Masafumi Kidoh

Background: Left atrial functional parameters are established predictors of atrial fibrillation (AF), but the role of right atrial (RA) function, particularly RA peak longitudinal strain (LS), in transthyretin amyloid cardiomyopathy (ATTR‐CM) remains unclear. This study aimed to investigate the relationship between RA function and AF onset in ATTR‐CM. Methods: The derivation cohort comprised 143 patients with ATTR‐CM without prior atrial arrhythmias at Kumamoto University Hospital. Association between baseline parameters and new‐onset AF during the follow‐up period was analyzed using Cox regression models. Discrimination was assessed using time‐dependent receiver operating characteristic analysis at 24 months. Results: During follow‐up (median, 30 months), 42 patients (29%) developed new‐onset AF. Lower RA peak LS was independently associated with incident AF and showed moderate discrimination (time‐dependent area under the curve, 0.72); the optimal cutoff at 24 months was 17.2%. Patients with RA peak LS <17.2% had significantly lower AF‐free survival. A novel risk score integrating RA and left atrial peak LS and LA volume index effectively stratified AF risk. External validation in an independent cohort of 81 patients from Oita and Miyazaki University Hospitals confirmed consistent associations between lower RA peak LS and higher AF incidence, supporting the reproducibility of the findings. Conclusions: RA peak LS is a novel, robust predictor of new‐onset AF in ATTR‐CM and provides additional information alongside established clinical and left atrial parameters. Incorporating RA functional assessment may improve risk stratification and guide early interventions in high‐risk patients.

Purpose: To investigate whether virtual-monoenergetic images (VMI) from dual-layer spectral-detector computed tomography (DLCT) improve right adrenal vein (RAV) assessment before adrenal venous sampling (AVS), and portal-venous-phase (PVP) images alone can replace conventional multiphase CT combining late-arterial phase (LAP) and PVP. Methods: Sixty-three patients with primary aldosteronism who underwent LAP and PVP DLCT before AVS were retrospectively analyzed. Conventional polyenergetic-images (PEI) and VMI at 40–70 keV (VMI _40–70 ) were reconstructed. Image noise and contrast-to-noise ratio (CNR) of RAV were quantified. VMI with the highest CNR was predefined as the best-VMI. Two radiologists evaluated four image series (PEI and best-VMI at LAP and PVP) separately for RAV visibility, accessory hepatic vein (AHV) assessability, and image noise using five-point scales (1 = worst, 5 = best). RAV detection and AHV assessability rates were compared among image series. Results: In both enhancement phases, VMI _40–70 showed lower image noise and VMI _40–60 higher CNR than PEI (all p < 0.05), with VMI ₄₀ providing the highest CNR and being designated as the best VMI. Compared to PEI at LAP, CNR was lower with PEI at PVP but higher with VMI ₄₀ at PVP (both, p < 0.001). In subjective analysis, VMI ₄₀ showed better scores than PEI for image noise (LAP: 4.0 ± 0.5 vs. 2.4 ± 0.6; PVP: 4.0 ± 0.6 vs. 2.5 ± 0.5) and RAV visibility (LAP: 4.5 ± 0.8 vs. 3.5 ± 0.8; PVP: 3.7 ± 1.0 vs. 2.6 ± 0.9) (all p < 0.001). With PEI, the RAV detection rate was lower at PVP than at LAP (54.8% vs. 89.7%, p < 0.001). Use of VMI ₄₀ at PVP achieved the same detection rate as PEI at LAP (89.7%, p = 1.0) and higher AHV assessability rate than PEI at PVP (96.8% vs. 80.2%, p < 0.001). Conclusion: DLCT-VMI improved RAV assessments before AVS. Using VMI ₄₀ for PVP provided RAV depiction equivalent to PEI at LAP and superior AHV assessability to PEI at PVP, suggesting its potential as a surrogate for dedicated multiphase CT.

BACKGROUND: Magnetic resonance imaging (MRI)-derived myocardial extracellular volume fraction (ECV) is elevated in the presence of fibrosis, amyloid deposition, inflammation, and edema. In patients with cardiac amyloidosis and prolonged T2 due to concomitant inflammation or edema, MRI-ECV may not correctly reflect histological amyloid load. The authors sought to determine whether MRI-ECV can accurately reflect histological amyloid load in 2 groups of patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM), with and without T2 prolongation. METHODS: This retrospective study included consecutive patients with ATTRwt-CM who underwent endomyocardial biopsy and cardiac MRI from March 2017 to October 2021 for initial evaluation of ATTRwt-CM. We measured MRI-ECV and T2, and evaluated correlation between MRI-ECV and amyloid load from endomyocardial biopsy by means of Pearson correlation analysis. RESULTS: Of 44 patients (mean age, 75±6 years [SD]; 40 men), 24 showed T2 prolongation (T2≥50 milliseconds). All specimens obtained by endomyocardial biopsy were suitable for analysis. The interval between endomyocardial biopsy and cardiac MRI examination was a median of 3 days (interquartile range, 2–4). In the absence of T2 prolongation due to increased water content, MRI-ECV and amyloid load showed a moderately significant correlation (Spearman ρ=0.50, P =0.03). However, in the presence of T2 prolongation, there was no significant correlation between MRI-ECV and amyloid load (Spearman ρ=−0.05, P =0.83). CONCLUSIONS: In patients with ATTRwt-CM and prolonged T2, MRI-ECV did not accurately reflect histological amyloid load. Our findings underscore the need for a multiparametric imaging approach, combining both ECV and T2 mapping, to better characterize myocardial tissue in patients with ATTRwt-CM, and further prospective research in larger and more diverse cohorts is needed to validate our results.

Objectives There is limited evidence of the pericoronary fat attenuation index (FAI) as an imaging marker to assess cancer therapy-related cardiovascular toxicity. We aimed to measure FAI in four consecutive coronary CT angiography (CTA) scans before and 3, 6, and 12 months after anthracycline treatment in patients with breast cancer to determine trends in dynamic changes in FAI after treatment. Methods We performed a post hoc analysis of a prospective study (between August 2019 and July 2020) in which anthracycline-induced myocardial injury was evaluated using cardiac CT. FAI was quantified using coronary CTA images before and 3, 6, and 12 months after anthracycline treatment. The FAIs of the three coronary arteries were averaged to calculate the FAI (Total). Results FAI was analyzed on 14 patients with breast cancer who had adequate CT image quality (mean age, 62 years ± 11 (SD); 14 women). During the observation period, all 14 patients treated with anthracycline developed mild asymptomatic cardiac dysfunction related to cancer treatment (CTRCD). FAI (Total) showed a gradual increase during the observation period compared to baseline (baseline: −77.3 ± 5.6 HU, 3 months: −77.1 ± 4.8 HU, 6 months: −76.5 ± 5.4 HU, 12 months: −73.8 ± 5.8 HU). FAI (Total) was significantly elevated at 12 months compared to baseline (p < 0.001). Conclusion In patients with breast cancer, FAI showed a gradual increase at 3, 6, and 12 months after treatment with anthracyclines compared to before treatment. FAI may be used as an imaging biomarker of coronary artery inflammation in the follow-up of anthracycline therapy and may contribute to the personalization of therapy through early detection of coronary toxicity. Key Points Question Is pericoronary fat attenuation index (FAI) a potential imaging biomarker for assessing changes in pericoronary adipose tissue related to cancer therapy-related cardiovascular toxicity? Findings In 14 patients with breast cancer, FAI showed a gradual increase at 3, 6, and 12 months after treatment with anthracyclines compared to before treatment. Clinical relevance FAI may be an imaging biomarker for the detection and treatment of cancer therapy-related cardiovascular toxicity. Graphical Abstract

Aims: To investigate CT-derived extracellular volume fraction (CT-ECV) in patients with lone aortic stenosis (AS), dual pathology of AS and transthyretin cardiac amyloidosis (AS-ATTR), and lone ATTR, and to examine the diagnostic performance and optimal cut-off values of CT-ECV for differentiating between patients with lone AS and AS-ATTR and between patients with lone AS and lone ATTR. Methods and results: This retrospective study included consecutive patients with severe AS (including lone AS and AS-ATTR) and lone ATTR who underwent CT-ECV analysis and technetium 99 m pyrophosphate (99mTc-PYP) scintigraphy. The diagnostic performance of CT-ECV for detecting cardiac amyloidosis was evaluated using the area under the receiver operating characteristic curve (AUC). Of 138 patients (mean age, 80 ± 8; 96 men), 55 had lone AS, 19 had AS-ATTR, and 64 had lone ATTR. CT-derived extracellular volume fraction of patients with lone AS was 31 ± 5%. CT-derived extracellular volume fraction was significantly lower in patients with AS-ATTR than lone ATTR (45 ± 12% vs. 53 ± 13%, P = 0.04). The AUC for differentiating patients with AS-ATTR from lone AS was lower than for lone ATTR from lone AS [0.90 (95% CI: 0.81, 0.96) vs. 0.95 (95% CI: 0.90, 0.98)]. The cut-off values of CT-ECV for differentiation between patients with lone AS and AS-ATTR were lower than those between patients with lone AS and lone ATTR [36.6% vs. 38.5% (Youden index)]. There was no significant difference in the proportion of 99mTc-PYP scintigraphy grade between patients with AS-ATTR and lone ATTR (P = 0.20). Conclusion: Despite no significant difference in degree of ATTR between patients with AS-ATTR and lone ATTR, CT-ECV of patients with dual AS-ATTR pathology was significantly lower than that of patients with lone ATTR. The diagnostic performance and optimal cut-off values of CT-ECV for differentiating between patients with lone AS and AS-ATTR were lower than those between patients with lone AS and lone ATTR.

To assess the diagnostic performance of unenhanced electrocardiogram (ECG)-gated cardiac computed tomography (CT) for detecting myocardial edema, using MRI T2 mapping as the reference standard. This retrospective study protocol was approved by our institutional review board, which waived the requirement for written informed consent. Between December 2017 to February 2019, consecutive patients who had undergone T2 mapping for myocardial tissue characterization were identified. We excluded patients who did not undergo unenhanced ECG-gated cardiac CT within 3 months from MRI T2 mapping or who had poor CT image quality. All patients underwent unenhanced ECG-gated cardiac CT with an axial scan using a third-generation, 320 × 0.5 mm detector-row CT unit. Two radiologists together drew regions of interest (ROIs) in the interventricular septum on the unenhanced ECG-gated cardiac CT images. Using T2 mapping as the reference standard, the diagnostic performance of unenhanced cardiac CT for detecting myocardial edema was evaluated by using the area under the receiver operating characteristic curve with sensitivity and specificity. Youden index was used to find an optimal sensitivity-specificity cutoff point. A cardiovascular radiologist independently performed the measurements, and interobserver reliability was assessed using intraclass correlation coefficients for CT value measurements. A P value of <.05 was considered statistically significant. We included 257 patients who had undergone MRI T2 mapping. Of the 257 patients, 35 patients underwent unenhanced ECG-gated cardiac CT. One patient was excluded from the study because of poor CT image quality. Finally, 34 patients (23 men; age 64.7 ± 14.6 years) comprised our study group. Using T2 mapping, we identified myocardial edema in 19 patients. Mean CT and T2 values for 34 patients were 46.3 ± 2.7 Hounsfield unit and 49.0 ± 4.9 ms, respectively. Mean CT values moderately correlated with mean T2 values (Rho = –0.41; P < .05). Mean CT values provided a sensitivity of 63.2% and a specificity of 93.3% for detecting myocardial edema, with a cutoff value of ≤45.0 Hounsfield unit (area under the receiver operating characteristic curve = 0.77; P < .01). Inter-observer reproducibility in measuring mean CT values was excellent (intraclass correlation coefficient = 0.93; [95% confidence interval: 0.86, 0.96]). Myocardial edema could be detected by CT value of myocardium in unenhanced ECG-gated cardiac CT.