Burden of arrhythmias in patients with obstructive sleep apnea and its impact on mortality: a descriptive study from the National Inpatient Sample

Background

Obstructive sleep apnea (OSA) accounts for significant mortality and morbidity worldwide. A limited but emerging literature has revealed increased risk of sudden cardiac death in patients with OSA. There is paucity of data on arrhythmia burden in patients with OSA, particularly in hospitalized patients.

Purpose

Therefore, we sought to study the prevalence of atrial and ventricular arrhythmias among hospitalized patients with OSA and examine its impact on sudden cardiac death and in-hospital mortality.

Methods

All patients over 18 years of age with OSA were extracted from the National Inpatient Sample (NIS) from 2009–10 using 9th revision of International Classification of Diseases (ICD-9) code 327.23. Demographic data, hospital characteristics, comorbid conditions, and arrhythmia burden including different types of arrhythmia were identified. Clinical outcomes were in-hospital mortality, length of stay and sudden cardiac death. Logistic regression analysis was performed to determine the impact of arrhythmia on in-hospital mortality in patients with OSA. Hospital level discharge weights provided by NIS were used to obtain national estimates of OSA hospitalizations.

Results

OSA was prevalent in 2.8% (n=1,114,297) of all hospitalizations among which 20.1% had any arrhythmia (n=223,974). Patients with arrhythmia were older, more likely to be males, and had higher prevalence of risk factors and comorbid conditions except for chronic liver disease, and smoking (p<0.0001 for all). Arrhythmia burden analysis revealed increase prevalence of both atrial and ventricular arrhythmia in patients with OSA compared to general population. In-hospital mortality (3.48% vs 1.27%; p<0.0001), length of hospital stay (6.4±0.1 vs 5±0.1; p<0.001) and sudden cardiac death (1.34% vs 0.4%; p<0.0001) were higher in OSA patients with arrhythmia compared to OSA patients without arrhythmia. Presence of arrhythmia in OSA patients was associated with increased in-hospital mortality in both unadjusted [OR 2.79 (2.62–2.98); p<0.001] and multivariable model adjusted for all risk factors and comorbid conditions [OR 1.83 (1.69–1.98); p<0.001].

Conclusion

Arrhythmia burden was higher in patients with OSA compared to the general population. Presence of arrhythmia among OSA patients was independently associated with increased in-hospital mortality and longer hospital stays. Routine evaluation to assess arrhythmia burden in patients in OSA could be a potential target to decrease sudden cardiac death in this high risk population.

Funding Acknowledgement

Type of funding sources: None.

Srinivasan S, Raja N, Reddy E. P–077 Performance of the postwash total motile sperm count as a predictor of pregnancy at the time of intrauterine insemination

Study question

Is the performance of the postwash total motile sperm count a predictor of pregnancy at the time of intrauterine insemination?

Summary answer

The number of motile spermatozoa inseminated (NMSI) in IUI can be used to define clear range of pre /postwash sperm parameters.

What is known already

There is no consensus about the optimal number of motile spermatozoa inseminated (NMSI) required for a reasonable chance of pregnancy after IUI. A meta-analysis of 16 studies assessing NMSI and IUI outcomes, concluded that at cut-off levels between 0.8 and 5 million, defined as the ability to predict failure to become pregnant. The purpose of this study is to determine the range of NMSI as a predictor of success in IUI.

Study design, size, duration

This prospective study includes 60 patients who underwent semen analysis at an academic infertility centre (SRIHER) during the month of December 2020 and January 2021.

Participants/materials, setting, methods

A total of 60 infertile couples who underwent IUI at our academic centre were enrolled in our study. A detailed history and infertility work up was done before proceeding for IUI, as per the department protocol. The semen was prepared by discontinuous 2 layered density gradient method. The results were analyzed by patient factors including age, BMI, semen parameters, NMSI. The NMSI were divided into 4 groups: A (<1), B (1–4), C (5–9), D (>10).

Main results and the role of chance

The mean age of the infertile couples who underwent IUI was (28.2 ± 3.8) in females and (31.8 ± 3.8) in males respectively. The sperm parameters such as concentration (21.8 ± 14.8), motility (53.15 ± 13.22), morphology (2.43 ± 1.33) respectively. When the NMSI was group C (5–9 x 10 6) the pregnancy rate was 38.5% whereas the pregnancy rate was 37.5% in group D ( >10 x 10 6). In the other sub groups such as group A(<1 x 10 6) and group C (1–4 x 10 6) the pregnancy rate was 14.2% and 12.5% respectively.

Limitations, reasons for caution

Infertile men with Azoospermia, Men with Retrograde ejaculation, Testicular samples, Epididymal samples, Infected samples. All of the above samples were avoided. It cannot be used for counselling during the initial infertility workup, but only during/after the IUI procedure.

Wider implications of the findings: The results suggest that NMSI can be a predictor of success in IUI in patients who are < 30 years of age & ≥35 years, NMSI does not appear to be a useful. The effect of NMSI on pregnancy rate needs to evaluated on a larger scale .

Trial registration number

Not applicable

Trilaciclib prior to chemotherapy and atezolizumab in patients with newly diagnosed extensive-stage small cell lung cancer: A multicentre, randomised, double-blind, placebo-controlled Phase II trial

Trilaciclib is an intravenous CDK4/6 inhibitor administered prior to chemotherapy to preserve haematopoietic stem and progenitor cells and immune system function from chemotherapy-induced damage (myelopreservation). The effects of administering trilaciclib prior to carboplatin, etoposide and atezolizumab (E/P/A) were evaluated in a randomised, double-blind, placebo-controlled Phase II study in patients with newly diagnosed extensive-stage small cell lung cancer (ES-SCLC) (NCT03041311). The primary endpoints were duration of severe neutropenia (SN; defined as absolute neutrophil count <0.5 × 109 cells per L) in Cycle 1 and occurrence of SN during the treatment period. Other endpoints were prespecified to assess the effects of trilaciclib on additional measures of myelopreservation, patient-reported outcomes, antitumour efficacy and safety. Fifty-two patients received trilaciclib prior to E/P/A and 53 patients received placebo. Compared to placebo, administration of trilaciclib resulted in statistically significant decreases in the mean duration of SN in Cycle 1 (0 vs 4 days; P < .0001) and occurrence of SN (1.9% vs 49.1%; P < .0001), with additional improvements in red blood cell and platelet measures and health-related quality of life (HRQoL). Trilaciclib was well tolerated, with fewer grade ≥3 adverse events compared with placebo, primarily due to less high-grade haematological toxicity. Antitumour efficacy outcomes were comparable. Administration of trilaciclib vs placebo generated more newly expanded peripheral T-cell clones (P = .019), with significantly greater expansion among patients with an antitumour response to E/P/A (P = .002). Compared with placebo, trilaciclib administered prior to E/P/A improved patients' experience of receiving treatment for ES-SCLC, as shown by reduced myelosuppression, and improved HRQoL and safety profiles.

Relationship between online cognition and personality traits: A questionnaire based study of medical college students

Introduction

Current classification systems are not sure where to place the internet use disorder. Is it an addiction, an impulse control disorder, a consequence of another psychiatric morbidity or a consequence of personality trait/personality disorder?

Objectives

We intended to study which personality traits associated with online cognition may contribute towards Problematic internet use(PIU). We also analysed the relationship between number of hours of use/week of internet and PIU along with its relation with two ‘screening’ questions.

Methods

Online cognition scale and Abbreviated Eysenck Personality questionnaires were our measurements of choice in addition to demographic measures and some questions pertaining to online behaviour patterns.

Results

Total 163 responses were analysed. The demographic pools consisted mostly of young adults who had, on average, used the internet for 5.2 years at present rate of 21.81hours/week. We observed significantly higher mean OCS scores in men, in people who thought that the internet interfered with their lives and in those who felt the need to ‘cut-down’. A moderate positive and significant correlation was observed between hpurs/week of internet use and OCS scores. Also, significant positive correlation was observed between Neuroticism and OCS, impulsivity, and loneliness/depression scores. Significant negative correlations were observed between the Lie trait and impulse control. Neuroticism and Lie together contributed to 21.8% of variance in OCS scores.

Conclusions

Neuroticism and Lie traits (representing need for social acceptance) were found to the causing significamn varience in the OCS scores of the subjects. High number of hours/week use of internet was related to the feeling of ‘need to cut down use’.

Gastrointestinal side effects of upper gastrointestinal cancer surgery

In this chapter, we describe the gastrointestinal side effects of oesophagectomy, gastrectomy and pancreaticoduodenectomy for cancer, with a focus on long-term functional impairments and their management. Improvements in upper gastrointestinal cancer surgery have led to a growing group of long-term survivors. The invasive nature of these surgeries profoundly alters the upper gastrointestinal anatomy, with lasting implications for long-term function, and how these impairments may be treated. Successfully maintaining a high quality of survivorship requires multidisciplinary approach, with survivorship care plans focused on function as much as the detection of recurrence.

Preoperative anthropomorphic radiographic measurements can predict postoperative pancreatic fistula formation following pancreatoduodenectomy

BACKGROUND

Postoperative pancreatic fistulae (POPF) are a major contributing factor to pancreatoduodenectomy-associated morbidity. Established risk calculators mostly rely on subjective or intraoperative assessments. We hypothesized that various objective preoperatively determined computed tomography (CT) measurements could predict POPF as well as validated models and allow for more informed operative consent in high-risk patients.

METHODS

Patients undergoing elective pancreatoduodenectomies between January 2013 and April 2018 were identified in a prospective database. Comparative statistical analyses and multivariable logistic regression models were generated to predict POPF development. Model performance was tested with receiver operating characteristics (ROC) curves. Pancreatic neck attenuation (Hounsfield units) was measured in triplicate by pancreatic protocol CT (venous phase, coronal plane) anterior to the portal vein. A pancreatic density index (PDI) was created to adjust for differences in contrast timing by dividing the mean of these measurements by the portal vein attenuation. Total areas of subcutaneous fat and skeletal muscle were calculated at the L3 vertebral level on axial CT. Pancreatic duct (PD) diameter was determined by CT.

RESULTS

In the study period 220 patients had elective pancreatoduodenectomies with 35 (16%) developing a POPF of any grade. Multivariable regression analysis revealed that demographics (age, sex, and race) were not associated with POPF, yet patients resected for pancreatic adenocarcinoma or chronic pancreatitis were less likely to develop a POPF (10 vs. 24%; p = 0.004). ROC curves were created using various combinations of gland texture, body mass index, skeletal muscle index, sarcopenia, PDI, PD diameter, and subcutaneous fat area indexed for height (SFI). A model replacing gland texture with SFI and PDI (AUC 0.844) had similar predictive performance as the established model (p = 0.169).

CONCLUSION

A combination of preoperative objective CT measurements can adequately predict POPF and is comparable to established models relying on subjective intraoperative variables. Validation in a larger dataset would allow for better preoperative stratification of high-risk patients and improve informed consent among this patient population.

SAT0434 MINIMAL CLINICALLY IMPORTANT DIFFERENCE IN OUTCOME MEASURES FOR USE IN CLINICAL CARE AND PRAGMATIC TRIALS IN PsA

Background:

While several outcome measures have been studied for use in clinical studies of psoriatic arthritis, little is known about thresholds of meaning such as minimal clinically important improvement (MCII).

Objectives:

To investigate the distribution of scores for candidate outcome measures for pragmatic trials in PsA and to calculate the MCII for each outcome measure.

Methods:

We performed a longitudinal cohort study within the Psoriatic Arthritis Research Consortium (PARC), a multi-center study based in the US. Patients completed validated PROs (patient reported outcomes) and rheumatologists completed skin, joint, enthesis and dactylitis scores at therapy initiation and follow up 12-16 weeks later. In addition, patients completed a global assessment of response at the follow up visit, categorizing their status as improved, stayed the same, or worsened and then ratied the importance of the change on a scale from 0-7.1We then calculated and plotted the change in each of the following measures: Routine Assessment of Patient Index Data (RAPID3), clinical Disease Activity of Psoriatic Arthritis (cDAPSA), Patient Reported Outcome Measure Information System (PROMIS) Global Health short form (10a) physical health (PH) subscore, patient pain assessment, patient global assessment (0-10 NRS), and physician global assessments (0-10 NRS) of the joints and overall. We calculated the MCII as the mean change in score (with 95% confidence interval) among patients who reported improvement and rated the level of improvement as “almost none/hardly at all” or “a little important.” Additionally, we calculated Spearman’s correlation coefficients between the measures and the global assessment of response.

Results:

Among 148 unique patients, 233 therapy change visits were eligible for analysis. The average age was 52.5 years, 52% were female and mean BMI was 29.6. Baseline RAPID3 was 11.1 (SD 6), cDAPSA 17.9 (SD 13.9), PROMIS PH 42 (SD 8), patient global 4.2 (SD 2.5), TJC 5.9 (SD 7.5), and SJC 2.9 (SD 4.5). TNFi comprised 61% of drug initiations, 21% were IL17i and the remainder were other biologics and oral systemic therapies. At follow up, 63 (27%) patients rated themselves as improved whereas 103 (44%) stayed the same and 67 (29%) reported worsening. The mean change in each measure by patient-reported response (improved, stayed the same, or worsened) are shown in Figures 1A & B. In general, the mean score increased from ‘improved’ to ‘worsened’ as expected (with the exception of PROMIS PH which declines given a different direction of scoring). The MCII for each measure was as follows: RAPID3 -1.8 (-4.1 to 0.5), Patient Global -0.6 (-1.6 to 0.4), Physician Global -1 (-1.9 to -0.1), cDAPSA -5.7 (-9.8 to -1.7), and PROMIS PH 1.9 (-2.1 to 5.8). Correlation for each measure with the global assessment of response were: RAPID3 0.48, Patient Global 0.37, Physician Global 0.39, cDAPSA 0.51, and PROMIS PH 0.39.

Figure 1

A. Distribution of change (median, IQR) in RAPID3, Physician Global, Patient Global, PROMIS10a physical therapy by patient reported response.

Conclusion:

This is the first study to test thresholds of meaning for these particular measures in PsA. The MCII values are relatively low for all outcome measures. This may be related to the relatively low disease activity at baseline but is consistent with patients seen in clinical practice initiating therapy.2

References:

[1]Ward MM et al. J Clinical Epi 2014;2Ward MM et al. J Clinical Epi 2015

Figure 2

B. Distribution of change (median, IQR) in clinical DAPSA by patient reported response.

Disclosure of Interests:

Alexis Ogdie Grant/research support from: Pfizer, Novartis, Consultant of: Abbvie, Amgen, BMS, Celgene, Corrona, Janssen, Lilly, Pfizer, Novartis, M Elaine Husni Grant/research support from: Pfizer, Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, Novartis, Regeneron, and UCB, Jose Scher Consultant of: Novartis, Janssen, UCB, Sanofi., Ethan Craig: None declared, Soumya Reddy Grant/research support from: Amgen

Celgene

Abbvie, Consultant of: Amgen

Pfizer

Novartis

Jaansen

UCB, Jessica A. Walsh Grant/research support from: AbbVie, Pfizer, Janssen, Consultant of: AbbVie, Novartis, Eli Lilly and Company, UCB

SWOG S1400F (NCT03373760): A phase II study of durvalumab plus tremelimumab for previously treated patients with acquired resistance to PD-1 checkpoint inhibitor therapy and stage IV squamous cell lung cancer (Lung-MAP Sub-study)

9623

Background: The Lung Cancer Master Protocol (Lung-MAP) is designed to evaluate novel targeted therapies in patients with advanced squamous lung carcinoma. In the S1400F sub-study (non-match), we tested whether combined CTLA-4 and PD-1 inhibition with durvalumab plus tremelimumab (D+T) could overcome primary or acquired resistance to anti-PD-(L)1 therapy. Response, progression-free (PFS) and overall survival, and safety in the acquired resistance cohort are reported herein. Methods: Patients with previously treated squamous lung carcinoma, performance status (PS) 0-1, and adequate organ function that developed disease progression after ≥24 weeks of anti-PD-(L)1 monotherapy were eligible. Prior severe immune-related toxicities, intervening systemic therapy and combination chemo-immunotherapy were not permitted. Patients received D1500 mg + T75 mg IV q28 days for 4 cycles then D maintenance until disease progression. The primary endpoint was best objective response (RECIST 1.1). Interim analysis for futility was planned after 20 patients evaluable for response were enrolled. If no responses were observed, the cohort would stop enrolment. Results: 30 eligible patients were accrued to the acquired resistance cohort. Median age was 68 years, 60% of patients were male, 33% PS 0 and had received a median of 2 prior lines of therapy (maximum 4). Best response to prior anti-PD-(L)1 therapy was CR/PR/SD in 3/7/20 patients, with a median duration of anti-PD-(L)1 therapy of 8.6 months (5.2-30.4). No objective responses were seen with D+T; 47% had SD as best response. Median PFS was 2.0 months (95% CI 1.6-2.9) and survival 7.5 months (95% CI 5.3-8.7). Among the 14 patients with SD as best response, the median PFS calculated from first disease assessment is 2.8 months (95% CI: 1.4-3.9). Grade≥3 adverse events at least possibly related to protocol therapy were seen in 10/30 patients. These include 1 treatment-related death due to pneumonitis and 1 death not otherwise specified. Other adverse events include grade 3 confusion (1), dehydration (2), diarrhea (3), encephalopathy (1), weakness (1), hyperglycemia (1), hypoxia (1), lymphopenia (1), nausea, (1), neutropenia (1), thrombocytopenia (1), rash (1), vomiting (1), grade 4 dyspnea (1), leucopenia (1) and lymphopenia (1). Conclusions: D+T did not demonstrate activity in patients with acquired resistance to PD-1 checkpoint inhibitors and pretreated advanced squamous lung carcinoma. Clinical trial information: NCT03373760 .

Molecular mechanisms of tobacco induced oral and oropharyngeal cancer: Results of a tissue microarray and immunohistochemistry-based study from a tertiary cancer center in India

BACKGROUND

It is well established that chronic exposure to tobacco induces head and neck cancers but the exact etiopathogenesis is not known. Though studies have shown expression of TIMP1, EPS8 and AXL in cancers, their role in tobacco-induced cancers is not known. We aimed this study to evaluate the role of these molecules in oral and oropharyngeal squamous cell cancers (SCC).

MATERIALS AND METHODS

In this single institutional study, 31 patients of oral and oropharyngeal SCC with history of chewing tobacco were included. Smokers were excluded from the study. After informed consent biopsies were taken from affected and contralateral normal mucosa. Paraffin blocks were made and tissue microarray (TMA) were constructed using these blocks. Immunohistochemistry (IHC) for TIMP1, EPS8, AXL kinase was carried out on these tissue microarrays. The intensity of staining was scored from 0 to 3+, related to expression of each of the three molecules.

RESULTS

The expression of TIMP1, EPS8 and AXL kinase was significantly more in the cancerous mucosa versus non-cancerous mucosa (P = 0.000 in all three) in oral and oropharyngeal SCC exposed to chewing tobacco.

CONCLUSION

Immunohistochemical expression of these molecular markers in oral and oropharyngeal SCC correlated with their molecular based studies. Significant IHC expression of TIMP1, EPS8 and AXL establishes their role in the pathogenesis of oral and oropharyngeal squamous cell carcinomas. Novel targeted therapies may be researched that can detect and target these molecules at an earlier stage of pathogenesis of these tumors.

Health-Related Quality of Life With Carboplatin-Paclitaxel or nab-Paclitaxel With or Without Pembrolizumab in Patients With Metastatic Squamous Non-Small-Cell Lung Cancer

PURPOSE

In the phase 3 KEYNOTE-407 study, the addition of pembrolizumab to carboplatin-paclitaxel/nab-paclitaxel significantly improved overall survival, progression-free survival, and objective response rate in patients with previously untreated metastatic squamous non-small-cell lung cancer (NSCLC), with little impact on severe toxicity. We present patient-reported outcomes (PROs) from KEYNOTE-407.

METHODS

Patients were randomly assigned to receive 4 cycles of pembrolizumab 200 mg or placebo once every 3 weeks plus carboplatin plus paclitaxel or nab-paclitaxel, followed by pembrolizumab or placebo for an additional 31 cycles. Health-related quality of life (HRQoL) was evaluated using the European Organisation for Research and Treatment of Cancer Treatment of Cancer Quality of Life Questionnaire-Core 30 (QLQ-C30) and Quality of Life Questionnaire-Lung Cancer Module 13 (QLQ-LC13). Key PRO endpoints were change from baseline to weeks 9 and 18 (during and after platinum therapy) in the QLQ-C30 global health status/quality of life (GHS/QoL) score and time to deterioration in the composite endpoint of cough, chest pain, or dyspnea from the QLQ-C30 and QLQ-LC13. Two-sided, nominal P values are provided.

RESULTS

A total of 554 and 553 patients completed ≥ 1 QLQ-C30 or ≥ 1 QLQ-LC13 assessment, respectively. GHS/QoL score improved for the pembrolizumab-combination group (least squares [LS] mean [95% CI] change from baseline: week 9, 1.8 [-0.9 to 4.4]; week 18, 4.3 [1.7 to 6.9]) and deteriorated in the placebo-combination group (week 9, -1.8 [-4.4 to 0.7]; week 18, -0.57 [-3.3 to 2.2]). Between-group differences were improved for the pembrolizumab-combination group (difference in LS mean scores: week 9, 3.6 [95% CI, 0.3 to 6.9], nominal P = .0337; week 18, 4.9 [1.4 to 8.3], nominal P = .0060). Median time to deterioration in cough, chest pain, or dyspnea was not reached in either group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06]; nominal P = .125).

CONCLUSION

Addition of pembrolizumab to chemotherapy maintained or improved HRQoL measurements relative to baseline and improved HRQoL versus chemotherapy alone at weeks 9 and 18. These results support use of pembrolizumab plus chemotherapy as first-line therapy for metastatic squamous NSCLC.

Robotic-assisted breast-axillo insufflation thyroidectomy (RABIT): a retrospective case series of thyroid carcinoma

OBJECTIVE

To evaluate the feasibility and safety of robotic-assisted breast-axillo insufflation thyroidectomy (RABIT) for differentiated thyroid cancer.

METHODS

In this retrospective case series, patients with differentiated thyroid carcinoma were enrolled in our hospital from January 2018 to December 2018. All patients underwent indirect laryngoscopy to assess the status of vocal cord preoperatively. RABIT was performed with five separate breast-axillo incisions. All the procedures were performed using da Vinci Xi Robotic Surgical System, a single docking method using CO₂ insufflation.

RESULTS

Twelve patients completed RABIT, in which one case needed conversion to open thyroidectomy. The mean age was 30.25 ± 7 with male to female ratio being 1:1. Preoperative diagnosis showed papillary carcinoma (n = 9) and follicular neoplasm (n = 3). The mean operative time for RABIT was 140 ± 50.45 min and average blood loss during surgery was 22.92 ± 9 mL. Mean hospital stay was 4.42 ± 1.08 days. Final pathology confirmed classical papillary thyroid carcinoma (n = 10; 83.3%) and follicular variant of papillary carcinoma (n = 2; 16.7%). None of the cases reported injury or paralysis to the recurrent laryngeal nerves.

CONCLUSION

RABIT is a safe and feasible approach for thyroidectomy. It has several advantages in that it provides similar symmetrical view to conventional open surgery and enables to maintain specimen integrity and use of assistant port permits better handling of the gland. Additionally, the largest operating angles with this technique prevent collision between the robotic arms and provide excellent cosmetic satisfaction due to very small, five separate breast-axillo incisions.

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