Development and validation of AI-derived segmentation of four-chamber cine cardiac magnetic resonance.

BACKGROUND: Cardiac magnetic resonance (CMR) in the four-chamber plane offers comprehensive insight into the volumetrics of the heart. We aimed to develop an artificial intelligence (AI) model of time-resolved segmentation using the four-chamber cine. METHODS: A fully automated deep learning algorithm was trained using retrospective multicentre and multivendor data of 814 subjects. Validation, reproducibility, and mortality prediction were evaluated on an independent cohort of 101 subjects. RESULTS: The mean age of the validation cohort was 54 years, and 66 (65%) were males. Left and right heart parameters demonstrated strong correlations between automated and manual analysis, with a ρ of 0.91-0.98 and 0.89-0.98, respectively, with minimal bias. All AI four-chamber volumetrics in repeatability analysis demonstrated high correlation (ρ = 0.99-1.00) and no bias. Automated four-chamber analysis underestimated both left ventricular (LV) and right ventricular (RV) volumes compared to ground-truth short-axis cine analysis. Two correction factors for LV and RV four-chamber analysis were proposed based on systematic bias. After applying the correction factors, a strong correlation and minimal bias for LV volumetrics were observed. During a mean follow-up period of 6.75 years, 16 patients died. On stepwise multivariable analysis, left atrial ejection fraction demonstrated an independent association with death in both manual (hazard ratio (HR) = 0.96, p = 0.003) and AI analyses (HR = 0.96, p < 0.001). CONCLUSION: Fully automated four-chamber CMR is feasible, reproducible, and has the same real-world prognostic value as manual analysis. LV volumes by four-chamber segmentation were comparable to short-axis volumetric assessment. TRIALS REGISTRATION: ClinicalTrials.gov: NCT05114785. RELEVANCE STATEMENT: Integrating fully automated AI in CMR promises to revolutionise clinical cardiac assessment, offering efficient, accurate, and prognostically valuable insights for improved patient care and outcomes. KEY POINTS: • Four-chamber cine sequences remain one of the most informative acquisitions in CMR examination. • This deep learning-based, time-resolved, fully automated four-chamber volumetric, functional, and deformation analysis solution. • LV and RV were underestimated by four-chamber analysis compared to ground truth short-axis segmentation. • Correction bias for both LV and RV volumes by four-chamber segmentation, minimises the systematic bias.

Treatments for intractable constipation in childhood.

BACKGROUND: Constipation that is prolonged and does not resolve with conventional therapeutic measures is called intractable constipation. The treatment of intractable constipation is challenging, involving pharmacological or non-pharmacological therapies, as well as surgical approaches. Unresolved constipation can negatively impact quality of life, with additional implications for health systems. Consequently, there is an urgent need to identify treatments that are efficacious and safe. OBJECTIVES: To evaluate the efficacy and safety of treatments used for intractable constipation in children. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and two trials registers up to 23 June 2023. We also searched reference lists of included studies for relevant studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing any pharmacological, non-pharmacological, or surgical treatment to placebo or another active comparator, in participants aged between 0 and 18 years with functional constipation who had not responded to conventional medical therapy. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were symptom resolution, frequency of defecation, treatment success, and adverse events; secondary outcomes were stool consistency, painful defecation, quality of life, faecal incontinence frequency, abdominal pain, hospital admission for disimpaction, and school absence. We used GRADE to assess the certainty of evidence for each primary outcome. MAIN RESULTS: This review included 10 RCTs with 1278 children who had intractable constipation. We assessed one study as at low risk of bias across all domains. There were serious concerns about risk of bias in six studies. One study compared the injection of 160 units botulinum toxin A (n = 44) to unspecified oral stool softeners (n = 44). We are very uncertain whether botulinum toxin A injection improves treatment success (risk ratio (RR) 37.00, 95% confidence interval (CI) 5.31 to 257.94; very low certainty evidence, downgraded due to serious concerns with risk of bias and imprecision). Frequency of defecation was reported only for the botulinum toxin A injection group (mean interval of 2.6 days). The study reported no data for the other primary outcomes. One study compared erythromycin estolate (n = 6) to placebo (n = 8). The only primary outcome reported was adverse events, which were 0 in both groups. The evidence is of very low certainty due to concerns with risk of bias and serious imprecision. One study compared 12 or 24 µg oral lubiprostone (n = 404) twice a day to placebo (n = 202) over 12 weeks. There may be little to no difference in treatment success (RR 1.29, 95% CI 0.87 to 1.92; low certainty evidence). We also found that lubiprostone probably results in little to no difference in adverse events (RR 1.05, 95% CI 0.91 to 1.21; moderate certainty evidence). The study reported no data for the other primary outcomes. One study compared three-weekly rectal sodium dioctyl sulfosuccinate and sorbitol enemas (n = 51) to 0.5 g/kg/day polyethylene glycol laxatives (n = 51) over a 52-week period. We are very uncertain whether rectal sodium dioctyl sulfosuccinate and sorbitol enemas improve treatment success (RR 1.33, 95% CI 0.83 to 2.14; very low certainty evidence, downgraded due to serious concerns with risk of bias and imprecision). Results of defecation frequency per week was reported only as modelled means using a linear mixed model. The study reported no data for the other primary outcomes. One study compared biofeedback therapy (n = 12) to no intervention (n = 12). We are very uncertain whether biofeedback therapy improves symptom resolution (RR 2.50, 95% CI 1.08 to 5.79; very low certainty evidence, downgraded due to serious concerns with risk of bias and imprecision). The study reported no data for the other primary outcomes. One study compared 20 minutes of intrarectal electromotive botulinum toxin A using 2800 Hz frequency and botulinum toxin A dose 10 international units/kg (n = 30) to 10 international units/kg botulinum toxin A injection (n = 30). We are very uncertain whether intrarectal electromotive botulinum toxin A improves symptom resolution (RR 0.96, 95% CI 0.76 to 1.22; very low certainty evidence) or if it increases the frequency of defecation (mean difference (MD) 0.00, 95% CI -1.87 to 1.87; very low certainty evidence). We are also very uncertain whether intrarectal electromotive botulinum toxin A has an improved safety profile (RR 0.20, 95% CI 0.01 to 4.00; very low certainty evidence). The evidence for these results is of very low certainty due to serious concerns with risk of bias and imprecision. The study did not report data on treatment success. One study compared the injection of 60 units botulinum toxin A (n = 21) to myectomy of the internal anal sphincter (n = 21). We are very uncertain whether botulinum toxin A injection improves treatment success (RR 1.00, 95% CI 0.75 to 1.34; very low certainty evidence). No adverse events were recorded. The study reported no data for the other primary outcomes. One study compared 0.04 mg/kg oral prucalopride (n = 107) once daily to placebo (n = 108) over eight weeks. Oral prucalopride probably results in little or no difference in defecation frequency (MD 0.50, 95% CI -0.06 to 1.06; moderate certainty evidence); treatment success (RR 0.96, 95% CI 0.53 to 1.72; moderate certainty evidence); and adverse events (RR 1.15, 95% CI 0.94 to 1.39; moderate certainty evidence). The study did not report data on symptom resolution. One study compared transcutaneous electrical stimulation to sham stimulation, and another study compared dietitian-prescribed Mediterranean diet with written instructions versus written instructions. These studies did not report any of our predefined primary outcomes. AUTHORS' CONCLUSIONS: We identified low to moderate certainty evidence that oral lubiprostone may result in little to no difference in treatment success and adverse events compared to placebo. Based on moderate certainty evidence, there is probably little or no difference between oral prucalopride and placebo in defecation frequency, treatment success, or adverse events. For all other comparisons, the certainty of the evidence for our predefined primary outcomes is very low due to serious concerns with study limitations and imprecision. Consequently, no robust conclusions could be drawn.

Sex-specific cardiac magnetic resonance pulmonary capillary wedge pressure.

Aims: Heart failure (HF) with preserved ejection fraction disproportionately affects women. There are no validated sex-specific tools for HF diagnosis despite widely reported differences in cardiac structure. This study investigates whether sex, as assigned at birth, influences cardiac magnetic resonance (CMR) assessment of left ventricular filling pressure (LVFP), a hallmark of HF agnostic to ejection fraction. Methods and results: A derivation cohort of patients with suspected pulmonary hypertension and HF from the Sheffield centre underwent invasive right heart catheterization and CMR within 24 h of each other. A sex-specific CMR model to estimate LVFP, measured as pulmonary capillary wedge pressure (PCWP), was developed using multivariable regression. A validation cohort of patients with confirmed HF from the Leeds centre was used to evaluate for the primary endpoints of HF hospitalization and major adverse cardiovascular events (MACEs). Comparison between generic and sex-specific CMR-derived PCWP was undertaken. A total of 835 (60% female) and 454 (36% female) patients were recruited into the derivation and validation cohorts respectively. A sex-specific model incorporating left atrial volume and left ventricular mass was created. The generic CMR PCWP showed significant differences between males and females (14.7 ± 4 vs. 13 ± 3.0 mmHg, P > 0.001), not present with the sex-specific CMR PCWP (14.1 ± 3 vs. 13.8 mmHg, P = 0.3). The sex-specific, but not the generic, CMR PCWP was associated with HF hospitalization (hazard ratio 3.9, P = 0.0002) and MACE (hazard ratio 2.5, P = 0.001) over a mean follow-up period of 2.4 ± 1.2 years. Conclusion: Accounting for sex improves precision and prognostic performance of CMR biomarkers for HF.

Validation of Left Atrial Volume Correction for Single Plane Method on Four-Chamber Cine Cardiac MRI.

BACKGROUND: Left atrial (LA) assessment is an important marker of adverse cardiovascular outcomes. Cardiovascular magnetic resonance (CMR) accurately quantifies LA volume and function based on biplane long-axis imaging. We aimed to validate single-plane-derived LA indices against the biplane method to simplify the post-processing of cine CMR. METHODS: In this study, 100 patients from Leeds Teaching Hospitals were used as the derivation cohort. Bias correction for the single plane method was applied and subsequently validated in 79 subjects. RESULTS: There were significant differences between the biplane and single plane mean LA maximum and minimum volumes and LA ejection fraction (EF) (all p < 0.01). After correcting for biases in the validation cohort, significant correlations in all LA indices were observed (0.89 to 0.98). The area under the curve (AUC) for the single plane to predict biplane cutoffs of LA maximum volume ≥ 112 mL was 0.97, LA minimum volume ≥ 44 mL was 0.99, LA stroke volume (SV) ≤ 21 mL was 1, and LA EF ≤ 46% was 1, (all p < 0.001). CONCLUSIONS: LA volumetric and functional assessment by the single plane method has a systematic bias compared to the biplane method. After bias correction, single plane LA volume and function are comparable to the biplane method.

Validation of 2D flow MRI for helical and vortical flows.

PURPOSE: The main objective of this study was to develop two-dimensional (2D) phase contrast (PC) methods to quantify the helicity and vorticity of blood flow in the aortic root. METHODS: This proof-of-concept study used four-dimensional (4D) flow cardiovascular MR (4D flow CMR) data of five healthy controls, five patients with heart failure with preserved ejection fraction and five patients with aortic stenosis (AS). A PC through-plane generated by 4D flow data was treated as a 2D PC plane and compared with the original 4D flow. Visual assessment of flow vectors was used to assess helicity and vorticity. We quantified flow displacement (FD), systolic flow reversal ratio (sFRR) and rotational angle (RA) using 2D PC. RESULTS: For visual vortex flow presence near the inner curvature of the ascending aortic root on 4D flow CMR, sFRR demonstrated an area under the curve (AUC) of 0.955, p<0.001. A threshold of >8% for sFRR had a sensitivity of 82% and specificity of 100% for visual vortex presence. In addition, the average late systolic FD, a marker of flow eccentricity, also demonstrated an AUC of 0.909, p<0.001 for visual vortex flow. Manual systolic rotational flow angle change (ΔsRA) demonstrated excellent association with semiautomated ΔsRA (r=0.99, 95% CI 0.9907 to 0.999, p<0.001). In reproducibility testing, average systolic FD (FDsavg) showed a minimal bias at 1.28% with a high intraclass correlation coefficient (ICC=0.92). Similarly, sFRR had a minimal bias of 1.14% with an ICC of 0.96. ΔsRA demonstrated an acceptable bias of 5.72°-and an ICC of 0.99. CONCLUSION: 2D PC flow imaging can possibly quantify blood flow helicity (ΔRA) and vorticity (FRR). These imaging biomarkers of flow helicity and vorticity demonstrate high reproducibility for clinical adoption. TRIALS REGISTRATION NUMBER: NCT05114785.

A scoping review of artificial intelligence in medical education: BEME Guide No. 84.

BACKGROUND: Artificial Intelligence (AI) is rapidly transforming healthcare, and there is a critical need for a nuanced understanding of how AI is reshaping teaching, learning, and educational practice in medical education. This review aimed to map the literature regarding AI applications in medical education, core areas of findings, potential candidates for formal systematic review and gaps for future research. METHODS: This rapid scoping review, conducted over 16 weeks, employed Arksey and O'Malley's framework and adhered to STORIES and BEME guidelines. A systematic and comprehensive search across PubMed/MEDLINE, EMBASE, and MedEdPublish was conducted without date or language restrictions. Publications included in the review spanned undergraduate, graduate, and continuing medical education, encompassing both original studies and perspective pieces. Data were charted by multiple author pairs and synthesized into various thematic maps and charts, ensuring a broad and detailed representation of the current landscape. RESULTS: The review synthesized 278 publications, with a majority (68%) from North American and European regions. The studies covered diverse AI applications in medical education, such as AI for admissions, teaching, assessment, and clinical reasoning. The review highlighted AI's varied roles, from augmenting traditional educational methods to introducing innovative practices, and underscores the urgent need for ethical guidelines in AI's application in medical education. CONCLUSION: The current literature has been charted. The findings underscore the need for ongoing research to explore uncharted areas and address potential risks associated with AI use in medical education. This work serves as a foundational resource for educators, policymakers, and researchers in navigating AI's evolving role in medical education. A framework to support future high utility reporting is proposed, the FACETS framework.

Cardiac MR modelling of systolic and diastolic blood pressure.

AIMS: Blood pressure (BP) is a crucial factor in cardiovascular health and can affect cardiac imaging assessments. However, standard outpatient cardiovascular MR (CMR) imaging procedures do not typically include BP measurements prior to image acquisition. This study proposes that brachial systolic BP (SBP) and diastolic BP (DBP) can be modelled using patient characteristics and CMR data. METHODS: In this multicentre study, 57 patients from the PREFER-CMR registry and 163 patients from other registries were used as the derivation cohort. All subjects had their brachial SBP and DBP measured using a sphygmomanometer. Multivariate linear regression analysis was applied to predict brachial BP. The model was subsequently validated in a cohort of 169 healthy individuals. RESULTS: Age and left ventricular ejection fraction were associated with SBP. Aortic forward flow, body surface area and left ventricular mass index were associated with DBP. When applied to the validation cohort, the correlation coefficient between CMR-derived SBP and brachial SBP was (r=0.16, 95% CI 0.011 to 0.305, p=0.03), and CMR-derived DBP and brachial DBP was (r=0.27, 95% CI 0.122 to 0.403, p=0.0004). The area under the curve (AUC) for CMR-derived SBP to predict SBP>120 mmHg was 0.59, p=0.038. Moreover, CMR-derived DBP to predict DBP>80 mmHg had an AUC of 0.64, p=0.002. CONCLUSION: CMR-derived SBP and DBP models can estimate brachial SBP and DBP. Such models may allow efficient prospective collection, as well as retrospective estimation of BP, which should be incorporated into assessments due to its critical effect on load-dependent parameters.

Cardiac Magnetic Resonance Left Ventricular Filling Pressure Is Associated with NT-proBNP in Patients with New Onset Heart Failure.

Background and Objectives: Cardiovascular magnetic resonance (CMR) is emerging as an important imaging tool for sub-phenotyping and estimating left ventricular (LV) filling pressure (LVFP). The N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) is released from cardiac myocytes in response to mechanical load and wall stress. This study sought to investigate if CMR-derived LVFP is associated with the serum levels of NT-proBNP and, in addition, if it provides any incremental prognostic value in heart failure (HF). Materials and Methods: This study recruited 380 patients diagnosed with HF who underwent same-day CMR and clinical assessment between February 2018 and January 2020. CMR-derived LVFP was calculated, as previously, from long- and short-axis cines. During CMR assessment, serum NT-proBNP was measured. The pathological cut-offs were defined as follows: NT-proBNP ≥ 125 pg/mL and CMR LVFP > 15 mmHg. The incidence of HF hospitalisation was treated as a clinical outcome. Results: In total, 305 patients had NT-proBNP ≥ 125 pg/mL. Patients with raised NT-proBNP were older (54 ± 14 vs. 64 ± 11 years, p < 0.0001). Patients with raised NT-proBNP had higher LV volumes and mass. In addition, CMR LVFP was higher in patients with raised NT-proBNP (13.2 ± 2.6 vs. 15.4 ± 3.2 mmHg, p < 0.0001). The serum levels of NT-proBNP were associated with CMR-derived LVFP (R = 0.42, p < 0.0001). In logistic regression analysis, this association between NT-proBNP and CMR LVFP was independent of all other CMR variables, including LV ejection fraction, LV mass, and left atrial volume (coefficient = 2.02, p = 0.002). CMR LVFP demonstrated an independent association with the incidence of HF hospitalisation above NT-proBNP (hazard ratio 2.7, 95% confidence interval 1.2 to 6, p = 0.01). Conclusions: A CMR-modelled LVFP is independently associated with serum NT-proBNP levels. Importantly, it provides an incremental prognostic value over and above serum NT-proBNP levels.

The Left Atrial Area Derived Cardiovascular Magnetic Resonance Left Ventricular Filling Pressure Equation Shows Superiority over Integrated Echocardiography.

Background and objectives: Evaluating left ventricular filling pressure (LVFP) plays a crucial role in diagnosing and managing heart failure (HF). While traditional assessment methods involve multi-parametric transthoracic echocardiography (TTE) or right heart catheterisation (RHC), cardiovascular magnetic resonance (CMR) has emerged as a valuable diagnostic tool in HF. This study aimed to assess a simple CMR-derived model to estimate pulmonary capillary wedge pressure (PCWP) in a cohort of patients with suspected or proven heart failure and to investigate its performance in risk-stratifying patients. Materials and methods: A total of 835 patients with breathlessness were evaluated using RHC and CMR and split into derivation (85%) and validation cohorts (15%). Uni-variate and multi-variate linear regression analyses were used to derive a model for PCWP estimation using CMR. The model's performance was evaluated by comparing CMR-derived PCWP with PCWP obtained from RHC. Results: A CMR-derived PCWP incorporating left ventricular mass and the left atrial area (LAA) demonstrated good diagnostic accuracy. The model correctly reclassified 66% of participants whose TTE was 'indeterminate' or 'incorrect' in identifying raised filling pressures. On survival analysis, the CMR-derived PCWP model was predictive for mortality (HR 1.15, 95% CI 1.04-1.28, p = 0.005), which was not the case for PCWP obtained using RHC or TTE. Conclusions: The simplified CMR-derived PCWP model provides an accurate and practical tool for estimating PCWP in patients with suspected or proven heart failure. Its predictive value for mortality suggests the ability to play a valuable adjunctive role in echocardiography, especially in cases with unclear echocardiographic assessment.

Cardiac magnetic resonance left ventricular filling pressure is linked to symptoms, signs and prognosis in heart failure.

AIMS: Left ventricular filling pressure (LVFP) can be estimated from cardiovascular magnetic resonance (CMR). We aimed to investigate whether CMR-derived LVFP is associated with signs, symptoms, and prognosis in patients with recently diagnosed heart failure (HF). METHODS AND RESULTS: This study recruited 454 patients diagnosed with HF who underwent same-day CMR and clinical assessment between February 2018 and January 2020. CMR-derived LVFP was calculated, as previously, from long- and short-axis cines. CMR-derived LVFP association with symptoms and signs of HF was investigated. Patients were followed for median 2.9 years (interquartile range 1.5-3.6 years) for major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, HF hospitalization, non-fatal stroke, and non-fatal myocardial infarction. The mean age was 62 ± 13 years, 36% were female (n = 163), and 30% (n = 135) had raised LVFP. Forty-seven per cent of patients had an ejection fraction < 40% during CMR assessment. Patients with raised LVFP were more likely to have pleural effusions [hazard ratio (HR) 3.2, P = 0.003], orthopnoea (HR 2.0, P = 0.008), lower limb oedema (HR 1.7, P = 0.04), and breathlessness (HR 1.7, P = 0.01). Raised CMR-derived LVFP was associated with a four-fold risk of HF hospitalization (HR 4.0, P < 0.0001) and a three-fold risk of MACE (HR 3.1, P < 0.0001). In the multivariable model, raised CMR-derived LVFP was independently associated with HF hospitalization (adjusted HR 3.8, P = 0.0001) and MACE (adjusted HR 3.0, P = 0.0001). CONCLUSIONS: Raised CMR-derived LVFP is strongly associated with symptoms and signs of HF. In addition, raised CMR-derived LVFP is independently associated with subsequent HF hospitalization and MACE.

An acute increase in Left Atrial volume and left ventricular filling pressure during Adenosine administered myocardial hyperaemia: CMR First-Pass Perfusion Study.

OBJECTIVE: To investigate whether left atrial (LA) volume and left ventricular filling pressure (LVFP) assessed by cardiovascular magnetic resonance (CMR) change during adenosine delivered myocardial hyperaemia as part of a first-pass stress perfusion study. METHODS AND RESULTS: We enrolled 33 patients who had stress CMR. These patients had a baseline four-chamber cine and stress four-chamber cine, which was done at peak myocardial hyperaemic state after administering adenosine. The left and right atria were segmented in the end ventricular diastolic and systolic phases. Short-axis cine stack was segmented for ventricular functional assessment. At peak hyperaemic state, left atrial end ventricular systolic volume just before mitral valve opening increased significantly from baseline in all (91 ± 35ml vs. 81 ± 33ml, P = 0.0002), in males only (99 ± 35ml vs. 88 ± 33ml, P = 0.002) and females only (70 ± 26ml vs. 62 ± 22ml, P = 0.02). The right atrial end ventricular systolic volume increased less significantly from baseline (68 ± 21ml vs. 63 ± 20ml, P = 0.0448). CMR-derived LVFP (equivalent to pulmonary capillary wedge pressure) increased significantly at the peak hyperaemic state in all (15.1 ± 2.9mmHg vs. 14.4 ± 2.8mmHg, P = 0.0002), females only (12.9 ± 2.1mmHg vs. 12.3 ± 1.9mmHg, P = 0.029) and males only (15.9 ± 2.8mmHg vs. 15.2 ± 2.7mmHg, P = 0.002) cohorts. CONCLUSION: Left atrial volume assessment by CMR can measure acute and dynamic changes in preloading conditions on the left ventricle. During adenosine administered first-pass perfusion CMR, left atrial volume and LVFP rise significantly.

The Role of High-Fidelity Simulation in the Acquisition of Endovascular Surgical Skills: A Systematic Review.

BACKGROUND: The widespread introduction of minimally invasive endovascular techniques in cardiovascular surgery has necessitated a transition in the psychomotor skillset of trainees and surgeons. Simulation has previously been used in surgical training; however, there is limited high-quality evidence regarding the role of simulation-based training on the acquisition of endovascular skills. This systematic review aimed to systematically appraise the currently available evidence regarding endovascular high-fidelity simulation interventions, to describe the overarching strategies used, the learning outcomes addressed, the choice of assessment methodology, and the impact of education on learner performance. METHODS: A comprehensive literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement using relevant keywords to identify studies evaluating simulation in the acquisition of endovascular surgical skills. References of review articles were screened for additional studies. RESULTS: A total of 1,081 studies were identified (474 after removal of duplicates). There was marked heterogeneity in methodologies and reporting of outcomes. Quantitative analysis was deemed inappropriate due to the risk of serious confounding and bias. Instead, a descriptive synthesis was performed, summarizing key findings and quality components. Eighteen studies were included in the synthesis (15 observational, 2 case-control and 1 randomized control studies). Most studies measured procedure time, contrast usage, and fluoroscopy time. Other metrics were recorded to a lesser extent. Significant reductions were noted in both procedure and fluoroscopy times with the introduction of simulation-based endovascular training. CONCLUSIONS: The evidence regarding the use of high-fidelity simulation in endovascular training is very heterogeneous. The current literature suggests simulation-based training leads to improvements in performance, mostly in terms of procedure and fluoroscopy time. High-quality randomized control trials are needed to establish the clinical benefits of simulation training, sustainability of improvements, transferability of skills and its cost-effectiveness.

The Importance of Mitral Valve Prolapse Doming Volume in the Assessment of Left Ventricular Stroke Volume with Cardiac MRI.

There remains a debate whether the ventricular volume within prolapsing mitral valve (MV) leaflets should be included in the left ventricular (LV) end-systolic volume, and therefore factored in LV stroke volume (SV), in cardiac magnetic resonance (CMR) assessments. This study aims to compare LV volumes during end-systolic phases, with and without the inclusion of the volume of blood on the left atrial aspect of the atrioventricular groove but still within the MV prolapsing leaflets, against the reference LV SV by four-dimensional flow (4DF). A total of 15 patients with MV prolapse (MVP) were retrospectively enrolled in this study. We compared LV SV with (LV SVMVP) and without (LV SVstandard) MVP left ventricular doming volume, using 4D flow (LV SV4DF) as the reference value. Significant differences were observed when comparing LV SVstandard and LV SVMVP (p < 0.001), and between LV SVstandard and LV SV4DF (p = 0.02). The Intraclass Correlation Coefficient (ICC) test demonstrated good repeatability between LV SVMVP and LV SV4DF (ICC = 0.86, p < 0.001) but only moderate repeatability between LV SVstandard and LV SV4DF (ICC = 0.75, p < 0.01). Calculating LV SV by including the MVP left ventricular doming volume has a higher consistency with LV SV derived from the 4DF assessment. In conclusion, LV SV short-axis cine assessment incorporating MVP dooming volume can significantly improve the precision of LV SV assessment compared to the reference 4DF method. Hence, in cases with bi-leaflet MVP, we recommend factoring in MVP dooming into the left ventricular end-systolic volume to improve the accuracy and precision of quantifying mitral regurgitation.

Automated 4D flow cardiac MRI pipeline to derive peak mitral inflow diastolic velocities using short-axis cine stack: two centre validation study against echocardiographic pulse-wave doppler.

BACKGROUND: Measurement of peak velocities is important in the evaluation of heart failure. This study compared the performance of automated 4D flow cardiac MRI (CMR) with traditional transthoracic Doppler echocardiography (TTE) for the measurement of mitral inflow peak diastolic velocities. METHODS: Patients with Doppler echocardiography and 4D flow cardiac magnetic resonance data were included retrospectively. An established automated technique was used to segment the left ventricular transvalvular flow using short-axis cine stack of images. Peak mitral E-wave and peak mitral A-wave velocities were automatically derived using in-plane velocity maps of transvalvular flow. Additionally, we checked the agreement between peak mitral E-wave velocity derived by 4D flow CMR and Doppler echocardiography in patients with sinus rhythm and atrial fibrillation (AF) separately. RESULTS: Forty-eight patients were included (median age 69 years, IQR 63 to 76; 46% female). Data were split into three groups according to heart rhythm. The median peak E-wave mitral inflow velocity by automated 4D flow CMR was comparable with Doppler echocardiography in all patients (0.90 ± 0.43 m/s vs 0.94 ± 0.48 m/s, P = 0.132), sinus rhythm-only group (0.88 ± 0.35 m/s vs 0.86 ± 0.38 m/s, P = 0.54) and in AF-only group (1.33 ± 0.56 m/s vs 1.18 ± 0.47 m/s, P = 0.06). Peak A-wave mitral inflow velocity results had no significant difference between Doppler TTE and automated 4D flow CMR (0.81 ± 0.44 m/s vs 0.81 ± 0.53 m/s, P = 0.09) in all patients and sinus rhythm-only groups. Automated 4D flow CMR showed a significant correlation with TTE for measurement of peak E-wave in all patients group (r = 0.73, P < 0.001) and peak A-wave velocities (r = 0.88, P < 0.001). Moreover, there was a significant correlation between automated 4D flow CMR and TTE for peak-E wave velocity in sinus rhythm-only patients (r = 0.68, P < 0.001) and AF-only patients (r = 0.81, P = 0.014). Excellent intra-and inter-observer variability was demonstrated for both parameters. CONCLUSION: Automated dynamic peak mitral inflow diastolic velocity tracing using 4D flow CMR is comparable to Doppler echocardiography and has excellent repeatability for clinical use. However, 4D flow CMR can potentially underestimate peak velocity in patients with AF.

Aortic flow is abnormal in HFpEF.

Aims: Turbulent aortic flow makes the cardiovascular system less effective. It remains unknown if patients with heart failure with preserved ejection fraction (HFpEF) have disturbed aortic flow. This study sought to investigate advanced markers of aortic flow disturbances in HFpEF. Methods: This case-controlled observational study used four-dimensional flow cardiovascular magnetic resonance derived, two-dimensional phase-contrast reformatted plane data at an orthogonal plane just above the sino-tubular junction. We recruited 10 young healthy controls (HCs), 10 old HCs and 23 patients with HFpEF. We analysed average systolic aortic flow displacement (FDsavg), systolic flow reversal ratio (sFRR) and pulse wave velocity (PWV). In a sub-group analysis, we compared old HCs versus age-gender-matched HFpEF (N=10). Results: Differences were significant in mean age (P<0.001) among young HCs (22.9±3.5 years), old HCs (60.5±10.2 years) and HFpEF patients (73.7±9.7 years). FDsavg, sFRR and PWV varied significantly (P<0.001) in young HCs (8±4%, 2±2%, 4±2m/s), old HCs (16±5%, 7±6%, 11±8m/s), and HFpEF patients (23±10%, 11±10%, 8±3). No significant PWV differences existed between old HCs and HFpEF.HFpEF had significantly higher FDsavg versus old HCs (23±10% vs 16±5%, P<0.001). A FDsavg > 17.7% achieved 74% sensitivity, 70% specificity for differentiating them. sFRR was notably higher in HFpEF (11±10% vs 7±6%, P<0.001). A sFRR > 7.3% yielded 78% sensitivity, 70% specificity in differentiating these groups. In sub-group analysis, FDsavg remained distinctly elevated in HFpEF (22.4±9.7% vs 16±4.9%, P=0.029). FDsavg of >16% showed 100% sensitivity and 70% specificity (P=0.01). Similarly, sFRR remained significantly higher in HFpEF (11.3±9.5% vs 6.6±6.4%, P=0.007). A sFRR of >7.2% showed 100% sensitivity and 60% specificity (P<0.001). Conclusion: Aortic flow haemodynamics namely FDsavg and sFRR are significantly affected in ageing and HFpEF patients.

Virtual interviewing for graduate medical education recruitment and selection: A BEME systematic review: BEME Guide No. 80.

BACKGROUND: The COVID-19 pandemic caused graduate medical education (GME) programs to pivot to virtual interviews (VIs) for recruitment and selection. This systematic review synthesizes the rapidly expanding evidence base on VIs, providing insights into preferred formats, strengths, and weaknesses. METHODS: PubMed/MEDLINE, Scopus, ERIC, PsycINFO, MedEdPublish, and Google Scholar were searched from 1 January 2012 to 21 February 2022. Two authors independently screened titles, abstracts, full texts, performed data extraction, and assessed risk of bias using the Medical Education Research Quality Instrument. Findings were reported according to Best Evidence in Medical Education guidance. RESULTS: One hundred ten studies were included. The majority (97%) were from North America. Fourteen were conducted before COVID-19 and 96 during the pandemic. Studies involved both medical students applying to residencies (61%) and residents applying to fellowships (39%). Surgical specialties were more represented than other specialties. Applicants preferred VI days that lasted 4-6 h, with three to five individual interviews (15-20 min each), with virtual tours and opportunities to connect with current faculty and trainees. Satisfaction with VIs was high, though both applicants and programs found VIs inferior to in-person interviews for assessing 'fit.' Confidence in ranking applicants and programs was decreased. Stakeholders universally noted significant cost and time savings with VIs, as well as equity gains and reduced carbon footprint due to eliminating travel. CONCLUSIONS: The use of VIs for GME recruitment and selection has accelerated rapidly. The findings of this review offer early insights that can guide future practice, policy, and research.

Kat-ARC accelerated 4D flow CMR: clinical validation for transvalvular flow and peak velocity assessment.

BACKGROUND: To validate the k-adaptive-t autocalibrating reconstruction for Cartesian sampling (kat-ARC), an exclusive sparse reconstruction technique for four-dimensional (4D) flow cardiac magnetic resonance (CMR) using conservation of mass principle applied to transvalvular flow. METHODS: This observational retrospective study (2020/21-075) was approved by the local ethics committee at the University of East Anglia. Consent was waived. Thirty-five patients who had a clinical CMR scan were included. CMR protocol included cine and 4D flow using Kat-ARC acceleration factor 6. No respiratory navigation was applied. For validation, the agreement between mitral net flow (MNF) and the aortic net flow (ANF) was investigated. Additionally, we checked the agreement between peak aortic valve velocity derived by 4D flow and that derived by continuous-wave Doppler echocardiography in 20 patients. RESULTS: The median age of our patient population was 63 years (interquartile range [IQR] 54-73), and 18/35 (51%) were male. Seventeen (49%) patients had mitral regurgitation, and seven (20%) patients had aortic regurgitation. Mean acquisition time was 8 ± 4 min. MNF and ANF were comparable: 60 mL (51-78) versus 63 mL (57-77), p = 0.310). There was an association between MNF and ANF (rho = 0.58, p < 0.001). Peak aortic valve velocity by Doppler and 4D flow were comparable (1.40 m/s, [1.30-1.75] versus 1.46 m/s [1.25-2.11], p = 0.602) and also correlated with each other (rho = 0.77, p < 0.001). CONCLUSIONS: Kat-ARC accelerated 4D flow CMR quantified transvalvular flow in accordance with the conservation of mass principle and is primed for clinical translation.

Validation of time-resolved, automated peak trans-mitral velocity tracking: Two center four-dimensional flow cardiovascular magnetic resonance study.

OBJECTIVE: We aim to validate four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) peak velocity tracking methods for measuring the peak velocity of mitral inflow against Doppler echocardiography. METHOD: Fifty patients were recruited who had 4D flow CMR and Doppler Echocardiography. After transvalvular flow segmentation using established valve tracking methods, peak velocity was automatically derived using three-dimensional streamlines of transvalvular flow. In addition, a static-planar method was used at the tip of mitral valve to mimic Doppler technique. RESULTS: Peak E-wave mitral inflow velocity was comparable between TTE and the novel 4D flow automated dynamic method (0.9 ± 0.5 vs 0.94 ± 0.6 m/s; p = 0.29) however there was a statistically significant difference when compared with the static planar method (0.85 ± 0.5 m/s; p = 0.01). Median A-wave peak velocity was also comparable across TTE and the automated dynamic streamline (0.77 ± 0.4 vs 0.76 ± 0.4 m/s; p = 0.77). A significant difference was seen with the static planar method (0.68 ± 0.5 m/s; p = 0.04). E/A ratio was comparable between TTE and both the automated dynamic and static planar method (1.1 ± 0.7 vs 1.15 ± 0.5 m/s; p = 0.74 and 1.15 ± 0.5 m/s; p = 0.5 respectively). Both novel 4D flow methods showed good correlation with TTE for E-wave (dynamic method; r = 0.70; P < 0.001 and static-planar method; r = 0.67; P < 0.001) and A-wave velocity measurements (dynamic method; r = 0.83; P < 0.001 and static method; r = 0.71; P < 0.001). The automated dynamic method demonstrated excellent intra/inter-observer reproducibility for all parameters. CONCLUSION: Automated dynamic peak velocity tracing method using 4D flow CMR is comparable to Doppler echocardiography for mitral inflow assessment and has excellent reproducibility for clinical use.

Mitral regurgitation quantified by CMR 4D-flow is associated with microvascular obstruction post reperfused ST-segment elevation myocardial infarction.

OBJECTIVES: Mitral regurgitation (MR) and microvascular obstruction (MVO) are common complications of myocardial infarction (MI). This study aimed to investigate the association between MR in ST-elevation MI (STEMI) subjects with MVO post-reperfusion. STEMI subjects undergoing primary percutaneous intervention were enrolled. Cardiovascular magnetic resonance (CMR) imaging was performed within 48-hours of initial presentation. 4D flow images of CMR were analysed using a retrospective valve tracking technique to quantify MR volume, and late gadolinium enhancement images of CMR to assess MVO. RESULTS: Among 69 patients in the study cohort, 41 had MVO (59%). Patients with MVO had lower left ventricular (LV) ejection fraction (EF) (42 ± 10% vs. 52 ± 8%, P < 0.01), higher end-systolic volume (98 ± 49 ml vs. 73 ± 28 ml, P < 0.001) and larger scar volume (26 ± 19% vs. 11 ± 9%, P < 0.001). Extent of MVO was associated with the degree of MR quantified by 4D flow (R = 0.54, P = 0.0003). In uni-variate regression analysis, investigating the association of CMR variables to the degree of acute MR, only the extent of MVO was associated (coefficient = 0.27, P = 0.001). The area under the curve for the presence of MVO was 0.66 (P = 0.01) for MR > 2.5 ml. We conclude that in patients with reperfused STEMI, the degree of acute MR is associated with the degree of MVO.

Antibiotics for the induction and maintenance of remission in ulcerative colitis.

BACKGROUND: Antibiotics have been considered to treat ulcerative colitis (UC) due to their antimicrobial properties against intestinal bacteria linked to inflammation. However, there are concerns about their efficacy and safety. OBJECTIVES: To determine whether antibiotic therapy is safe and effective for the induction and maintenance of remission in people with UC. SEARCH METHODS: We searched five electronic databases on 10 December 2021 for randomised controlled trials (RCTs) comparing antibiotic therapy to placebo or an active comparator. SELECTION CRITERIA: We considered people with UC of all ages, treated with antibiotics of any type, dose, and route of administration for inclusion. Induction studies required a minimum duration of two weeks for inclusion. Maintenance studies required a minimum duration of three months to be considered for inclusion. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary outcome for induction studies was failure to achieve remission and for maintenance studies was relapse, as defined by the primary studies. MAIN RESULTS: We included 12 RCTs (847 participants). One maintenance of remission study used sole antibiotic therapy compared with 5-aminosalicylic acid (5-ASA). All other trials used concurrent medications or standard care regimens and antibiotics as an adjunct therapy or compared antibiotics with other adjunct therapies to examine the effect on induction of remission. There is high certainty evidence that antibiotics (154/304 participants) compared to placebo (175/304 participants) result in no difference in failure to achieve clinical remission (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.74 to 1.06). A subgroup analysis found no differences when steroids, steroids plus 5-ASA, or steroids plus 5-ASA plus probiotics were used as additional therapies to antibiotics and placebo. There is low certainty evidence that antibiotics (102/168 participants) compared to placebo (121/175 participants) may result in no difference in failure to achieve clinical response (RR 0.75, 95% CI 0.47 to 1.22). A subgroup analysis found no differences when steroids or steroids plus 5-ASA were used as additional therapies to antibiotics and placebo. There is low certainty evidence that antibiotics (6/342 participants) compared to placebo (5/349 participants) may result in no difference in serious adverse events (RR 1.19, 95% CI 0.38 to 3.71). A subgroup analysis found no differences when steroids were additional therapies to antibiotics and placebo. There is low certainty evidence that antibiotics (3/342 participants) compared to placebo (1/349 participants) may result in no difference in withdrawals due to adverse events (RR 2.06, 95% CI 0.27 to 15.72). A subgroup analysis found no differences when steroids or steroids plus 5-ASA were additional therapies to antibiotics and placebo. It is unclear if there is any difference between antibiotics in combination with probiotics compared to no treatment or placebo for failure to achieve clinical remission (RR 0.68, 95% CI 0.39 to 1.19), serious adverse events (RR 1.00, 95% CI 0.07 to 15.08), or withdrawals due to adverse events (RR 1.00, 95% CI 0.07 to 15.08). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to 5-ASA for failure to achieve clinical remission (RR 2.20, 95% CI 1.17 to 4.14). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to probiotics for failure to achieve clinical remission (RR 0.47, 95% CI 0.23 to 0.94). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to 5-ASA for failure to maintain clinical remission (RR 0.71, 95% CI 0.47 to 1.06). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to no treatment for failure to achieve clinical remission in a mixed population of people with active and inactive disease (RR 0.56, 95% CI 0.29 to 1.07). The certainty of the evidence is very low. For all other outcomes, no effects could be estimated due to a lack of data. AUTHORS' CONCLUSIONS: There is high certainty evidence that there is no difference between antibiotics and placebo in the proportion of people who achieve clinical remission at the end of the intervention period. However, there is evidence that there may be a greater proportion of people who achieve clinical remission and probably a greater proportion who achieve clinical response with antibiotics when compared with placebo at 12 months. There may be no difference in serious adverse events or withdrawals due to adverse events between antibiotics and placebo. No clear conclusions can be drawn for any other comparisons. A clear direction for future research appears to be comparisons of antibiotics and placebo (in addition to standard therapies) with longer-term measurement of outcomes. Additionally. As there were single studies of other head-to-head comparisons, there may be scope for future studies in this area.