P1460Seismocardiographic measurement of systolic time intervals in left ventricular dysfunction: validation with transthoracic echo

Background

Systolic time intervals (STI) measured using Transthoracic Echo (TTE) have been shown to be sensitive indicators of contractile performance, but TTE is limited to a hospital setting. Recent advances in technology have enabled the simultaneous measurement of Electrocardiograms (ECG) and Seismocardiograms (SCG) using wearable devices. However, the use SCG to measure STIs has not been validated in a mobile setting, or on pathological subjects.

Purpose

To test the validity of an automated algorithm for measuring STIs using a wearable device recording ECG and SCG, in subjects with varying degrees of left ventricular dysfunction.

Methods

179 Patients with suspected left ventricular dysfunction were assessed using TTE performed by a Cardiologist. Patients were simultaneously fitted with a novel wearable device worn on a chest strap, recording SCG and single-lead ECG data, while the cardiologist measured the pre-ejection period (PEP) and left ventricular ejection time (LVET) with the patient in a supine position. Of these subjects 29 (16.2%) were diagnosed with Dilated cardiomyopathy (DCM), and 109 (60.8%) had Ischemic Heart disease.

The SCG and ECG data recorded on the wearable device was then analysed using a peak-detection algorithm, which detected the Q,R,S points on the ECG, and then determined the 4 most prominent peaks in the SCG signal corresponding to each R-peak. Heart rate, patient's age, gender and SCG time intervals were then used in a DecisionTree algorithm to determine the values of PEP and LVET, which were were then compared against those determined by the cardiologist using TTE.

Results

The correlation coefficient (r2) between PEP calculated using TTE, and the values obtained from the algorithm analyzing SCG data was 0.92 while the mean error was 7.47%. The r2 between the LVET calculated using the TTE and the algorithm was 0.75, while the mean error was 8.53% (p-value<0.001 for all cases).

Results All Subjects With IHD Without IHD With DCM Without DCM Number of Subjects 178 109 69 29 149 PEP (r2) 0.92 0.89 0.94 0.88 0.91 PEP (% age error) 7.47 7.50 7.42 6.99 7.56 LVET (r2) 0.75 0.81 0.66 0.55 0.83 LVET (% age error) 8.53 6.69 11.4 20.42 6.16 DCM, Dilate Cardiomyopathy; IHD, Ischemic Heart Disease.

ECG + SCG signals for a DCM patient

Conclusion

The algorithm-derived STIs measured by SCG correlate well with those measured by TTE across most patient groups, including those with Dilated Cardiomyopathy and Ischemic Heart Disease, opening prospects for continuous remote monitoring of STIs in a mobile setting.

Acknowledgement/Funding

Fourth Frontier Technologies

A novel study to examine the association of PCSK9 rs505151 polymorphism and coronary artery disease in north Indian population

There is a drastic increase in the number of people suffering from coronary artery disease (CAD) worldwide with Indians being no exception. Being a developing country and experiencing a dramatic shift in lifestyle and eating habits, urbanization and industrialization, all these factors have collectively predisposed the Indian population towards CAD and the prevalence data arequite alarming. Genetic studies have disclosed the role of genes in CAD susceptibility and severity. One such gene is proprotein convertase subtilisin/kexin type 9 (PCSK9) which is sought to modulate the cholesterol levels and hence, has implications in CAD. We aim to explore the association of PCSK9 A/G (rs505151) polymorphism and hence, the susceptibility towards CAD in the north Indian population. Five-hundred angiographically confirmed CAD patients and 500 healthy individuals as control were genotyped by polymerase chain reaction-restriction fragment length polymorphism. Statistical analysis revealed a significant association with the G allele with odds ratio (OR)=1.50, 95% confidence interval (CI)=1.22-1.85 and P=0.000. Also, a strong association was observedfor CAD risk with OR=1.590, 95% CI=1.106-2.284 and P=0.012. However, the homozygous GG mutant genotype was found to be completely absent from our population. Analysis of the dominant model also revealed an association with CAD risk. Our work demonstrated for the first time the association of PCSK9 A/G (rs505151) polymorphism with CAD risk in the north Indian population.

Transtracheal endoscopic-assisted resection of a rare inflammatory myofibroblastic tumour in adult trachea: a case report

SUMMARY

Inflammatory myofibroblastic tumours (IMTs) are rare and clinically benign in childhood, and malignant in adults. The aetiology of IMTs is not clear, and recent studies report it as true neoplasm rather than a reactive or inflammatory lesion. IMTs can involve any part of the body, but are usually common in lungs. These are rarely seen in adults and tracheal involvement is also rare in both adults and children. We describe an 18-year-old woman who presented with respiratory difficulty to the emergency department. On clinical examination, the patient had complete absence of breath sounds on the right side of the chest. CT of the chest and virtual bronchoscopy revealed a polypoidal soft tissue mass lesion involving the carina with occlusion of right main bronchus. Endoscopic-assisted resection was performed under general anaesthesia and the final pathological diagnosis was tracheal IMT.

Detecting Mycobacterium tuberculosis using the loop-mediated isothermal amplification test in South Africa

SETTING

In South Africa, KwaZulu-Natal is the epicentre of the human immunodeficiency virus (HIV) epidemic, where approximately 70% of people with tuberculosis (TB) are co-infected with HIV. Undiagnosed TB contributes to high mortality in HIV-infected patients. Delays in diagnosing TB and treatment initiation result in prolonged transmission and increased infectiousness.

OBJECTIVE

To evaluate the LoopampTM MTBC Detection kit (TB-LAMP; based on the loop-mediated isothermal amplification assay), smear microscopy and Xpert test with the gold standard of mycobacterial culture.

METHODS

Sputum samples were collected from 705 patients with symptoms of pulmonary TB attending a primary health care clinic.

RESULTS

The TB-LAMP assay had significantly higher sensitivity than smear microscopy (72.6% vs. 45.4%, P < 0.001), whereas specificity was slightly lower (99% vs. 96.8%, P = 0.05), but significantly higher than Xpert (92.9%, P = 0.004). There was no significant difference in sensitivity of smear-positive, culture-positive and smear-negative, culture-positive sputum samples using TB-LAMP vs. Xpert (respectively 95.9%/55.9% vs. 97.6%/66.1%; P =0.65, P = 0.27). The positive predictive value of TB-LAMP was significantly higher than that of Xpert (87.5% vs. 77.0%; P = 0.02), but similar to that of smear microscopy (94.2%; P = 0.18). The negative predictive value was respectively 91.9%, 92.5% (P = 0.73) and 83.1% (P = 0.0001).

CONCLUSION

Given its ease of operability, the TB-LAMP assay could be implemented as a point-of-care test in primary health care settings, and contribute to reducing treatment waiting times and TB prevalence.

Effect of the Factor V Leiden Mutation on the Clinical Expression of Severe Hemophilia A

To determine whether the factor V Leiden mutation is associated with decreased bleeding in individuals with severe hemophilia A, factor concentrate utilization, maximum annual number of bleeding episodes, and the prevalence of hemophilic arthropathy between carriers and non-carriers of the factor V Leiden mutation were compared. Heterozygosity for the factor V Leiden mutation was found in 6 of 137 subjects (4.4%). Carriers of the factor V Leiden mutation utilized less factor concentrate (geometric mean: 310 vs. 1185 units/kg/year) and had fewer bleeding episodes than non-carriers (proportion with 10 or fewer bleeding episodes in their worst year: 50 vs. 11%). However, the factor V Leiden mutation was not associated with the absence of arthropathy. The intron 22 inversion mutation of the factor VIII gene was tested for in a subgroup of 80 subjects, but it was not found to be a significant variable for any of the bleeding endpoints. The results of this small study are consistent with the hypothesis that the factor V Leiden mutation imparts a protective effect; however, a larger confirmatory study in which the factor VIII molecular defects can be controlled for is needed. Furthermore, most severe hemophiliacs who used fewer than 200 units/kg/year of factor concentrate or who had experienced 10 or fewer bleeding episodes per year did not carry the factor V Leiden mutation, suggesting that the proportion of severe hemophiliacs whose mild clinical course can be attributed to the factor V Leiden mutation is small.

The rise and potential fall of pancreas transplantation

BACKGROUND

The aim of this review is to bring pancreatic transplantation out of the specialist realm, informing practitioners about this important procedure, so that they feel better equipped to refer suitable patients for transplantation and manage, counsel and support when encountering them within their own speciality.

SOURCES OF DATA

Narrative review conducted in May 2017. OVID interface searching EMBASE and MEDLINE databases, using Timeframe: Inception to June 1, 2017. Articles were assessed for clinical relevance and most up to date content with articles written in english as the only inclusion criteria. Other sources, used included conference proceedings/presentations, unpublished data from our institution (Oxford Transplant Centre).

AREAS OF AGREEMENT

Pancreas transplantation has evolved from an experimental procedure to the gold standard of care for patients with type 1 diabetes and uraemia. Currently, it remains the most effective method of establishing and maintaining euglycemia over the longer term, halting and potentially reversing many of the secondary complications associated with diabetes. Significant improvements to quality of life and better life expectancy make it in the longer term, a lifesaving procedure compared to waiting candidates.

AREAS OF CONTROVERSY

The future of solid organ pancreas transplantation remains uncertain, with extensive comorbidity and advances in alternative therapies makes the long-term growth of the procedure questionable.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

Therapies to alleviate problems associated with ischaemia reperfusion injury, graft pancreatitis and more effective monitoring methods for detecting and treating organ rejection are the key areas of growth.

Splenic artery pseudoaneurysm causing delayed gastrointestinal bleeding after gastrocolonic fistula following sleeve gastrectomy

Delayed gastrointestinal bleeding in the context of a gastric fistula is a very rare complication of longitudinal sleeve gastrectomy. We report the case of a patient who presented with massive gastrointestinal bleeding from a pseudoaneurysm arising from the splenic artery following complications after a longitudinal sleeve gastrectomy several months previously. The case was successfully managed with angiographic embolisation and we present our experience with recommendations for managing this rare but life-threatening complication.

Are we Overdiagnosing Bipolar Disorder?

Bipolar disorder (BD) is an established diagnostic entity used by clinicians for over a century. It is distinguished by the distinct manic and depressive episodes with interepisode euthymia. It has an illness course where both recovery and recurrences are a rule and has a good long-term prognosis, as reported earlier by Emil Kraeplin. There is an opinion in the current literature that BD is often underdiagnosed as unipolar depression, and based on that opinion, spectrum concept was introduced. Here, we present 5 cases to highlight that overdiagnosis of BD is also not infrequent and we discuss its reasons and therapeutic implications.

Listeria monocytogenes PdeE, a phosphodiesterase that contributes to virulence and has hydrolytic activity against cyclic mononucleotides and cyclic dinucleotides

We have identified and partially characterized a putative HD domain hydrolase, LMOf2365_2464, which is highly expressed during listerial intracellular replication. LMOf2365_2464 is annotated as a putative HD domain-containing hydrolase. The ability of an isogenic mutant strain, F2365Δ2464, to adhere, invade and replicate in intestinal epithelial cells (Caco-2) was significantly lower than parent strain F2365. Colonization of mouse liver and spleen by L. monocytogenes F2365 was significantly higher than it was for the mutant. The recombinant protein showed phosphodiesterase activity in the presence of divalent metal ions, indicating its role in nucleotide metabolism. It has activity against several cyclic nucleotides and cyclic dinucleotides, but its strongest activity is against cyclic di-AMP and cyclic AMP. Based on this enzymatic activity, we designated LMOf2365_2464 phosphodiesterase E (PdeE).

Adhesion and Invasion Assay Procedure Using Caco-2 Cells for Listeria monocytogenes

Listeria monocytogenes is an important Gram-positive foodborne pathogen that is a particular problem in ready-to-eat food. It has an ability to survive in harsh conditions like refrigeration temperatures and high salt concentrations and is known to cross intestinal, placental and blood-brain barriers. Several cancerous cell lines like cervical, liver, dendritic, intestinal and macrophages have been used to study in vitro propagation and survival of listeria in human cells. Human intestinal epithelial cells have been used to study how listeria crosses the intestinal barrier and cause infection. The protocol in this articles describes the procedures to grow Caco-2 cells, maintain cells and use them for adhesion and invasion assays. During adhesion assay the cells are incubated with listeria for 30 min but in invasion assay the cell growth is arrested at several time points after infection to monitor the growth and survival rate of listeria in cells.

Abstract P1-05-01: Landscape of somatic mutations in inflammatory breast cancer whole-genome sequences

Goal: Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer that is characterized by a highly metastatic phenotype. Numerous previous attempts failed to identify, recurrent, IBC-specific gene expression or DNA copy number alterations. We performed whole genome sequencing (WGS) of IBC biopsies obtained before any therapy to define a comprehensive genomic landscape of this disease.

Methods: Illumina paired-end whole genome sequencing (WGS) of 20 IBC (n=9 ER+, n=11 ER-) and matched normal samples were performed with median coverage of 60X and 40X for cancer and normal, the percentages of mapped reads were 99.3% and 99.2%, respectively. We identified germ-line and somatic variants, indels as well as large scale structural variants, using GATK Haplotype Caller, MuTect and CREST, respectively. We performed the same analysis on WGS data from 23, age, race and ER and HER2 matched, non-IBC (n=12 ER+, n=11 ER-) from the TCGA for comparison. Variants in both coding and noncoding sequences were categorized by FunSeq to identify potential drivers. Mutation clustering in each gene, as well as significantly mutated non-coding regulatory modules, were identified using LARVA. DeconstructSigs were used to decompose the mutational spectrum of each cancer into 30 validated, mutational signatures provided by COSMIC. Contributions of each validated signature to mutations in IBC vs. non-IBC were compared using Welch's t-test.

Results: We identified 118,818 somatic variants in the IBC samples (median: 3,856; minimum: 1,109; maximum: 24,815) including 1,060 variants (~0.9%) in coding regions. 5,287 somatic indels and 5,959 large scale structural variants were detected including 1,028 insertions and 1,857 deletions. Recurrent, non-synonymous mutations were detected in the coding region of GRIN2A gene in 3/20 IBC samples (15%), (previously reported as a potential driver mutation in 1.7% of breast cancers). Other significant mutations in coding regions included GRHL1, PIK3R2, ESR1, FLG2 and etc. Three DNase I hypersensitive sites (DHSs) in non-coding regions were altered in 20% (4/20) IBC samples vs. fewer than 8.7% (2/23) in non-IBC. Mutational frequency of GATA3 is 80.0% vs. 47.8% (p=0.03), and PTEN is 45.0% vs. 73.9% (p=0.05), in IBC vs. non-IBC samples when including both coding and non-coding variants. Contributions of mutational signature 9, that is associated with polymerase η , were significantly higher in IBC cohort than non-IBC cohort (p-value=0.056).

Conclusion: This is the first whole genome sequencing analysis of IBC and comparison with the results from non-IBC. We identified promising candidate drivers in the coding sequence and in non-coding regulatory modules of expressed genes. We also identified mutational signature 9, and mutations in several DHS as significantly more frequent alterations in IBC compared to non-IBC.

Citation Format: Li X, Krishnamurthy S, Kumar S, Reddy S, Woodward W, Reuben J, Hatzis C, Ueno NT, Gerstein M, Pusztai L. Landscape of somatic mutations in inflammatory breast cancer whole-genome sequences [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-01.