Extracellular Volume Fraction by Computed Tomography Predicts Prognosis After Transcatheter Aortic Valve Replacement.

BACKGROUND: Extracellular volume fraction (ECV) on magnetic resonance imaging can predict prognosis after aortic valve replacement in patients with aortic stenosis (AS). However, the usefulness of ECV on computed tomography (CT) for patients who have undergone transcatheter aortic valve replacement (TAVR) is unclear, so we investigated whether ECV analysis on CT is associated with clinical outcomes in TAVR candidates.Methods and Results: We analyzed 127 patients with severe AS who underwent preoperative CT for TAVR. We evaluated the utility of ECV analysis on single-energy CT for predicting patient prognosis after TAVR. The primary outcome was a composite of all-cause death and hospitalization due to heart failure (HF) after TAVR. 15 patients (12%) had composite outcomes: 4 deaths and 11 hospitalizations due to HF. In multivariate survival analysis using the Cox proportional hazard model, atrial fibrillation (AF) (hazard ratio (HR), 7.86; 95% confidence interval (CI), 2.57-24.03; P<0.001), history of congestive HF (HR, 4.91; 95% CI, 1.49-16.2; P=0.009) and ECV ≥32.6% on CT (HR, 6.96; 95% CI, 1.92-25.12; P=0.003) were independent predictors of composite outcomes. On Kaplan-Meier analysis, the higher ECV group (≥32.6%) had a significantly greater number of composite outcomes than the lower ECV group (P<0.001). CONCLUSIONS: ECV on CT is an independent predictor of prognosis after TAVR.

Computed tomography angiography assessment of Adamkiewicz artery with sublingual nitroglycerin administration.

PURPOSE: Identification of the Adamkiewicz artery before aortic surgery is important for preventing postoperative complications due to spinal cord ischemia. The Adamkiewicz artery is difficult to identify due to its small diameter. Nitroglycerin has a vasodilatory effect and is used clinically to improve visualization of blood vessels on coronary computed tomography (CT) angiography. We investigated whether the vasodilatory effect of nitroglycerin could improve the ability to visualize the Adamkiewicz artery. METHODS: We extracted 33 cases wherein contrast-enhanced CT images were taken before and after aortic aneurysm surgery. Nitroglycerin was administered for coronary artery evaluation on the preoperative CT. However, no nitroglycerin was administered before the postoperative CT. Aortic contrast-to-noise ratio, CT value, image noise, and diameter of the Adamkiewicz artery and anterior spinal artery were measured. The depiction of the Adamkiewicz artery was graded into four grades and evaluated. These measurements were performed by two independent reviewers. RESULTS: In nitroglycerin-administered cases, the contrast-to-noise ratio and CT values were significantly higher (P < 0.001, P < 0.001, respectively); the Adamkiewicz artery and anterior spinal artery diameters were dilated (P = 0.005, P = 0.001, respectively). The Adamkiewicz artery score also improved significantly (P < 0.001). No significant difference was found in image noise. CONCLUSION: Nitroglycerin contributed to improving the Adamkiewicz artery's visualization.

Cardiac Magnetic Resonance Feature Tracking Analysis for Change in Right Ventricular Function After Cardioplegic Arrest.

BACKGROUND: Using echocardiography to assess right ventricular (RV) function after cardioplegic arrest is challenging. Cardiac magnetic resonance (CMR) imaging is a superior alternative, with the feature tracking technique enabling quantitative assessment of myocardial deformation. METHODS: This single-center, prospective study from 2020 to 2022 assessed RV function in 42 patients who underwent open heart surgery with cardioplegic arrest. CMR data were collected preoperatively, one week postoperatively, and at follow-up (6-12 months after surgery), and assessed using the CMR feature tracking technique. RESULTS: Postoperatively, there was no significant change in RV end-diastolic volume, but RV end-systolic volume significantly decreased, leading to a notable increase in RV ejection fraction. By follow-up, both RV end-diastolic and end-systolic volumes had significantly reduced compared with the preoperative values. Right ventricular longitudinal contractility decreased after surgery but recovered to the preoperative values by follow-up, while RV circumferential contractility improved postoperatively and remained superior to the preoperative levels at follow-up. CONCLUSION: On CMR imaging, significant changes in RV systolic motion were observed after cardioplegic arrest, with decreased longitudinal but increased circumferential contractility. At follow up, these changes had reverted to the preoperative patterns by the mid-term (6-12 months).

Evaluation of extracellular volume by computed tomography is useful for prediction of prognosis in dilated cardiomyopathy.

Cardiac computed tomography (CT) is useful for the screening of coronary artery stenosis, and extracellular volume fraction (ECV) analysis by CT using new dedicated software is now available. Here, we evaluated the utility of ECV analysis using cardiac CT to predict patient prognosis in cases with dilated cardiomyopathy (DCM). We analyzed 70 cases with DCM and cardiac computed tomography (CT) with available late-phase images. We evaluated the ECV of the left ventricular myocardium (LVM) using commercially available software (Ziostation 2, Ziosoft Inc, Japan). ECV on LVM was 33.96 ± 5.04%. Major adverse cardiac events (MACE) occurred in 21 cases (30%). ECV of the LVM on CT, endo-systolic volume, and rate of significant valvular disease were significantly higher in cases with MACE than in those without (37.16 ± 5.91% vs. 32.59 ± 3.95%, 194 ± 109 vs. 138 ± 78 ml and 57% vs. 20%, all P values < 0.05). LVEF was significantly lower in cases with MACE than in those without (23 ± 8 vs. 31 ± 11%, P = 0.0024). The best cut-off value of ECV on LVM for prediction of MACE was 32.26% based on receiver operating characteristics analysis. Cases with ECV ≥ 32.26% had significantly higher MACE based on Kaplan-Meier analysis (P = 0.0032). Only ECV on LVM was an independent predictor of MACE based on a multivariate Cox proportional hazards model (P = 0.0354). Evaluation of ECV on LVM by CT is useful for predicting MACE in patients with DCM.

A new composite indicator consisting of left ventricular extracellular volume, N-terminal fragment of B-type natriuretic peptide, and left ventricular end-diastolic volume is useful for predicting reverse remodeling after catheter ablation for atrial fibrillation.

Recently, myocardial extracellular volume (ECV) analysis has been measurable on computed tomography (CT) using new software. We evaluated the use of cardiac CT to estimate the myocardial ECV of left ventricular (LV) myocardium (LVM) to predict reverse remodeling (RR) in cases of atrial fibrillation (AF) after catheter ablation (CA). Four hundred and seven patients underwent CA for AF in our institution from April 2014 to Feb 2021. Of these, 33 patients (8%) with an LVEF ≤ 50% and who had undergone CT were included in our study. We estimated the LVM ECV using commercial software to analyze the CT data. RR was defined as an improvement in LVEF to > 50% after CA. LVEF increased to > 50% in 24 patients (73%) after CA. In all 24 patients, LVM ECV, LV end-diastolic and end-systolic volumes (LVEDV and LVESV), and the n-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) were significantly lower than in the other nine patients (P = 0.0037, 0.0273, 0.0443, and < 0.0001). On receiver operating characteristic curve analysis, the best cut-off of ECV, LVEDV, LVESV and NT-proBNP for the prediction of RR were 37.73%, 120 mL, 82 mL, and 1267 pg/mL, respectively. We newly defined the ENL (ECV, NT-proBNP, and LVEDV) score as the summed score for the presence or absence (1 or 0; maximum score = 3) of ECV, NT-proBNP, and LVEDV values less than or equal to each best cut-off value, and found that this score gave the highest area under the curve for the prediction of RR (0.9583, P < 0.0001). The ENL score may be useful for predicting RR in patients with AF undergoing CA.

Deep learning-based coronary computed tomography analysis to predict functionally significant coronary artery stenosis.

Fractional flow reserve derived from coronary CT (FFR-CT) is a noninvasive physiological technique that has shown a good correlation with invasive FFR. However, the use of FFR-CT is restricted by strict application standards, and the diagnostic accuracy of FFR-CT analysis may potentially be decreased by severely calcified coronary arteries because of blooming and beam hardening artifacts. The aim of this study was to evaluate the utility of deep learning (DL)-based coronary computed tomography (CT) data analysis in predicting invasive fractional flow reserve (FFR), especially in cases with severely calcified coronary arteries. We analyzed 184 consecutive cases (241 coronary arteries) which underwent coronary CT and invasive coronary angiography, including invasive FFR, within a three-month period. Mean coronary artery calcium scores were 963 ± 1226. We evaluated and compared the vessel-based diagnostic accuracy of our proposed DL model and a visual assessment to evaluate functionally significant coronary artery stenosis (invasive FFR < 0.80). A deep neural network was trained with consecutive short axial images of coronary arteries on coronary CT. Ninety-one coronary arteries of 89 cases (48%) had FFR-positive functionally significant stenosis. On receiver operating characteristics (ROC) analysis to predict FFR-positive stenosis using the trained DL model, average area under the curve (AUC) of the ROC curve was 0.756, which was superior to the AUC of visual assessment of significant (≥ 70%) coronary artery stenosis on CT (0.574, P = 0.011). The sensitivity, specificity, positive and negative predictive value (PPV and NPV), and accuracy of the DL model and visual assessment for detecting FFR-positive stenosis were 82 and 36%, 68 and 78%, 59 and 48%, 87 and 69%, and 73 and 63%, respectively. Sensitivity and NPV for the prediction of FFR-positive stenosis were significantly higher with our DL model than visual assessment (P = 0.0004, and P = 0.024). DL-based coronary CT data analysis has a higher diagnostic accuracy for functionally significant coronary artery stenosis than visual assessment.

Vasospastic angina and overlapping cardiac disorders in patients resuscitated from cardiac arrest.

BACKGROUND: Vasospastic angina (VSA) reportedly accounts for one form of sudden cardiac arrest (SCA). Intracoronary acetylcholine (ACh) testing is useful for diagnosing VSA although invasive provocation testing after SCA is a clinical challenge. In addition, even if the ACh test is positive, any causal relationship between VSA and SCA is often unclear because patients with VSA may have other underlying cardiac disorders. METHODS: A total of 20 patients without overt structural heart disease who had been fully resuscitated from SCA were included. All patients underwent the ACh provocation test and scrutiny such as cardiac computed tomography or magnetic resonance imaging. Patients were followed up for all-cause death or recurrent SCA including appropriate implantable cardioverter defibrillator therapy. RESULTS: An ACh provocation test was performed 20 ± 17 days after cardiac arrest. Fifteen out of 20 (75.0%) patients had a positive ACh test and 2 (10.0%) had adverse events such as ventricular tachycardia and transient cardiogenic shock during the test. In patients with a positive ACh test, 6 of 15 (40.0%) patients had other overlapping cardiac disorders such as long QT syndrome, Brugada syndrome, cardiac sarcoidosis, myocarditis, or cardiomyopathy. Long-term prognosis was not different regardless of a positive ACh test or the presence of other cardiac disorders overlapping with VSA. CONCLUSIONS: Three-quarters of the patients who had been resuscitated from SCA had a positive ACh test. Further examinations revealed other overlapping cardiac disorders in addition to VSA in 40% of patients with a positive ACh test.

Sexually anomalous individuals of the black fly Simulium trangense (Diptera: Simuliidae) infected with mermithid parasites (Nematoda: Mermithidae).

Sexually anomalous individuals, typically intersexes or gynandromorphs, bear a mixture of male and female traits. Twelve sexually anomalous individuals of the black fly Simulium (Gomphostilbia) trangense Jitklang, Kuvangkadilok, Baimai, Takaoka & Adler were discovered among 49 adults reared from pupae. All 12 sexually anomalous adults were parasitized by mermithid nematodes, although five additional parasitized adults had no overt external anomalies. Sequence analysis of the 18S rRNA gene revealed that the mermithids, possibly representing a new species, are related to Mesomermis spp., with genetic distances of 5.09-6.87%. All 12 anomalous individuals had female phenotypical traits on the head, thorax, forelegs, midlegs, and claws, but male features on the left and right hind basitarsi. One individual had mixed male and female genitalia. The findings are in accord with the trend that mermithid infections are associated with sexually anomalous adult black flies.

Characterization of IgE-binding proteins in the salivary glands of Simulium nigrogilvum (Diptera: Simuliidae).

Simulium dermatitis is an IgE-mediated skin reaction in animals and humans caused by the bites of black flies. Although Simulium nigrogilvum has been incriminated as the main human-biting black fly species in Thailand, information on its salivary allergens is lacking. Salivary gland extract of S. nigrogilvum females was subjected to sodium dodecylsulfate-polyacrylamide gel electrophoresis, and the separated components were applied onto nitrocellulose membranes for immunoblotting, which was performed by probing the protein blots with sera from 17 individuals who were allergic to the bites of S. nigrogilvum. IgE-reactive protein bands were characterized further by liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Nine protein bands (79, 42, 32, 25, 24, 22, 15, 13, and 11 kDa) were recognized in the serum of the subjects. Four of the nine protein bands (32, 24, 15, and 11 kDa) showed IgE reactivity in all (100%) of the tested sera, and they were identified as salivary secreted antigen 5-related protein, salivary serine protease, erythema protein, and hypothetical secreted protein, respectively. Three other proteins, salivary serine protease (25 kDa), salivary D7 secreted protein (22 kDa), and hypothetical protein (13 kDa), reacted with > 50% of the sera. The relevance of the identified protein bands as allergens needs to be confirmed by using pure recombinant proteins, either in the in vivo skin prick test or in vitro detection of the specific IgE in the serum samples of allergic subjects. This will be useful for the rational design of component-resolved diagnosis and allergen immunotherapy for the allergy mediated by the bites of black flies.

2D speckle-tracking TTE-based quantitative classification of left ventricular myocardium in patients with hypertrophic cardiomyopathy by the presence or the absence of fibrosis and/or hypertrophy.

We used peak longitudinal strain (PLS) on TTE in HCM patients to differentiate LV myocardium (LVM) into the following 4 groups: group 1-no fibrosis or hypertrophy (≥ 13 mm), group 2-no fibrosis but hypertrophy evident, group 3-fibrosis present but without hypertrophy, and group 4-both fibrosis and hypertrophy. Seventeen HCM patients (13 males, 56 ± 16 years) underwent both 1.5 T CMR and TTE. On TTE, PLS (absolute values) for each LVM segment from 17 AHA-defined lesions was calculated. Of 289 LVM lesions, the numbers in each group, 1-4, were 156, 53, 39, and 41, respectively. PLS for LVM segments in group 1 (13.6 ± 6.4%) were significantly greater than those in group 2 (8.5 ± 4.9%, P < 0.001), group 3 (10.4 ± 5.0%, P = 0.006), and group 4 (7.1 ± 4.4%, P < 0.001). PLS for LVM segments in group 3 was significantly greater than those in group 4 (P = 0.016). However, significant differences in PLS in LVM between groups 2 and 3, and between 2 and 4 were not observed. Using regional PLS, we demonstrate successful differentiation of LVM in HCM patients for group 1 (LVM with zero fibrosis or hypertrophy) from LVM belonging to groups 2-4 and we also demonstrate successful differentiation of LVM with fibrosis present but without hypertrophy from LVM with both fibrosis and hypertrophy. However, it is not possible to differentiate between LVM with no fibrosis but hypertrophy evident and those with fibrosis present but without hypertrophy and also between LVM with no fibrosis but hypertrophy evident and those with both fibrosis and hypertrophy. Our findings have significant implications for the management of HCM patients.

A novel molecular and chromosomal lineage of the anthropophilic Simulium (Simulium) rufibasis subgroup (Diptera: Simuliidae) in Taiwan.

The Simulium rufibasis subgroup is one of three subgroups of the Simulium (Simulium) tuberosum species-group; it is characterized by a pair of clustered stout hairs on the ventral surface of female abdominal segment 7. A member of the S. rufibasis subgroup in Taiwan was investigated morphologically and genetically using the universal cytochrome c oxidase subunit I (COI) barcoding gene and polytene chromosomal banding pattern. The Taiwanese material is morphologically similar to S. rosliramlii Takaoka & Chen from Vietnam and represents the second species of the S. rufibasis subgroup known from Taiwan. It also represents a novel molecular lineage that is distinct from three other primary lineages identified as S. doipuiense, S. doipuiense/S. rufibasis, and S. weji previously reported from Thailand. The mitochondrial evidence for a distinct lineage in Taiwan is supported by chromosomal analysis, which revealed unique sex chromosomes. For nomenclatural stability, we associate the name S. arisanum Shiraki with the Taiwanese entity. Originally described from females from Taiwan, S. arisanum until now has remained an enigmatic species.

Endocardial Fibrotic Lesions Have a Greater Effect on Peak Longitudinal Strain than Epicardial Fibrotic Lesions in Hypertrophic Cardiomyopathy Patients.

Peak longitudinal strain (PLS) of the left ventricular (LV) myocardium by transthoracic echocardiogram (TTE) is useful to detect LV myocardial damage. We hypothesized that myocardial fibrosis (MF) in the LV myocardium may influence PLS. Eighteen hypertrophic cardiomyopathy (HCM) patients (14 males; 58 ± 17 years old) underwent 1.5 Tesla cardiac magnetic resonance (CMR) and TTE. Patients with previous myocardial infarction were excluded. We used TTE to assess whole-layer PLS in an American Heart Association-defined 17-segment LV model. Whole-layer PLS was calculated using Echo PAC, version 113 (GE Healthcare). MF was assessed by T1-weighted CMR of the LV endocardial layer, the LV epicardial layer, or both the LV endocardial and epicardial layers for each lesion. Of the 306 segments, MF was detected in the LV endocardial layer only (13 segments), in the LV epicardial layer only (9 segments), or in both LV endocardial and epicardial layers (59 segments). PLS values were significantly lower in segments with MF affecting only the LV endocardial layer (7% ± 4%) (P < 0.05) and where MF was observed in both the LV endocardial and epicardial layers (9% ± 5%) (P = 0.001) compared with segments without MF (13% ± 7%). No significant difference in PLS values was detected between the MF segments for the LV epicardial layer only (10% ± 6%) and those without MF (13% ± 7%) (P > 0.05). In HCM patients, fibrotic lesions in the LV endocardium have a greater adverse effect on PLS than those in the LV epicardium. Our results are significant for HCM patients with fibrotic lesions within the LV endocardium.

Improved Diagnosis of Detection of Late Enhancement in Left Ventricular Myocardium Using 2nd Generation 320-Slice CT Reconstructed with FIRST in Non-Ischemic Cardiomyopathy.

Forward Projected Model-based Iterative Reconstruction SoluTion (FIRST) is a new reconstruction technique using CT, which provides successful reconstruction of high-quality CT images, especially in low contrast imaging. To evaluate improvements in the diagnostic accuracy of the detection of abnormal late enhancement (LE) in left-ventricular myocardium (LVM) using 320-slice CT with FIRST, we compared this modality with previous CT methods in patients with non-ischemic cardiomyopathy or a cardiac tumor.This was a retrospective study of 88 patients (56 males; 57 ± 15 years) suspected of having non-ischemic myocardial disease or a cardiac tumor. The first 52 consecutive patients (Group 1) underwent 16-slice CT at 140 kV tube voltage and an average tube current of 337 ± 20 mA, and 1.5 T MRI. The next 18 patients (Group 2) underwent 1st generation 320-slice CT at 120 kV tube voltage and an average tube current of 255 ± 106 mA, and 1.5T MRI; the remaining 18 patients (Group 3) underwent 2nd generation 320-slice CT with FIRST, at 80 kV tube voltage and a tube current of 800 mA, and 1.5T or 3T MRI.On patient-based analysis, no significant differences were observed between the 3 groups. For segment-based analysis, the specificity and overall accuracy were significantly higher (both P < 0.05) in Group 3 than in Group 1. Positive predictive value (PPV) was significantly higher in Group 3 than in Groups 1 and 2.The diagnostic accuracy of LE on CT for detecting myocardial fibrosis determined by late gadolinium-enhanced MRI was improved with the use of 2nd generation 320-slice CT with FIRST, in particular regarding specificity, PPV, and overall accuracy.

Quantitative Differentiation of LV Myocardium with and without Layer-Specific Fibrosis Using MRI in Hypertrophic Cardiomyopathy and Layer-Specific Strain TTE Analysis.

To achieve further risk stratification in hypertrophic cardiomyopathy (HCM) patients, we localized and quantified layer-specific LVM fibrosis on MRI in HCM patients using regional layer-specific peak longitudinal strain (PLS) and peak circumferential strain (PCS) in LV myocardium (LVM) on speckle tracking transthoracic echocardiography (TTE). A total of 18 HCM patients (14 males; 58 ± 17 years) underwent 1.5T-MRI and TTE. PLS and PCS in each layer of the LVM (endocardium, epicardium, and whole-layer myocardium) were calculated for 17 AHA-defined lesions. MRI assessment showed that fibrosis was classified as endocardial, epicardial, or whole-layer (= either or both of these). Regional PLS was smaller in fibrotic endocardial lesions than in non-fibrotic endocardial lesions (P = 0.004). To detect LV endocardial lesions with fibrosis, ROC curves of regional PLS revealed an area under the curve (AUC) of 0.609 and a best cut-off point of 13.5%, with sensitivity of 65.3% and specificity of 54.3%. Regional PLS was also smaller in fibrotic epicardial lesions than in non-fibrotic epicardial lesions (P < 0.001). To detect LV epicardial lesions with fibrosis, ROC curves of PLS revealed an AUC of 0.684 and a best cut-off point of 9.5%, with sensitivity of 73.5% and specificity of 55.5%. Using whole-layer myocardium analysis, PLS was smaller in fibrotic lesions than in non-fibrotic lesions (P < 0.001). To detect whole-layer LV lesions with fibrosis, ROC curves of regional PLS revealed an AUC of 0.674 and a best cut-off point of 12.5%, with sensitivity of 79.0% and specificity of 50.7%. There were no significant differences in PCS of LV myocardium (endocardium, epicardium, and whole-layer) between fibrotic and non-fibrotic lesions. Quantitative regional PLS but not PCS in LV endocardium, epicardium, and whole-layer myocardium provides useful non-invasive information for layer-specific localization of fibrosis in HCM patients.

Scanning electron microscopy of antennal sensilla of the eight Anopheles species of the Hyrcanus Group (Diptera: Culicidae) in Thailand.

Antennal sensilla were first investigated in the eight medically and veterinary important Anopheles mosquito species (Anopheles argyropus, Anopheles crawfordi, Anopheles nigerrimus, Anopheles nitidus, Anopheles paraliae (= Anopheles lesteri), Anopheles peditaeniatus, Anopheles pursati, and Anopheles sinensis) of the Hyrcanus Group in Thailand, using scanning electron microscopy (SEM). Four types of sensilla, including sensilla chaetica (large and small), sensilla trichodea (sharp- and blunt-tipped), sensilla basiconica or grooved pegs (types I, II, and III), and sensilla coeloconica (large and small), were observed on the female antennae of the eight species. The greatest number of sensilla found along the flagellum of all the Anopheles species consisted of sensilla trichodea. Grooved pegs type II were not found on the antennae of An. peditaeniatus. Interestingly, clusters of 10-15 grooved pegs type III, with blunt-tipped and unevenly grooved-lengthwise sensilla, and a sunken group of 7-12 grooved pegs type III, with slightly curved and point-tipped sensilla, were found distally on flagellomeres 3-7 of An. argyropus and An. peditaeniatus, respectively. In addition, the key for species identification, based on fine structure and morphometrics of antennal sensilla among the eight species, was constructed and differentiated successfully. However, in order to focus intensively on the exact function of these sensilla, further electrophysiological study is needed in understanding their significant role in mosquito behavior, especially when these insects seek hosts for transmitting pathogens to humans.