Non-invasive delineation of ventricular tachycardia substrates for cardiac stereotactic body radiotherapy: utility of in-silico pace-mapping

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): EPSRC

Background

Cardiac stereotactive body radiotherapy (CSBRT) is an emerging, non-invasive ablation modality that targets ventricular tachycardia (VT) substrates in patients with limited conventional treatment options. Success of CSBRT hinges primarily on the correct identification of VT targets, which requires non-invasive planning. Current non-invasive, pre-procedure strategies employ multi-electrode electrocardiographic imaging (ECGi). Given its significant cost and potential challenges in detecting endocardial, intramural and/or septal VT sites, there is a need to optimise VT delineation strategies for CSBRT; patient-specific simulations may show promise at guiding such planning non-invasively.

Purpose

We aim to perform non-invasive, in-silico pace-mapping on an image-based computational model to identify VT substrates for CSBRT. We intend to show the utility of our fast computational pipeline - relying on CT imaging data only - to provide further insights on inaccessible, scar-related VT episodes.

Methods

A detailed computational torso model of a CSBRT candidate with incessant VT was generated from CT imaging data. Extracellular content volumes (ECVs) were used to identify different tissue types (healthy, border zone and non-conducting), and scale model tissue conductivities accordingly. In-silico pace-mapping was performed by simulating ~360 paced beats across the LV, and computing corresponding 12-lead ECGs within a fast electrophysiological (EP) simulation environment combining reaction-eikonal and lead field methods. QRS complexes from simulated paced beats were used to construct the virtual correlation pace-map against the measured QRS of the clinically-induced VT, along with a ‘reference-less’ virtual pace-map constructed from neighbouring paced-beat QRSs (within a 20 mm radius). An epicardial activation map of the clinically-induced VT was reconstructed from ECGi measurement, and used for comparison against our virtual pace-maps.

Results

Correlations between simulated paced-beat QRS complexes and the clinically-induced VT QRS were higher in mid-apical, infero-septal segments - segment 9 (85.71%), 10 (87.95%) and 15 (89.58%) - identifying septal origin and pathway of the induced re-entrant circuit. A possible septal VT isthmus was also identified by a high gradient in the virtual reference-less pace-map in segment 9 (> 2.5%/mm). Our in-silico predictions were in agreement with the clinical regions identified for CSBRT (segment 9 and 15), and provided additional information on the 3D and septal dynamics of the VT episode.

Conclusions

Our in-silico pace-mapping study successfully localised VT substrates in a patient unable to receive standard ablative procedures, and provided further clinical insight on the induced VT dynamics. Our rapid in-silico pace-mapping approach may be utilised to support optimal identification of VT target volumes for CSBRT.

In-silico optimisation of ICD defibrillation efficacy by modifying lead/can configurations using a cohort of high-resolution whole-torso heart models

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Research Council, UK

Background

ICD is an effective direct therapy against VT/VF by applying a strong electrical shock across the heart between the shocking coil and can. Conventionally, patients will have a shocking coil inside the right ventricle (RV) and a can at the upper left chest. However, due to infections or other conditions, the can may need to place towards the right chest. The placement of the RV coil may also vary in different cases, for example avoiding scar. However, it is unclear how defibrillation efficacy may be altered by these unavoidable modifications to conventional lead/can configurations and whether optimisation may be possible.

Purpose

To compare defibrillation efficacy of modifications of ICD configurations in a cohort of whole-torso models.

Methods

A cohort of 15 whole torso models was generated from high resolution CT data and contrast CT cardiac scans, including 5 dilated cardiomyopathy (DCM), 5 hypertrophic cardiomyopathy (HCM) and 5 structurally normal patients (Fig A). Transvenous ICDs were represented by a shocking coil inside the RV (near apex) and a (ground) can at the upper left chest as default settings. Configurations were then varied by moving the can to the right chest, moving the RV coil up the mid-septum or adding extra grounds (Superior Vena Cava (SVC) coil, coronary sinus (CS) coil (Fig A)). Defibrillation-strength shocks were applied to all models (Fig B). DFTs and mean electrical field were evaluated across the whole heart as well as specific LV, RV, RV insertion regions, along with overall impedance.

Results

Shifting the can from left to right significantly increased DFT for the whole heart (23 J vs 15 J, P=0.03) and LV (25 J vs 17 J, P=0.03) (Fig C) and reduced the mean electrical field. Moving the RV coil further up the septum did not significantly alter DFT (Fig D), but did reduce mean electrical field for all regions and reduce impedance significantly. Additional separate coils significantly reduced DFT for all regions (Fig D) by increasing mean electrical field, whilst adding both coils significantly reduced DFT the most (whole heart: 15 J vs 6 J, P=0.03) (Fig E). Impedance was increased significantly by adding SVC coil, but reduced significantly by adding CS coil. Adding both coils increased impedance slightly.

Conclusions

Although a right-sided can increases DFT by over 50%, additional leads (grounds) may mitigate this increase by increasing mean electrical field. Moving the RV coil closer to the mid-septum reduces DFT slightly, but also reduces mean electrical field and impedance significantly.

Automated detection of scar-related ventricular tachycardia origins from implanted device electrograms: a combined computational-AI platform

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): EPSRC

Background

Existing strategies that identify ventricular tachycardia (VT) ablation targets either employ invasive and time-consuming electrophysiological (EP) mapping, or non-invasive modalities that utilise standard electrocardiogram (ECG) signals. Success of these pre-procedure ablation approaches in localising re-entrant VTs often relies on VT induction, which could be avoided by utilising recordings of clinical VT episodes stored as electrograms (EGMs) in implanted devices. Such a non-invasive approach that localises VT substrates from EGMs may aid ablation planning, enhancing safety and speed.

Purpose

Our goal is to automate scar-related VT localisation by utilising EGM recordings of VT episodes from implanted devices. To achieve this, deep-learning algorithms will be trained on computational data to return VT sites of origin from implanted device EGMs. Ultimately, we intend to utilise this computational-artificial intelligence (AI) framework to detect ablation targets of clinical VT episodes and guide pre-procedure ablation planning non-invasively.

Methods

A comprehensive library of ECGs and EGMs from simulated paced beats (~15000) and scar-related VTs (500) was generated across five detailed torso models within a fast EP computational environment, combining reaction-eikonal and lead field methods. ECG (or EGM) traces from simulated paced beats were used to initially pre-train two convolutional neural network (CNN) long short-term (LSTM) attention-based architectures. Subsequently, signals of the in-silico, re-entrant VTs were used to re-train the networks to output the sites of origin of these episodes in a standardised ventricular coordinate space. Finally, the retrained CNN architectures were tested on re-entrant VTs of unseen models, and median localisation errors (LEs) were estimated against known VT origins from simulations.

Results

The performance of the networks to localise scar-related VT episodes was asserted for each torso model. When a torso model was only seen during initial training on simulated paced beats, implanted device EGMs and ECGs successfully localised VT sources with LEs 10.04 – 16.36 mm and 10.05 – 12.79 mm, respectively. When a torso model was not seen during pacing or VT training, recreating potential clinical application settings where ECGs or EGMs of clinical VTs would be the only inputs to the networks, LEs ranged 12.42 - 22.79 mm and 12.41 - 19.68 mm for EGM and ECG-based testing, respectively.

Conclusions

Our study successfully detected VT ablation substrates with accuracy that could be beneficial in clinical ablation settings. The proposed computational-AI framework may be used to automate the localisation of scar-related VTs from clinical ECGs or EGM recordings from implanted devices, ultimately aiding ablation planning.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

Automated left ventricular dimension assessment using artificial intelligence

Background and purpose

Artificial intelligence (AI) has the potential to greatly improve efficiency and reproducibility of quantification in echocardiography, but to gain widespread use it must both meet expert standards of excellence and have a transparent methodology. We developed an online platform to enable multiple collaborators to annotate medical images for training and validating neural networks.

Methods

Using our online collaborative platform 9 expert echocardiographers labelled 2056 images that comprised the training dataset. They labelled the four points from where the standard parasternal long axis (PLAX) measurements (interventricular septum, posterior wall, left ventricular dimension) would be made. Using these labelled images we trained a 2d convolutional neural network to replicate these labels. Separately, we curated an external validation dataset of the systolic and diastolic frames of 100 PLAX acquisitions. Each of these images were labelled twice by 13 different experts, and the average of the 26 measurements was taken as the consensus standard.

We then compared the individual experts and the AI measurements on the external validation dataset to the consensus standard, and calculated the precision standard deviation (SD) of the signed differences from the consensus standard.

Results

For diastolic septum thickness, the AI had a precision SD of 1.8 mm (ICC 0.81; 95% CI 0.73 to 0.97), compared with 2.0 mm for the individual experts (ICC 0.64; 95% CI 0.57 to 0.72). For diastolic posterior wall thickness, the AI had a precision SD 1.4 mm (ICC 0.54; 95% CI 0.38 to 0.66), and the individual experts 2.2 mm (ICC 0.37; 95% CI 0.29 to 0.46).

The AI's precision SD for left ventricular internal dimension was 3.5 mm (ICC 0.93, 95% CI 0.90 to 0.94), and for individual experts was 4.4mm (ICC 0.82, 95% CI 0.78 to 0.95). Both the experts and AI performed better in diastole than systole (precision SD AI 2.5mm vs 4.3mm, p&lt;0.0001; experts 3.3mm vs 5.3mm, p&lt;0.0001).

Conclusions

AI trained by a group of echocardiography experts was able to perform PLAX measurements which matched the reference standard more closely than any individual expert's own measurements.

This open, collaborative approach may be a model for the development of AI that is explainable to, and trusted by clinicians.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHR Imperil BRC ITMATDr Howard was additionally funded by Wellcome. Online collaborative platformResults of AI and experts

Fully automated global longitudinal strain assessment using artificial intelligence developed and validated by a UK-wide echocardiography expert collaborative

Background

Left ventricular longitudinal strain has been reported to deliver reproducibility, sensitivity and prognostic value over and above ejection fraction. However, it currently relies on uninspectable proprietary algorithms and suffers from a lack of widespread clinical use. Uptake may be improved by increasing user trust through greater transparency.

Purpose

We therefore developed a machine-learning based method, trained, and validated with accredited experts from our AI Echocardiography Collaborative. We make the dataset, code, and trained network freely available under an open-source license.

Methods

AI enables strain to be calculated without relying on speckle tracking by directly locating key points and borders across frames. Strain can then be calculated as the fractional shortening of the left ventricular perimeter. We first curated a dataset of 7523 images, including 2587 apical four chamber, each labelled by a single expert from our collaboration of 17 hospitals, using our online platform (Figure 1). Using both this dataset and a semi-supervised approach, we trained a 3d convolutional neural network to identify the annulus, apex, and the endocardial border throughout the cardiac cycle.

Separately, we constructed an external validation dataset of 100 apical 4 chamber video-loops. The systolic and diastolic frame were identified, and each image was separately labelled by 11 experts. From these labels we then derived the expert consensus strain for each of the 100 video loops. These experts also ordered all 100 echocardiograms by their visual grading of left ventricular longitudinal function. Finally, a single expert calculated strain using two different proprietary commercial packages (A and B).

Results

Consensus strain measurements (obtained by averaging individual assessments by the 11 experts) across the 100 cases ranged from −4% to −27%, with strong correlations with the individual experts and machine methods (Figure 2). Using each cases' consensus across experts as the gold standard, median error from consensus was 3.1% for individual experts, 3.4% for Propriety A, 2.6% for Proprietary B, 2.6% for our AI.

Using the visual grading of longitudinal strain as the reference, the 11 individual experts and 4 machine methods each showed significant correlation: coefficients ranged from 0.55 to 0.69 for experts, and for Proprietary A was 0.68, Proprietary B 0.69, and our AI 0.69.

Conclusions

Our open-source, vendor-independent AI-based strain measure automatically produces values that agree with expert consensus, as strongly as the individual experts do. It also agrees with the subjective visual ranking by longitudinal function. Our open-source AI strain performs at least as well as closed-source speckle-based approaches, and may enable increased clinical and research use of longitudinal strain.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHR Imperial BRC ITMAT.Dr Howard was additionally funded by Wellcome. Figure 1. Collaborative online platformFigure 2. Correlations between strain methods

Fractional flow reserve derived from computed tomography coronary angiography in the assessment and management of stable chest pain: the FORECAST randomized trial

Aims 

Fractional flow reserve (FFR_CT) using computed tomography coronary angiography (CTCA) determines both the presence of coronary artery disease and vessel-specific ischaemia. We tested whether an evaluation strategy based on FFR_CT would improve economic and clinical outcomes compared with standard care.

Methods and results 

Overall, 1400 patients with stable chest pain in 11 centres were randomized to initial testing with CTCA with selective FFR_CT (experimental group) or standard clinical care pathways (standard group). The primary endpoint was total cardiac costs at 9 months. Secondary endpoints were angina status, quality of life, major adverse cardiac and cerebrovascular events, and use of invasive coronary angiography. Randomized groups were similar at baseline. Most patients had an initial CTCA: 439 (63%) in the standard group vs. 674 (96%) in the experimental group, 254 of whom (38%) underwent FFR_CT. Mean total cardiac costs were higher by £114 (+8%) in the experimental group, with a 95% confidence interval from −£112 (−8%) to +£337 (+23%), though the difference was not significant (P = 0.10). Major adverse cardiac and cerebrovascular events did not differ significantly (10.2% in the experimental group vs. 10.6% in the standard group) and angina and quality of life improved to a similar degree over follow-up in both randomized groups. Invasive angiography was reduced significantly in the experimental group (19% vs. 25%, P = 0.01).

Conclusion 

A strategy of CTCA with selective FFR_CT in patients with stable angina did not differ significantly from standard clinical care pathways in cost or clinical outcomes, but did reduce the use of invasive coronary angiography.

The tricuspid annular peak systolic excursion to systolic pulmonary artery pressure index: association with all-cause mortality in patients with moderate or severe tricuspid regurgitation

Background

In patients with significant tricuspid regurgitation (TR) the conventional markers for the assessment of right ventricular (RV) systolic function may be less accurate. Tricuspid annular plane systolic excursion (TAPSE) indexed to systolic pulmonary artery pressure (SPAP) (TAPSE/SPAP) may be prognostically useful in pulmonary hypertension and right ventricular (RV) dysfunction.

Objective

Our aim was to explore the prognostic value of TAPSE/SPAP index in patients with moderate or severe TR.

Methods

A total of 209 patients (72±14 years, 56% women) with moderate (n=123) or severe (n=86) TR (primary in 6% and secondary in 94%) were followed up for a median of 80 months (mean 70±33 months). The clinical correlates of TAPSE/SPAP ratio and association with all-cause mortality were assessed.

Results

The TAPSE/SPAP index was inversely correlated with all-cause mortality with an optimal threshold of 0.49 mm/mmHg. A low index was found in 139 (68%) patients and was associated with reduced survival (Figure). In a multivariate Cox regression analysis adjusted for age, smoking, coronary artery disease, left ventricular ejection fraction, right atrium area and mitral valve replacement, low TAPSE/SPAP index was associated with significantly higher hazard ratio of all-cause mortality (HR: 2.0; 95% CI 1.27–3.14, p=0.003). Age, coronary artery disease, left ventricular ejection fraction and right atrium area were other independent predictors of all-cause mortality.

Conclusions

The TAPSE/SPAP index, reflecting RV systolic function in the longitudinal axis corrected for force generating by the RV is a powerful predictor of all-cause mortality in patients with moderate or severe TR.

Figure 1

Funding Acknowledgement

Type of funding source: None

Consensus and development of document for management of stabilized acute decompensated heart failure with reduced ejection fraction in India

Aim

Ensuring adherence to guideline-directed medical therapy (GDMT) is an effective strategy to reduce mortality and readmission rates for heart failure (HF). Use of a checklist is one of the best tools to ensure GDMT. The aim was to develop a consensus document with a robust checklist for stabilized acute decompensated HF patients with reduced ejection fraction. While there are multiple checklists available, an India-specific checklist that is easy to fill and validated by regional and national subject matter experts (SMEs) is required.

Methodology

A total of 25 Cardiology SMEs who consented to participate from India discussed data from literature, current evidence, international guidelines and practical experiences in two national and four regional meetings.

Results

Recommendations included HF management, treatment optimization, and patient education. The checklist should be filled at four time points- (a) transition from intensive care unit to ward, (b) at discharge, (c) 1st follow-up and (d) subsequent follow-up. The checklist is the responsibility of the consultant or the treating physician which can be delegated to a junior resident or a trained HF nurse.

Conclusion

This checklist will ensure GDMT, simplify transition of care and can be used by all doctors across India. Institutions, associations, and societies should recommend this checklist for adaptability in public and private hospital. Hospital administrations should roll out policy for adoption of checklist by ensuring patient files have the checklist at the time of discharge and encourage practice of filling it diligently during follow-up visits.

Evaluation of a comprehensive diabetic foot ulcer care quality model

AIMS

Diabetes-related amputations are typically preceded by a diabetic foot ulcer (DFU) but models to assess the quality of care are lacking. We investigated a model to measure inpatient and outpatient quality.

METHODS

Cohort study among adults hospitalized with a DFU to a safety-net hospital during 2016. We measured adherence to DFU-related quality metrics based on guidelines during and 12 months following hospitalization. Inpatient metrics included ankle-brachial index measurement during or 6 months prior to hospitalization, receiving diabetes education and a wound offloading device prior to discharge. Outpatient metrics included wound care ≤30 days of discharge, in addition to hemoglobin A1c (HbA1c) ≤8%, tobacco cessation, and retention in care (≥2 clinic visits ≥90 days apart) 12 months following discharge.

RESULTS

323 patients were included. Regarding inpatient metrics, 8% had an ankle brachial index measurement, 37% received diabetes education, and 20% received offloading prior to discharge. Regarding outpatient metrics, 33% received wound care ≤30 days of discharge. Twelve months following discharge, 34% achieved a HbA1c ≤8%, 13% quit tobacco, and 52% were retained in care. Twelve-month amputation-free survival was 71%.

CONCLUSIONS

Our model demonstrated large gaps in DFU guideline-adherent care. Implementing measures to close these gaps could prevent amputations.

P3381Quantification of hypo-attenuated leaflet thickening after transcatheter aortic valve implantation - clinical relevance of HALT volume

Background

Hypo-attenuated leaflet thickening (HALT) is a recently recognized phenomenon following transcatheter aortic valve implantation (TAVI) and there is no consensus over the standardized assessment of HALT and its clinical relevance is poorly understood. We sought to determine the predictors and clinical significance of HALT volume.

Methods

Patients, who previously underwent TAVI between 2011 and 2016 were prospectively enrolled in the RETORIC (Rule out Transcatheter Aortic Valve Thrombosis with Post Implantation Computed Tomography) study, a single-center observational study. At inclusion cardiac computed tomography angiography (CTA), transthoracic echocardiography (TTE) and brain magnetic resonance imaging (MRI) was performed. HALT was volumetrically quantified on cardiac CTA images by segmenting the inner volume of the TAVI frame at the level of the leaflets and applying a threshold of −200 to 200 Hounsfield units. We evaluated the clinical predictors of HALT volume, and its association with ischemic brain MRI lesions (recent and chronic large vessel ischemic focuses, microbleed/microembolization, white matter or small vessel disease) and all-cause mortality.

Results

In total, we analyzed 111 patients with CoreValve bioprosthesis (56.7% female, mean age 80.3±7.4 years). A median of 19 [IQR: 11–29] months passed between TAVI procedure and enrollment. The mean HALT volume was 111.0±163.4 mm3. Current malignant disease, prosthesis implantation depth measured on CTA images acquired at inclusion, and aortic mean gradient and aortic valve area evaluated on TTE images at inclusion predicted HALT volume by univariate analysis (all p<0.05). After multivariate adjustment, aortic mean gradient remained a significant predictor of HALT volume (beta-coefficient: 11.5, 95% CI: 5.0–18.0; p<0.001). HALT volume was not associated with ischemic brain MRI lesions (all p>0.05) and did not predict all-cause mortality (median follow-up: 20 months [IQR: 18–23]; HR: 1.0; 95% CI: 1.0–1.0; p=0.15).

Volumetric quantification of HALT.

Conclusion

Aortic mean gradient was the only predictor independently associated with HALT volume. Our results suggest that TAVI valve function is negatively affected by HALT volume, however, we found no association of HALT volume with cerebrovascular ischemic lesions or increased risk for all-cause mortality.

P2650Antihypertensive treatment with calcium channel blockers in patients with moderate or severe aortic stenosis: relationship with all-cause mortality

Background

Hypertension is prevalent in patients with aortic stenosis (AS) and optimal blood pressure (BP) control is advised to reduce arterial load and avoid cardiovascular events. Whether calcium channel blockers (CCB) are safe is not known.

Methods

A total of 314 patients (age 65±12 y, 68% men) with moderate or severe asymptomatic AS were included.

Results

The prevalence of hypertension was 73.6%, and 65% took antihypertensive treatment. Patients who used a CCB (25%) (CCB+) were older, had higher clinic systolic BP, were more likely to have hypercholesterolemia and coronary artery disease (CAD), and to use a diuretic or alpha blocker compared to CCB- patients (all p<0.05) (Table). During the baseline ETT, patients who used a CCB achieved a lower peak heart rate, a shorter exercise time and were more likely to have a blunted BP response compared to those who did not use a CCB (all p<0.05) (Table). Event-free survival was significantly lower in CCB+ than CCB- patients (Fig) (all-cause mortality 16 [20.3%] versus 13 (5.6%); p<0.001). In a multivariable Cox regression model, CCB+ was associated with a 6.8-fold increased hazard ratio (HR) for all-cause mortality (HR 6.77 95% CI 1.66–27.54, p=0.008), independent of age, gender, systolic BP, hypertension, diabetes, CAD, hypercholesterolemia and aortic valve area.

Table 1. Baseline characteristics of patients CCB− (n=234) CCB+ (n=80) p Age, y 64±12 70±10 <0.001 CAD, % 45 66 0.006 Hypercholesterolemia, % 62 78 0.015 Clinic systolic BP, mmHg 139±19 150±17 <0.001 Left atrial diameter, cm 3.7±0.7 3.9±0.6 0.007 LV end-diastolic diameter, cm 4.5±0.7 4.8±0.6 0.002 LV mass index, g/m2.7 50±17 57±17 0.007 Aortic valve area, cm2 0.94±0.22 0.93±0.22 0.716 LV stroke work, g-m/bmp 155±46 175±69 0.046 Peak HR at baseline ETT, bmp 138±24 120±25 <0.001 Blunted BP response, % 33 49 0.013 Exercise duration, min 10.1±4.5 8.3±3.7 0.001 Double Product, mmHg·bmp 1.85±0.43 2.08±0.54 <0.001

Figure 1

Conclusion

The use of calcium channel blockers was associated with an adverse effect on treadmill exercise and reduced survival in apparently asymptomatic patients with moderate or severe AS.

Acknowledgement/Funding

None

Are all metal-on-metal hip revision operations contributing to the National Joint Registry implant survival curves? : a study comparing the London Implant Retrieval Centre and National Joint Registry datasets

AIMS

The National Joint Registry for England, Wales and Northern Ireland (NJR) has extended its scope to report on hospital, surgeon and implant performance. Data linkage of the NJR to the London Implant Retrieval Centre (LIRC) has previously evaluated data quality for hip primary procedures, but did not assess revision records.

METHODS

We analysed metal-on-metal hip revision procedures performed between 2003 and 2013. A total of 69 929 revision procedures from the NJR and 929 revised pairs of components from the LIRC were included.

RESULTS

We were able to link 716 (77.1%) revision procedures on the NJR to the LIRC. This meant that 213 (22.9%) revision procedures at the LIRC could not be identified on the NJR. We found that 349 (37.6%) explants at the LIRC completed the full linkage process to both NJR primary and revision databases. Data completion was excellent (> 99.9%) for revision procedures reported to the NJR.

DISCUSSION

This study has shown that only approximately one third of retrieved components at the LIRC, contributed to survival curves on the NJR. We recommend prospective registry-retrieval linkage as a tool to feedback missing and erroneous data to the NJR and improve data quality.

TAKE HOME MESSAGE

Prospective Registry - retrieval linkage is a simple tool to evaluate and improve data quality on the NJR.

Coronary computed tomography angiography for the evaluation of patients with acute chest pain

Acute chest pain is a common presenting complaint of patients attending emergency room departments. Despite this, it can often be challenging to completely exclude a diagnosis of acute coronary syndrome following an initial standard clinical and biochemical evaluation. As a result of this, patients are often admitted to hospital until the treating clinician is satisfied that this diagnosis can be excluded. This process imparts a significant health economic burden by not only increasing hospital bed occupancy rates but also by the unnecessary layering of diagnostic investigations. With the rapid advances in coronary computed tomography angiography (CTA), there has been considerable interest in whether coronary CTA may be a viable alternative to this current standard care. We review the current literature and supporting evidence for utilising coronary CTA in the evaluation of patients presenting with acute chest pain in terms of its diagnostic accuracy, safety, cost-effectiveness and prognostic implications.

Permanent pacemaker insertion after CoreValve transcatheter aortic valve implantation: incidence and contributing factors (the UK CoreValve Collaborative)

BACKGROUND

Permanent pacemaker (PPM) requirement is a recognized complication of transcatheter aortic valve implantation. We assessed the UK incidence of permanent pacing within 30 days of CoreValve implantation and formulated an anatomic and electrophysiological model.

METHODS AND RESULTS

Data from 270 patients at 10 centers in the United Kingdom were examined. Twenty-five patients (8%) had preexisting PPMs; 2 patients had incomplete data. The remaining 243 were 81.3±6.7 years of age; 50.6% were male. QRS duration increased from 105±23 to 135±29 milliseconds (P<0.01). Left bundle-branch block incidence was 13% at baseline and 61% after the procedure (P<0.001). Eighty-one patients (33.3%) required a PPM within 30 days. Rates of pacing according to preexisting ECG abnormalities were as follows: right bundle-branch block, 65.2%; left bundle-branch block, 43.75%; normal QRS, 27.6%. Among patients who required PPM implantation, the median time to insertion was 4.0 days (interquartile range, 2.0 to 7.75 days). Multivariable analysis revealed that periprocedural atrioventricular block (odds ratio, 6.29; 95% confidence interval, 3.55 to 11.15), balloon predilatation (odds ratio, 2.68; 95% confidence interval, 2.00 to 3.47), use of the larger (29 mm) CoreValve prosthesis (odds ratio, 2.50; 95% confidence interval, 1.22 to 5.11), interventricular septum diameter (odds ratio, 1.18; 95% confidence interval, 1.10 to 3.06), and prolonged QRS duration (odds ratio, 3.45; 95% confidence interval, 1.61 to 7.40) were independently associated with the need for PPM.

CONCLUSION

One third of patients undergoing a CoreValve transcatheter aortic valve implantation procedure require a PPM within 30 days. Periprocedural atrioventricular block, balloon predilatation, use of the larger CoreValve prosthesis, increased interventricular septum diameter and prolonged QRS duration were associated with the need for PPM.

Primary facial cutaneous nocardiosis in a HIV patient and review of cutaneous nocardiosis in India

Nocardiosis is an acute, subacute or chronic bacterial infection caused by several species of geophilic aerobic bacteria of the genus Nocardia. Cutaneous nocardiosis is an uncommon infectious disease that presents as primary cutaneous infection or as a sequale of disseminated pulmonary nocardiosis. Its rarity and as nocardiosis is not an AIDS defined disease it is often underreported. The global incidence of cutaneous nocardiosis is not exactly known. The frequency of nocardiosis in HIV patients has increased from 0.3 to1.85%. In Immunocompetent persons Primary Cutaneous Nocardiosis is more commonly seen among gardeners and agriculturists. We report a case of extensive primary facial cutaneous nocardiosis due to Nocardia asteroides, in an adult immunocompromised lady who had no pulmonary focus. The lesions were seen as sinus tracts on the zygomatic arch, preauricular and Infraauricular regions. Bacteriological examination of the pus confirmed the presence of N. asteroides. The rarity of the presentation and Cutaneous nocardiosis in India is reviewed.

Primary facial cutaneous nocardiosis in a HIV patient and review of cutaneous nocardiosis in India

Nocardiosis is an acute, subacute or chronic bacterial infection caused by several species of geophilic aerobic bacteria of the genus Nocardia. Cutaneous nocardiosis is an uncommon infectious disease that presents as primary cutaneous infection or as a sequale of disseminated pulmonary nocardiosis. Its rarity and as nocardiosis is not an AIDS defined disease it is often underreported. The global incidence of cutaneous nocardiosis is not exactly known. The frequency of nocardiosis in HIV patients has increased from 0.3 to1.85%. In Immunocompetent persons Primary Cutaneous Nocardiosis is more commonly seen among gardeners and agriculturists. We report a case of extensive primary facial cutaneous nocardiosis due to Nocardia asteroides, in an adult immunocompromised lady who had no pulmonary focus. The lesions were seen as sinus tracts on the zygomatic arch, preauricular and Infraauricular regions. Bacteriological examination of the pus confirmed the presence of N. asteroides. The rarity of the presentation and Cutaneous nocardiosis in India is reviewed.

The epidemiology and clinical features of portal vein thrombosis: a multicentre study

BACKGROUND

Reliable epidemiological data for portal vein thrombosis are lacking.

AIMS

To investigate the incidence, prevalence and survival rates for patients with portal vein thrombosis.

METHODS

Retrospective multicentre study of all patients registered with the diagnosis of portal vein thrombosis between 1995 and 2004.

RESULTS

A total of 173 patients (median age 57 years, 93 men) with portal vein thrombosis were identified and followed up for a median of 2.5 years (range 0-9.7). The mean age-standardized incidence and prevalence rates were 0.7 per 100,000 per year and 3.7 per 100,000 inhabitants, respectively. Liver disease was present in 70 patients (40%), malignancy in 27%, thrombophilic factors in 22% and myeloproliferative disorders in 11%. Two or more risk factors were identified in 80 patients (46%). At diagnosis, 65% were put on anticoagulant therapy. Thrombolysis, TIPS, surgical shunting and liver transplantation were performed in 6, 3, 2 and 8 patients, respectively. The overall survival at 1 year and 5 years was 69% and 54%. In the absence of malignancy and cirrhosis, the survival was 92% and 76%, respectively.

CONCLUSIONS

The incidence and prevalence rates of portal vein thrombosis were 0.7 per 100,000 inhabitants per year and 3.7 per 100,000 inhabitants, respectively. Concurrent prothrombotic risk factors are common. The prognosis is variable and highly dependent on underlying disease.

Cobalamin, folate, methylmalonic acid, homocysteine, and gastritis markers in dementia

The prevalence of dementia disorders, cobalamin and/or folate deficiency as well as gastritis increases with age. To investigate whether there is an association between these conditions, plasma homocysteine (Hcy), serum methylmalonic acid, serum cobalamin and blood folate concentrations were measured. Gastritis was indirectly diagnosed by measuring serum antibodies against H,K-ATPase, HELICOBACTER PYLORI and intrinsic factor, using enzyme-linked immunosorbent assays. The studied groups consisted of 47 patients with Alzheimer's disease (AD), 9 with AD pathology in combination with additive vascular lesions, 59 with vascular dementia, 8 who were cognitively impaired, and 101 control cases. Plasma Hcy concentrations were significantly elevated in the dementia groups, with the highest levels in patients with vascular pathology. We conclude that hyperhomocysteinemia is a common finding in patients with dementia disorders of different etiologies. The markers for gastritis did not contribute to an elucidation of a possible connection between this condition, dementia disorders, or cobalamin/folate deficiency.

Body composition, physiological function and psychological changes in patients with predicted severe acute pancreatitis

BACKGROUND

Serious sepsis and major blunt trauma have adverse effects on body composition, physiological function and psychological state. The effect of severe acute pancreatitis on these groups of variables has not yet been reported.

METHODS

We have studied the effect of predicted severe acute pancreatitis (admission APACHE II score > or = 6) on body fat and mid arm muscle circumference (assessed by dual-energy X-ray absorptiometry and anthropometry), respiratory function (measured by spirometry and vitalography), voluntary muscle function (measured by hand dynamometry) and psychological state (measured by use of the hospital anxiety and depression score and visual analogue scale for fatigue) on admission, and three and seven days thereafter.

RESULTS

The median APACHE II score of the 15 patients (7 men) in this study was 10 (6-13). The patients showed significant improvement in respiratory function (FEV1 1.3, 1.6, 2.3 litres/s, p < 0.01; FVC 1.5, 2.0, 2.9 litres, p < 0.01; PEFR 304, 372, 409 litres/min, p = 0.01 but no change in voluntary muscle function (210, 205, 213 N, p = 0.41) over the 7-day study period. Psychological state improved in terms of fatigue (2.4, 4.2, 7.0, p < 0.01) and depression (6, 9, 4, p = 0.12) but not in anxiety (8, 6, 7, p = 0.07). Body fat measured by DEXA (17.3 kg on admission, 16.7 kg on day 7, p = 0.13) and the mid upper arm muscle circumference (262, 248, 251 mm, p = 0.10) did not change implying that energy and nitrogen balance over the 7-day study period was achieved.

CONCLUSION

Predicted severe acute pancreatitis has an adverse effect on respiratory function and psychological state similar to that observed in serious sepsis. Improvement in these variables is apparent over 7 days of effective treatment. Further research is indicated to examine the effect of nutritional support on these variables.

Effect of Blalock Taussig shunt on clinical parameters, left ventricular function and pulmonary arteries

Twenty children (mean age 3.25 years) with congenital cyanotic heart disease undergoing modified left Blalock-Taussig (BT) shunt were studied. The mean follow-up period was 9.5 months (range 6 months to 1 year). The shunt was performed for cyanotic spells in 15 (75%) and hypoplastic pulmonary arteries in 5 (25%) patients. There were no immediate or late complications. None had cyanotic spell after the shunt. The mean arterial oxygen saturation improved from 66.47 +/- 11.9 to 76.97 +/- 8.16% (p = 0.0003) and mean hematocrit decreased from 51.55 +/- 9.5 to 46.5 +/- 9.7 (p = 0.002) after the shunt. The left atrial systolic volume and left ventricular diastolic volume also increased significantly following the shunt (from 15.82 +/- 6.37 to 20.83 +/- 8.91 ml p = 0.006 and from 36.13 +/- 16.08 to 41.08 +/- 20.07 ml (p = 0.01) respectively. There was significant growth of main, right and left pulmonary arteries and pulmonary valve annulus after the procedure.

Unruptured aneurysm of sinus of Valsalva: report of 2 cases

2 cases of unruptured aneurysm of the sinus of Valsalva are presented. Both the patients had involvement of the right sinus of Valsalva. One of the patients had associated systemic lupus erythematosus (SLE). Such an association has not been described in the literature. Clinical, echocardiographic and the angiographic features have been discussed and literature reviewed.

Rupture of an intra-aortic balloon. A case report

A case of rupture of an intra-aortic balloon is reported. The rupture, noted 34 hours after insertion of the balloon, was caused by perforation by an atheromatous plaque. The patient exhibited no adverse effects from the episode.