Safety and Usefulness of Intracoronary Acetylcholine 200 µg Into the Left Coronary Artery as Vasoreactivity Testing: Comparisons With Intracoronary Acetylcholine Maximum 100 µg.

OBJECTIVES: We retrospectively analyzed the usefulness and safety of intracoronary acetylcholine (ACh) 200 µg into the left coronary artery (LCA) as vasoreactivity testing compared with intracoronary ACh 100 µg. METHODS: We recruited 1433 patients who had angina-like chest pain and intracoronary ACh testing in the LCA, including 1234 patients with a maximum ACh 100 µg and 199 patients with a maximum ACh 200 µg. ACh was injected in incremental doses of 20/50/100/200 µg into the LCA. Positive spasm was defined as ≥ 90% stenosis, usual chest pain, and ischemic electrocardiogram (ECG) changes. RESULTS: The incidence of coronary constriction ≥ 90%, usual chest pain, and ischemic ECG changes with a maximum ACh of 100 µg was markedly higher than that with a maximum ACh of 200 µg. The frequency of unusual chest pain in patients with a maximum ACh of 200 µg was higher than that in those with a maximum ACh of 100 µg (13% vs. 3%, p < 0.001). In patients with rest angina, positive spasm of maximum ACh 100 µg was significantly higher than that of maximum ACh 200 µg, whereas there was no difference regarding positive spasm in patients with atypical chest pain between the two ACh doses. Major complications (1.38% vs. 1.51%, p = 0.8565) and the occurrence of paroxysmal atrial fibrillation (1.81% vs. 2.63%, p = 0.6307) during ACh testing in the LCA were not different between the two maximum ACH doses. CONCLUSIONS: Intracoronary ACh 200 µg into the LCA is clinically useful and safe for vasoreactivity testing when intracoronary ACh 100 µg dose not provoke spasms.

Diagnosis of COVID-19: Is Fever the Best Indicator of COVID-19 in Vaccinated SARS-CoV-2-Positive Adults?

OBJECTIVES: Coronavirus disease 2019 (COVID-19) vaccination is highly recommended to prevent the onset and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Japan. However, the impact of COVID-19 vaccination on the manifestations or presenting symptoms of SARS-CoV-2 infection in daily clinical practice remains unclear. METHODS: This retrospective single-center study was conducted from April 2021 to July 2022 in Japan. We compared the clinical manifestations of SARS-CoV-2 infection in 636 COVID-19-positive patients who visited our outpatient fever clinic, both COVID-19-vaccinated and unvaccinated. RESULTS: During the study period, the COVID-19 vaccination rate at the time of infection was 77.2% (n=491/636), with a median of two doses. Most manifestations, including fever, were reduced in the vaccinated group (n=196) compared to the non-vaccinated group (n=142). The temperature at the clinic decreased significantly as the number of vaccinations increased. Fever was the most common manifestation in the non-vaccinated group (76%, n=108/142), while only 30% (n=59/196) of those who received three or more COVID-19 vaccinations experienced fever. However, sore throat and cough were observed more frequently in the vaccinated group compared to the non-vaccinated group. CONCLUSION: Fever may not be a reliable indicator of SARS-CoV-2 infection in vaccinated individuals, as its frequency is significantly reduced by vaccination. However, since sore throat and cough are more frequently observed in vaccinated individuals, these symptoms could be useful for recommending COVID-19 testing even in the absence of fever, aiding in the prevention of infectious outbreaks.

Impact of Aromatase Inhibitors Treatment Duration on Coronary Artery Calcification in Postoperative Patients With Breast Cancer.

BACKGROUND: Aromatase inhibitors (AIs) are the standard therapeutic approach for hormone receptor-positive postmenopausal breast cancer. However, there are concerns about increased cardiovascular risk due to their antioestrogenic effects. This study aimed to investigate the potential association between duration of AI treatment and the severity of coronary artery calcification (CAC). METHODS: The study included outpatients who initiated adjuvant endocrine therapy with AIs for breast cancer from August 2010 to October 2022. CAC was quantified according to a visual ordinal scoring system. Patient characteristics were assessed based on the presence of CAC. Independent risk factors for elevated CAC scores were identified through a multivariable logistic regression model. RESULTS: Among 357 patients, 44.8% exhibited CAC. No significant difference in AI treatment duration was observed between groups (1268 d [interquartile range (IQR) 725-1743 d] vs 1104 d [IQR 685-1683.25 d]; P = 0.236). Patients with CAC were characterised by higher age (63.06 y [56.81-68.78 y] vs 74.39 y [68.98-80.03 y]; P < 0.001), lower hemoglobin levels (g/dL: 13.20L [IQR 12.60-13.70L] vs 12.60 [IQR 11.60-13.43]; P < 0.001), and reduced estimated glomerular filtration rate (mL/min/1.73 m2: 72.00 [IQR 61.80-81.50] vs 62.80 [IQR 51.27-71.90]; P < 0.001) compared with those without CAC. The prevalences of hypertension, diabetes mellitus, and dyslipidemia were significantly higher in patients with CAC. No correlation was found between the duration of AI treatment and CAC score (R = -0.02; P = 0.78). Independent risk factors for CAC included higher age, lower hemoglobin levels, and the presence of hypertension and diabetes mellitus in postoperative patients with breast cancer. CONCLUSIONS: The duration of AI treatment does not exert a significant influence on CAC in postoperative patients with breast cancer.

Lack of Class I Vasoreactivity Testing for Diagnosing Patients With Coronary Artery Spasm.

BACKGROUND: Vasoreactivity testing, such as intracoronary acetylcholine (ACh) or ergometrine (EM), is defined as Class I for the diagnosis of patients with vasospastic angina (VSA) according to recommendations from the Coronary Vasomotion Disorders International Study (COVADIS) group and guidelines from the Japanese Circulation Society (JCS). HYPOTHESIS: Although vasoreactivity testing is a clinically useful tool, it carries some risks and limitations in diagnosing coronary artery spasm. METHODS: Previous reports on vasoreactivity testing for diagnosing the presence of coronary spasm are summarized from the perspective of Class I. RESULTS: There are several problems such as reproducibility, underestimation, overestimation, and inconclusive/nonspecific results associated with daily spasm. Because provoked spasm caused by intracoronary ACh is not always similar to that caused by intracoronary EM, possibly due to different mediators, supplementary use of these vasoreactivity tests is necessary for cardiologists to diagnose VSA when a provoked spasm is not revealed by each vasoactive agent. CONCLUSIONS: Cardiologists should understand the imperfection of these vasoreactivity tests when diagnosing patients with VSA.

An Increase in the Ratio of Brain Natriuretic Peptide to Peak Transvalvular Pressure Gradient Suggests Coexistence of Cardiovascular Complications in Elderly Aortic Stenosis Patients.

The aim of this study was to differentiate between elderly aortic stenosis (AS) patients with and without cardiovascular complications (CCs).In total, 156 consecutive patients with AS aged ≥ 70 years were enrolled. Patients were divided into 2 groups as follows: AS without CCs (group I; n = 110) and AS with CCs (group II; n = 46). Routine electrocardiographic and echocardiographic parameters, peak and mean transvalvular pressure gradients (TPGs), aortic valve area (AVA), brain natriuretic peptide (BNP) levels, and BNP/peak TPG ratio were measured.The mean ages in groups I and II were 80.4 ± 5.5 and 82.5 ± 7.2 years. Left ventricular hypertrophy was greater in group II than in group I. Left ventricular end-diastolic and end-systolic dimensions and left ventricular fractional shortening were normal in both groups. Peak and mean TPGs were greater in group II (67.2 ± 39.3 and 40.2 ± 26.4 mmHg) than in group I (52.0 ± 23.0 and 30.2 ± 13.9, both P < 0.005); however, the AVA showed no significant difference between the 2 groups. The median BNP levels were 65.9 and 433.7 pg/mL in groups I and II (P < 0.0001). A correlation between peak TPG and BNP levels was observed in both groups. The BNP/peak TPG ratio was < 3.0 in all patients of group I and ≥ 3.0 in almost all patients of group II (P< 0.0001). The area under the curve using BNP/peak TPG ratio was 0.9883.BNP and BNP/peak TPG ratio could differentiate between AS with and without CCs in elderly patients.

Treatment Outcomes in Patients with Conjunctival Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma.

Purpose: To report the outcomes of different therapies in patients with conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma. Patients and Methods: This retrospective study included patients diagnosed with conjunctival MALT lymphoma between August 2000 and April 2022. Patients were classified into three groups according to their treatment: an observation group, a radiation therapy (RT) group, and a rituximab group (rituximab with or without chemotherapy). We analyzed overall survival (OS), overall, local, and systemic relapse-free survival (RFS), and adverse events after treatment. Results: This study included 15 patients (22 eyes). The 10-year OS was 100%. The 2-, 5-, and 10-year overall RFS rates were 80.1%, 41.2%, and 41.2% in all patients, respectively. The 2- and 5-year local RFS rates in the observation group were 100% and 0%, respectively. The 2-, 5-, and 10-year local RFS rates were 87%, 87%, and 87% in the RT group and 83%, 67%, and 67% in the rituximab group, respectively. The 2- and 5-year systemic RFS rates in the observation group were both 100%, and the 2-, 5-, and 10-year systemic RFS rates were 92%, 55%, and 55% in the RT group, and 100%, 60%, and 60% in the rituximab group, respectively. After RT, 53.3% of the eyes developed cataracts and 75% of these were treated with cataract surgery. In addition, 53.3% of the eyes developed dry eyes and were treated with eye drops. Rituximab with or without chemotherapy resulted in some systemic adverse events, but these improved following symptomatic therapies. Conclusion: RT resulted in good local control of conjunctival MALT lymphoma; however, systemic relapse may occur during long-term follow-up. Local and/or systemic relapse may also occur during long-term follow-up in patients treated by observation or rituximab with or without chemotherapy. Patients with conjunctival MALT lymphoma should be followed-up carefully for as long as possible after treatment.

Remote dielectric sensing predicts elevated left atrial pressure in patients with atrial fibrillation.

Background: There are currently no established non-invasive indices of echocardiography for elevated left atrial pressure (LAP) especially in patients with atrial fibrillation (AF). Remote dielectric sensing (ReDS) is a novel non-invasive electromagnetic energy-based technology that quantifies total lung fluid, enabling the monitoring of volume status in patients with heart failure. The utility of ReDS for estimating LAP in patients with AF remains unknown. Methods: We prospectively investigated patients with AF in whom LAP was directly measured during catheter ablation for AF, and ReDS measurements were conducted the day before ablation. Elevated LAP was defined as LAP ≥ 15 mmHg. Results: A total of 61 patients were included (median age 66 years, 38 % female). Among them, 26 patients had elevated LAP. There was a positive correlation between ReDS and LAP (r = 0.363, P = 0.004). Receiver operating characteristic curve analysis for the prediction of elevated LAP demonstrated that the best cut-off value of ReDS was 30 %, with a sensitivity of 65 %, specificity of 69 %, and an area under the curve of 0.703 (95 % confidence interval 0.568-0.837). Multivariate logistic regression analysis revealed that ReDS was an independent predictor of elevated LAP, among covariates including left ventricular ejection fraction, the ratio of early transmitral flow velocity to septal mitral annular early diastolic velocity, and left atrial volume index. Conclusions: Our results suggest ReDS could be a valuable marker of elevated LAP even in patients with AF. Further studies are needed to elucidate the effectiveness of a ReDS-guided decongestive strategy in patients with heart failure.

NSUN5 is essential for proper cell proliferation and differentiation of mouse preimplantation embryos.

In brief: Proper early embryonic development in mammals relies on precise cellular signaling pathways. This study reveals that NSUN5 is crucial for the regulation of the Hippo pathway, ensuring normal proliferation and differentiation in mouse preimplantation embryos. Abstract: NOL1/NOP2/Sun domain family, member 5 (NSUN5) is an enzyme belonging to the 5-methylcytosine (m5C) writer family that modifies rRNA and mRNA. Our data revealed an upregulation of Nsun5 at the two-cell stage of mouse preimplantation development, suggesting its significance in early embryonic development. Given m5C's important role in stabilizing rRNA and mRNA and the Hippo signaling pathway's critical function in lineage segregation during embryogenesis, we hypothesized that NSUN5 controls cell differentiation by regulating the expression of components of the Hippo signaling pathway in mouse early embryos. To examine this hypothesis, we employed Nsun5-specific small interfering RNAs for targeted gene silencing in mouse preimplantation embryos. Nsun5 knockdown resulted in significant developmental impairments including reduced blastocyst formation, smaller size of blastocysts, and impaired hatching from the zona pellucida. Nsun5 knockdown also led to decreased cell numbers and increased apoptosis in embryos. We also observed diminished nuclear translocation of yes-associated protein 1 (YAP1) in Nsun5 knockdown embryos at the morula stage, indicating disrupted cell differentiation. This disruption was further evidenced by an altered ratio of CDX2-positive to OCT4-positive cells. Furthermore, Nsun5 depletion was found to upregulate the Hippo signaling-related key genes, Lats1 and Lats2 at the morula stage. Our findings underscore the essential role of Nsun5 in early embryonic development by affecting cell proliferation, YAP1 nuclear translocation, and the Hippo pathway.

Incremental value of tricuspid annular enlargement to progressive tricuspid regurgitation in patients with longstanding persistent atrial fibrillation.

Tricuspid annular enlargement in patients with atrial fibrillation (AF) can induce tricuspid regurgitation (TR). However, risk factors associated with TR progression in patients with AF have not been defined. This study aimed to clarify an association between tricuspid annular diameter (TAD) and TR progression in patients with longstanding persistent AF. We retrospectively analyzed data from 228 patients who had longstanding persistent AF for > 1 year and mild or less TR on baseline echocardiograms. We defined significant TR as moderate or greater TR, graded according to the jet area and vena contracta. The optimal cut-off value of the TAD index (TADI), based on body surface area for predicting progression to significant TR, was estimated using receiver operating characteristic (ROC) curves. The independence and incremental value of the TADI were evaluated using multivariate Cox proportional hazard regression analysis and likelihood ratio tests. Over a median follow-up of 3.7 years, 55 (24.1%) patients developed significant TR. The optimal cut-off value of 21.1 mm/m2 for the TADI at baseline and ROC curves predicted TR progression with 70.4% sensitivity and 86% specificity. Furthermore, TADI was an independent predictor of TR progression (hazard ratio, 1.32; 95% confidence interval, 1.17-1.49, P < 0.001) and had a significant incremental value that exceeded that of models constructed using clinical parameters. In conclusion, TADI was significantly associated with TR progression and was an independent predictor of TR progression in longstanding persistent AF.

Analysis of histone H3K4me3 modifications in bovine placenta derived from different calf-production methods.

In ruminants, the overgrowth of offspring produced by in vitro fertilization (IVF) is a common problem. Abnormal epigenetic modifications caused by environmental factors during the early embryonic period are suspected as an aetiology of overgrowth. In this study, we investigated the genome-wide histone H3K4me3 profiles of bovine placentae that play a pivotal role in foetal development and compared their characteristics between artificial insemination (AI)- and IVF-derived samples. Cotyledons were harvested from the placentae obtained at parturition of 5 AI- and 13 IVF-derived calves, and chromatin immunoprecipitation sequencing was performed for H3K4me3. We confirmed no significant maternal tissue contamination in the samples we used. The revealed H3K4me3 profiles reflected the general characteristics of the H3K4me3 modification, which is abundantly distributed in the promoter region of active genes. By extracting common modifications from multiple samples, the genes involved in placenta-specific biological processes could be enriched. Comparison with the H3K4me3 modifications of blastocyst samples was also effective for enriching the placenta-specific features. Principal component analysis suggested the presence of differential H3K4me3 modifications in AI- and IVF-derived samples. The genes contributing to the difference were related to the developmental biological processes. Imprinted genes such as BEGAIN, ZNF215 and DLX5 were among the extracted genes. Principal component and discriminant analyses using only male samples categorized the samples into three groups based on foetal weight and calf-production methods. To our knowledge, this is the first study to profile the genome-wide histone modifications of bovine foetal placentae and reveal their differential characteristics between different calf-production methods.

Evaluating histone modification analysis of individual preimplantation embryos.

BACKGROUND: We previously reported a modification of the CUT&Tag method (NTU-CAT) that allows genome-wide histone modification analysis in individual preimplantation embryos. In the present study, NTU-CAT was further simplified by taking advantage of the Well-of-the-Well (WOW) system, which enables the processing of multiple embryos in a shorter time with less reagent and cell loss during the procedure (WOW-CUT&Tag, WOW-CAT). RESULTS: WOW-CAT allowed histone modification profiling from not only a single blastocyst but also from a portion of it. WOW-CAT generated similar H3K4me3 profiles as NTU-CAT, but they were closer to the profiles produced by chromatin immunoprecipitation-sequencing, such as a valley-like trend and relatively lower false positive rates, indicating that WOW-CAT may attenuate the bias of Tn5 transposase to cut open chromatin regions. Simultaneous WOW-CAT of two halves of single blastocysts was conducted to analyze two different histone modifications (H3K4me3 and H3K27ac) within the same embryo. Furthermore, trophectoderm cells were biopsied and subjected to WOW-CAT in anticipation of preimplantation diagnosis of histone modifications. WOW-CAT allowed the monitoring of epigenetic modifications in the main body of the embryo. For example, analysis of H3K4me3 modifications of XIST and DDX3Y in trophectoderm biopsies could be used to sex embryos in combination with quantitative PCR, but without the need for deep sequencing. CONCLUSIONS: These results suggest the applicability of WOW-CAT for flexible epigenetic analysis of individual embryos in preimplantation epigenetic diagnosis.

Chimeric PRMT6 protein produced by an endogenous retrovirus promoter regulates cell fate decision in mouse preimplantation embryos†.

Murine endogenous retrovirus with leucine tRNA primer, also known as MERVL, is expressed during zygotic genome activation in mammalian embryos. Here we show that protein arginine N-methyltransferase 6 (Prmt6) forms a chimeric transcript with MT2B2, one of the long terminal repeat sequences of murine endogenous retrovirus with leucine tRNA primer, and is translated into an elongated chimeric protein (PRMT6MT2B2) whose function differs from that of the canonical PRMT6 protein (PRMT6CAN) in mouse preimplantation embryos. Overexpression of PRMT6CAN in fibroblast cells increased asymmetric dimethylation of the third arginine residue of both histone H2A (H2AR3me2a) and histone H4 (H4R3me2a), while overexpression of PRMT6MT2B2 increased only H2AR3me2a. In addition, overexpression of PRMT6MT2B2 in one blastomere of mouse two-cell embryos promoted cell proliferation and differentiation of the blastomere into epiblast cells at the blastocyst stage, while overexpression of PRMT6CAN repressed cell proliferation. This is the first report of the translation of a chimeric protein (PRMT6MT2B2) in mouse preimplantation embryos. Our results suggest that analyzing chimeric transcripts with murine endogenous retrovirus with leucine tRNA primer will provide insight into the relationship between zygotic genome activation and subsequent intra- and extra-cellular lineage determination.

Technetium-99m-pyrophosphate imaging-based computed tomography-guided core-needle biopsy of internal oblique muscle in wild-type transthyretin cardiac amyloidosis.

BACKGROUND: Technetium-99m-pyrophosphate (99mTc-PYP) uptake in the internal oblique muscle (IOM), which is often observed in patients with wild-type transthyretin cardiac amyloidosis (ATTR-CA), indicates amyloid transthyretin (ATTR) deposition. OBJECTIVE: This study aimed to assess the safety and efficacy of 99mTc-PYP imaging-based computed tomography (CT)-guided core-needle biopsy of the IOM as a new extracardiac screening biopsy for confirming the presence of ATTR deposits. METHODS: Patients with suspected ATTR-CA in whom myocardial tracer uptake was detected on chest- and abdomen-centered images of 99mTc-PYP scintigraphy underwent CT-guided core-needle biopsy at the site with the highest tracer uptake in the IOM between September 2021 and November 2022. RESULTS: All 18 consecutive patients (mean age, 86.3 years ± 6.5; 61.1% male) enrolled in the study showed 99mTc-PYP uptake into the IOM. Adequate tissue samples were obtained from all patients except one without serious complications. Immunohistochemical analysis confirmed ATTR deposits in 16/18 (88.9%) patients. In the remaining two patients, ATTR deposits were observed via endomyocardial biopsy. All patients were diagnosed with wild-type ATTR-CA based on transthyretin gene sequence testing results. CONCLUSION: In wild-type ATTR-CA, 99mTc-PYP imaging-based CT-guided core-needle biopsy of the IOM could be used as an extracardiac screening biopsy to confirm the presence of ATTR deposits.

What is the meaning of provoked spasm phenotypes by vasoreactivity testing?

Coronary artery epicardial spasm is involved in the pathogenesis of many cardiac disorders. Vasoreactivity testing, such as intracoronary injection of acetylcholine (ACH) or ergonovine (ER), is the gold standard method for the diagnosis of vasospastic angina. Provoked epicardial spasm phenotypes are classified as focal spasm and diffuse spasm. Multiple factors, including sex, ethnicity, and use of coronary vasoactive stimulators, are related to the provoked phenotypes of epicardial spasm. Diffuse-provoked spasm is often observed in females, where focal-provoked spasm is markedly more common in males. ACH provokes more diffuse and distal spasms, whereas ER induces more focal and proximal spasms. Yellow plaque and coronary thrombi are often observed in lesions with focal spasms, and intimal thickness with a sonolucent zone is significantly more common in lesions with focal spasm. Furthermore, clinical outcomes in patients with focal spasm are unsatisfactory compared with those in patients with diffuse spasm. However, the reproducibility and eternality of provoked spasm phenotypes by vasoreactivity testing is uncertain. Coronary atherosclerosis or endothelial damage may affect coronary vasomotor tone. Although coronary artery spasm may persist in the same coronary artery, provoked coronary spasm phenotypes may exhibit a momentary coronary reaction by intracoronary ACH or ER testing.

Feasibility of four-dimensional similarity filter for radiation dose reduction in dynamic myocardial computed tomography perfusion imaging.

Rationale and objectives: We aimed to evaluate the impact of four-dimensional noise reduction filtering using a four-dimensional similarity filter (4D-SF) on radiation dose reduction in dynamic myocardial computed tomography perfusion (CTP). Materials and methods: Forty-three patients who underwent dynamic myocardial CTP using 320-row computed tomography (CT) were included in the study. The original images were reconstructed using iterative reconstruction (IR). Three different CTP datasets with simulated noise, corresponding to 25%, 50%, and 75% reduction of the original dose (300 mA), were reconstructed using a combination of IR and 4D-SF. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed, and CT-derived myocardial blood flow (CT-MBF) was quantified. The results were compared between the original and simulated images with radiation dose reduction. Results: The median SNR (first quartile-third quartile) at the original, 25%-, 50%-, and 75%-dose reduced-simulated images with 4D-SF was 8.3 (6.5-10.2), 16.5 (11.9-21.7), 15.6 (11.0-20.1), and 12.8 (8.8-18.1) and that of CNR was 4.4 (3.2-5.8), 6.7 (4.6-10.3), 6.6 (4.3-10.1), and 5.5 (3.5-9.1), respectively. All the dose-reduced-simulated CTPs with 4D-SF had significantly higher image quality scores in SNR and CNR than the original ones (25%-, 50%-, and 75%-dose reduced vs. original images, p < 0.05, in each). The CT-MBF in 75%-dose reduced-simulated CTP was significantly lower than 25%-, 50%- dose-reduced-simulated, and original CTPs (vs. 75%-dose reduced-simulated images, p < 0.05, in each). Conclusion: 4D-SF has the potential to reduce the radiation dose associated with dynamic myocardial CTP imaging by half, without impairing the robustness of MBF quantification.

Acute Lymphocytic Myocarditis With Mobile Left Ventricular Thrombus.

A left ventricular thrombus (LVT) in cardiac disease is associated with various adverse events. To understand the risk of thromboembolism, it is necessary to recognize when LVT is most likely to occur. We present a case of acute lymphocytic myocarditis in a young patient, where the LVT manifestation occurred within 48 hours after the beginning of the disease and was treated by thrombectomy. We have not found any reports of LVT formation earlier than in this case. Patients with acute myocarditis are younger, at a median age of 34 years, and the social impact of embolic complications is considerable. Echocardiography is effective in detecting LVT noninvasively in low- and high-risk patients. Patients with myocarditis can benefit from careful observation by echocardiography.

A Gluteus Medius Muscle Biopsy to Confirm Amyloid Transthyretin Deposition in Wild-type Transthyretin Cardiac Amyloidosis: A Report of Two Cases.

In patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), the uptake of the tracer on technetium-99m-labeled pyrophosphate (99mTc-PYP) scintigraphy, which indicates amyloid transthyretin (ATTR) per se, is often observed in skeletal muscles, such as the abdominal oblique and gluteal muscles. Among extracardiac biopsies for confirming ATTR deposition in ATTRwt-CA, a 99mTc-PYP imaging-based computed tomography (CT)-guided core needle biopsy of the internal oblique muscle has relatively high sensitivity. In some patients, the 99mTc-PYP uptake is more pronounced in the gluteal muscles than in oblique muscles. We herein report two cases of ATTRwt-CA in which a CT-guided biopsy of the gluteus medius muscle with 99mTc-PYP uptake confirmed the presence of ATTR deposits.