His bundle pacing, learning curve, procedure characteristics, safety, and feasibility: Insights from a large international observational study.

BACKGROUND: His-bundle pacing (HBP) provides physiological ventricular activation. Observational studies have demonstrated the techniques' feasibility; however, data have come from a limited number of centers. OBJECTIVES: We set out to explore the contemporary global practice in HBP focusing on the learning curve, procedural characteristics, and outcomes. METHODS: This is a retrospective, multicenter observational study of patients undergoing attempted HBP at seven centers. Pacing indication, fluoroscopy time, HBP thresholds, and lead reintervention and deactivation rates were recorded. Where centers had systematically recorded implant success rates from the outset, these were collated. RESULTS: A total of 529 patients underwent attempted HBP during the study period (2014-19) with a mean follow-up of 217 ± 303 days. Most implants were for bradycardia indications. In the three centers with the systematic collation of all attempts, the overall implant success rate was 81%, which improved to 87% after completion of 40 cases. All seven centers reported data on successful implants. The mean fluoroscopy time was 11.7 ± 12.0 minutes, the His-bundle capture threshold at implant was 1.4 ± 0.9 V at 0.8 ± 0.3 ms, and it was 1.3 ± 1.2 V at 0.9 ± 0.2 ms at last device check. HBP lead reintervention or deactivation (for lead displacement or rise in threshold) occurred in 7.5% of successful implants. There was evidence of a learning curve: fluoroscopy time and HBP capture threshold reduced with greater experience, plateauing after approximately 30-50 cases. CONCLUSION: We found that it is feasible to establish a successful HBP program, using the currently available implantation tools. For physicians who are experienced at pacemaker implantation, the steepest part of the learning curve appears to be over the first 30-50 cases.

Mitral Valve Diverticulum Presenting with Severe Mitral Stenosis: Case Report.

The case is presented of a non-infectious anterior mitral valve leaflet diverticulum, which appeared as symptomatic mitral stenosis. Unlike previous reports, there was no histological myxomatous degeneration of the valve. To the authors' knowledge, this is the first time a mitral valve diverticulum resulting in severe mitral stenosis has been reported in the literature.

Giant proximal left anterior descending aneurysm causing multi-vessel myocardial ischaemia: the pressure is on-a case report.

Background: Giant coronary artery aneurysms are a rare cause of myocardial ischaemia. Due to the rarity and variety of presentation of these cases, no standardized investigation or treatment has been established for management. We report a case study of a giant proximal left anterior descending (LAD) coronary aneurysm causing myocardial ischaemia due to the pressure effect from the weight of the aneurysm as well as from a change in rheology from a 'steal effect' on both the LAD and left circumflex (LCx) arteries. Case summary: A 55-year-old patient presents initially with a history of angina. Initial investigation with computed tomography (CT) was suboptimal, requiring invasive diagnostic angiography, which detects a giant proximal LAD aneurysm. Subsequent investigations, with CT-fractional flow reserve (FFR) and stress echocardiography (ECHO), correlated to identify multi-vessel ischaemia resulting from the aneurysm. The patient was managed with multi-disciplinary team-led surgical resection and triple coronary artery bypass grafts with good results. Discussion: This case highlights the complexity of coronary anomalies and importance of additional functional three-dimensional imaging on top of the static computational tomography coronary angiography analysis. Together, these two complimentary investigations qualitatively enabled the assessment of anomaly with surrounding structures such that the possibility of a mass effect on the LCx artery results in a positive stress test. Furthermore, this is a novel use of CT-FFR for coronary anomalies and it demonstrated good correlation of LAD territory ischaemia between CT-FFR and the stress ECHO.

Contrast echocardiography: a practical guideline from the British Society of Echocardiography.

Ultrasound contrast agents (UCAs) have a well-established role in clinical cardiology. Contrast echocardiography has evolved into a routine technique through the establishment of contrast protocols, an excellent safety profile, and clinical guidelines which highlight the incremental prognostic utility of contrast enhanced echocardiography. This document aims to provide practical guidance on the safe and effective use of contrast; reviews the role of individual staff groups; and training requirements to facilitate its routine use in the echocardiography laboratory.

Time to TAVI: streamlining the pathway to treatment.

INTRODUCTION: Severe aortic stenosis is a major cause of morbidity and mortality. The existing treatment pathway for transcatheter aortic valve implantation (TAVI) traditionally relies on tertiary Heart Valve Centre workup. However, this has been associated with delays to treatment, in breach of British Cardiovascular Intervention Society targets. A novel pathway with emphasis on comprehensive patient workup at a local centre, alongside close collaboration with a Heart Valve Centre, may help reduce the time to TAVI. METHODS: The centre performing local workup implemented a novel TAVI referral pathway. Data were collected retrospectively for all outpatients referred for consideration of TAVI to a Heart Valve Centre from November 2020 to November 2021. The main outcome of time to TAVI was calculated as the time from Heart Valve Centre referral to TAVI, or alternative intervention, expressed in days. For the centre performing local workup, referral was defined as the date of multidisciplinary team discussion. For this centre, a total pathway time from echocardiographic diagnosis to TAVI was also evaluated. A secondary outcome of the proportion of referrals proceeding to TAVI at the Heart Valve Centre was analysed. RESULTS: Mean±SD time from referral to TAVI was significantly lower at the centre performing local workup, when compared with centres with traditional referral pathways (32.4±64 to 126±257 days, p<0.00001). The total pathway time from echocardiographic diagnosis to TAVI for the centre performing local workup was 89.9±67.6 days, which was also significantly shorter than referral to TAVI time from all other centres (p<0.003). Centres without local workup had a significantly lower percentage of patients accepted for TAVI (49.5% vs 97.8%, p<0.00001). DISCUSSION: A novel TAVI pathway with emphasis on local workup within a non-surgical centre significantly reduced both the time to TAVI and rejection rates from a Heart Valve Centre. If adopted across the other centres, this approach may help improve access to TAVI.

A case report of successful physiological pacing in a patient with lamin A/C cardiomyopathy.

Background: Lamin A/C (LMNA) mutations account for 5-8% of familial dilated cardiomyopathies, and can manifest with conduction abnormalities and ventricular arrhythmias in 78% of patients. Therefore, when suspected, it is important to implant the correct type of device. Case summary: A 52-year-old gentleman with a family history of cardiomyopathy, presented with asymptomatic atrial fibrillation and complete atrioventricular block associated with a narrow QRS interval. Investigations confirmed dilated and severely impaired left ventricular systolic function. He underwent successful conduction system pacing in combination with a primary prevention defibrillator. Genetic screening confirmed LMNA cardiomyopathy. During 3 years follow up, his left ventricular function remained unchanged with stable conduction system capture and he received appropriate therapy from his device for ventricular tachycardia. Discussion: His-bundle pacing promotes rapid and synchronous activation of the ventricles via the intrinsic conduction system of the heart. In selected individuals with LMNA cardiomyopathy, conduction system pacing is viable alternative to conventional cardiac resynchronization therapy using coronary sinus tributaries.

Real-world evidence in a national health service: results of the UK CardioMEMS HF System Post-Market Study.

AIMS: The CardioMEMS HF System Post-Market Study (COAST) was designed to evaluate the safety, effectiveness, and feasibility of haemodynamic-guided heart failure (HF) management using a small sensor implanted in the pulmonary artery of New York Heart Association (NYHA) Class III HF patients in the UK, Europe, and Australia. METHODS AND RESULTS: COAST is a prospective, international, multicentre, open-label clinical study (NCT02954341). The primary clinical endpoint compares annualized HF hospitalization rates after 1 year of haemodynamic-guided management vs. the year prior to sensor implantation in patients with NYHA Class III symptoms and a previous HF hospitalization. The primary safety endpoints assess freedom from device/system-related complications and pressure sensor failure after 2 years. Results from the first 100 patients implanted at 14 out of the 15 participating centres in the UK are reported here. At baseline, all patients were in NYHA Class III, 70% were male, mean age was 69 ± 12 years, and 39% had an aetiology of ischaemic cardiomyopathy. The annualized HF hospitalization rate after 12 months was 82% lower [95% confidence interval 72-88%] than the previous 12 months (0.27 vs. 1.52 events/patient-year, respectively, P < 0.0001). Freedom from device/system-related complications and pressure sensor failure at 2 years was 100% and 99%, respectively. CONCLUSIONS: Remote haemodynamic-guided HF management, using frequent assessment of pulmonary artery pressures, was successfully implemented at 14 specialist centres in the UK. Haemodynamic-guided HF management was safe and significantly reduced hospitalization in a group of high-risk patients. These results support implementation of this innovative remote management strategy to improve outcome for patients with symptomatic HF. Clinical registration number: ClinicalTrials.gov identifier: NCT02954341.

Left ventricular assessment with artificial intelligence increases the diagnostic accuracy of stress echocardiography.

Aims: To evaluate whether left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS), automatically calculated by artificial intelligence (AI), increases the diagnostic performance of stress echocardiography (SE) for coronary artery disease (CAD) detection. Methods and results: SEs from 512 participants who underwent a clinically indicated SE (with or without contrast) for the evaluation of CAD from seven hospitals in the UK and US were studied. Visual wall motion scoring (WMS) was performed to identify inducible ischaemia. In addition, SE images at rest and stress underwent AI contouring for automated calculation of AI-LVEF and AI-GLS (apical two and four chamber images only) with Ultromics EchoGo Core 1.0. Receiver operator characteristic curves and multivariable risk models were used to assess accuracy for identification of participants subsequently found to have CAD on angiography. Participants with significant CAD were more likely to have abnormal WMS, AI-LVEF, and AI-GLS values at rest and stress (all P < 0.001). The areas under the receiver operating characteristics for WMS index, AI-LVEF, and AI-GLS at peak stress were 0.92, 0.86, and 0.82, respectively, with cut-offs of 1.12, 64%, and -17.2%, respectively. Multivariable analysis demonstrated that addition of peak AI-LVEF or peak AI-GLS to WMS significantly improved model discrimination of CAD [C-statistic (bootstrapping 2.5th, 97.5th percentile)] from 0.78 (0.69-0.87) to 0.83 (0.74-0.91) or 0.84 (0.75-0.92), respectively. Conclusion: AI calculation of LVEF and GLS by contouring of contrast-enhanced and unenhanced SEs at rest and stress is feasible and independently improves the identification of obstructive CAD beyond conventional WMSI.

Real-world performance and accuracy of stress echocardiography: the EVAREST observational multi-centre study.

AIMS: Stress echocardiography is widely used to identify obstructive coronary artery disease (CAD). High accuracy is reported in expert hands but is dependent on operator training and image quality. The EVAREST study provides UK-wide data to evaluate real-world performance and accuracy of stress echocardiography. METHODS AND RESULTS: Participants undergoing stress echocardiography for CAD were recruited from 31 hospitals. Participants were followed up through health records which underwent expert adjudication. Cardiac outcome was defined as anatomically or functionally significant stenosis on angiography, revascularization, medical management of ischaemia, acute coronary syndrome, or cardiac-related death within 6 months. A total of 5131 patients (55% male) participated with a median age of 65 years (interquartile range 57-74). 72.9% of studies used dobutamine and 68.5% were contrast studies. Inducible ischaemia was present in 19.3% of scans. Sensitivity and specificity for prediction of a cardiac outcome were 95.4% and 96.0%, respectively, with an accuracy of 95.9%. Sub-group analysis revealed high levels of predictive accuracy across a wide range of patient and protocol sub-groups, with the presence of a resting regional wall motion abnormalitiy significantly reducing the performance of both dobutamine (P < 0.01) and exercise (P < 0.05) stress echocardiography. Overall accuracy remained consistently high across all participating hospitals. CONCLUSION: Stress echocardiography has high accuracy across UK-based hospitals and thus indicates stress echocardiography is being delivered effectively in real-world practice, reinforcing its role as a first-line investigation in the assessment of patients with stable chest pain.

Piloting structured focused TTE in outpatients during the COVID-19 pandemic: 'old habits die hard'.

Transthoracic echocardiography presents a risk of COVID-19 transmission between an echocardiographer and the patient. Reducing the scanning time is likely to mitigate this risk for them both. British Society of Echocardiography (BSE) level 1 echocardiography offers a potential framework for focused scanning in an outpatient setting. There were 116 outpatients scheduled for a level 1 scan supplemented with additional predefined views, if required. Unexpectedly, a fifth of the scans were performed as an unintended full scan for a variety of reasons. Our results showed that focused scans were performed more quickly than full scans and below the NHS Test and Trace exposure cut-off of 15 minutes. However, if more than three sets of additional measurements were required then a full scan could be performed more quickly. Seniority of the echocardiographer and scan time had an inverse relationship. By examining the patients' clinical records we were confident that all of the scans, whether focused or full, had answered the requestor's clinical question. Although the COVID-19 vaccination programme should reduce the necessity of minimising exposure time during a scan there could still be a role for level 1 scanning during the COVID-19 recovery programme to tackle the vast lists of patients waiting for an echocardiogram.

Myocardial apelin production is reduced in humans with left ventricular systolic dysfunction.

BACKGROUND: Apelin is a novel endogenous peptide with inotropic and vasodilatory properties that is the ligand for the APJ receptor. Apelin and APJ are widely distributed in the vasculature of a number of organs and peripheral venous apelin is reduced in heart failure (HF). The location of apelin production in humans with and without HF was investigated. METHODS AND RESULTS: Plasma apelin and brain natriuretic peptide (BNP) concentrations in coronary sinus (CS), aorta (Ao), and renal vein (RV) of individuals with HF (n = 9) were compared to subjects with normal structural hearts (n = 8). In HF the concentration of CS apelin was reduced compared with controls (310 pg/mL [interquartile range 290-390] vs. 470 pg/mL [340-570], P < .035) but Ao apelin (330 pg/mL [275-375] vs. 340 pg/mL [230-455], P = .76) and RV apelin (290 pg/mL [280-360] vs. 370 pg/mL [273-410], P = .56) were unchanged. Plasma BNP was increased at all sampling sites in patients with HF as compared with controls. A step down from CS to Ao to RV in all subjects was observed. The step down in apelin from CS to Ao (470 pg/mL [310-595] vs. 320 pg/mL [225-482], P < .04) in control subjects was not apparent in patients with HF. CONCLUSIONS: These novel data show that apelin is produced in the human heart and that production is reduced in individuals with HF. In contrast to BNP, apelin production is not exclusive to the heart.

The role of apelin in cardiovascular function and heart failure.

Apelin is a novel peptide that acts through the APJ receptor, sharing similarities with the angiotensin II-angiotensin II type 1 receptor pathway. It is a peripheral vasodilator, powerful inotrope and may affect central fluid homeostasis. Animal and human studies suggest that it may play a role in the pathogenesis of heart failure by modulating the harmful effects of angiotensin II. Apelin is reduced in patients with heart failure and up regulated following favourable left ventricular remodelling. It is widely distributed in a number of tissues, mainly restricted to vascular endothelium. This comprehensive review of the literature highlights the important studies that have led to the discovery of apelin and its role in cardiovascular function and heart failure.

Iatrogenic mitral stenosis following transcatheter aortic valve replacement (TAVR).

A 57 year old female underwent transcatheter aortic valve replacement (TAVR) for severe aortic stenosis. Mild iatrogenic mitral stenosis was noted intraoperatively. Attempts to reposition the device were hampered by aortic angulation. One year later, severe mitral stenosis was confirmed on transoesophageal echocardiography. It is important to recognise that iatorgenic mitral stenosis due to TAVR may progress over time. Care should be taken to minimise the risk of this rare complication.