Safety of Intranasal Insulin in Type 2 Diabetes on Systemic Insulin: A Double-Blinded Placebo-Controlled Sub-Study of Memaid Trial

AIMS

To determine safety of intranasal insulin (INI) in MemAID trial participants with diabetes treated with systemic insulins.

MATERIALS AND METHODS

This randomized, double-blinded trial consisted of 24-week INI or placebo treatment once daily and 24-week follow-up. Safety outcomes were: 1) Short-term effects on glycemic variability, hypoglycemic episodes on continuous glucose monitoring (CGM) at baseline and on-treatment. 2) Long-term effects on glucose metabolism and weight on INI/placebo treatment and post-treatment follow-up. Of 86 screened subjects, 14 were randomized, 9 (5 INI, 4 Placebo) completed CGM at baseline and on-treatment, and 5 (2 INI, 3 Placebo) completed treatment and follow-up.

RESULTS

INI was safe and was not associated with serious adverse events, hypoglycemic episodes or weight gain. INI administration did not acutely affect capillary glucose. Glycemic variability on CGM decreased with INI, compared to baseline. On INI treatment, there was a long-term trend toward lower HbA1c, plasma glucose and insulin. No interactions with subcutaneous insulins were observed.

CONCLUSIONS

INI is safe in older people with diabetes treated with systemic insulins, and it is not associated with adverse events, hypoglycemia or weight gain. Future studies are needed to determine whether INI administration can reduce glycemic variability, improve insulin sensitivity and thus potentially lessen diabetes burden in this population.

Transseptal puncture for left atrial ablation: risk factors for cardiac tamponade and a proposed causative classification system

Aims

Cardiac tamponade is a high morbidity complication of transseptal puncture (TSP). We examined the associations of TSP‐related cardiac tamponade (TRCT) for all patients undergoing left atrial ablation at our center from 2016 to 2020.

Methods and Results

Patient and procedural variables were extracted retrospectively. Cases of cardiac tamponade were scrutinized to adjudicate TSP culpability. Adjusted multivariate analysis examined predictors of TRCT. A total of 3239 consecutive TSPs were performed; cardiac tamponade occurred in 51 patients (incidence: 1.6%) and was adjudicated as TSP‐related in 35 (incidence: 1.1%; 68.6% of all tamponades). Patients of above‐median age [odds ratio (OR): 2.4 (1.19–4.2), p = .006] and those undergoing re‐do procedures [OR: 1.95 (1.29–3.43, p = .042] were at higher risk of TRCT. Of the operator‐dependent variables, choice of transseptal needle (Endrys vs. Brockenbrough, p > .1) or puncture sheath (Swartz vs. Mullins vs. Agilis vs. Vizigo vs. Cryosheath, all p > .1) did not predict TRCT. Adjusting for operator, equipment and demographics, failure to cross the septum first pass increased TRCT risk [OR: 4.42 (2.45–8.2), p = .001], whilst top quartile operator experience [OR: 0.4 (0.17–0.85), p = .002], transoesophageal echocardiogram [TOE prevalence: 26%, OR: 0.51 (0.11–0.94), p = .023], and use of the SafeSept transseptal guidewire [OR: 0.22 (0.08–0.62), p = .001] reduced TRCT risk. An increase in transseptal guidewire use over time (2016: 15.6%, 2020: 60.2%) correlated with an annual reduction in TRCT (R² = 0.72, p < .001) and was associated with a relative risk reduction of 70%.

Conclusions

During left atrial ablation, the risk of TRCT was reduced by operator experience, TOE‐guidance, and use of a transseptal guidewire, and was increased by patient age, re‐do procedures, and failure to cross the septum first pass.

A phenomenological study to understand gender diversity and inclusion in the tech industry

Various researches have established that diversity with inclusion yields a competitive advantage and promotes innovation in workplaces. Gender diversity and retention of top women talent, however, remains a problem. This study explored the reasons leading to the lower representation of women in the tech industry and the impact of the diversity and inclusion initiatives on the lives of working women. Purposive sampling has been used to select four women and two men working in tech, and in-depth interviews over the telephone were conducted for a phenomenological study. Analysis of data was carried out by Interpretative Phenomenological Analysis (IPA). The results highlight common issues women face in the tech industry and compare it to their male counterparts’ experiences. Women highlight unconscious biases, internal and external obstacles, lack of women mentors at senior positions, and family restrictions. This paper gives a deeper understanding of the lived experience of entry-level men and women currently working in the tech industry, which will help identify gaps in our current approach towards inclusivity and the way forward for these practices for employees in STEM fields. The study is significant for organizations struggling to maintain gender balance in the tech industry despite implementing several diversity and inclusion practices. It will help the organizations understand a relatively new term, including inclusion and adopting specific measures to create an inclusive work environment.

Pre-ablation interatrial conduction delay or block predicts atrial fibrillation recurrence after ablation among obese patients

Funding Acknowledgements

Type of funding sources: None.

Background

Obesity is associated with greater risk of atrial fibrillation (AF) recurrence post-ablation and higher incidence of conduction delay compared to non-obese patients. Pre-ablation P-wave duration (PWD) and morphology (PWM) indicating interatrial delay are easily assessed in the clinic and may predict AF recurrence post-ablation in these patients.

Purpose

Evaluate the predictive value of PWD and PWM on AF recurrence post-ablation in obese patients.

Methods

Pre-ablation PWD and PWM (negative P-wave in lead II or III) were analyzed on consecutive patients with BMI ≥30 kg/m2 who underwent initial AF ablation from 2012–19. The primary outcome was recurrent AF after a 3-month post-ablation blanking period. Multivariate analysis adjusted for baseline characteristics was performed.

Results

For 205 patients (61.0±9.5 years old, 39.0% female), mean BMI was 36.9±5.7 kg/m2 and 71.7% had persistent AF pre-ablation. Recurrent AF post-ablation occurred in 115 (56.1%) during a median follow up of 491 (270, 1001) days. PWD &gt;130 ms was significantly associated with higher AF recurrence (AHR of 1.62, 95%CI 1.04-2.57, p=0.03) after adjusting for age, persistent AF and left atrial volume index (LAVI). In a subgroup with LAVI &lt;42 mL/m2 (n=112), PWD &gt;130 ms and negative P-waves in lead II or III were independently associated with increased risk of recurrent AF (AHR 2.06, 95%CI 1.12-3.91; p=0.019 and AHR 1.94, 95% CI 1.00-3.56; p=0.05, respectively) (Figure 1).

Conclusion

AF recurred in &gt;50% of obese patients within 1.5 years of ablation. Pre-ablation PWD &gt;130 ms and negative P-waves in lead II or III independently predicted recurrent AF post-ablation in this cohort of obese patients. These easily assessed findings add predictive value to other risk factors.

A Novel Genetic Variant Resulting in Familial Hypocalciuric Hypercalcaemia

Presentation A 17-year-old male was referred to the endocrinology service with an incidental finding of hypercalcaemia. Over the course of the previous year his calcium ranged from 2.64-2.77mmol/L (reference range: 2.2-2.6mmol/L) in the setting of a normal/low parathyroid hormone (PTH) of 14-35pg/ml (reference range: 15-65pg/ml). Diagnosis Following biochemical confirmation of hypocalciuric hypercalcaemia he was referred for molecular genetic analysis which showed a heterozygous variant in the CASR gene previously undescribed in the literature: c.491A>G; p.GIn164Arg. Treatment The patient and his parents were reassured with regard to the benign nature of the condition and counselled with regard to its inheritance. Discussion Though there is little data on this genetic variant, it is assumed to have caused familial hypocalciuric hypercalcaemia (FHH) in this gentleman. FHH is an important differential in hypercalcaemia as it can be misdiagnosed as primary hyperparathyroidism, potentially leading to unnecessary surgical intervention.

Parenchymal involvement on CT pulmonary angiography in SARS-CoV-2 Alpha variant infection and correlation of COVID-19 CT severity score with clinical disease severity and short-term prognosis in a UK cohort

AIM

To determine if there is a difference in radiological, biochemical, or clinical severity between patients infected with Alpha-variant SARS-CoV-2 compared with those infected with pre-existing strains, and to determine if the computed tomography (CT) severity score (CTSS) for COVID-19 pneumonitis correlates with clinical severity and can prognosticate outcomes.

MATERIALS AND METHODS

Blinded CTSS scoring was applied to 137 hospital patients who had undergone both CT pulmonary angiography (CTPA) and whole-genome sequencing of SARS-CoV-2 within 14 days of CTPA between 1/12/20–5/1/21.

RESULTS

There was no evidence of a difference in imaging severity on CTPA, viral load, clinical parameters of severity, or outcomes between Alpha and preceding variants. CTSS on CTPA strongly correlates with clinical and biochemical severity at the time of CTPA, and with patient outcomes. Classifying CTSS into a binary value of “high” and “low”, with a cut-off score of 14, patients with a high score have a significantly increased risk of deterioration, as defined by subsequent admission to critical care or death (multivariate hazard ratio [HR] 2.76, p<0.001), and hospital length of stay (17.4 versus 7.9 days, p<0.0001).

CONCLUSION

There was no evidence of a difference in radiological severity of Alpha variant infection compared with pre-existing strains. High CTSS applied to CTPA is associated with increased risk of COVID-19 severity and poorer clinical outcomes and may be of use particularly in settings where CT is not performed for diagnosis of COVID-19 but rather is used following clinical deterioration.

Synchronous Schwannoma and Gastrointestinal Stromal Tumor in Small Intestine – A Rare Case

Introduction/Objective

Small bowel Schwannoma is a benign neoplasm of nerve sheath cells. The Gastrointestinal stromal tumor (GIST) constitutes only about 1-2% of small bowel spindle cell tumors. The simultaneous presence of two tumors in the small bowel is extremely uncommon.

Methods/Case Report

We report a case of small bowel GIST co-existing with Schwannoma. A 64-year-old female with a known history of Neurofibromatosis was admitted for excision of a small bowel tumor. MRI of the abdomen revealed two enhancing lesions in the left upper quadrant adjacent to the small bowel. Differential considerations included GIST versus Neurofibroma. Left hemicolectomy with small bowel resection was performed. The proximal small bowel revealed GIST, spindle cell type, low risk (3.5 cm), low grade (&lt;5 mitoses/ 5mm2). Tumor cells were diffusely reactive to CD34, CD117, and DOG1 immunostains and were nonreactive to S100 and SOX10 immunostains confirming the diagnosis of GIST. Another segment of the small bowel revealed a 1.5 cm well-circumscribed, predominantly spindle cell tumor with abundant myxoid stroma and prominent cyst formation. Tumor cells were diffusely reactive to S100 and SOX10 immunostains but nonreactive to CD34, CD117, and DOG1, favoring a diagnosis of Schwannoma. Gastrointestinal Schwannomas may be associated with Neurofibromatosis in some cases. GIST, a KIT- or PGDFRA-signaling driven mesenchymal tumor has also rarely been reported to be associated with Neurofibromatosis type 1. However, synchronous small bowel Schwannoma and GIST represent a rare co-existence of two different histopathologic subtypes of spindle cell tumors.

Results (if a Case Study enter NA)

NA

Conclusion

In summary, we present the rare co-existence of two different spindle cell lesions in Neurofibromatosis patient.

HPV-Related Multi-Phenotypic Sinonasal Carcinoma with Aggressive Clinical Behavior; A Rare Case

Introduction/Objective

Human Papilloma Virus (HPV)-related multiphenotypic sinonasal carcinoma, previously known as HPV-related sinonasal carcinoma with adenoid cystic carcinoma-like features, is a rare type of sinonasal carcinoma with both epithelial-derived and salivary gland-type morphologic features. It is associated with high-risk HPV, but lacks MYB gene rearrangements.

Methods/Case Report

We report a case of a 59-year-old male who presented with a rapidly growing sinonasal mass. On MRI, a left nasal cavity lesion was identified growing laterally along the frontal process of the maxilla, extending into the middle meatus and into the maxillary sinus. Patient underwent a complex left medial maxillectomy, spheno- ethmoidectomy, and sinusotomy. On gross evaluation, the left inferior turbinate and sidewall demonstrated a 4 cm unremarkable turbinate with attached friable soft tissue. Microscopic examination revealed sections of carcinoma with various architectural patterns comprised of foci with adenoid cystic carcinoma-like morphology, basaloid squamous cell carcinoma and adenocarcinoma. The tumor showed positive immunostaining for P40, but focal reactivity to S100 and rare scattered reactivity with CD117. INI-1 immunostain was retained in tumor cells. P16 immunostain was strong and diffuse and high-risk cocktail HPV RNA ISH was positive. However, MYB FISH testing was equivocal.

Morphologic and immunophenotypic findings were consistent with HPV-related multiphenotypic sinonasal carcinoma. The tumor involved the olfactory nerve fibers requiring a skull base resection and showed extension into the dura mater.

Results (if a Case Study enter NA)

NA

Conclusion

HPV related multiphenotypic sinonasal carcinoma is a recently described entity that can pose significant diagnostic challenge. It typically has an indolent clinical course with potential for late recurrences. This case study highlights the potential aggressive nature of this type of sinonasal carcinoma, despite association with high-risk HPV, and use of ancillary testing in aiding diagnosis.

High-Grade Sarcoma Arising in the Background of Growing Teratoma Syndrome; A Rare Case

Introduction/Objective

Growing teratoma syndrome is a rare condition seen in patients with a history of immature teratomas or mixed germ cell tumor status post-treatment. It usually occurs within the first two years of diagnosis but rarely can be seen years later.

Methods/Case Report

We report a case of a 48-year-old female with a previous history of ovarian malignancy in adolescence status post-TAH/BSO and chemotherapy, now presenting with a 23 cm multi cystic septate mass with some solid components in the subdiaphragmatic area, extending into the liver on imaging. Nodular implants along the surface of the right hepatic lobe and multiple peritoneal implants were seen. Histology of peritoneal implants showed fibro adipose tissue admixed with rare scattered glandular elements, epithelial fragments, and mature neuroglial tissue, consistent with mature teratoma. Liver biopsy revealed short fascicles of spindled, epithelioid and rhabdoid tumor cells admixed with foci of the myxoid stroma. Scattered moderate cytologic atypia, atypical mitosis, and necrosis were appreciated. Tumor cells showed strong and diffuse reactivity to vimentin while being negative for epithelial, neural/mesenchymal, mesothelial, sex cord-stromal, and germ cell differentiation markers. Differential diagnostic considerations included spindle cell transformation of a germ cell tumor or high-grade sarcoma, not otherwise specified arising in the background of growing teratoma syndrome. FISH testing for isochromosome 12p was negative excluding sarcomatoid germ cell tumor.

Results (if a Case Study enter NA)

NA

Conclusion

This case study highlights the importance of considering the rare complication of high-grade sarcoma arising in the background of growing teratoma syndrome.

A 37-Year-Old Woman with Hypertrophic Cardiomyopathy with a Dual-Chamber Implantable Cardioverter-Defibrillator Requiring Percutaneous Transvenous Lead Extraction and Multidisciplinary Management

Patient: Female, 37-year-old

Final Diagnosis: Hypertrophic cardiomyopathy

Symptoms: None

Medication:—

Clinical Procedure: Percutaneous ICD lead extraction • Surgical ICD lead extraction

Specialty: Cardiac Electrophysiology • Cardiac Surgery • Cardiology

Diagnostic analysis of baseline brain MRI features in infants with congenital cytomegalovirus infection: a simplified scoring system

AIM

To characterise the magnetic resonance imaging (MRI) features of infants with congenital cytomegalovirus (CMV) and categorise those into a simplified MRI scoring system.

MATERIALS AND METHODS

Three neuroradiologists reviewed the examinations of 71 infants retrospectively and scored for the presence of a white matter signal abnormality and structural lesion and each MRI was given a score of 0, 1, 2, or 3 for normal, structural abnormality alone, white matter abnormality alone, white matter abnormality plus structural lesion, respectively. Imaging features were outlines according to symptomatology. Chi-square and Spearman's rho were used to test relationships between MRI features and viral loads and MRI score/symptomatic disease respectively. Cohen's Kappa coefficient was used to assess interobserver agreement.

RESULTS

Of the 49 abnormal studies, 40% (n=20) were seen in asymptomatic infants. The commonest finding was white matter signal abnormality, followed by cyst formation and polymicrogyria (86%, n=42; 71%, n=35; and 33%, n=16, respectively). Cysts were significantly positively correlated with white matter abnormalities and polymicrogyria. On the MRI score, 31%, 10%, 15%, and 44% obtained a score of 0, 1, 2, and 3, respectively; the MRI score was positively correlated with log-transformed viral loads. Interobserver agreement for the presence of white matter signal abnormality, cyst formation, malformations of cortical development (MCD), and global MRI score was excellent (k = 0.82, 0.94, 0.96, and 0.86, respectively).

CONCLUSION

Baseline MRI provides information valuable for treatment decisions, especially in "asymptomatic" infants. The simplified scoring system is easier to use, incorporating solely the imaging findings that are anticipated to have an effect on clinical outcome.

Poor glycemic control in diabetic patients increases the risk of recurrent atrial arrhythmia and cardiovascular hospitalizations among morbidly obese patients undergoing atrial fibrillation ablation

Background/Introduction

Obesity and atrial fibrillation (AF) coexist and share multiple cardiovascular risk factors. Lifestyle modifications can reduce AF burden in obese patients. However, the time invested in pursing lifestyle changes may delay AF ablation, which could negate the procedural benefit.

Purpose

To examine the effects of lifestyle modifications and the timing of catheter ablation on morbidly obese patients with AF.

Methods

This retrospective study included 217 consecutive AF patients with a body mass index (BMI) ≥35 kg/m2 undergoing AF ablation at a tertiary care center from 2012 to 2019. Modifiable risks were examined, including the time from AF diagnosis to ablation, fluctuation of BMI &gt;5% or an increase in BMI &gt;3% prior to ablation, mean systolic blood pressure &gt;130 mmHg or diastolic blood pressure &gt;80 mmHg, obstructive sleep apnea with CPAP noncompliance, hyperlipidemia without statin therapy, tobacco use, excessive alcohol use, and diabetes mellitus with hemoglobin A1c (HbA1c) ≥6.5%. The primary outcome was a composite of recurrent atrial arrhythmias and cardiovascular (CV) hospitalizations following AF ablation. A multivariate analysis adjusting for age, gender and modifiable risks was performed.

Results

The mean age was 61±9 years old, 58% were female and 45% had persistent AF. A substantial portion of the study patients had modifiable risk factors, ranging from 2.7% with excessive alcohol use to 67.3% experiencing delayed AF ablation, Figure 1. The median time from diagnosed AF to ablation was 1.3 years. During a mean follow-up of 2.9 years after AF ablation, 136 (62.7%) patients met the primary outcome. Only HbA1c ≥6.5% was an independent risk factor with adjusted hazard ratio of 1.57, 95% confidence interval 1.02–2.36, P=0.0412, Figure 2A. Delayed AF ablation did not alter the outcome, Figure 2B. There was no interaction between time of ablation and HbA1c ≥6.5% (P=0.67).

Conclusion

Substantial portions of morbidly obese patients undergoing AF ablation have potentially modifiable risk factors. Poor glycemic control with HbA1c ≥6.5% predicts an increased risk of recurrent atrial arrhythmias and CV hospitalizations, while delayed AF ablation does not. This finding underscores an importance of optimizing HbA1c in morbidly obese patients with AF to reduce adverse outcomes after ablation.

Funding Acknowledgement

Type of funding sources: None.

Can machine learning augment clinician adjudication of events in cardiovascular trials? A case study of major adverse cardiovascular events (MACE) across CVRM trials

Background and introduction

Accurate identification of clinical outcome events is critical to obtaining reliable results in cardiovascular outcomes trials (CVOTs). Current processes for event adjudication are expensive and hampered by delays. As part of a larger project to more reliably identify outcomes, we evaluated the use of machine learning to automate event adjudication using data from the SOCRATES trial (NCT01994720), a large randomized trial comparing ticagrelor and aspirin in reducing risk of major cardiovascular events after acute ischemic stroke or transient ischemic attack (TIA).

Purpose

We studied whether machine learning algorithms could replicate the outcome of the expert adjudication process for clinical events of ischemic stroke and TIA. Could classification models be trained on historical CVOT data and demonstrate performance comparable to human adjudicators?

Methods

Using data from the SOCRATES trial, multiple machine learning algorithms were tested using grid search and cross validation. Models tested included Support Vector Machines, Random Forest and XGBoost. Performance was assessed on a validation subset of the adjudication data not used for training or testing in model development. Metrics used to evaluate model performance were Receiver Operating Characteristic (ROC), Matthews Correlation Coefficient, Precision and Recall. The contribution of features, attributes of data used by the algorithm as it is trained to classify an event, that contributed to a classification were examined using both Mutual Information and Recursive Feature Elimination.

Results

Classification models were trained on historical CVOT data using adjudicator consensus decision as the ground truth. Best performance was observed on models trained to classify ischemic stroke (ROC 0.95) and TIA (ROC 0.97). Top ranked features that contributed to classification of Ischemic Stroke or TIA corresponded to site investigator decision or variables used to define the event in the trial charter, such as duration of symptoms. Model performance was comparable across the different machine learning algorithms tested with XGBoost demonstrating the best ROC on the validation set for correctly classifying both stroke and TIA.

Conclusions

Our results indicate that machine learning may augment or even replace clinician adjudication in clinical trials, with potential to gain efficiencies, speed up clinical development, and retain reliability. Our current models demonstrate good performance at binary classification of ischemic stroke and TIA within a single CVOT with high consistency and accuracy between automated and clinician adjudication. Further work will focus on harmonizing features between multiple historical clinical trials and training models to classify several different endpoint events across trials. Our aim is to utilize these clinical trial datasets to optimize the delivery of CVOTs in further cardiovascular drug development.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): AstraZenca Plc

Cigarette smokers' perceptions of smoking cessation and associated factors in Karachi, Pakistan

OBJECTIVES

The study explored the perceptions of adult smokers with cardiovascular and respiratory diseases regarding cigarette smoking cessation. We also explored factors that may hinder or facilitate smoking cessation process.

DESIGN

Qualitative descriptive exploratory design SAMPLE: Purposive sample of 13 adult smokers with cardiovascular or respiratory diseases visiting outpatient cardiac and respiratory clinics at a private tertiary care hospital MEASUREMENTS: In-depth, face-to-face, and semi-structured interviews were conducted. The interviews were digitally recorded and transcribed verbatim followed by a six steps process of manual thematic analysis of data.

RESULTS

Meaningful statements were assigned codes and grouped into categories. Categories were clustered under three themes representing individual factors, socio-cultural factors, and institutional factors.

CONCLUSIONS

Smoking cessation is influenced by personal, cultural, as well as social aspects. Institutionally, there is a need to recognize that smoking is a learned behavior; hence, prohibiting public smoking will potentially contribute to non-smoking behaviors. Although the nature of misconceptions varies, this is imperative to ensure consistency in messaging, programming, and supports led by healthcare professionals.

Relatively Benign yet a Reversible Cause of Dilated Cardiomyopathy

Arrhythmia-induced cardiomyopathy secondary to frequent ventricular premature contractions is a well-studied phenomenon; however, there is a paucity of data showing a similar association with frequent atrial premature contractions (APCs). Early recognition and successful APC ablation can reverse left ventricular dysfunction in these patients. (Level of Difficulty: Beginner.).

The novel collagen matrikine, endotrophin, is associated with mortality and cardiovascular events in patients with atherosclerosis

BACKGROUND

Rupture of atherosclerotic plaques is the major cause of acute cardiovascular events. The biomarker PRO-C6 measuring Endotrophin, a matrikine of collagen type VI, may provide valuable information detecting subjects in need of intensified strategies for secondary prevention.

OBJECTIVE

In this study, we evaluate endotrophin in human atherosclerotic plaques and circulating levels of PRO-C6 in patients with atherosclerosis, to determine the predictive potential of the biomarker.

METHODS

Sections from the stenotic human carotid plaques were stained with the PRO-C6 antibody. PRO-C6 was measured in serum of patients enrolled in the Carotid Plaque Imagining Project (CPIP) (discovery cohort, n = 577) and the innovative medicines initiative surrogate markers for micro- and macrovascular hard end-points for innovative diabetes tools (IMI-SUMMIT, validation cohort, n = 1,378). Median follow-up was 43 months. Kaplan-Meier curves and log-rank tests were performed in the discovery cohort. Cox proportional hazard regression analysis (HR with 95% CI) was used in the discovery cohort and binary logistic regression (OR with 95% CI) in the validation cohort.

RESULTS

PRO-C6 was localized in the core and shoulder of the atherosclerotic plaque. In the discovery cohort, PRO-C6 independently predicted future cardiovascular events (HR 1.089 [95% CI 1.019 -1.164], p = 0.01), cardiovascular death (HR 1.118 [95% CI 1.008 -1.241], p = 0.04) and all-cause death (HR 1.087 [95% CI 1.008 -1.172], p = 0.03). In the validation cohort, PRO-C6 predicted future cardiovascular events (OR 1.063 [95% CI 1.011 -1.117], p = 0.017).

CONCLUSION

PRO-C6 is present in the atherosclerotic plaque and associated with future cardiovascular events, cardiovascular death and all-cause mortality in two large prospective cohorts.

Duration of the preejection phase is less preload dependent and therefore a better marker of acute response to cardiac resynchronization therapy than maximum pressure rise

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie

Background

There is no consensus on which haemodynamic marker should be used to quantify acute response to cardiac resynchronization therapy (CRT) during implantation of the device. CRT has been shown to acutely reduce left ventricular (LV) end systolic as well as end-diastolic volume (EDV), precluding the use of preload dependent markers such as LV maximum pressure rise (dP/dtmax).

Purpose

As resynchronization will abolish the uncoordinated regional early systolic contractions of the LV, it will shorten the time to maximal pressure rise and aortic valve opening. For this reason, the purpose of this study was to investigate if duration from the time-point of ventricular pacing to dP/dtmax is less preload dependent and a better marker of acute response to CRT than dP/dtmax by comparing how the 2 markers reflected LV function during different CRT configurations.

Methods

LV pressure by micromanometer and volume by sonomicrometry were measured in 6 anaesthetized canines with left bundle branch block. Transient caval constrictions were performed to vary preload. Preload dependency of the 2 markers was compared by normalizing their values and calculating their relations to EDV. In 4 of the animals, biventricular pacing was performed at 3 different pacing sites with variations in atrioventricular delays that provided a range of response to CRT. To correct for acute

changes in preload by CRT, stroke volume (SV) at identical EDV found from transient caval constrictions, were assessed and used as reference to grade improved LV function. Linear regression analysis was used to assess the correlation of both the duration of the preejection phase and dP/dtmax with SV.

Results

The duration of the preejection phase varied less with changes in preload compared to dP/dtmax: the slopes of their relation to EDV were -0.6 ± 0.7 %/ml and 4.8 ± 2.1 %/ml (p = 0.004), respectively. Turning CRT on, acutely reduced EDV from 74 ± 16 to 69 ± 17 ml (p &lt; 0.001) at the best pacing configuration. For the different pacing sites and settings, there was a consistent relation in all animals where the preejection phase shortened as SV increased (average r2 = 0.75) (Figure A). dP/dtmax showed no clear relation to SV (average r2 = 0.22) and included cases with both negative and positive slopes (Figure B).

Conclusions

The duration of the preejection phase correlated with changes in LV function induced by CRT while dP/dtmax performed poorly as preload was changed. Hence, the novel timing parameter was less preload dependent and may be a better marker for assessing acute response to CRT. Abstract Figure.