Abstract Background Patients with systemic hypertension (HTN) of African ancestry (Afr-a) are at greater risk of incident heart failure (HF), hospitalisation and death than those of European ancestry (Eu-a). This has been related to higher prevalence of HTN-related target organ damage, including high level of circulating cardiac troponins, which is not fully explained by blood pressure level. Thus, one may speculate that Afr-a hypertensives have a higher tendency to develop myocardial damage in response to arterial afterload. However, myocardial composition differences between Afr-a and Eu-a hypertensives remain speculative. Purpose To investigate ethnic-specific differences in myocardial tissue composition in Eu-a and Afr-a hypertensives by multi-parametric cardiovascular magnetic resonance (CMR). Methods This cross-sectional study included 63 Afr-a and 47 Eu-a hypertensive patients. All patients underwent multi-parametric CMR (1.5-Tesla Aera, Siemens-Healthcare, Erlangen-Germany). Left (LV) and right ventricular (RV) volumes, mass and function, atrial dimensions, and myocardial tissue characterisation (including T1- and T2-mapping) were measured using a standardised imaging protocol, and post-processing recommendations from international scientific societies. Analysis was completed using a commercially available cardiac-software (CVI-42, Calgary-Canada). Central pulse-wave-velocity (PWV) between the ascending and proximal descending thoracic aorta was measured by high-temporal, resolution 2D phase-contrast velocity-encoded parasagittal cine images, using in-house MATLAB software. Results Although Afr-a were 5 years older than Eu-a hypertensives, cardiovascular risk factors, anthropometric, body composition and haemodynamic measures were similar between the two groups (Figure 1). Segmental PWV was greater in Afr-a than Eu-a patients (8.16±2.71 vs 6.97±2.82 m/s, P=0.044), underlying higher aortic stiffness in Afr-a hypertensives. Afr-a hypertensives also had greater LV mass and LV-mass/end-diastolic volume ratio than Eu-a (Figure 2), whilst no difference was observed in LV systolic/diastolic function. Native T1 relaxation time and synthetic extracellular volume were also similar between the two ethnicities, though T2 relaxation time was significantly higher in Afr-a hypertensives. Late gadolinium enhancement (LGE), a well-established metric of replacement fibrosis (scarring), was more prevalent in Afr-a than Eu-a hypertensives (14% vs 4%, P=0.001). In patients with LGE, the extent of LGE was higher in Afr-a than Eu-a hypertensives (Figure 2). Conclusion Afr-a hypertensives have higher arterial afterload, LV mass and remodelling than Eu-a, despite comparable mean blood pressure, body-mass-index, and body composition. These changes in LV structure and geometry were associated with higher T2 relaxation time, likely reflecting low-grade inflammation, as well as higher prevalence and extent of replacement myocardial fibrosis. Funding Acknowledgement Type of funding sources: None.

Abstract Background Patients with systemic hypertension (HTN) of African ancestry (Afr-a) are at greater risk of heart failure (HF), hospitalisation and death than those of European ancestry (Eu-a). Compelling evidence suggests that left ventricular (LV) remodelling and hypertrophy are more prevalent in Afr-a than Eu-a hypertensives due to either a high clustering of cardiovascular risk-factors and/or a difference in genetic background. Prior studies in Eu-a subjects have shown that uncomplicated HTN is associated with right ventricular (RV) hypertrophy and remodelling which may contribute to development of HF. However, the impact of ethnicity on RV remodelling in HTN remains speculative. Purpose To investigate the influence of ethnicity on RV remodelling/hypertrophy in patients with HTN using cardiovascular magnetic resonance (CMR). Methods In this cross-sectional study we included 16 Afr-a and 32 Eu-a age- and sex-matched healthy-volunteers, and 63 Afr-a and 47 Eu-a hypertensives. All participants underwent a CMR exam (1.5-Tesla, Aera, Siemens-Healthcare, Erlangen-Germany). LV and RV volumes, masses and function were measured according to the current recommendations. Blood pressure was recorded during the CMR. Results Age- and sex-matched Afr-a and Eur-a healthy-volunteers (37±10 vs 37±12 years, P=0.975; male 53% vs 44%; P=0.539) exhibited closely comparable LV and RV volumes, masses, and end-diastolic volume/mass ratios. In the HTN group, despite Afr-a hypertensives being roughly 5 years older than Eu-a, baseline characteristics including cardiovascular risk factors, mean blood pressure, body-mass-index, and body composition metrics were similar between the two groups (Figure 1). Afr-a hypertensives also had greater LV and RV masses and mass/end-diastolic volume ratios than Eur-a hypertensives (Figure 2). RV mass correlated with LV mass in both ethnic groups (r=0.593 in Eu-a and r=0.569 in Afr-a; both P<0.001). Multivariable linear regression analysis showed that RV mass was independently associated with African descendance after correction for major confounders including LV mass, biventricular volumes, and body composition. Conclusion Our findings support the notion that Afr-a and Eur-a healthy-volunteers have comparable left and right ventricular geometry and masses, arguing against genetic-determinate ventricular geometry and myocardial mass in this population. However, Afr-a individuals exhibit higher sensitivity to myocardial hypertrophy in response to HTN which translates into greater biventricular masses and remodelling, compared to Eu-a hypertensives. Funding Acknowledgement Type of funding sources: None.

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Advancing Impact Award scheme of the EPSRC Impact Acceleration Account at King’s College London Background Artificial intelligence (AI) has the potential to facilitate the automation of CMR analysis for biomarker extraction. However, most AI algorithms are trained on a specific input domain (e.g., scanner vendor or hospital-tailored imaging protocol) and lack the robustness to perform optimally when applied to CMR data from other input domains. Purpose To develop and validate a robust CMR analysis tool for automatic segmentation and cardiac function analysis which achieves state-of-the-art performance for multi-vendor short-axis cine CMR images. Methods The current work is an extension of our previously published quality-controlled AI-based tool for cine CMR analysis [1]. We deployed an AI algorithm that is equipped to handle different image sizes and domains automatically - the ‘nnU-Net’ framework [2] - and retrained our tool using the UK Biobank (UKBB) cohort population (n = 4,872) and a large database of clinical CMR studies obtained from two NHS hospitals (n = 3,406). The NHS hospital data came from three different scanner types: Siemens Aera 1.5T (n = 1,419), Philips Achieva 1.5T and 3T (n = 1,160), and Philips Ingenia 1.5T (n = 827). The ‘nnU-net’ was used to segment both ventricles and the myocardium. The proposed method was evaluated on randomly selected test sets from UKBB (n = 488) and NHS (n = 331) and on two external publicly available databases of clinical CMRs acquired on Philips, Siemens, General Electric (GE), and Canon CMR scanners – ACDC (n = 100) [3] and M&Ms (n = 321) [4]. We calculated the Dice scores - which measure the overlap between manual and automatic segmentations - and compared manual vs AI-based measures of biventricular volumes and function. Results Table 1 shows that the Dice scores for the NHS, ACDC, and M&Ms scans are similar to those obtained in the highly controlled, single vendor and single field strength UKBB scans. Although our AI-based tool was only trained on CMR scans from two vendors (Philips and Siemens), it performs similarly in unseen vendors (GE and Canon). Furthermore, it achieves state-of-the-art performance in online segmentation challenges, without being specifically trained on these databases. Table 1 also shows good agreement between manual and automated clinical measures of ejection fraction and ventricular volume and mass. Conclusions We show that our proposed AI-based tool, which combines training on a large-scale multi-domain CMR database with a state-of-the-art AI algorithm, allows us to robustly deal with routine clinical data from multiple centres, vendors, and field strengths. This is a fundamental step for the clinical translation of AI algorithms. Moreover, our method yields a range of additional metrics of cardiac function (filling and ejection rates, regional wall motion, and strain) at no extra computational cost.

Abstract Aim Effective skin graft fixation is fundamental in preventing sheering forces, seroma and haematoma from compromising graft take. However, determining the ideal method of graft fixation remains a contentious subject. Currently, there is significant variation in fixation techniques used, based not only on clinical requirement, but also surgeon preference. Evidence-based recommendations are necessary to guide the decision-making process. Method We undertook a PRISMA-based assessment of the literature to define all fixation techniques and analyse their outcomes. Inclusion and exclusion criteria were composed. A search of Medline and Embase was performed, yielding 399 articles. After abstract screening, 96 were included for qualitative data analysis. Results Nine fixation techniques were identified: ‘tie over bolster’, ‘staple fixation’, ‘simple dressings’, ‘quilting sutures’, ‘re-look methods’, ‘foam sponge bolster’, ‘adhesive glues’, ‘negative pressure wound therapy’ and ‘less common techniques. We analyse the available evidence for each technique, identifying 13 studies with level I/II evidence. We summarise the research that underpins these nine categories, proposing an algorithm to facilitate technique selection based on anatomical and patient-specific factors. Conclusions An array of skin graft fixation techniques are used in plastic surgery, without clear guidelines. To our knowledge, this is the first time all fixation techniques have been defined. Our suggested algorithm is intended to aid surgeons in selecting an appropriate fixation technique and should be challenged by future research, particularly randomised control trials.

Abstract Aim Diagnostic nailbed biopsy is indicated for pathology including malignancy, persistent and suspected mycomial infection and rheumatological disease. Operatively, the challenge resides in establishing an equilibrium between harvesting ample histological sample for diagnostic value without the creation of a functionally and aesthetically unacceptable nail due to significant disruption of the nailbed. We illustrate a simple and reproducible biopsy technique through one small forgiving defect without disruption of surrounding soft tissue. Method The procedure is carried out under normal sterile conditions with local anaesthetic and a ring tourniquet. A 5mm punch biopsy is taken of the nail, adjacent to the eponychium, followed by a 4mm punch biopsy of the underlying nailbed at a 45-degree angle. The subungual surface of the nail is tangentially transected generating a mycomial sample and the nailbed is sent for histology. The remaining nail is replaced if not required for histology, and cyanoacrylate glue applied followed by a finger dressing. Results Figures show an example of how the nail biopsy is carried out. Biopsy sample and the resulting defect in the nail is also displayed. Conclusions The double punch technique reliably harvests adequate diagnostic specimens through one wound, without the disruption of adjacent nail plate, nailbed and perionychium. This is even more a priority when histology identifies no pathology requiring further operative resection. Whilst the nail undergoes its normal growth cycle post-operatively, aesthetically, the fingertip does not draw undue patient dissatisfaction once the dressing is removed in comparison to alternative biopsy techniques.