Platelet-rich plasma does not accelerate the healing of damaged muscle following muscle strain

Although platelet-rich plasma (PRP) has been widely used regardless of the severity of muscle strain, there have been very few basic studies in which its effects on muscle injury were examined by using models that accurately mimic the clinical muscle strain injury process. Therefore, the aim of this study was to confirm by physiological and structural analyses whether PRP purified by a general preparation method has a muscle healing effect on muscle damage caused by eccentric contraction (ECC). Male Wistar rats were subjected to muscle injury induced by ECC in bilateral plantar flexor muscles using electrical stimulation and an automatically dorsiflexing footplate. The rats were randomly assigned to three groups by type of injection: phosphate-buffered saline (PBS), leukocyte-poor PRP (LP-PRP), or leukocyte-rich PRP (LR-PRP) injection into gastrocnemius muscles three times at weekly intervals. The platelet concentrations of the LP-PRP and LR-PRP were three to five times higher than that of whole blood. The recovery process of torque strength in the plantar flexor muscle, signal changes in MRI images, and histological evaluation 3 weeks after injury showed no obvious differences among the three groups, and every muscle recovered well from the injury without marked fibrosis. The results that neither LP-PRP nor LR-PRP was found to accelerate healing of muscle injuries suggested that conventional preparation and use of PRP for simple muscle injuries caused by muscle strain should be carefully considered, and further basic research using models that accurately mimic clinical practice should be carried out to determine the optimal use of PRP.

Remission of hypersensitivity by simple weight load stimuli in a complex regional pain syndrome mouse model

Painful sensitivity of the hand or foot are the most common and debilitating symptoms of complex regional pain syndrome (CRPS). Physical therapy is standard treatment for CRPS, but evidence supporting its efficacy is minimal and it can be essentially impossible for CRPS patients to actively exercise the painful limb. Using the well-characterized distal tibial fracture CRPS mouse model, we compared the therapeutic effects of several weeks of daily hindlimb loading versus rotarod walking exercise. The effects of loading and exercise were evaluated by weekly testing of hind-paw withdrawal thresholds to von Frey fibers and radiant heat, as well as measurements of paw and ankle edema. At 6 weeks after fracture, the mice were killed and the ipsilateral femur, spinal cord and L4/5 dorsal root ganglia, and hind-paw skin collected for PCR assays and paw skin Immunohistochemistry evaluation. Hindlimb loading reduced hind-paw von Frey allodynia and heat hyperalgesia and edema within a week and these effects persisted for at least a week after discontinuing treatment. These therapeutic effects of loading exceeded the beneficial effects observed with rotarod walking exercise in fracture mice. Levels of nerve growth factor and transient receptor potential vanilloid 1 (TRPV1) immunostaining in the hind-paw skin were increased at 6 weeks after fracture, and both loading and exercise treatment reduced increases. Collectively, these results suggest that loading may be an effective and possibly curative treatment in CRPS patients with sensitivity in the affected limb.

Coefficient of variation of T2-weighted MRI may predict the prognosis of malignant peripheral nerve sheath tumor

BACKGROUND

We investigated whether non-enhancement MRI features, including measurement of the heterogeneity of the tumor with MR T2 imaging by calculating coefficient of variation (CV) values, were associated with the prognosis of non-metastatic malignant peripheral nerve sheath tumors (MPNST).

METHODS

This retrospective study included 42 patients with MPNST who had undergone surgical resection (mean age, 50 years ± 21; 20 male participants). Non-enhancement MR images were evaluated for signal intensity heterogeneity on T1- and T2-weighted imaging, tumor margin definition on T1- and T2-weighted imaging, peritumoral edema on T2-weight imaging, and CV. We measured the signal intensities of MR T2-weighted images and calculated the corresponding CV values. CV is defined as the ratio of the standard deviation to the mean. The associations between factors and overall survival (OS) were investigated via the Kaplan-Meier method with log-rank tests and the Cox proportional hazards model.

RESULTS

The mean CV value of MR T2 images was 0.2299 ± 0.1339 (standard deviation) (range, 0.0381-0.8053). Applying receiver operating characteristics analysis, the optimal cut-off level for CV value was 0.137. This cut-off CV value was used for its stratification into high and low CV values. At multivariate survival analysis, a high CV value (hazard ratio = 3.63; 95% confidence interval = 1.16-16.0; p = 0.047) was identified as an independent predictor of OS.

CONCLUSION

The CV value of the signal intensity of heterogenous MPNSTs MR T2-weighted images is an independent predictor of patients' OS.

Quantitative assessment of anterior talofibular ligament quality in chronic lateral ankle instability using magnetic resonance imaging T2* value

OBJECTIVE

To determine T2* normal reference values for anterior talofibular ligament (ATFL) and to investigate the feasibility of the quantitative ATFL quality evaluation in chronic lateral ankle instability (CLAI) using T2* values.

MATERIALS AND METHODS

This study enrolled 15 patients with CLAI and 30 healthy volunteers. The entire ATFL T2* values from the MRI T2* mapping were measured. The prediction equation (variables: age, height, and weight) in a multiple linear regression model was used to calculate the T2* normal reference value in the healthy group. T2* ratio was defined as the ratio of the actual T2* value of the patient's ATFL to the normal reference value for each patient. A Telos device was used to measure the talar tilt angle (TTA) from the stress radiograph.

RESULTS

T2* values of ATFL in the healthy and CLAI groups were 10.82 ± 1.84 ms and 14.36 ± 4.30 ms, respectively, which are significantly higher in the CLAI group (P < 0.05). The prediction equation of the normal reference T2* value was [14.9 + 0.14 × age (years) - 4.7 × height (m) - 0.03 × weight (kg)] (R2 = 0.65, P < 0.0001). A significant positive correlation was found between the T2* ratio and TTA (r = 0.66, P = 0.007).

CONCLUSION

MRI T2* values in patients with CLAI were higher than those in healthy participants, and the T2* ratio correlated with TTA, suggesting that T2* values are promising for quantitative assessment of ATFL quality preoperatively.

Trastuzumab deruxtecan in previously treated patients with HER2-positive metastatic breast cancer: updated survival results from a phase II trial (DESTINY-Breast01)

BACKGROUND

Primary analysis of the multicenter, open-label, single-arm, phase II DESTINY-Breast01 trial (median follow-up 11.1 months) demonstrated durable antitumor activity with trastuzumab deruxtecan (T-DXd) in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (mBC) previously treated with trastuzumab emtansine (T-DM1). We report updated cumulative survival outcomes with a median follow-up of 26.5 months (data cut-off 26 March 2021).

PATIENTS AND METHODS

Patients with HER2-positive mBC resistant or refractory to T-DM1 received T-DXd 5.4 mg/kg intravenously every 3 weeks until disease progression, unacceptable adverse events, or withdrawal of consent. The primary endpoint was confirmed objective response rate (ORR) by independent central review (ICR). Secondary endpoints included overall survival (OS), duration of response (DoR), progression-free survival (PFS), and safety.

RESULTS

The ORR by ICR was 62.0% [95% confidence interval (CI) 54.5% to 69.0%] in patients who received T-DXd 5.4 mg/kg every 3 weeks (n = 184). Median OS was 29.1 months (95% CI 24.6-36.1 months). Median PFS and DoR were 19.4 months (95% CI 14.1-25.0 months) and 18.2 months (95% CI 15.0 months-not evaluable), respectively. Drug-related treatment-emergent adverse events (TEAEs) were observed in 183 patients (99.5%), and 99 patients (53.8%) had one or more grade ≥3 TEAEs. Adjudicated drug-related interstitial lung disease/pneumonitis occurred in 15.8% of patients (n = 29), of which 2.7% (n = 5) were grade 5.

CONCLUSIONS

These updated results provide further evidence of sustained antitumor activity of T-DXd with a consistent safety profile in heavily pretreated patients with HER2-positive mBC.

Pediatric Synovial Osteochondromatosis of the Knee with Leg Length Discrepancy: A Case Report

Introduction

Synovial chondromatosis (SC) is very rare among children. We are aware of no reports of patients with SC accompanied by leg length discrepancy (LLD).

Case Report

We describe a case of synovial osteochondromatosis of a 7-year-old boy complicated by LLD. We performed epiphysiodesis of the distal femur and arthroscopic resection of loose bodies and total synovectomy. Three years after surgery, LLD had been corrected and there was no sign of recurrence.

Conclusion

Physicians should be aware of synovial osteochondromatosis complicated by LLD in childhood and take radiographs of the whole length of lower legs when this condition is suspected.

Development of T cell receptor-engineered T cells targeting the sarcoma-associated antigen papillomavirus binding factor

We previously identified papillomavirus binding factor (PBF) as an osteosarcoma antigen recognized by an autologous cytotoxic T lymphocyte clone. Vaccination with PBF-derived peptide presented by HLA-A24 (PBF peptide) elicited strong immune responses. In the present study, we generated T cell receptor-engineered T cells (TCR-T cells) directed against the PBF peptide (PBF TCR-T cells). PBF TCR was successfully transduced into T cells and detected using HLA-A*24:02/PBF peptide tetramer. PBF TCR-T cells generated from a healthy donor were highly expanded and recognized T2-A24 cells pulsed with PBF peptide, HLA-A24+ 293T cells transfected with PBF cDNA, and sarcoma cell lines. To establish an adoptive cell therapy model, we modified the PBF TCR by replacing both α and β constant regions with those of mice (hybrid PBF TCR). Hybrid PBF TCR-T cells also showed reactivity against T2-A24 cells pulsed with PBF peptide and to HLA-A24+ 293T cells transfected with various lengths of PBF cDNA including the PBF peptide sequence. Subsequently, we generated target cell lines highly expressing PBF (MFH03-PBF [short] epitope [+]) containing PBF peptide with in vivo tumorigenicity. Hybrid PBF TCR-T cells exhibited antitumor effects compared with mock T cells in NSG mice xenografted with MFH03-PBF (short) epitope (+) cells. CD45+ T cells significantly infiltrated xenografted tumors only in the hybrid PBF TCR T cell group and most of these cells were CD8-positive. CD8+ T cells also showed Ki-67 expression and surrounded the CD8-negative tumor cells expressing Ki-67. These findings suggest that PBF TCR-T cell therapy might be a candidate immunotherapy for sarcoma highly expressing PBF.

Minimizing the risk of injury to the popliteal artery during pullout repair of medial meniscus posterior root tears: A cadaveric study

Background

The purpose of this study was to investigate the positional effect of guide pins used in the transtibial pullout repair of medial meniscus posterior root tears on the popliteal artery.

Methods

We used eight cadaveric knees. Two 2.4-mm guide pins were inserted into the posterior root of the medial meniscus at 50° to the articular surface from the medial edge of the tibial tuberosity (anteromedial group) and the anterior edge of the medial collateral ligament (posteromedial group) using an aiming guide placed at the posterior root attachment of the medial meniscus from the anteromedial portal. The posterior capsule was dissected, and the popliteal artery was identified. The positional effect of the guide pins on the popliteal artery was photographed arthroscopically at 0°, 30°, 60°, and 90° knee flexion angles. The popliteal artery diameter and the minimum distance between the popliteal artery center and the guide pin tip were measured.

Results

At 90° knee flexion, most of the guide pins in the anteromedial (6 knees; 75 %) and posteromedial groups (7 knees; 87.5 %) collided with the femoral intercondylar wall. The rate of collision was significantly higher at the 90° knee flexion position than that at other angles (p = 0.02). The average shortest distance between the popliteal artery center and the guide pin tip at 0° knee flexion in the posteromedial group (5.4 mm ± 3.4 mm) was significantly greater than that at other knee flexion angles, although the mean distance in the posteromedial group was so negligible that the guide pin could penetrate the popliteal artery.

Conclusions

Knee flexion at 90° causes less damage to the popliteal artery during the transtibial pullout repair of medial meniscus posterior root tears.

Prognostic Factors for Respiratory Dysfunction for Cervical Spinal Cord Injury and/or Cervical Fractures in Elderly Patients: A Multicenter Survey

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

The purpose of this study was to investigate the prognosis of respiratory function in elderly patients with cervical spinal cord injury (SCI) and to identify predictive factors.

METHODS

We included 1353 cases of elderly cervical SCI patients collected from 78 institutions in Japan. Patients who required early tracheostomy and ventilator management and those who developed respiratory complications were defined as the respiratory disability group. Patients' background characteristics, injury mechanism, injury form, neurological disability, complications, and treatment methods were compared between the disability and non-disability groups. Multiple logistic regression analysis was used to examine the independent factors. Patients who required respiratory management for 6 months or longer after injury and those who died of respiratory complications were classified into the severe disability group and were compared with minor cases who were weaned off the respirator.

RESULTS

A total of 104 patients (7.8%) had impaired respiratory function. Comparisons between the disabled and non-disabled groups and between the severe and mild injury groups yielded distinct trends. In multiple logistic regression analysis, age, blood glucose level, presence of ossification of posterior longitudinal ligament (OPLL), anterior vertebral hematoma, and critical paralysis were selected as independent risk factors.

CONCLUSION

Age, OPLL, severe paralysis, anterior vertebral hematoma, hypoalbuminemia, and blood glucose level at the time of injury were independent factors for respiratory failure. Hyperglycemia may have a negative effect on respiratory function in this condition.

Standalone Percutaneous Vertebroplasty for Hyperextension Injuries of the Ankylosed Thoracolumbar Spinal Kyphosis

Hyperextension injuries of the ankylosed thoracolumbar spine, particularly those with preexisting kyphotic deformity, present significant therapeutic challenges. The authors viewed that such injuries without displacement or fractures of the posterior elements are reasonable candidates for standalone percutaneous vertebroplasty (PVP). In such cases, the posterior tension band is spared; thus, fractures are unstable not in the lateral direction, which would lead to the translation of the fracture, but in the vertical direction. Such vertical instability of the fracture can be stabilized if the open mouth-type vertebral cleft is adequately filled with a sufficiently large amount of polymethylmethacrylate (PMMA) cement. Our three patients receiving standalone PVP received injections of 12 mL, 16.5 mL, and 18 mL of PMMA cement. This minimally invasive surgical procedure achieved both short-term (immediate pain relief and mobilization) and long-term (fracture healing) goals.

Ultra-Short Echo Time-MRI T2* Mapping of Articular Cartilage Layers Is Associated with Histological Early Degeneration

OBJECTIVE

Ultra-short TE (UTE) sequences on MRI are a technique that improves the visualization of tissues with short T2 relaxation time, such as deep cartilage layers. In addition, T2* relaxation time calculated from the UTE has the potential to evaluate water molecules bound to the cartilage matrix. This study was performed to determine if there is an association between UTE-T2* relaxation time by cartilage layer and histological degeneration in knee osteoarthritis (OA).

DESIGN

Seven knees that had undergone total knee arthroplasty (TKA) were included in the study, and the lateral tibial cartilage, which had the least degeneration of the resected bones, was used as the sample. The T2* relaxation time of 4 patients with no abnormal findings on MRI was the reference relaxation time. Histological degeneration of TKA samples was assessed by the Mankin score and graded as the early OA group (≤3 points) and the advanced OA group (≥4 points). The association between T2* relaxation time and Mankin grade in each cartilage layer was compared. The effect of angiogenesis to the tidemark on T2* relaxation time was also compared.

RESULTS

T2* relaxation time of the cartilage layer was significantly longer in early OA than that in the control group. In the deep cartilage layer, the mean T2* relaxation time for angiogenesis (-) was 15.7 ms, whereas it was significantly shorter for angiogenesis (+) at 8.2 ms.

CONCLUSIONS

The UTE-T2* relaxation time was associated with histological cartilage degeneration, suggesting a potential application in monitoring early cartilage degeneration.

Repeated intravenous infusion of mesenchymal stem cells enhances recovery of motor function in a rat model with chronic spinal cord injury

Spinal cord injury (SCI) can cause paralysis with a high disease burden with limited treatment options. A single intravenous infusion of mesenchymal stem cells (MSCs) improves motor function in rat SCI models, possibly through the induction of axonal sprouting and remyelination. Repeated infusions (thrice at weekly intervals) of MSCs were administered to rats with chronic SCI to determine if multiple-dosing regimens enhance motor improvement. Chronic SCI rats were randomized and infused with vehicle (vehicle), single MSC injection at week 6 (MSC-1) or repeatedly injections of MSCs at 6, 7, and 8 weeks (MSC-3) after SCI induction. In addition, a single high dose of MSCs (HD-MSC) equivalent to thrice the single dose was infused at week 6. Locomotor function, light and electron microscopy, immunohistochemistry and ex vivo diffusion tensor imaging were performed. Repeated infusion of MSCs (MSC-3) provided the greatest functional recovery compared to single and single high-dose infusions. The density of remyelinated axons in the injured spinal cord was the greatest in the MSC-3 group, followed by the MSC-1, HD-MSC and vehicle groups. Increased sprouting of the corticospinal tract and serotonergic axon density was the greatest in the MSC-3 group, followed by MSC-1, HD-MSC, and vehicle groups. Repeated infusion of MSCs over three weeks resulted in greater functional improvement than single administration of MSCs, even when the number of infused cells was tripled. MSC-treated rats showed axonal sprouting and remyelination in the chronic phase of SCI.

Patient-reported outcome measures after mobile-bearing unicompartmental knee arthroplasty were better than medial opening-wedge high tibial osteotomy in early elderly patients with severe osteoarthritis

BACKGROUND

Many countries are faced with aging populations. However, few studies have directly compared the clinical outcomes of medial opening-wedge high tibial osteotomy (OWHTO) and mobile-bearing unicompartmental knee arthroplasty (MB-UKA) in early elderly patients. Thus, we aimed to investigate the clinical outcomes after OWHTO and MB-UKA in early elderly patients with similar demographics and osteoarthritis (OA) severity.

METHODS

Three hundred and fifteen OWHTO and 142 MB-UKA were performed for medial compartment OA by a single surgeon between August 2009 and April 2020. Among them, patients aged 65-74 years with more than two years of follow-up were enrolled. The patient-reported outcome measures (PROMs), including visual analog scale (VAS) score and Japanese Knee Osteoarthritis Measure (JKOM) score, were compared between both procedures preoperatively and at the last follow-up. The PROMs were compared between the groups by Kellgren-Lawrence (K-L) OA grades.

RESULTS

Seventy-three OWHTO and 37 MB-UKA patients were enrolled. No significant differences were found in the distribution of age, gender, follow-up period, body mass index, and Tegner activity scale between the two procedures. The postoperative PROMs in patients with K-L grade 4 were better after MB-UKA than OWHTO at the mean follow-up of 5 years. No significant difference was found in PROMs in patients with K-L grades 2 and 3.

CONCLUSION

ThePROMs after MB-UKA were superior to that after OWHTO in early elderly patients with severe OA. In particular, pain relief was better after MB-UKA than OWHTO with severe OA. Meanwhile, no significant difference in PROMs was found with moderate OA patients.

LEVEL OF EVIDENCE

Level IVprospective cohort study.

Prognostic impact of respiratory dysfunction in elderly patients with cervical spinal cord injury and/or fractures: a multicenter survey

PURPOSE

To investigate the impact of early post-injury respiratory dysfunction for neurological and ambulatory ability recovery in patients with cervical spinal cord injury (SCI) and/or fractures.

METHODS

We included 1,353 elderly patients with SCI and/or fractures from 78 institutions in Japan. Patients who required early tracheostomy and ventilator management and those who developed respiratory complications were included in the respiratory dysfunction group, which was further classified into mild and severe respiratory groups based on respiratory weaning management. Patient characteristics, laboratory data, neurological impairment scale scores, complications at injury, and surgical treatment were evaluated. We performed a propensity score-matched analysis to compare neurological outcomes and mobility between groups.

RESULTS

Overall, 104 patients (7.8%) had impaired respiratory function. In propensity score-matched analysis, the respiratory dysfunction group had a lower home discharge and ambulation rates (p = 0.018, p = 0.001, respectively), and higher rate of severe paralysis (p < 0.001) at discharge. At the final follow-up, the respiratory dysfunction group had a lower ambulation rate (p = 0.004) and higher rate of severe paralysis (p < 0.001). Twenty-six patients with severe disability required respiratory management for up to 6 months post-injury and died of respiratory complications. The mild and severe respiratory dysfunction groups had a high percentage of severe paraplegic cases with low ambulatory ability; there was no significant difference between them. The severe respiratory dysfunction group tended to have a poorer prognosis.

CONCLUSION

Respiratory dysfunction in elderly patients with SCI and/or cervical fracture in the early post-injury period reflects the severity of the condition and may be a useful prognostic predictor.

Skeletal muscle endurance declines with impaired mitochondrial respiration and inadequate supply of acetyl-CoA during muscle fatigue in 5/6 nephrectomized rats

Chronic kidney disease (CKD)-related cachexia increases the risks of reduced physical activity and mortality. However, the physiological phenotype of skeletal muscle fatigue and changes in intramuscular metabolites during muscle fatigue in CKD-related cachexia remain unclear. In the present study, we performed detailed muscle physiological evaluation, analysis of mitochondrial function, and comprehensive analysis of metabolic changes before and after muscle fatigue in a 5/6 nephrectomized rat model of CKD. Wistar rats were randomized to a sham-operation (Sham) group that served as a control group or a 5/6 nephrectomy (Nx) group. Eight weeks after the operation, in situ torque and force measurements in plantar flexor muscles in Nx rats using electrical stimulation revealed a significant decrease in muscle endurance during subacute phase related to mitochondrial function. Muscle mass was reduced without changes in the proportions of fiber type-specific myosin heavy chain isoforms in Nx rats. Pyruvate-malate-driven state 3 respiration in isolated mitochondria was impaired in Nx rats. Protein expression levels of mitochondrial respiratory chain complexes III and V were decreased in Nx rats. Metabolome analysis revealed that the increased supply of acetyl CoA in response to fatigue was blunted in Nx rats. These findings suggest that CKD deteriorates skeletal muscle endurance in association with mitochondrial dysfunction and inadequate supply of acetyl-CoA during muscle fatigue.NEW & NOTEWORTHY Mitochondrial dysfunction is associated with decreased skeletal muscle endurance in chronic kidney disease (CKD), but the muscle physiological phenotype and major changes in intramuscular metabolites during muscle fatigue in CKD-related cachexia remain unclear. By using a 5/6 nephrectomized CKD rat model, the present study revealed that CKD is associated with reduced tetanic force in response to repetitive stimuli in a subacute phase, impaired mitochondrial respiration, and inadequate supply of acetyl-CoA during muscle fatigue.

Corrigendum: Influences of Orogastric and Nasogastric Tubes on Sucking Pressure during Bottle Feeding in Immature Infants

This corrects the article in Kobe J Med Sci. 2023 May 31; 69(1): E25-E32.

Less tunnel enlargement in triple-bundle versus double-bundle anterior cruciate ligament reconstruction: A randomized clinical trial

BACKGROUND

No study thus far has compared tunnel enlargement between double-bundle and triple-bundle anterior cruciate ligament reconstruction. We compared tibial tunnel enlargement and rate of tibial tunnel coalition between these two reconstructions, hypothesizing that tibial tunnel enlargement in triple-bundle reconstruction is less than that in double-bundle reconstruction, and that the tunnel coalition rate is equal between the two procedures.

METHODS

This prospective randomized clinical trial included 25 patients who underwent computed tomography 2 weeks and 1 year postoperatively. Eleven patients underwent double-bundle anterior cruciate ligament reconstruction and 14 underwent triple-bundle anterior cruciate ligament reconstruction. Tunnel positions and tunnel coalition at the tibial tunnel aperture were assessed using three-dimensional computed tomography. Tunnel enlargement rate was calculated by measuring the sagittal and axial widths of the tibial bone tunnel 10 mm from the tibial tunnel aperture. These parameters were then compared between the groups.

RESULTS

The changes in tunnel positions and tunnel coalitions between groups were not significantly different. On both sagittal and axial views, the tunnel enlargement rates of the medial and lateral sections of the anteromedial bundle in the triple-bundle group were significantly smaller than those in the double-bundle group (sagittal view, p = 0.02 and < 0.01, respectively; axial view, p = 0.02 and ≤ 0.05, respectively). The groups did not differ significantly in terms of posterolateral tunnel enlargement.

CONCLUSION

Tunnel widening in the medial and lateral sections of the anteromedial bundle-associated tibial tunnel in triple-bundle anterior cruciate ligament reconstruction was smaller than that of double-bundle reconstruction. The tunnel coalition rates between the two reconstructions were not significantly different.

Osteophyte Bridge Formation Correlates with Vascular Calcification and Cardiovascular Disease in Diffuse Idiopathic Skeletal Hyperostosis

Diffuse idiopathic skeletal hyperostosis (DISH) is a noninflammatory spondyloarthropathy characterized by ectopic calcification of spinal cord tissue. Its etiology is possibly polygenic. However, its pathogenesis and systemic effects remain unclear. Recent studies have reported a high prevalence of DISH in heart failure patients. The authors investigated how the incidence and severity of DISH are associated with vascular calcification and the occurrence of cardiovascular events. In this retrospective chart review study, 500 patients with cardiovascular disease who underwent surgery (cardiovascular events group) and 500 patients with non-cardiovascular disease who underwent computed tomography scans (non-cardiovascular events group) were randomly selected to investigate the degree of ossification of the anterior longitudinal ligament and the incidence of DISH. We found that the incidence of DISH was higher in patients with cardiovascular events and that patients with DISH had more calcification of the coronary arteries and aorta. Next, we examined the relationship between the degree of coronary and aortic calcification, the incidence of DISH, and the degree of ossification of the anterior longitudinal ligament in the non-cardiovascular event group. The prevalence of DISH in the cardiovascular and non-cardiovascular groups was 31.4% and 16.5%, respectively (p = 0.007). Aortic calcification and a predominant degree of vascular calcification with a certain level of ossification of the anterior longitudinal ligament suggest some correlation between DISH and cardiovascular events. This study is important in understanding the pathophysiology and pathogenesis of DISH.

Static stretching of the ankle prevents cold hypersensitivity associated with limb immobilization in model mice

BACKGROUND

Limb immobilization is considered to contribute to limb pain including hyperalgesia. Approximately 50% of patients with such chronic limb pain complain that their abnormal pain worsens after exposure to cold. However, there have been few studies on the relationship between limb immobilization and cold hypersensitivity. The aim of this study was to examine whether limb immobilization induces cold hypersensitivity, and whether physical exercise such as ankle stretching prevents its induction in model mice.

METHOD

We used forty-four 8-week-old male C57Bl/6J mice, consisting of 32 immobilized mice and 12 control mice. The bilateral hind limbs of the mice were immobilized by a thermoplastic cast. After limb-immobilization for 1 week, changes in mechanical, thermal and cold hypersensitivity, and the expression levels of TRPV1, TRPA1, TRPM8, IL-1β, IL-6, and TNFα in the spinal cord, dorsal root ganglia and the affected hind paw were evaluated in comparison with those in the control mice. In addition, we examined the effect of ankle stretching on the hypersensitivity and expression levels in the limb-immobilized mice.

RESULTS

Mechanical, thermal and cold hypersensitivity were significantly increased in the limb-immobilized mice. In addition, ankle stretching during the immobilization period significantly prevented the increases in those hypersensitivities. There were no significant differences in the expression levels of TRPV1, TRPA1 and TRPM8 among the control, and limb-immobilized mice with and without ankle stretching. The expression levels of IL-1 and IL-6 were significantly increased in the immobilized hind limb paw. Furthermore, ankle stretching significantly prevented the increases in their expression levels.

CONCLUSION

Limb-immobilization induced cold hypersensitivity as well as mechanical and thermal hypersensitivity, and ankle stretching significantly prevented the hypersensitivity induction in the model mice. It would be of great interest to clarify whether a patient with limb-immobilization experiences cold hypersensitivity and whether ankle stretching might prevent hypersensitivity induction in the future.

Mesenchymal Stem Cell Transplantation for Spinal Cord Injury: Current Status and Prospects

Since the 1990s, our group has been conducting basic research on regenerative medicine using various cell types to treat several central nervous system diseases, including spinal cord injury (SCI). We have reported many positive effects of the intravenous administration of mesenchymal stem cells (MSCs) derived from the bone marrow. In the current study, MSCs were administered intravenously to a rat model of severe SCI (crush injury) during the acute to subacute stages-considerable motor function recovery was observed. Furthermore, MSC transplantation in a chronic-phase SCI model improved motor function. In this review, we discuss recent updates in basic research on the intravenous infusion of MSCs and prospects for SCI research.

The function of cruciate ligaments in bi-cruciate retaining Total knee arthroplasty with asymmetrical design

BACKGROUND

Bi-cruciate retaining total knee arthroplasty with an asymmetrical design may improve knee function and clinical outcomes. This study aimed to compare the kinematics, anteroposterior laxity, and in situ forces of the anterior and posterior cruciate ligaments of knees subjected to this treatment with those of healthy knees.

METHODS

Seven fresh-frozen cadaveric knees were tested using a robotic/universal force-moment sensor system. The kinematics during passive flexion-extension motion and anteroposterior laxity for native knee, treated knee, and treated knee with cruciate ligament transection states were investigated. The motions of the intact and treated knees during each test were repeated after anterior/posterior cruciate ligament transection to calculate the in situ force in the ligaments.

FINDINGS

The screw-home movement of normal knees disappeared after treatment. The in situ force of the anterior cruciate ligament in treated knees was higher than that in intact knees at ˃15° during flexion and at 60° and 90° against an anterior force. The in situ force of the posterior cruciate ligament in treated knees was higher at 0°, 15°, and 30° during flexion and at all flexion angles against a posterior force.

INTERPRETATION

The screw-home movement of normal knees decreased, and the in situ force of the anterior and posterior cruciate ligaments increased after treatment.

Relationships of cross-sectional area of the thigh muscles before or after total knee arthroplasty with postoperative pain or patient satisfaction: A retrospective, exploratory study

Background

It has been suggested that lower limb strength related to persistent postsurgical pain. The aim of the present study was to investigate the relationships of pre-operative or postoperative cross-sectional area (CSA) of the thigh muscles with knee pain or patient satisfaction after total knee arthroplasty (TKA).

Methods

Twenty patients who had undergone TKA (3 men and 17 women; mean age 75.2 ± 8.7 years) were included. CSAs of the thigh muscle (THIGH) and quadriceps muscle (QUAD) were retrospectively measured at the CT slice 10-cm superior to the quadriceps tendon insertion at the proximal pole of the patella. THIGH CSA and QUAD CSA to body weight ratios (mm2/kg), THIGH/W and QUAD/W ratios, respectively, were calculated. Knee pain and patient satisfaction postoperatively were also quantified by patient-reported measurements based on the 2011 Knee Society Score (KSS). The correlations between the THIGH/W and QUAD/W ratios and the KSS were evaluated using Spearman's rank correlation coefficient.

Results

The preoperative THIGH/W ratio was positively correlated with KSS-pain, (r = 0.58, p < 0.05). The preoperative QUAD/W ratio was positively correlated with KSS-pain (r = 0.52, p < 0.05) and KSS-satisfaction (r = 0.44, p < 0.05). The postoperative THIGH/W ratio was positively correlated with KSS-pain (r = 0.45, p < 0.05). The postoperative QUAD/W ratio was positively correlated with KSS-pain (r = 0.49, p < 0.05) and KSS-satisfaction (r = 0.48, p < 0.05).

Conclusion

There were significant correlations between quadriceps or thigh muscle CSA and pain or patient satisfaction after TKA. This research may help relieve pain and increase patient satisfaction after TKA in the future.

How Much Experience is Required to Acquire the Skills to Independently Perform Spine Surgery? What Milestones are Needed for Successful Surgery?

Purpose

To assess the number of surgeries needed to acquire the necessary skills to perform spine surgery independently.

Patients and Methods

A questionnaire on 12 different spinal procedures was sent to orthopedic surgeons affiliated with the spine teams of orthopedic departments at either the Akita University or Sapporo Medical University. Participants were asked to identify whether they (A) could independently perform each procedure, (B) could perform each procedure with the assistance of a senior doctor, or (C) were unable to perform each procedure. Those whose response was (A) were asked how many surgeries were required to acquire the necessary skills. Those who responded to (B) or (C) were asked how many surgeries they believed were required to acquire the skills necessary to operate independently. Participants also responded to 10 questions on surgical training techniques and rated the usefulness of each method.

Results

A total of 55 spine surgeons responded to the questionnaire. Group A required significantly fewer surgeries in the following categories to become independent than required Group C: upper cervical spine surgery (7.3/19.3), anterior cervical decompression/fusion (6.7/28.8), posterior cervical decompression/fusion (9.5/27.3), lumbar discectomy (12.6/26.7), endoscopic lumbar discectomy (10.2/24.2), spinal tumor resection (6.5/37.2), and spinal kyphosis surgery (10.3/32.3). Over 80% of participants responded that the following were effective methods: "surgeries where a senior doctor is the main surgeon, and the respondent is the assistant and observer"; "surgeries where the respondent is the main surgeon, and a senior doctor is an assistant"; "self-study using surgery manuals, articles, and textbooks"; and "training through video surgery sessions".

Conclusion

Surgeons who do not perform specific procedures independently require more surgical experience than those who operate independently. Our results may help develop more efficient training methods for spine surgeons.

Development of CAR-T cells specifically targeting cancer stem cell antigen DNAJB8 against solid tumours

BACKGROUND

As therapy for solid tumours, various tumour antigens have been selected as targets, but CAR-T cells targeting these antigens have shown limited efficacy, in contrast to the effectiveness of CAR-T cells targeting haematological malignancies. In a previous report, we identified a cancer-testis antigen, DNAJB8. DNAJB8 plays a major role in tumorigenicity in cancer stem-like cells/cancer-initiating cells (CSCs/CICs). Here, we report a DNAJB8-reactive CAR yielding anti-tumour effects against renal cell carcinoma (RCC) and osteosarcoma.

METHODS

We constructed a second-generation chimeric antigen receptor (CAR) against HLA-A*24:02/DNAJB8-derived peptide (DNAJB_143) complex (B10 CAR). The reactivity of B10-CAR T cells against T2-A24 cells pulsed with the cognate peptide and an RCC and osteosarcoma cell lines were quantified. The effects of adoptive cell transfer (ACT) therapy were assessed using in vivo xenografted mice models.

RESULTS

B10 CAR-T cells recognised DNAJB8_143-pulsed T2-A24 cells and HLA-A*24:02(+)/DNAJB8(+) renal cell carcinoma and osteosarcoma cell lines. Moreover, ACT using B10 CAR-T cells showed anti-tumour effects against RCC and osteosarcoma cells.

CONCLUSION

B10 CAR-T cells could show specific cytotoxicity against RCC and osteosarcoma cells in vitro and in vivo. B10 CAR-T cells targeting the CSC/CIC antigen DNAJB8 might be a candidate immunotherapy for carcinoma and sarcoma.

T1rho, T2, and T2* relaxation time based on grading of intervertebral disc degeneration

BACKGROUND

Previous studies have explored the biochemical changes of disc degeneration and its relevance in low back pain using various quantitative magnetic resonance imaging (MRI) techniques. However, quantitative evaluation of intervertebral disc (IVD) with MRI such as T1rho, T2, and T2* have not been previously analyzed and compared directly in the same patients.

PURPOSE

To investigate T1rho, T2, and T2* of IVD degeneration in the same patients, reveal the correlation coefficients of these values, and evaluate which values are more sensitive to detect the degree of IVD degeneration.

MATERIAL AND METHODS

The participants were 55 patients who underwent MRI examinations which the investigator classified the degree of IVD degeneration according to the Pfirrmann classification. The T1rho, T2, and T2* values of IVD were analyzed for their classification and were compared.

RESULTS

T1rho, T2, and T2* values were 74.3 ± 7.1, 61.2 ± 6.7, and 46.5 ± 16.3 ms (grade II); 61.6 ± 11.8, 48.9 ± 8.2, and 34.1 ± 11.8 ms (grade III); 50.8 ± 10.8, 38.9 ± 9.8, and 25.4 ± 8.1 ms, (grade IV); 44.5 ± 13.3, 34.8 ± 9.5, and 11.2 ± 6.6 ms (grade V), respectively. Those values significantly decreased with increasing grades, but T1rho and T2 values for grades IV and V were not different.

CONCLUSION

The T1rho and T2 values were excellent for the evaluation of initial to moderate IVD degeneration with water and proteoglycan content. In contrast, the T2* value was suitable for detailed evaluation of progressive IVD, even with poor water content.

High reproducibility of a novel supported anterior drawer test for diagnosing ankle instability

BACKGROUND

The manual traditional anterior drawer test (ADT) is essential for deciding the treatment for chronic ankle instability, but it has been shown to have a comparatively low reproducibility and accuracy, especially in less experienced hands. To clarify the inter-examiner reproducibility, we compared the actual distance of anterior translation between junior and senior examiners in ADT. We also evaluated the diagnostic abilities of traditional ADT, and a novel modified ADT (supported ADT).

METHODS

Thirty ankles were included in this study, and ankle instability was defined using stress radiography. All subjects underwent two methods of manual ADT by junior and senior examiners, and ankle instability was judged in a blinded fashion. The anterior drawer distance was calculated from the lengthening measured using a capacitance-type sensor device.

RESULTS

The degree of anterior translation determined by the junior examiner was significantly lower than that determined by the senior examiner when traditional ADT was performed (3.3 vs. 4.5 mm, P = 0.016), but there was no significant difference in anterior translation between the two examiners when supported ADT was performed (4.6 vs. 4.1 mm, P = 0.168). The inter-examiner reliability of supported ADT was higher than that of traditional ADT. For the junior examiner, the diagnostic accuracy of supported ADT was higher than that of traditional ADT (sensitivity, 0.40 vs. 0.80; specificity, 0.75 vs. 0.80).

CONCLUSION

Supported ADT may have the advantage of being a simple manual test of ankle instability with less error between examiners.

The Relationship between Numbness and Quality of Life

BACKGROUND

Numbness is a term commonly used in clinical practice to describe an abnormal sensory experience that is produced by a stimulus or is present even without a stimulus. However, there is still much that remains obscure in this field, and also, few reports have focused on its symptoms. In addition, while pain itself is known to have a significant impact on quality of life (QOL), the relationship between numbness and QOL is often unclear. Therefore, we conducted an epidemiological survey and analyzed the relationship between painless numbness and QOL, using type, location, and age as influencing factors, respectively.

METHODS

A nationwide epidemiological survey was conducted by mail using a survey panel designed by the Nippon Research Center. Questionnaires were sent to 10,000 randomly selected people aged 18 and over from all over Japan. Out of the 5682 people who responded, the relationship between numbness and QOL was analyzed using the EuroQol 5 Dimension-3L (EQ5D-3L) for patients who are currently experiencing painless numbness.

FINDINGS

The results suggest that painless numbness affects QOL and that QOL decreases as its intensity increases. Furthermore, the two factors of numbness of feet and numbness among the young may be less likely to affect QOL. This study may be of great significance in the field of numbness research.

Risk factors of lower extremity injuries in youth athletes

Objective

Lower extremity sports injuries frequently occur during an individual's growth period. The object of the current study was to analyse the risk factors for lower extremity sports injuries for youth athletes. The secondary objective was to clarify the factors related to new injuries after a lower extremity injury.

Methods

We extracted information on youth athletes (aged 10-15 years) with sports-related disorders. Background data and injury situations were collected via a specific application. During the follow-up period, new injuries were also recorded. The athletes were divided into two groups according to injury location (lower extremity or other). We performed a multiple logistic regression analysis to clarify the association between injury location and background data.

Results

1575 complaints of lower extremity disorders and 328 complaints in other body parts were registered. According to the multiple regression analysis, practice time per week was significantly shorter for the lower extremity group than the other locations group (OR 0.98; 95% CI 0.963 to 0.999). Athletes whose future goal was at the recreational level had a significantly low incidence of new injuries after experiencing lower extremity disorders.

Conclusion

The practice environments and psychological factors should receive more attention to prevent lower extremity injuries.

Measurement of the median nerve strain within the carpal tunnel using a capacitance-type strain sensor: A cadaver study

BACKGROUND

Direct and quantitative measurement of median nerve strain within the carpal tunnel has been difficult because of the technical limitations associated with conventional devices. We used capacitive sensors (C-stretch), which are thin and flexible, to measure the median nerve strain within the carpal tunnel.

METHODS

We used 12 fresh frozen upper extremity specimens. The transverse carpal ligament was left in situ, and we attached the sensor to the palmar surface of the median nerve to measure the nerve strain at 60 degrees of wrist extension. The sensor measured the median nerve strain at both the carpal tunnel site and the proximal to the carpal tunnel site before and after the carpal tunnel release. The amount of nerve excursion during wrist extension was also measured with the length change of the attached suture by a digital caliper.

FINDINGS

The mean median nerve strain within the carpal tunnel [8.07% (95 %CI:7.17-8.97)] was significantly higher than that proximal to the carpal tunnel [5.21% (95 %CI:4.46-5.97)] at the wrist extension. There was no significant difference of the mean nerve excursion within and proximal to the carpal tunnel. The mean nerve strain and excursion were unaffected by carpal tunnel release.

INTERPRETATION

These results indicated that wrist extension position might lead to increased strain on the median nerve within the carpal tunnel compared with at the proximal to the carpal tunnel. We believe that the current study might provide new information and help us understand the pathogenesis of carpal tunnel syndrome.

Reliability and accuracy of the critical shoulder angle measured by anteroposterior radiographs: using digitally reconstructed radiograph from 3-dimensional computed tomography images

BACKGROUND

Accuracy of current standard radiographic measurement of the critical shoulder angle (CSA) is not well established. This study analyzed the reliability and accuracy of the CSA measurements obtained via anteroposterior (AP) radiographs, using a digitally reconstructed radiograph (true AP view) generated from a computed tomography image as the gold standard.

METHODS

The CSA was measured on the radiographs and true AP views of 88 consecutive patients who had undergone shoulder arthroscopy for rotator cuff tears. Intraobserver and interobserver reliabilities of the CSA, measured by 2 orthopedic surgeons, were evaluated, and the average deviation of the CSA between radiographs and true AP views was calculated. Moreover, we compared the deviation of CSA between standard AP films (types A1 and C1) and nonstandard AP films (other types) against the Suter-Henninger criteria.

RESULTS

Intraobserver and interobserver reliabilities were almost perfect on radiographs (0.96, 0.86) and true AP views (0.93, 0.85). The average deviation of CSA was 2.1° ± 1.6° for observer 1 and 2.2° ± 1.9° for observer 2. The percentage of cases with deviations of 2° or more when compared with the true AP view was 42% (37 of 88) for observer 1 and 53% (47 of 88) for observer 2. Only 22% (19 of 88) of films were standard AP films. The average deviation of CSA was not significantly different between standard and nonstandard AP films for observer 1 (standard 1.9° ± 1.3°; nonstandard 2.1° ± 1.7°; P = .76) and observer 2 (standard 1.6° ± 1.5°; nonstandard 2.4° ± 1.9°; P = .09).

CONCLUSION

The CSA measurements using radiography were highly congruent, but a large measurement deviation occurred between radiographs and true AP views. The clinical usefulness and role of CSA in diagnosis require careful consideration.

Ten-year trends in the treatment and intervention timing for patients with metastatic spinal tumors: a retrospective observational study

BACKGROUND

Cancer treatment has recently evolved due to the advances in comprehensive therapies, including chemotherapy and radiotherapy. The aspect of cancer-related bone metastasis has undergone a paradigm shift with the transformation of orthopedic interventions for spinal metastasis. We performed this retrospective observational study to investigate the changes in patient status and metastatic spine-tumor treatment over the past decade.

METHODS

We included 186 patients (122 men and 64 women; mean age: 67.6 years) who were referred to our hospital between 2009 and 2018 and were diagnosed and treated for metastatic spinal tumors. We classified the patients into early (81 patients from 2009 to 2013) and late (105 patients from 2014 to 2018) groups. The following components were investigated and compared between the groups: primary tumor, time taken from subjective-symptom onset to hospital visit, primary tumor evaluation during the visit, walking capacity due to lower paralysis during the visit, local treatment details, and post-treatment functional prognosis.

RESULTS

Predominant primary tumors with similar trends in both groups included lung cancer, multiple myeloma, and prostate cancer. The percentage of non-ambulatory patients during the consultation was significantly lower in the late group (28% vs. 16%, P = 0.04). Among non-ambulatory patients at the time of hospital visit, the mean time from the primary doctor consultation to our hospital visit was 2.8 and 2.1 days in the early and late groups, respectively. In both groups, surgical procedures were performed promptly on the non-ambulatory patients; however, postoperative lower function did not improve in approximately half of the patients.

CONCLUSIONS

Our findings demonstrated that in recent years, patients tended to be referred promptly from their previous doctors under a favorable collaboration system. However, the effectiveness of lower paralysis treatment remains limited, and it is important to raise awareness regarding the importance of early consultation among the general public for earlier detection.

Evaluation of segmental mobility in patients with lumbar spondylolisthesis : A comparison of images from standing flexion-extension and standing/supine slippage

PURPOSE

To evaluate segmental mobility with degenerative lumbar spondylolisthesis (DLS), upright lateral flexion-extension radiographs (FE) are widely used. However, some authors have described that a combination of lateral radiographs in the standing position and supine sagittal image (SS) reveal more segmental mobility than FE. The purpose of this study was to investigate the optimal method for evaluating segmental mobility with DLS.

METHODS

We included 92 consecutive Japanese patients diagnosed with DLS. Sagittal translation (ST) determined by FE and SS were compared. Pathological instability was defined as ST more than 8% of the upper vertebra. Patients were divided into those diagnosed with pathological instability in FE (PI-FE) and those diagnosed with SS (PI-SS), and lumbar lordosis (LL) in the standing position in each group were compared.

RESULTS

ST in FE was significantly greater than in SS. Of 92 patients, 31 had pathological instability in FE or SS ; 17 patients had PI-FE, and 10 patients had PI-SS. LL in the standing position in PI-FE was significantly smaller than in PI-SS.

CONCLUSIONS

ST in FE was greater than that in SS, contrary to previous studies' reports on Caucasians. Since Japanese individuals have smaller LL than Caucasians, FE tends to reveal more segmental mobility than SS. J. Med. Invest. 70 : 135-139, February, 2023.

Effects and limitations of home-based motor-control exercise for chronic low back pain: A single center prospective study

STUDY DESIGN

Prospective single-center observational study.

OBJECTIVE

To investigate the effects and limitations of self-motor-control exercise in patients with chronic low back pain.

SUMMARY OF BACKGROUND DATA

Although exercise therapy and physical therapy have been shown to be effective in treating chronic low back pain, these therapies are often discontinued due to patients' non-compliance, and their effectiveness cannot be fully demonstrated.

METHODS

Fifteen patients with low back pain, no apparent organic disease, who had been symptomatic for at least three months, and could continue motor-control exercise at home for at least six months were included in the study. Low back pain (visual analog scale [VAS]), locomotor 25, stand-up test, two-step test, trunk and total body muscle mass by the impedance method, and spinal sagittal alignment were examined before the intervention to establish a baseline, and at two and six months after the intervention.

RESULT

Significant improvement was observed in the back pain VAS (p<0.01), stand-up test (p = 0.03), two-step test (p = 0.01), and locomotor 25 (p = 0.04) before and after the intervention. In contrast, there were no significant changes in muscle mass and sagittal alignment. The effect of long-term exercise was more pronounced in patients without spinal deformity.

CONCLUSIONS

Self-exercise for patients with chronic low back pain was effective in improving pain and function, although it did not directly affect muscle mass or alignment. Moreover, strength training of the lumbar back muscles alone was not found to be effective in patients with spinal deformities.

A Comparative Study of Foot Range of Motion and Activities of Daily Living Status of Patients Following Ankle Arthrodesis and Tibiotalocalcaneal Arthrodesis

Subtalar arthrodesis in addition to ankle arthrodesis (AA) should have effect on foot motion and functional capabilities pertaining to activities of daily living (ADL); however, it is not well characterized. We compared the foot range of motion and ADL-related functional capabilities between patients who had undergone AA and tibiotalocalcaneal arthrodesis (TTC). Twenty-one AA patients and 10 TTC patients were enrolled. Foot sagittal motion arc was measured by radiographs. Patient satisfaction, ADL, footwear restriction, and rating scale scores were compared between the 2 groups. The mean sagittal motion arc in the AA group (23.5 ± 6.2°) was significantly greater than that in the TTC group (15.3 ± 3.5°). Patient satisfaction and overall ADL status was comparable in the 2 groups. Difficulties in climbing stairs, wearing rubber boots, and sitting in cross-legged position were more frequently reported in the TTC group. Our findings may be valuable for both surgeons and patients in predicting post-treatment ADL status and avoiding over expectations.

A Biomechanical Comparison of 2 Over-the-Top Anterior Cruciate Ligament Reconstruction Techniques: A Cadaveric Study Using a Robotic Simulator

Background

For skeletally immature patients, over-the-top (OTT) anterior cruciate ligament (ACL) reconstruction (ACLR) is preferred. However, increased anterior laxity at deep knee flexion angles remains concerning. We modified the procedure to proximally shift the graft fixation site on the femur to prevent graft loosening at higher knee flexion angles and named it the supra-OTT procedure.

Purpose

To compare anterior laxity and in situ forces of the ACL graft between conventional OTT and supra-OTT ACLR in a cadaveric model.

Study Design

Controlled laboratory study.

Methods

A total of 11 fresh-frozen cadaveric knee specimens underwent 4 robotic testing conditions: ACL intact, ACL resected, conventional OTT, and supra-OTT. For each condition, a 100-N load was applied at 0°, 15°, 30°, 60°, and 90° of knee flexion to simulate the Lachman test or anterior drawer test. In addition, a combined load of 5-N·m internal tibial torque and 10-N·m valgus torque was applied at 15° and 30° of knee flexion as a simulated pivot-shift test. Anterior tibial translation and in situ graft forces were recorded. The only difference between conventional OTT and supra-OTT ACLR was the graft fixation site on the femur. For conventional OTT ACLR, graft fixation was performed just on the proximal and lateral ends of the posterior condyle. For supra-OTT ACLR, the fixation point was around the proximal insertion of the lateral head of the gastrocnemius and the lateral edge of the posterior cortex, approximately 2 cm proximal to the conventional OTT position.

Results

On the simulated anterior drawer test at 60° and 90° of knee flexion, anterior tibial translation after supra-OTT ACLR was significantly smaller than after conventional OTT ACLR (P < .01). However, no significant differences were noted at other flexion angles or on the simulated pivot-shift test between the conventional OTT and supra-OTT procedures. Some overconstraint and higher graft forces were noted with both techniques, but the supra-OTT technique caused even more overconstraint at higher flexion angles.

Conclusion

Supra-OTT ACLR showed better biomechanical performance to control anterior laxity than conventional OTT ACLR at higher knee flexion angles.

Clinical Relevance

The supra-OTT procedure may improve anterior stability at deep knee flexion angles.

Enhanced Network in Corticospinal Tracts after Infused Mesenchymal Stem Cells in Spinal Cord Injury

Although limited spontaneous recovery occurs after spinal cord injury (SCI), current knowledge reveals that multiple forms of axon growth in spared axons can lead to circuit reorganization and a detour or relay pathways. This hypothesis has been derived mainly from studies of the corticospinal tract (CST), which is the primary descending motor pathway in mammals. The major CST is the dorsal CST (dCST), being the major projection from cortex to spinal cord. Two other components often called "minor" pathways are the ventral and the dorsal lateral CSTs, which may play an important role in spontaneous recovery. Intravenous infusion of mesenchymal stem cells (MSCs) provides functional improvement after SCI with an enhancement of axonal sprouting of CSTs. Detailed morphological changes of CST pathways, however, have not been fully elucidated. The primary objective was to evaluate detailed changes in descending CST projections in SCI after MSC infusion. The MSCs were infused intravenously one day after SCI. A combination of adeno-associated viral vector (AAV), which is an anterograde and non-transsynaptic axonal tracer, was injected 14 days after SCI induction. The AAV with advanced tissue clearing techniques were used to visualize the distribution pattern and high-resolution features of the individual axons coursing from above to below the lesion. The results demonstrated increased observable axonal connections between the dCST and axons in the lateral funiculus, both rostral and caudal to the lesion core, and an increase in observable axons in the dCST below the lesion. This increased axonal network could contribute to functional recovery by providing greater input to the spinal cord below the lesion.

The Role of the Medial Meniscus in Anterior Knee Stability

BACKGROUND

Few studies have compared the force distribution between the anterolateral, posterolateral, and medial structures of the knee.

PURPOSE

To investigate the important structures in an intact knee contributing to force distribution in response to anterior tibial load.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine fresh-frozen cadaveric knee specimens underwent robotic testing. First, 100 N of anterior tibial load was applied to the intact knee at 0°, 15°, 30°, 60°, and 90° of knee flexion. The anterior cruciate ligament (ACL), anterolateral capsule, lateral collateral ligament, popliteal tendon, posterior root of the lateral meniscus, superficial medial collateral ligament, posterior root of the medial meniscus (MM), and posterior cruciate ligament were then completely transected in sequential order. After each transection, the authors reproduced the intact knee motion when a 100-N anterior tibial load was applied. By applying the principle of superposition, the resultant force of each structure was determined based on the 6 degrees of freedom force/torque data of each state.

RESULTS

At every measured knee flexion angle, the resultant force of the ACL was the largest of the tested structures. At knee flexion angles of 60° and 90°, the resultant force of the MM was larger than that of all other structures with the exception of the ACL.

CONCLUSION

The MM was identified as playing an important role in response to anterior tibial load at 60° and 90° of flexion.

CLINICAL RELEVANCE

In clinical settings, the ACL of patients with a poorly functioning MM, such as tear of the MM posterior root, should be monitored considering the large resultant force in response to an anterior tibial load.

Usefulness of echocardiographic parameters in predicting the incidence of ischemic stroke in Japanese patients with non-valvular atrial fibrillation

Background

Atrial fibrillation (AF) is a risk factor for ischemic stroke (IS). We developed a novel risk score of IS (HELT-E2S2 score) in non-valvular atrial fibrillation (NVAF) patients from the combined database of 5 major AF registries in Japan. However, this score does not include echocardiographic (Echo) parameters that have been reported to be risk factors of IS, such as left atrial diameter (LAD) enlargement or increased relative wall thickness (RWT) of left ventricle (LV).

Purpose

To investigate the predictive value of Echo parameters in Japanese patients with NVAF.

Methods

After excluding patients without the Echo data, 6,032 NVAF patients were analyzed in the present study. LAD was measured in the parasternal long axis view at the end-ventricular systole. RWT was calculated as (2x posterior wall thickness)/ LV end-diastolic dimension. We compared clinical characteristics and the incidence of IS between NVAF patients divided by LAD level (High/Low LAD group) and RWT level (High/Low RWT group). To balance the follow-up period among the registries, event data from individuals whose follow-up period exceeded 730 days were excluded from the analysis.

Results

The optimal cut-off value of LAD and RWT to predict the incidence of IS with the receiver operating characteristic analysis was 43.3 mm and 0.4167, respectively. Between the High/Low LAD groups (High LAD: n=2,640 vs. Low LAD: n=3,392), age (70.3±12.1 vs. 68.3±12.5 years; p&lt;0.001), CHA2DS2-VASc score (3.02±1.84 vs. 2.57±1.78; p&lt;0.001), HELT-E2S2 score (2.20±1.31 vs. 1.55±1.33; p&lt;0.001), the prescription of oral anticoagulants (OACs) (69.5 vs. 51.5%; p&lt;0.001), LV ejection fraction (60.4±13.4 vs. 64.4±10.7%; p&lt;0.001) and RWT (0.401±0.091 vs. 0.396±0.082; p=0.02) were significantly different. Between the High/Low RWT groups (High RWT: n=2,293 vs. Low RWT: n=3,739), percentage of female (35.6 vs. 27.8%; p&lt;0.001), age (71.2±12.1 vs. 68.0±12.4 years; p&lt;0.001), CHA2DS2-VASc score (3.08±1.82 vs. 2.58±1.79; p&lt;0.001), HELT-E2S2 score (2.10±1.39 vs. 1.67±1.31; p&lt;0.001), the prescription of OACs (62.6 vs. 57.4%; p&lt;0.001), LV ejection fraction (65.5±9.9 vs. 60.9±13.0%; p&lt;0.001) and LAD (43.0±8.1 vs. 42.4±8.3; p=0.004) were significantly different. In Kaplan-Meier analysis, the incidence of IS was different between the groups during the median follow-up period of 730 days (High LAD vs. Low LAD; 1.82 vs. 1.00 per 100 person-years; p&lt;0.001, by log-rank test, High RWT vs. Low RWT; 1.86 vs. 1.06; p&lt;0.001) (Figure). Both High LAD (hazard ratio: 1.65, 95% CI: 1.12–2.46; p=0.01) and High RWT (hazard ratio: 1.43, 95% CI: 1.01–2.04; p=0.045) were independent predictors of the incidence of IS after adjustment by the components of the HELT-E2S2 score and other clinically relevant variables including co-existing diseases, gender, and the prescription of OACs (Table).

Conclusion

Echo parameters, LAD and RWT, were independently associated with the incidence of IS among Japanese patients with NVAF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Prediction of recurrence after catheter ablation for atrial fibrillation using left atrial morphology on preprocedural computed tomography: application of radiomics

Background

Radiomics is a comprehensive analysis methodology of medical image and involves the extraction of numerous features from standard imaging. Its usefulness has been reported mainly in the field of cancer for diagnosis and prediction of prognosis. In the territory of cardiac imaging, several reports have investigated the utility of radiomics for classifying the risk of prognosis in coronary artery disease, and few practical applications have been reported for patients with atrial fibrillation (AF) who underwent pulmonary vein isolation (PVI). Although the left atrial morphology can affect the clinical course after the PVI procedure, it is unclear whether the radiomics feature values of the left atrial morphology on cardiac computed tomography (CT) is useful for predicting the AF recurrence after PVI.

Purpose

To predict the recurrence of AF after PVI using the radiomics feature values of the left atrial morphology on cardiac computed tomography (CT).

Methods

We analyzed 525 consecutive three-dimensional cardiac CT in patients with atrial fibrillation who underwent PVI from 2018 to 2019 in our institute. After marking the region of interest on left atrium (including the root of pulmonary veins) semiautomatically, 107 radiomics feature values were obtained by Python program. After excluding the parameters having collinearity or with low predictive capability for the recurrence of AF after PVI, 42 parameters were applied to the final prediction model. Two prediction models were constructed by multivariate Cox regression analysis and machine learning model by support vector machine algorithm.

Results

The area under the curve (AUC) for predicting the recurrence of AF was 0.815 for the multivariate Cox regression model and 0.826 for the machine learning model by support vector machine.

Conclusion

The radiomics feature values on preprocedural cardiac CT could be helpful for predicting the recurrence of AF after PVI. Since radiomics feature analysis yields a huge number of numerical values representing the left atrial morphology in a reproducible manner, it would provide a new direction to construct a good prediction model using machine learning including artificial intelligence out of a routine cardiac CT scan.

Funding Acknowledgement

Type of funding sources: None.

Advantage of POLARx over ARCTIC FRONT ADVANCE PRO during pulmonary vein isolation for paroxysmal atrial fibrillation

Introduction

The electrical pulmonary vein (PV) isolation has been established as a curative therapy for paroxysmal atrial fibrillation (AF). Arctic Front™cryoballoon has been used worldwide for AF cryoablation. Recently, a new cryoballoon, POLARxTM CRYOABLATION system have been introduced, of which material of the balloon is softer and the N2O gas flow rate is higher.

Purpose

The aim was to investigate the procedural parameter and efficacy of POLARx comparing with Arctic Front.

Methods

This retrospective single center study included 101 consecutive patients who underwent paroxysmal AF ablation using cryoballoon at Keio University hospital from April 2021 to March 2022. The procedural data including the cryoballoon temperature and the number and duration of cryoablation were compared between POLARx (POLARx group) and ARCTIC FRONT ADVANCE PRO (AFA group). After the cryoablation, we added the radiofrequency application in order to maximize the isolated area when the voltage was remained inside PV (Figure 1). The necessities of the additional radiofrequency applications were also compared.

Results

In the present study, 64 patients in AFA group and 37 patients in POLARx group were analyzed. POLARx group included younger population and less females (62.8±9.9 vs 67.5±9.4 year of age, P=0.02; 13.5 vs 32.8%, P=0.04). There was no significant difference in comorbidities and examination data such as left atrium diameter or brain natriuretic peptide level. The minimal cryoballoon temperatures reached in POLARx group were lower than AFA group (−59.3±6.2 vs −47.7±7.5°C, P&lt;0.01). No difference was found in the total number and duration of cryoablation and the time to isolate PV (6.1±2.1 vs 5.9±1.6, P=0.69; 790.2±256.1 vs 776.1±235.0 sec, P=0.69; 41.8±21.3 vs 47.1±29.6 sec, P=0.44, respectively). With regard to individual PVs, the total number and duration were tended to be larger at right superior PV in POLARx group (1.9±1.1 vs 1.4±0.7, P=0.01; 231.8±123.8 vs 193.2±83.0 sec, P=0.07), while there was no significant difference at the other PVs. The rate of successful PV isolation by a single cryo-application was not different between AFA and POLARx group (54.3 vs 61.4%, P=0.17). The additional radiofrequency applications were more frequent in AFA group (14.8 vs. 4.9%, P=0.003). There was a significant difference at right inferior PV (32.8 vs 8.1%, P=0.01), while not at left superior PV, left inferior PV and right superior PV (9.4 vs 2.9%, P=0.42; 9.4 vs 5.7%, P=0.71; 7.8 vs 2.7%, P=0.41). Phrenic nerve injury was occurred 1 case in both group and esophageal ulcer was occurred in 1 case in AFA group. No other complication including cardiac tamponade was occurred.

Conclusion

The total number and duration of cryoablation were not significantly different between AFA and POLARx group, except for right superior PV. There was an advantage in largely isolating right inferior PV in POLARx group comparing with AFA group.

Funding Acknowledgement

Type of funding sources: None.

Real-world effectiveness and safety of edoxaban in patients with and without a history of ischaemic stroke: results from the ETNA-AF programme

Background

Atrial fibrillation (AF) patients with a history of ischaemic stroke (IS) have a higher risk for recurrent IS events and were largely excluded from the pivotal, randomised, controlled phase 3 trials on oral anticoagulants. Thus, the effectiveness and safety of edoxaban in these patients need to be studied in a real-world setting.

Purpose

To compare edoxaban real-world effectiveness and safety in AF patients with or without an IS history.

Methods

The Global ETNA-AF programme (EU: NCT02944019, Japan: UMIN000017011, South Korea/Taiwan: NCT02951039) integrates data from multiple prospective, observational, noninterventional regional studies of AF patients receiving edoxaban for stroke prevention. This snapshot analysis summarises baseline characteristics with medical history and 2-year annualised rates of all-cause death, cardiovascular (CV) death, stroke (haemorrhagic, ischaemic, any), and bleeding (including major bleeding [MB], major gastrointestinal [GI] bleeding, intracranial haemorrhage [ICH], clinically relevant nonmajor bleeding [CRNMB], and any bleeding) in patients with or without IS history.

Results

Data from 27,333 patients (3215 with prior IS and 24,118 without) from Europe, Japan, South Korea, and Taiwan were analysed. Patients with IS history were significantly older, more likely ≥75 years of age, and had a lower mean body weight and creatinine clearance (P&lt;0.0001 for all; Table). Patients with IS history also had significantly higher baseline stroke (CHA2DS2-VASc) and bleeding (HAS-BLED) risk scores (P&lt;0.0001 for both; Table). A significantly higher percentage of patients with IS history had previous transient ischaemic attacks (TIA), MB, and ICH (P&lt;0.0001 for all; Table). Patients with IS history more likely received edoxaban 30 mg vs 60 mg at baseline (P&lt;0.0001). Effectiveness and safety outcomes hazard ratios are shown in the Figure. Patients with IS history had significantly higher rates of all-cause death (4.5% vs 3.0%; P&lt;0.0001), CV death (1.9% vs 1.4%; P=0.004), IS (2.5% vs 0.5%; P&lt;0.0001), any stroke (3.1% vs 0.7%; P&lt;0.0001), and TIA (0.5% vs 0.2%; P=0.0002). Patients with IS history had significantly higher annualised rates of MB (1.6% vs 1.0%; P&lt;0.0001), major GI bleeding (0.8% vs 0.5%; P=0.003), ICH (0.6% vs 0.3%; P&lt;0.0001), haemorrhagic stroke (0.5% vs 0.2%; P&lt;0.0001), CRNMB (2.3% vs 1.3%; P&lt;0.0001), and any bleeding (6.1% vs 4.1%; P&lt;0.0001).

Conclusions

Patients with AF who have a history of IS are more likely elderly; have histories of MB, ICH, and TIA; and have high baseline stroke and bleeding risk scores. Patients with IS history receiving edoxaban have a considerably higher likelihood of experiencing IS or TIA, whereas the risk of experiencing any bleeding event (with the exception of ICH) is only modestly higher than in those without IS history.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo

Clinical phenotypes of older adults with non-valvular atrial fibrillation not treated with oral anticoagulants by hierarchical cluster analysis in the ANAFIE registry

Background and purpose

The All Nippon AF In the Elderly (ANAFIE) registry evaluated the current status of anticoagulant therapy in older adult patients (aged ≥75 years) with non-valvular atrial fibrillation (NVAF) in Japan. Although older adult NVAF patients requires anticoagulation therapy, some of them do not receive it and the reasons would be diverse. Therefore, we aimed to identify the phenotypes of older adult NVAF patients not treated with oral anticoagulants using data from the ANAFIE registry.

Methods

In this sub-analysis of the ANAFIE registry, the phenotypes of patients who were not receiving anticoagulants at baseline were evaluated by cluster analysis using Ward's linkage hierarchical algorithm. We used 20 categorical variables and 6 continuous variables for the cluster analysis which were used as the risk factors in the main analysis of the ANAFIE registry [1].

Results

Of 33,275 enrolled patients, 2445 (7.3%) were not receiving anticoagulants. Two clusters were identified: (1) elderly paroxysmal AF (PAF) patients with a low prevalence of comorbidities (58%) and (2) very elderly patients with a high previous major bleeding prevalence (42%). For each cluster, mean ages were 79.9 and 85.7 years, mean CHADS2 scores were 2.3 and 3.1, PAF prevalences were 83% and 54%, heart failure prevalences were 18% and 48%, the proportions of patients with a history of major bleeding were 0% and 25%, the proportions of patients with a history of catheter ablation were 21% and 8%, respectively. Annual incidence rates of each cluster were 2.62% and 9.08% for all-cause death, 1.72% and 5.83% for major adverse cardiovascular or neurological events, 1.22% and 3.14% for stroke or systemic embolism, and 0.53% and 1.43% for major bleeding.

Conclusions

In this cohort of elderly NVAF patients not receiving anticoagulants, more than half (∼60%) were PAF patients and had a low incidence of adverse outcomes. The remaining ∼40% were characterized as very elderly patients with a high prevalence of previous major bleeding and a high incidence of adverse outcomes.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Co., Ltd.

Prediction of persistent form of atrial fibrillation using left atrial morphology on preprocedural computed tomography: application of radiomics

Background

Radiomics is a comprehensive analysis methodology of medical image and involves the extraction of numerous features from standard imaging. Its usefulness has been reported mainly in the field of cancer for diagnosis and prediction of prognosis. In the territory of cardiac imaging, several reports have investigated the utility of radiomics for classifying the risk of prognosis in coronary artery disease, and few practical applications have been reported for patients with atrial fibrillation (AF) who underwent catheter ablation (CA).

Purpose

The objective of this study was to evaluate the utility of radiomics analysis applying to the preprocedural cardiac computerized tomography (CT) in AF patients.

Methods

We analyzed 525 consecutive three-dimensional CT in patients with AF who underwent CA. After marking the region of interest on left atrium (LA) (including the root of pulmonary veins) semiautomatically, 107 radiomics feature values were obtained by Python program. We calculated the amount of representative statistics for each radiomics feature for prediction of persistent AF (PeAF) (Wald statistic in logistic regression analysis) and LA diameter (LAD) (coefficient correlation), respectively. To compare the distribution of the two statistics, the relative importance (calculated as the ratio of statistic to the maximum statistics among 107 radiomics features [%]) was calculated for each statistic. Further, we compared the area under the curve (AUC) in receiver operation characteristic (ROC) curve analysis for predicting PeAF between radiomics features (multivariate model) and LAD (single parameter).

Results

In 525 study patients (age 63±10 years old and male 80%), 253 (48%) were PeAF and remaining were paroxysmal AF (PAF). LAD was 43±6 mm and 38±6 mm in patients with PeAF and PAF, respectively. The relative importance of the two statistics (Wald statistic for PeAF and coefficient correlation for LAD) of 107 radiomics features are displayed in Figure 1, which shows similar distribution of two statistics. It means the close relationship between LA morphology and the form of PeAF in AF patients and the radiomics features possibly well explain the relationship. In Figure 2, the predictive capability for PeAF was compared between radiomics feature values and LAD, where the AUC was 0.85 (95% confidence interval [CI], 0.82–0.88) and 0.73 (95% CI, 0.69–0.78) for radiomics feature values and LAD, respectively (Delong test, P&lt;0.001).

Conclusion

We applied the radiomics features for the evaluation of LA morphology. The predictive capability for PeAF in the prediction model with the radiomics feature values was much better than that with LAD alone. Since radiomics feature analysis yields a huge number of numerical values representing the LA morphology in a reproducible manner, it would provide a new direction to construct a good prediction model using machine learning including artificial intelligence out of a routine cardiac CT scan.

Funding Acknowledgement

Type of funding sources: None.

Two-year effectiveness and safety outcomes in 27,333 edoxaban-treated patients with and without a history of major bleeding from the Global ETNA-AF programme

Background

Atrial fibrillation patients with a history of major bleeding (MB) are at high risk of future bleeding events; this history was an exclusion criterion in pivotal phase 3 trials of anticoagulation for stroke prevention. Real-world edoxaban effectiveness and safety in patients with a history of MB were analysed from the global ETNA programme.

Purpose

To compare edoxaban effectiveness and safety in AF patients with or without an MB history.

Methods

The Global ETNA-AF programme (EU: NCT02944019, Japan: UMIN000017011, South Korea/Taiwan: NCT02951039) integrates data from multiple prospective, observational, noninterventional regional studies of AF patients treated with edoxaban for stroke prevention. This snapshot analysis summarises global baseline characteristics and 2-year annualised rates of all-cause death, cardiovascular death, stroke (haemorrhagic, ischaemic, any), and bleeding (including MB, major gastrointestinal bleeding [MGIB], intracranial haemorrhage [ICH], clinically relevant nonmajor bleeding, and any bleeding) in patients with or without MB history.

Results

Data from 27,333 patients (479 with MB history and 26,854 without) from Europe, Japan, South Korea, and Taiwan were analysed. Patients with MB history were significantly older (P&lt;0.0001) and more likely to be ≥75 years of age (P=0.0003), to be male (P=0.024), and to have a lower body weight and creatinine clearance (P&lt;0.0001 for both) (Table). Globally, antiplatelet use was significantly higher in patients with MB history compared with patients without (P=0.005). Patients with MB history were more likely to have previously diagnosed heart failure (HF, P=0.001) and to receive 30 mg vs 60 mg edoxaban at baseline (P&lt;0.0001). Hazard ratios for effectiveness and safety outcomes are shown in the Figure. Patients with MB history had significantly higher annualised rates of all-cause death (5.7% vs 3.1%; P&lt;0.0001), ischaemic stroke (1.8% vs 0.7%; P=0.002), and any stroke (3.1% vs 0.9%; P&lt;0.0001) than patients without MB history. Patients with MB history also had significantly higher annualised rates of MB (3.6% vs 1.0%; P&lt;0.0001), MGIB (1.5% vs 0.5%; P=0.001), ICH (1.5% vs 0.3%; P&lt;0.0001), fatal bleeding (0.9% vs 0.2%; P&lt;0.0001), and fatal ICH (0.5% vs 0.1%; P=0.0002). Among patients with MB history, the annualised rate of ICH did not differ between patients with ICH history (1.42%/yr) vs without (1.65%/yr); whereas the annualised rate of MGIB was significantly higher in patients with MGIB history vs without (4.14%/yr vs 1.08%/yr; P=0.0337).

Conclusions

Patients with AF receiving edoxaban and who have a history of MB are more likely elderly, male, and have comorbidities, including HF. These patients are also more susceptible to any adverse cardiovascular event. ICH event rates were not higher in patients with prior ICH than those with non-ICH major bleedings, whereas history of MGIB was associated with a high risk of MGIB recurrence.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo

Prognosis of low-flow low-gradient aortic valve stenosis with atrial fibrillation

Background

Patients with Low-flow low-gradient (LFLG) aortic valve stenosis (AS) have possibly poor prognosis. Recently, it was reported that the LFLG AS patients have similar outcomes compared to high-gradient (HG) patients but worse outcomes compared to the normal-flow low-gradient [NFLG: SVi≥35 ml/m2, mPG &lt;40mmHg] subgroup. The main determinant of LF state in severe AS patients with preserved LVEF are male gender, heart rate, LV volume and atrial fibrillation (AF). However, the relationship between the comorbidity with AF in LFLG AS and the risk of heart failure (HF) remains unclear.

Purpose

We elucidated about the prognosis of LFLG AS with AF.

Methods

We included 225 consecutive patients with severe AS (SAS, iAVA&lt;0.6 cm2/m2) from 2013 to 2020. Among these patients, high-gradient SAS [HG-SAS; mean pressure gradient (mPG) ≥40 mmHg, n=88] and LFLG AS [stroke volume index (SVi) ≤35 ml/m2, mPG &lt;40 mmHg, n=82] patients was extracted and the baseline characteristics including the presence or absence of AF were evaluated. The primary endpoint was worsening HF that required unplanned hospitalization or readjustment of HF drug therapy.

Results

Among patients with HG SAS and LFLG AS, worsening HF was observed in 65 patients. LFLG AS patients exhibited a higher oral rate of renin-angiotensin-system inhibitors (p=0.02). In addition, SVi and E/e' was lower in LFLG AS patients compared with HG SAS [SVi; 29.4 (24.4–34.0) versus 37.7 (28.2–45.3), p&lt;0.0001, E/E'; 16.0 (13.1–21.5) vs 20.9 (16.0–27.4), p=0.002]. There is no differences between 2 groups in AF prevalence. Furthermore, 2 groups were subdivided as follow; HG SAS with AF (n=25), HG SAS without AF (n=63), LFLG AS with AF (n=24), LFLG AS without AF (n=58). The Kaplan Meier curves demonstrated LFLG SAS with AF experienced higher rate of worsening HF compared with HG SAS without AF and equivalent rate of worsening HF compared with HG SAS with AF (log rank, p&lt;0.001). In the Cox hazard analysis among the LFLG AS patients, LFLG AS with paroxysmal AF (pAF, n=12) instead of chronic AF (cAF, n=12) showed a higher risk for worsening HF compared with those without AF (HR 5.0; 95% CI, 1.8–14; p=0.0028, HR 1.9; 95% CI, 0.62–5.8; p=0.26, respectively).

Conclusion

LFLG AS with AF exhibited a poor prognosis for HF compared with HG SAS without AF and equivalent rate of worsening HF compared with HG SAS with AF. Furthermore, the presence of pAf was associated with an increased risk of HF in patients with LFLF AS. Thus, intervention including drugs and catheter ablation for pAF in LFLG AS patients could lead to prevent worsening clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.