of the mechanisms of its cardio-protective effect, but clinical studies need to be conducted to verify this finding.

Prognostic value of lower limb perfusion single-photon emission computed tomography-computed tomography in patients with lower limb atherosclerotic peripheral artery disease.

PURPOSE: The purpose of this study was to estimate the severity of the participants' lower limb ischemia by calculating the lower limb muscle-to-background ratio (LMBR) using lower limb perfusion single-photon emission computed tomography-computed tomography (SPECT/CT) and to evaluate the prognostic value of LMBR in peripheral artery disease (PAD) patients. MATERIALS AND METHODS: This retrospective study consists of 38 patients with PAD (70 ± 12 years) and observed over 1 year who were included in the analysis. All participants underwent lower limb perfusion SPECT/CT. LMBR was calculated by dividing counts/volume in lower limb muscle by mean counts/volume of background. All patients were divided into two groups based on their LMBR value and observed for the occurrence of a major adverse event (MAE). RESULTS: The high and low LMBR groups consisted of 26 and 12 patients, respectively. The median LMBR in the high group was 9.59 (6.11-11.87) while that in the low group was 4.35 (3.85-4.99). A significantly higher number of patients in the low LMBR group experienced MAE than in the high LMBR group (7 of 12 vs. 1 of 26, p < 0.001). CONCLUSION: This study demonstrated that the LMBR derived from lower limb perfusion SPECT/CT may have a high prognostic value in patients with PAD.

Three-dimensional Cardiac MR Imaging: Related Techniques and Clinical Applications.

Three-dimensional (3D) cardiac magnetic resonance (MR) imaging has several advantages, including the easy coverage of the entire heart without misregistration, reduction of breath-holding times, and availability for postprocessing reconstruction. These advantages are associated with some techniques such as breath-hold or navigator gating and parallel imaging. However, the image quality of 3D cardiac MR images is compromised by the use of a shorter repetition time and parallel imaging. Thus, a steady-state free precession sequence, contrast agent administration, and presaturation pulses are used to maintain the image quality. In this review, we introduce the MR imaging techniques used in 3D cardiac MR imaging and demonstrate the typical 3D cardiac MR images, followed by discussion about their advantages and disadvantages.