Cardiac amyloidosis screening using a relative apical sparing pattern in patients with left ventricular hypertrophy.

BACKGROUND: Cardiac amyloidosis (CA) mimics left ventricular hypertrophy (LVH). It is treatable, but its prognosis is poor. A simple screening tool for CA would be valuable. CA is more precisely diagnosed with echocardiographic deformation parameters (e.g., relative apical sparing pattern [RASP]) than with conventional parameters. We aimed to 1) investigate incremental benefits of echocardiographic deformation parameters over established parameters for CA screening; 2) determine the resultant risk score for CA screening; and 3) externally validate the score in LVH patients. METHODS: We retrospectively studied 295 consecutive non-ischemic LVH patients who underwent detailed diagnostic tests. CA was diagnosed with biopsy or 99mTc-PYP scintigraphy. The base model comprised age (≥65 years [men], ≥70 years [women]), low voltage on the electrocardiogram, and posterior wall thickness ≥ 14 mm in reference to the literature. The incremental benefit of each binarized echocardiographic parameter over the base model was assessed using receiver operating characteristic curve analysis and comparisons of the area under the curve (AUC). RESULTS: Fifty-four (18%) patients had CA. RASP showed the most incremental benefit for CA screening over the base model. After conducting multiple logistic regression analysis for CA screening using four variables (RASP and base model components), a score was determined (range, 0-4 points). The score demonstrated adequate discrimination ability for CA (AUC = 0.86). This result was confirmed in another validation cohort (178 patients, AUC = 0.88). CONCLUSIONS: We developed a score incorporating RASP for CA screening. This score is potentially useful in the risk stratification and management of LVH patients.

Semiquantitative assessment of the relative apical sparing pattern of longitudinal strain for cardiac amyloidosis identification.

BACKGROUNDS: The relative apical sparing pattern (RASP) of left ventricular (LV) longitudinal strain (LS) is frequently associated with cardiac amyloidosis (CA). However, the visual assessment of RASP is inconsistent, and the quantitative assessment of RASP is time-consuming. This study aimed to compare assessments of RASP for the identification of CA with conventional assessments and investigate their reproducibility and relevance on the assessments. METHODS: Forty patients with biopsy-proven CA were compared with 80 hypertrophied patients matched for mean LV wall thickness. We compared the discriminative abilities of three assessments of RASP to identify CA (visual, quantitative, and semiquantitative). Nine patterns of semiquantitative RASP were investigated; finally, it was defined as "reduction of LS" (≥ -10%) in ≥5 (of 6) basal segments, relative to "preserved LS" (< -15%) in at least one apical segment. RESULTS: The concordance between the two observers for visual RASP was modest (κ = 0.65). On the other hand, the consistency for semiquantitative RASP was perfect (κ = 1.00). The discriminative ability of semiquantitative RASP (area under the curve [AUC]  = 0.74) was significantly better than that of visual RASP (AUC = 0.65) and equivalent to that of binary quantitative RASP. CONCLUSION: Semiquantitative RASP assessment is reproducible and accurately discriminates CA. This simple assessment may help readily refine the risk stratification of patients with diffuse LV hypertrophy.

Automated interpretation of the coronary angioscopy with deep convolutional neural networks.

BACKGROUND: Coronary angioscopy (CAS) is a useful modality to assess atherosclerotic changes, but interpretation of the images requires expert knowledge. Deep convolutional neural networks (DCNN) can be used for diagnostic prediction and image synthesis. METHODS: 107 images from 47 patients, who underwent CAS in our hospital between 2014 and 2017, and 864 images, selected from 142 MEDLINE-indexed articles published between 2000 and 2019, were analysed. First, we developed a prediction model for the angioscopic findings. Next, we made a generative adversarial networks (GAN) model to simulate the CAS images. Finally, we tried to control the output images according to the angioscopic findings with conditional GAN architecture. RESULTS: For both yellow colour (YC) grade and neointimal coverage (NC) grade, we could observe strong correlations between the true grades and the predicted values (YC grade, average r=0.80±0.02, p<0.001; NC grade, average r=0.73±0.02, p<0.001). The binary classification model for the red thrombus yielded 0.71±0.03 F1-score and the area under the receiver operator characteristic curve was 0.91±0.02. The standard GAN model could generate realistic CAS images (average Inception score=3.57±0.06). GAN-based data augmentation improved the performance of the prediction models. In the conditional GAN model, there were significant correlations between given values and the expert's diagnosis in YC grade but not in NC grade. CONCLUSION: DCNN is useful in both predictive and generative modelling that can help develop the diagnostic support system for CAS.

Characterization of high-intensity plaques on noncontrast T1-weighted magnetic resonance imaging by coronary angioscopy.

BACKGROUND: A recent study showed that coronary high-intensity plaques (HIPs) visualized by noncontrast T1-weighted imaging (T1WI) in cardiac magnetic resonance were associated with coronary events. We used coronary angioscopy to analyze HIP plaque morphology. METHODS AND RESULTS: A total 17 lesions from 17 patients with stable or unstable angina pectoris were evaluated at the culprit lesion by noncontrast T1WI using 1.5-T magnetic resonance; of them, nine (53%) were HIPs and eight (47%) were non-HIPs, and all were analyzed by coronary angioscopy. We assessed the existence of thrombus and plaque yellow color grade (YG). YG was assessed visually according to a four-grade scale: 0, white; 1, light yellow; 2, yellow; 3, intense yellow. The frequency of thrombus was significantly higher in HIPs than in non-HIPs (89% vs. 25%, respectively; p=0.007). YG was significantly more frequent in HIPs than in non-HIPs (2.2±0.4 vs. 0.7±0.7, respectively; p=0.01). CONCLUSIONS: These data indicated that HIPs on noncontrast T1WI were associated with the presence of high-grade yellow plaque with thrombus.

Relationship between yellow plaque grade and tissue protrusion after stent implantation: A coronary angioscopy study.

BACKGROUND: Tissue protrusion detected with optical coherence tomography after percutaneous coronary intervention using stents is one of the risk factors for early stent thrombosis. However, tissue protrusion features have not been described. The aim of this study was to compare tissue morphology at stented sites with or without tissue protrusion by using coronary angioscopy. METHODS: Using optical coherence tomography and coronary angioscopy, we assessed 42 patients [31 men, 11 women; age, 70.7±7.4years; acute coronary syndrome (ACS), n=19; effort angina pectoris (EAP), n=23] after stenting. RESULTS: Twenty patients had tissue protrusion. ACS patients had a higher incidence of tissue protrusion than EAP patients (70.0% vs 29.4%; p=0.002). The plaque at the protrusion site had higher-grade yellow plaque with thrombus than those without protrusion (2.35±0.67 vs 1.40±0.67; p<0.001). The plaque at protrusion sites developed more thrombi (60.0% vs 22.7%; p=0.041). CONCLUSIONS: Tissue protrusion after stent implantation was associated with high-grade yellow plaque with thrombi.

Comparison of Chronic Angioscopic Findings of Bare Metal Stents, 1st-Generation Drug-Eluting Stents and 2nd-Generation Drug-Eluting Stents　- Multicenter Study of Intra-Coronary Angioscopy After Stent (MICASA).

BACKGROUND: No previous study has reported a comprehensive comparison of the chronic angioscopic findings after bare metal stent (BMS), and 1st- and 2nd-generation drug-eluting stents (DES). METHODS AND RESULTS: The Multicenter Study on Intra-Coronary Angioscopy after Stent (MICASA) is a multicenter registry of coronary angioscopy. A total of 264 stents were observed by coronary angioscopy 1 year after PCI. There were 15 BMS, 90 1st-generation DES, and 159 2nd-generation DES. Neointimal coverage (NC) of the stent was classified into 4 grades from 0 (no coverage) to 3 (complete coverage). Yellow color (YC) of plaque at the stented segment was graded from 0 (white) to 3 (bright yellow). Minimum (Min-) and Maximum (Max-) NC grade were significantly lower with 1st- and 2nd-generation DES than with BMS. Although the Max-NC grade was similar, the Min-NC grade was significantly higher for 2nd-generation DES than for 1st-generation DES. Both the YC grade and the incidence of thrombus with 2nd-generation DES were lower than with the 1st-generation DES and were comparable to BMS. Multivariate analysis showed that low-density lipoprotein, 1st-generation DES, and acute coronary syndrome were independent factors for yellow plaque (YG2 or 3), and that hypertension and 1st-generation DES were independent factors for the incidence of thrombus. CONCLUSIONS: Coronary angioscopy revealed more homogeneous coverage with white neointima and less thrombus after 2nd-generation DES as compared with 1st-generation DES. These findings may explain the favorable clinical outcomes observed for patients treated with 2nd-generation DES. (Circ J 2016; 80: 1916-1921).

A case of a newly developed yellow neointima at stent implanted site 1 year after sirolimus-eluting stent placement: angioscopic findings.

Coronary angioscopy is a useful tool for understanding plaque characteristics through the plaque color and surface thrombus formation. We experienced an interesting case of a newly developed yellow neointima 400 days after a sirolimus-eluting stent implantation. A 72-year-old woman suffering from angina pectoris was admitted to our hospital. Coronary angiography revealed severe stenosis at the proximal left descending artery and she was implanted with a sirolimus-eluting stent. Coronary angioscopic observation immediately after stent implantation revealed the presence of yellow plaque only at the most severe stenosis lesion in the stent placement site. We performed a coronary angiography 400 days after the sirolimus-eluting stent implantation and did not find an in-stent restenosis. An intravascular ultrasound indicated minimum neointimal formation. By coronary angioscopy, we could clearly observe that the neointima had covered the surface of the stent struts; the stent struts were barely visible under the neointima. Surprisingly, neointima formed in response to the sirolimus-eluting stent was entirely yellow. Precise mechanisms of producing yellow neointima was unknown, we may observe a pathologic neointima induced by sirolimus-eluting stent.

Detection of myocardial ischemia using 64-slice MDCT.

BACKGROUND: The purpose is to investigate the ability of 64-slice multidetector computed tomography (MDCT) at rest in detecting myocardial ischemia, conventionally depicted by myocardial perfusion scintigraphy (MPS). METHODS AND RESULTS: In 75 patients with suspected coronary artery disease, cardiac CE-MDCT at rest and stress/rest MPS were performed. The 2D myocardial images were reconstructed in diastolic and systolic phases using raw data from coronary computed tomography (CT) angiography. CT numbers in the myocardium were used as an estimate of myocardial enhancement. The myocardium was shown using a color scale that depicts faint low-density areas more clearly than gray scale. The variation in myocardial enhancement was evaluated at systole and diastole for those segments depicted as ischemia on MPS. A pattern of transient endocardial hypo-enhancement at systole and normal enhancement at diastole as the ischemic pattern on CT myocardial image was defined. MPS diagnosed myocardial ischemia in 40 of 75 patients. Use of the ischemic pattern on CT images distinguished patients with and without ischemia with a sensitivity of 90%, specificity of 83%, positive predictive value of 86% and negative predictive value of 88%. CONCLUSIONS: CT myocardial imaging at rest demonstrates a characteristic enhancement pattern for ischemia. This has potential as a non-invasive method for detecting ischemia.

Graft healing in a bone tunnel: bone-attached graft with screw fixation versus bone-free graft with extra-articular suture fixation.

The purpose of this study was to clarify differences in tendon graft-to-bone tunnel healing between bone-attached tendon grafts with interference-screw fixation and bone-free tendon grafts with extra-articular suture fixation. In 42 Japanese White rabbits, anterior half replacement of the medial collateral ligament was performed using half of the ipsilateral patellar tendon. At the femoral attachment, the bone-plug-attached graft was fixed with an interference screw (group A). The bone-plug-free graft was fixed by the extra-articular suture fixation technique with sutures tied over a button (group B). Biomechanical and histological evaluations were performed at 2, 4 and 8 weeks postoperatively. In biomechanical evaluation, at 2 or 4 weeks 27 of 28 specimens (96%) were pulled out from the femoral tunnel, while one 4-week specimen and all four 8-week specimens failed at the graft's mid-substance. At 2 weeks, the maximum failure load was 25+/-10 N and 24+/-6 N for group A and group B respectively (mean+/-SD). At 4 weeks, the maximum failure load was 42+/-17 N and 35+/-15 N respectively. There were no significant differences in maximum pullout failure load between the groups at 2 or 4 weeks postoperatively. (P=0.887 at 2 weeks and P=0.339 at 4 weeks using ANOVA measurement). Histologically, the bone-attached grafts showed partial bone-to-bone union at the graft-bone tunnel interface at 4 weeks, and complete bony union at 8 weeks. The bone-free grafts exhibited newly formed Sharpey-like collagen fibers at 4 weeks, and strong connection by mature granulation tissue at 8 weeks. Graft-to-bone tunnel healing of bone-attached graft with screw fixation and bone-free graft with extra-articular suture fixation are comparable in terms of biomechanical evaluation during the early postoperative periods.

Recovery of walking speed and symmetrical movement of the pelvis and lower extremity joints after unilateral THA.

In 17 patients with unilateral hip disease who underwent total hip arthroplasty (THA), the gait was analyzed preoperatively and 1, 3, 6, and 12 months after unilateral THA using a Vicon system to assess the recovery of walking speed and symmetrical movement of the hip, knee, ankle, and pelvis. The walking speed of these patients reached that of normal Japanese persons by 12 months after surgery. Walking speed was correlated with the range of hip motion on the operated side at 1 month postoperatively, and was correlated with the hip joint extension moment of force on both sides from 3 to 6 months after surgery. Before THA, asymmetry was observed in the range of the hip motion, maximum hip flexion, maximum hip extension, maximum knee flexion, as well as in pelvic obliquity, pelvic tilt, and pelvic rotation. There were no differences of the stride length or step length between both sides throughout the observation period. The preoperative range of hip flexion on the operated side during a gait cycle (21.3+/-7.9 degrees ) was significantly smaller than on the non-operated side (46.7+/-7.1 degrees ), and the difference between sides was still significant at 12 months after surgery (35.1+/-6.2 degrees on the operated side and 43.6+/-5.7 degrees on the non-operated side). The majority (74%) of the difference in hip motion range during this period was due to the difference in maximum extension of the hip. The increase in the range of pelvic tilt and the range of motion of the opposite hip showed an inverse correlation with the range of motion of the operated hip, suggesting a compensatory preoperative role. However, this correlation became insignificant after 6 months postoperatively. Asymmetry of the range of hip motion persisted at 12 months after THA in patients with unilateral coxoarthropathy during free level walking, while the operation normalized the spatial asymmetry of other joints and the walking speed prior to the recovery of hip motion.

Graft fixation with predetermined tension using a new device, the double spike plate.

PURPOSE: To biomechanically evaluate a new fixation device, DSP (Double Spike Plate; Meira Corp, Nagoya, Aichi, Japan), for pullout graft fixation. TYPE OF STUDY: Biomechanical study. METHODS: A porcine tibia in which 8-mm diameter drill holes had been made from the medial tibial metaphysis to the anterior cruciate ligament attachment was rigidly fixed to a tension analyzer. A quadrupled graft consisting of 2 double-looped bovine tendons was prepared with No. 3 polyester sutures placed distally. The graft was passed through the drill hole, and its proximal loop ends were rigidly fixed to a load cell for monitoring graft tension. The graft's distal ends were connected to the DSP by tying the sutures to the top hole in the DSP. The graft tension was predetermined at 49 N (n = 5) or 98 N (n = 5). This tension was maintained for 5 minutes with a suture passed through the bottom hole of the DSP. The plate was fixed to the tibia by hammering its spikes into the bone under the index tension. Finally, the fixation was completed by inserting a screw. RESULTS: Although the graft tension immediately increased to 69 +/- 11 N or 133 +/- 14 N during hammering, it gradually reduced to 49 +/- 10 N or 100 +/- 7 N 5 minutes later. CONCLUSIONS: This study shows that graft fixation under a predetermined tension can be achieved with the DSP.