Defining refractoriness in single atrial beats using autoencoder neural networks

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIH

Background

Mapping atrial fibrillation (AF) is complicated by signals which may be local or far-field, but which cannot currently be separated. This could be clarified by a knowledge of atrial refractory periods, yet these are difficult to define from monophasic action potentials (MAP) in patients. We hypothesized that transfer learning using an autoencoder neural network (ANN), first trained with less-noisy ventricular signals, can be applied to de-noise and classify atrial MAPs.

Methods

We first developed an ANN to encode MAPs in 5706 ventricular MAPs from N=42 patients (age 65±13y) during pacing (fig1. A-B). This created a latent feature space. We now tuned the ANN to classify atrial MAPs in a different cohort of patients with AF. We used a statistical loss function based on mathematical optimization to evaluate the accuracy of final representations of the MAP and classify the different signals.

Results

The autoencoder ANN reconstructed ventricular MAPs with an average similarity of 0.85 (range 0-1) (an example is shown in fig 1.B). We tested on 3000 atrial MAPs in AF patients (N=21; 67±5y, 13 women). Atrial MAPs were accurately represented (fig 1.E-F) with similarity indices that were higher than those obtained by a panel of 3 experts. Fig. 1 shows the reconstruction of different signals: ventricular MAP (fig 1.A-B), ventricular MAP with pacing artifact (fig. 1.C-D), atrial MAP (transfer learning is assumed in here; fig 1.E-F) and noise or signals with morphologies of no interest (fig 1.G-H). Fig. 2 shows the classification of signals according to the similarity metric that allows distinguishing among the different types of signals without manual annotation (p<0.05 between groups).

Conclusion

Atrial refractory periods can be defined in single beats in AF patients using autoencoder neural networks and transfer learning. This approach can separate atrial beats from far-field ventricular beats and other sources of noise. Future work can study if this approach can be used to improve AF mapping or define novel physiological phenotypes.

Machine-learned physiological signatures from the ECG predict sudden death in ischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institute of Health (NIH)

Background

Low left ventricular ejection fraction (LVEF) is an imperfect predictor of sudden cardiac death (SCD) in patients with ischemic cardiomyopathy. Novel features from the ECG might provide a readily available tool to better predict risk.

Purpose

We hypothesized that machine learning (ML) of the ECG can be used to predict SCD, and the ML-learned ECG features could be referenced to interpretable intracardiac signals (monophasic action potentials: MAP) to provide mechanistic insights.

Methods

We studied 5603 ECG Lead V1 beats in 41 patients (64±10 Y) with coronary disease and LVEF≤40% in steady-state pacing. Patients were randomly allocated to independent training and test cohorts in a 70:30 ratio, repeated K=10-fold. Support vector machines were trained to predict mortality at 3Y from the top 20 features derived from these beats. Patient-level predictions were made by computing an ECG score that indicates the proportion of test set beats in that patient computed by the beat-level model to predict death. Explainability analysis was performed using the arithmetic mean of MAP and ECG beats that predicted SCD versus those that predicted survival.

Results

Fig 1A. shows ECG lead V1 and MAP in a 79 Y man with LVEF 29%. Fig 1B shows the dataflow in the study. Predictive accuracies of ML models were 78 and 70% and optimal with 20 features for both ECG and MAP models respectively (Fig. 1C). Beat-level predictions in the validation (n=1678 Lead I beats) cohorts yielded c-statistics of 0.78 with the ECG (95% CI, 0.62–0.91) and 0.75 with MAPs (95% CI, 0.75-0.76) (data not shown). In multivariable patient-level models, c-statistic was 0.87 with ECGs (95% CI, 0.76-0.98) (Fig 1D) and 0.82 with MAPs. On explainability analysis, ECG beats that predicted SCD (Fig 2; red) had lower amplitude and more notched T-waves in lead V1 than beats that predicted no SCD (Fig 2; blue). MAP that predicted SCD had higher repolarization current at the same time points. Both QT duration (ECG) and action potential duration (MAP) did not differ (Fig 2).

Conclusions

Machine learning of the ECG reveals novel predictors of SCD risk in patients with ischemic cardiomyopathy analogous to those identified in intracardiac signals. This approach can be used as a point-of-care ECG risk tool to improve risk stratification and allocation for ICD therapy beyond LVEF alone and may shed insights into the pathophysiology of ventricular arrhythmias.

[The prognostic effects of two comprehensive geriatric assessment methods in elderly patients with acute myeloid leukemia]

Objective: To evaluate the prognostic effects of two comprehensive geriatric assessment (CGA) methods in elderly patients with acute myeloid leukemia (AML). Methods: Ninety-seven patients with newly diagnosed AML at Beijing Hospital from August 2008 to December 2019 were included (≥60 years old). All patients were evaluated by two methods of CGA. One was IACA index proposed by Beijing Hospital, including instrumental activities of daily living (IADL), age, Charlson comorbidity index (CCI), albumin; the other was proposed by Italian FIL study group (FIL-CGA), including activities of daily living (ADL), IADL, age, and modified cumulative illness rating score for geriatrics (MCIRS-G). Results: Among 97 patients, 54 patients received standard chemotherapy, 16 with decitabine, 2 with targeted therapy and 25 with the best supportive therapy. The overall response rate (ORR) in 72 treated patients were 67.7%, 33.3% and 0 respectively in fit, unfit and frail groups according to IACA index (P=0.001). Based on FIL-CGA, the ORRs of fit, unfit and frail groups were 52.5%, 41.7% and 35.0% respectively (P=0.418). The 1-year OS rates of fit, unfit and frail groups regarding IACA method were 78.7%, 27.7% and 0 respectively (P<0.01). The 1-year OS rates of fit, unfit and frail groups regarding FIL-CGA method were 67.8%, 28.2% and 13.9% respectively (P<0.01), while no significant difference was seen between unfit group and frail group (P=0.111). The early death rates of fit, unfit and frail groups by IACA were 0, 6.0% and 28.6% respectively (P=0.006), while those by FIL-CGA were 2.3%, 5.9%, 13.9% respectively (P=0.123). Conclusion: Compared with FIL-CGA method, IACA predicts more effectively the treatment response, survival and early mortality in elderly patients with AML.

[Reoperation and perioperative management of residual cyst wall with perineal intractable sinus after resection of presacral cyst tumors]

Objective: To investigate the reoperation and perioperative management of residual cyst wall with perineal intractable sinus after resection of presacral cyst tumors. Methods: The clinical data of 29 patients with residual cyst wall and perineal intractable sinus after resection of presacral cyst tumors in Affiliated Cancer Hospital of Zhengzhou University from January 2014 to August 2019 were reviewed, including the characteristics of the residual cyst wall with perineal intractable sinus after resection of presacral cyst tumors, surgical method, and perioperative management. Results: Twenty-nine patients with residual cyst wall and perineal intractable sinus after resection of presacral cyst tumors, including 9 cases of epidermoid cysts, 7 cases of dermoid cysts, 10 cases of mature teratomas and 3 cases of malignant cysts (including malignant transformation of caudate cyst and teratoma); The 29 patients underwent posterior approaches for cyst resection in other hospital before, of whom 1 patient underwent posterior combined with transabdominal approach. All of thes patients underwent resection of residual presacral cyst wall and perineal intractable sinus in our hospital, of whom 25 patients underwent a transperineal approach through an arc-shaped incision anterior to the apex of the coccyx, and the other 4 patients underwent transperineal arc-shaped incision combined with transabdominal approach. All of the patients were cured without serious complications occurring, postoperative pathological and the magnetic resonance imaging diagnosis showed that the residual cyst wall and perineal intractable sinus were all completely removed. Conclusion: Appropriate surgical approache and perioperative treatment for the patients with residual cyst wall and perineal intractable sinus are very important to promote the resection of residual cyst wall and the healing of perineal intractable sinus.

[Autologous stem cell transplantation improves outcomes of patients with multiple myeloma receiving proteasome inhibitors and lenalidomide treatment]

OBJECTIVE

To evaluate the effect of autologous stem cell transplantation (ASCT) on treatment response and survival outcomes in patients with newly diagnosed multiple myeloma (MM) receiving treatments with proteasome inhibitors and lenalidomide.

METHODS

We retrospectively collected the clinical data of newly diagnosed MM patients, who were eligible for ASCT and received proteasome inhibitors or lenalidomide-based treatment in our hospital from January, 2015 to December, 2019. The patients were divided into transplantation group and non-transplantation group, and in transplantation group, the patients received 4 to 6 courses of induction therapy with proteasome inhibitors or lenalidomide before ASCT, while those in the non-transplantation group received more than 8 courses of induction and consolidation therapy with proteasome inhibitors or lenalidomide-based regimens. The therapeutic efficacy and survival outcomes of the patinets were compared between the two groups.

RESULTS

A total of 105 patients were enrolled in the study, including 48 (45.7%) in transplantation group and 57 (54.3%) in non-transplantation group. The two groups were matched for gender, age and treatment response after 4 courses of induction therapy (P > 0.05). The rate of optimal response before relapse differed significantly between the two groups (P=0.000), and the patients receiving ASCT had significantly higher rates of complete response (85.4% vs 54.4%, P= 0.001) and very good partial response or better (95.8% vs 73.7%, P=0.002) than those without ASCT. At the end of follow-up, the median progression-free survival in the transplantation group was not reached, as compared with 29 months in the nontransplantation group (P=0.013). The median overall survival (OS) in the two groups was not reached, but the OS was better in the transplant group than in the non-transplant group (P=0.022).

CONCLUSION

ASCT can further improve the depth of remission and survival outcomes in patients with newly diagnosed MM receiving treatments with proteasome inhibitors and lenalidomide.

POS0315 LONG-TERM SAFETY AND EFFICACY OF LENABASUM DURING 3 YEARS IN AN OPEN-LABEL EXTENSION (OLE) OF A PHASE 2 STUDY OF LENABASUM IN REFRACTORY SKIN DISEASE IN DERMATOMYOSITIS (DM)

Background:

Lenabasum is a synthetic, non-immunosuppressive, selective cannabinoid receptor type 2 agonist that activates resolution of inflammation. Lenabasum had acceptable safety and tolerability and improved efficacy outcomes in the initial 16-week double-blinded, randomized, placebo-controlled Part A of Phase 2 trial JBT101-DM-001 (NCT02466243) in DM subjects with refractory skin involvement. In that study, lenabasum or placebo was added to stable background treatment, with immunosuppressive therapies allowed.

Objectives:

To assess long-term safety and efficacy in DM subjects in this study.

Methods:

Subjects who completed Part A of the Phase 2 study (n = 22) were eligible to receive oral lenabasum 20 mg BID in an open-label extension (OLE) that assessed safety and efficacy at 4 weeks, then every 8 weeks.

Results:

20/22 (91%) eligible subjects enrolled in the OLE, following a mean interval of 31 weeks from the end of Part A, during which they continued to receive standard-of care treatments, to the start of the OLE during which lenabasum 20 mg BID was added. 17/20 (85%) subjects were on stable baseline immunosuppressive drugs. At the time of this data cut-off, 17 subjects were still enrolled, 17 had completed 140 months (2.7 years), and 15 had completed 156 months (3 years) of OLE dosing.

All OLE subjects experienced at least 1 adverse event (AE), with 118 AEs during the OLE through Dec 2020. Most AEs were mild (n = 111, 94%), with 2 severe AEs (fatigue and metastatic prostate cancer) considered unrelated to lenabasum. AEs occurring in ≥ 3/20 OLE subjects were: URI (n = 5); fatigue (n = 4); nausea (n = 3); common cold (n = 3); UTI (n = 3); and DM flare (n = 3). No serious AEs related to lenabasum have been reported in this OLE to date. No subject discontinued the OLE because of an AE related to lenabasum.

Improvement was seen in multiple physician- and patient-reported efficacy outcomes. CDASI activity score improved through the first 15 months of lenabasum treatment in the OLE and remained stable thereafter, with an improvement of ~20 points from the beginning of the study maintained from Month 15 through Year 3 in the OLE. CDASI damage score increased through the first year of the OLE, even though skin activity was decreasing, but lessened thereafter, returning after 3 years to about the same level it was at the beginning of the OLE. Other outcomes shown in Figure 1 followed the same general pattern as CDASI activity score, with improvement through the first 12-16 months of the OLE, then stability thereafter. Of note, 2 subjects had disease flares shortly after stopping lenabasum for conclusion of the OLE.

Conclusion:

Lenabasum continues to have a favorable safety and tolerability profile in the OLE of the Phase 2 trial JBT101-DM-001 with no serious AEs or study discontinuations related to lenabasum. The CDASI activity score and multiple other physician and patient-reported outcomes improved and have remained stable, showing durability of improvement in these patients with refractory skin disease. Skin damage was reversible and began to improve once skin activity stabilized. The limitations of attributing this improvement to lenabasum in the setting of open-label dosing is acknowledged. These data support further testing of lenabasum for the treatment of DM, and a Phase 3 study of lenabasum in DM is ongoing.

Figure 1.

Change from Baseline in Selected Efficacy Outcomes in OLE of Phase 2 Trial JBT101-DM-001

Disclosure of Interests:

Victoria Werth Grant/research support from: Investigator for Corbus Pharmaceuticals and received funding to conduct trials, Josef Concha: None declared, Julie Burroughs: None declared, Joyce Okawa: None declared, Rui Feng: None declared, Anisha Jobanputra: None declared, Robert Borucki: None declared, Kathleen Hally Employee of: Employee of Corbus Pharmaceuticals, Emily Hejazi: None declared, Michael Tillinger Employee of: Employee of Corbus Pharmaceuticals, Scott Constantine Employee of: Employee of Corbus Pharmaceuticals, Nancy Dgetluck Employee of: Employee of Corbus Pharmaceuticals, Barbara White Employee of: Employee and stockholder of Corbus Pharmaceuticals

[The efficacy and safety of daratumumab in relapsed and refractory multiple myeloma]

Objective: To investigate the efficacy and safety of daratumumab in relapsed and refractory multiple myeloma (RRMM). Methods: The efficacy and adverse events (AEs) of daratumumab based regimens were retrospectively analyzed in 37 patients with RRMM from Peking University People's Hospital, Beijing Hospital and Fu Xing Hospital affiliated to Capital Medical University in China. The deadline for inclusion was December, 2019. Results: Among the 37 patients, 35 patients were available for response evaluation. The overall response rate (ORR) was 68.6%, which was better in patients receiving 16 mg/kg daratumumab than in those with fixed doses of 800 mg daratumumab [ORR: 78.3%(18/23) vs. 40.0%(4/10)]. The percentage of infusion related reactions of daratumumab was 27.0%(10/37). The most common hematological AEs were lymphocytopenia and thrombocytopenia, with the incidences of grade 3 or more severe 59.5%(22/37) and 43.2%(16/37) respectively. Pulmonary infections(37.8%, 14/37) were the most common non-hematological AEs. One patient with positive hepatitis B surface antigen (HBsAg) and two patients dependent on dialysis were safely treated with daratumumab. Conclusion: Daratumumab is highly effective in relapsed and refractory multiple myeloma. Adverse reactions are mild and well tolerable.

[Clinical study of exploring new axillary zone in sentinel lymph node biopsy of breast cancer]

Objective: To explore the application of axillary reverse mapping (ARM) in breast cancer sentinel lymph node biopsy (SLNB), and to collect and record patient's data during operation. Through the specific experimental data, the anatomical location and morphology of the intercostal brachial nerve (ICBN) and the anatomic relationship of the axillary lymph nodes were analyzed to accurately locate the anatomical division of the axillary fossa of sentinel lymph node (SLN) and ARM lymph nodes. Methods: The technique of methylene blue staining for SLN combined with indocyanine green fluorescent staining for axillary reverse mapping was used to analyze the patients of Tianjin Central Hospital of Gynecology Obstetrics from June 2017 to June 2018. The clinical data of 35 patients with T1-2N0M0 breast cancer were analyzed. Results: Of the 35 patients, two cases were excluded from metastatic carcinoma of the SLN. Thirty-three cases were included in the data analysis. Three cases of ICBN were located 0-2.0 cm (9.09%) from the lower edge of the iliac vein, 27 cases were located at 2.0-4.0 cm (81.82%), and 3 cases of ICBN were located greater than 4.0 cm (9.09%). In the region of 0-2.0 cm from the lower edge of the iliac vein, 1-2 ARM lymph nodes were found in 5 cases; in the 2.0-4.0 cm area, SLN was found in 33 cases, 4 of which found 1 coincident lymph node; at>4.0 cm ARM lymph nodes and overlapping lymph nodes were not found in the cm region, and 1-2 SLNs were found in 3 cases. Conclusions: Individual ICBNs vary greatly, with different shapes and distances from the lower edge of the axillary vein. The axillary region below the iliac vein can be divided into three regions: ARM region (0-2.0 cm); SLN region (2.0-4.0 cm); and sentinel gate region (>4.0 cm). The position 2.0 cm from the lower edge of the iliac vein can be used as the boundary between the ARM lymph node and the SLN. 4. There is a certain proportion of coincidence rate between SLN and ARM lymph nodes.

Metallic elements and Pb isotopes in PM2.5 in three Chinese typical megacities: spatial distribution and source apportionment

Heavy metal pollution in fine particulate matter (PM_2.5) is a serious environmental and health concern in China, particularly during winter. Here, we detected 40 elements in 24 h integrated daily PM_2.5 samples collected in January 2014 from three typical Chinese metropolises (Beijing, Changchun, and Chengdu) to reflect elemental spatial variations, local sources, and regional transport. The measured elemental concentrations in Changchun were 11.1% and 48.4% higher than those in Beijing and Chengdu, respectively. Thus, PM_2.5 from Changchun exhibited high levels and diversity in the elemental profile (characterized by high concentrations of industrial emission elemental markers). The results of elemental ratios and Pb isotopes proved that, except for a coal combustion source, vehicular emissions contributed more to PM_2.5 heavy metals in Beijing than in the other two cities; Changchun PM_2.5 elements received large contributions from industrial sources, including iron and steel manufacturing, and automobile industry. Moreover, crustal dust from long-range transport of regional air masses from the northwest regions of China played a crucial role in determining elemental levels in Beijing and Changchun, accounting for more than 50% of source intensity. However, a specific dominant source was not determined in Chengdu; the contribution of anthropogenic dust, mainly from construction activities, needs to be paid attention in Chengdu eastern area. This study contributed to enhancing our understanding of elemental spatial distribution characteristics and sources and to setting more judicious standards and strategies for PM_2.5 bound heavy metals in China.

[Thalidomide in refractory Crohn's disease: long-term efficacy and safety]

Objective: To analyze the long-term efficacy and safety of thalidomide on refractory Crohn's disease (CD). Methods: A total of 79 patients with refractory CD in the First Affiliated Hospital of Sun Yat-sen University treated with thalidomide were enrolled in this retrospective study from September 2005 to July 2018. Clinical effects and adverse drug reactions were recorded and assessed. Results: In this cohort,69 patients were treated with thalidomide for ≥6 months. Sixty-eight patients among the 69 patients achieved complete clinical remission and were followed up for a median 33.5 months (range, 7-110 months). Seventeen cases relapsed during follow-up. The cumulative probabilities of remaining in remission at 12, 24, 60 months were 88.6% (95%CI 80.6%-96.6%), 80.7% (95%CI 70.3%-91.1%), 53.7% (95%CI 32.1%-75.3%) respectively. Disease activity was the only variable associated with relapse risk, with a hazard ratio (HR) of 3.559 for Crohn's disease activity index (CDAI) ≥220(95%CI 1.213-10.449, P<0.05). Adverse reactions were recorded in 42 (53.2%) patients including12 (15.2%) leading to discontinuation of thalidomide. No serious side effects were observed in all subjects. Conclusions: This study suggests a long-term benefit of maintenance treatment with thalidomide in refractory CD.Moderate to severe patients have an increased risk of relapse. The high incidence of drug adverse reactions may restrain the clinical application of thalidomide.

CT characteristics of patients infected with 2019 novel coronavirus: association with clinical type

AIM

To summarise the features of chest computed tomography (CT) of a series of patients infected with 2019 novel coronavirus (2019-nCov) to speed up recognition and have a better understanding of COVID-19 disease.

MATERIALS AND METHODS

The clinical information and chest CT images of 93 patients infected with 2019-nCov from multiple centres were reviewed.

RESULTS

Of the 93 cases, abnormalities in 91 cases were located at the subpleural level, presenting with ground-glass opacity (GGO; n=69, 74.2%) and consolidation (n=56, 60.2%) in multiple lobes. Other CT features included vascular dilatation (n=83, 89.2%), interlobular septal thickening (n=29, 31.2%), bronchodilatation (n=44, 47.3%), the crazy-paving sign (n=34, 36.6%), the sieve-hole sign (n=12, 12.9%), pleural thickening (n=21, 22.6%), and pleural effusion (n=8, 8.6%). Multiple lobe involvement, including the presence of consolidation, the crazy-paving sign, interlobular septal thickening, pleural thickening and pleural effusion, was more common in critical patients with heavy/critical infection (p<0.05), whereas the presence of GGO, involvement of one or two lobes, and the halo sign were more common in patients with mild/common-type infections (p<0.05). Moreover, older age, higher body temperature, complaints of chest tightness and breathlessness, and lymphopenia was associated with heavy/critical infections.

CONCLUSION

The CT and clinical appearances of COVID-19 are variable and reflect the severity of COVID-19 to some extent.