Thrombocytopenia after sutureless and standard stented aortic valve replacement: a retrospective analysis of risk factors, clinical course, and early outcome.

OBJECTIVES: Thrombocytopenia following Perceval aortic valve replacement has been described previously with variable outcome. Studies have lacked a robust analysis of platelet fluctuation and factors affecting it. We aimed to statistically describe the trend in thrombocyte variability as compared with conventional aortic valve replacement, and to assess predictors as well as impact on associated outcomes. METHODS: One hundred consecutive patients with first-time Perceval were retrospectively compared to 219 patients after Perimount Magna Ease valve replacement. The primary outcome was the serial thrombocyte count on day 0-6. Generalized estimating equations were used to analyse the data using fixed-effect models: for the effect of the post-operative day on platelet count, and random-effect models estimating both time-variant (platelets) and time in-variant variables (valve type, age, LV function, pre-op platelet level). RESULTS: Perceval patients were older (72 ± 1 vs 68 ± 1 years, p < 0.01) with higher NYHA status (3(2-3) vs 2(1-2), p < 0.001). Mean platelet count in the sutureless group was lowest on day 2 (91.9 ± 31.6 vs 121.7 ± 53.8 × 103 µl-1), and lower on day 4 (97.9 ± 44) and 6 (110.6 ± 61) compared to the conventional group (157.2 ± 60 and 181.7 ± 79) but did not result in a higher number of transfusions, bleeding or longer hospital stay (p > 0.05). Reduced platelet count was a strong predictor of red cell transfusion in the conventional (p = 0.016), but not in the sutureless group (p = 0.457). Age (Coef -1.025, 95%CI-1.649--0.401, p < 0.001) and CPB-time (Coef 0.186, 95%CI-0.371--0.001, p = 0.048) were predictors for lower platelet levels. CONCLUSION: Considering the older patient profile treated with Perceval, postoperative thrombocytopenia does not impact on outcome in terms of transfusions, complications or hospital stay.

Perceval sutureless bioprosthesis versus Perimount sutured bioprosthesis for aortic valve replacement in patients with aortic stenosis: a retrospective, propensity-matched study.

BACKGROUND: Rapid-deployment aortic valve replacement (RDAVR) is an alternative to conventional AVR (cAVR) for aortic stenosis. Benefits include a reduction in operative times, facilitation of minimal access surgery and superior haemodynamics compared to conventional valves. However, further evidence is required to inform guidelines, preferably in the form of propensity-matched studies that include mid-term follow-up data. METHODS: This was a single-centre, retrospective, propensity-matched cohort study comparing the Perceval and conventional Perimount Magna Ease valve for short- and mid-term clinical parameters and size-matched mid-term echocardiographic parameters (n = 102 in both groups) from 2014 to 2020. Data were extracted from a nationally managed dataset. RESULTS: There were no demographic differences between the matched groups. The Perceval group had shorter cross-clamp time (Perceval 62 [49-81] minutes; Perimount 79 [63-102] minutes, P < 0.001), shorter bypass time (Perceval 89 [74-114] minutes; Perimount 104 [84-137] minutes, P < 0.001), and more frequent minimally-invasive approaches (Perceval 28%; Perimount 5%, P < 0.001). Size-matched haemodynamics showed initially higher gradients in the Perceval group, but haemodynamics equalised at 12 + months. The Perceval group had a more favourable % change in the left ventricular posterior wall dimension at 2 + years (Perceval - 4.8 ± 18; Perimount 17 ± 2). CONCLUSIONS: The Perceval facilitated shorter operations, which may benefit intermediate-high-risk, elderly patients with comorbidities requiring concomitant procedures. It also facilitated minimally invasive surgery. Size-matched haemodynamic performance was similar at mid-term follow-up, with the Perceval possibly better facilitating regression of left ventricular hypertrophy.

Temporal Trends and Lesion Sets for Persistent Atrial Fibrillation Ablation: A Meta-Analysis With Trial Sequential Analysis and Meta-Regression.

BACKGROUND: Ablation for persistent atrial fibrillation (PsAF) has been performed for over 20 years, although success rates have remained modest. Several adjunctive lesion sets have been studied but none have become standard of practice. We sought to describe how the efficacy of ablation for PsAF has evolved in this time period with a focus on the effect of adjunctive ablation strategies. METHODS: Databases were searched for prospective studies of PsAF ablation. We performed meta-regression and trial sequential analysis. RESULTS: A total of 99 studies (15 424 patients) were included. Ablation for PsAF achieved the primary outcome (freedom of atrial fibrillation/atrial tachycardia rate at 12 months follow-up) in 48.2% (5% CI, 44.0-52.3). Meta-regression showed freedom from atrial arrhythmia at 12 months has improved over time, while procedure time and fluoroscopy time have significantly reduced. Through the use of cumulative meta-analyses and trial sequential analysis, we show that some ablation strategies may initially seem promising, but after several randomized controlled trials may be found to be ineffective. Trial sequential analysis showed that complex fractionated atrial electrogram ablation is ineffective and further study of this treatment would be futile, while posterior wall isolation currently does not have sufficient evidence for routine use in PsAF ablation. CONCLUSIONS: Overall success rates from PsAF ablation and procedure/fluoroscopy times have improved over time. However, no adjunctive lesion set, in addition to pulmonary vein isolation, has been conclusively demonstrated to be beneficial. Through the use of trial sequential analysis, we highlight the importance of adequately powered randomized controlled trials, to avoid reaching premature conclusions, before widespread adoption of novel therapies.

Sex disparities in left ventricular assist device implantation outcomes: A systematic review and meta-analysis of over 50 000 patients.

BACKGROUND: Left ventricular assist devices (LVAD) represent an important therapeutic option for patients progressing to end-stage heart failure. Women have been historically underrepresented in LVAD studies, and have been reported to have worse outcomes despite technological optimisation. We aimed to systematically explore the evidence on sex disparities in the use and outcomes of LVAD implantation. METHODS: A systematic database search with meta-analysis was conducted of comparative original articles of men versus women undergoing LVAD implantation, in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to July 2022. Primary outcomes were stroke (haemorrhagic and ischaemic) and early/overall mortality. Secondary outcomes were LVAD thrombosis, right VAD implantation, major bleeding, kidney dysfunction, and device/driveline infection. RESULTS: Our search yielded 137 relevant studies, including 22 meeting the inclusion criteria with a total of 53 227 patients (24.2% women). Overall mortality was higher in women (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.05-1.62, p = 0.02), as was overall stroke (OR 1.32, 95%CI 1.06-1.66, p = 0.01), including ischemic (OR 1.80, 95%CI 1.22-2.64, p = 0.003) and haemorrhagic (OR 1.72, 95%CI 1.09-2.70, p = 0.02). Women had more frequent right VAD implantation (OR 2.11, 95%CI 1.24-3.57, p = 0.006) and major bleeding (OR 1.40, 95%CI 1.06-1.85, p = 0.02). Kidney dysfunction, LVAD thrombosis, and device/driveline infections were comparable between sexes. CONCLUSIONS: Our analysis suggests that women face a greater risk of adverse events and mortality post-LVAD implantation. Although the mechanisms remain unclear, the difference in outcomes is thought to be multifactorial. Further research, that includes comprehensive pre-operative characteristics and post-operative outcomes, is encouraged.

Basis, Process and Outcomes of a Student Involvement Project for Curriculum Review at the Imperial College School of Medicine.

Introduction: To help create a Bachelor of Medicine, Bachelor of Surgery (MBBS) curriculum centred around the student voice, the Imperial College School of Medicine (ICSM) recruited two medical students for a two-week student-staff collaboration in Summer 2019 for its wider curriculum review. This write-up discusses the background, processes, and outcomes of the collaboration and includes some student reflections. Methods: The team comprised a member of the faculty and two medical students (the authors). We met daily for two weeks and focussed on the Bioregulatory Systems (BRS) module of Year 1. There were three key areas of work: learning objectives, large-group sessions, and small-group sessions. Each aspect involved planning, implementation, and reflection. For example, learning objectives were recategorized and reorganised, students fed back on a new slide template for large-group sessions, and new small-group sessions were designed. Feedback from the staff was collected verbally, and the medical students submitted feedback in the form of a mid-project interview, a post-project report, and informally. Results: We achieved such outcomes as reorganising and refining learning objectives, improving large-group teaching sessions, and refining and creating small-group teaching sessions. Following the collaboration, we had a debrief session. Conclusions: This collaboration was highly valuable for both students and faculty; the feedback revealed that the ideas, discussions, and outputs had a substantial impact. Overall, student-staff collaboration will become increasingly valuable as we emerge from COVID-19; we hope this write-up informs and inspires more 'students as partners' projects worldwide.

A remotely-delivered community action project to promote a diabetes lifestyle intervention programme in northwest London: basis, process and outcomes.

Background : The prevalence of type 2 diabetes mellitus (T2DM) in London is rising, obesity being a major driver. As part of a primary care placement, the authors (two medical students and a lead general practitioner) directly promoted the Reducing Weight with Intensive Dietary Support (REWIND) programme to patients in Northwest London and collected feedback on the promotion. Methods : The team developed and delivered three remote interventions: a redesigned patient-facing information leaflet, phone calls and text messages, and a live, interactive webinar, to directly engage patients and raise awareness about REWIND. Feedback was collected pre and post-webinar using an anonymised, online survey (essentially functioning as a 'teaching' evaluation). Results : Mean interest in REWIND had increased from 2.7 (pre-promotion) to 4.7 (post-promotion), knowledge about REWIND had increased from 2.1 to 4, and self-reported likelihood of enrolling had increased from 2.6 to 4.2 (P<0.01 in all cases). The reported usefulness of the leaflet and webinar was scored 3.7 and 4.4 respectively. Within two weeks of the webinar, two of these patients had joined REWIND. Conclusion : Feedback from the patients and GP revealed that the project successfully raised awareness, improved knowledge, and increased the likelihood of enrolment in REWIND. Diabetes programmes and organisations are encouraged to adapt the methods of this project to their own contexts, especially in light of COVID-19 where remote interventions will remain essential.

Perspectives of a 2nd-year medical student on 'Students as Partners' in higher education - What are the benefits, and how can we manage the power dynamics?

The 'Students as Partners' model has been redefining the way we see student-staff relationships in Higher Education. In a world where hierarchical teaching and learning has dominated for decades, this concept has been refreshing. I have seen the benefits first-hand, having participated in a 2-week student-staff collaboration to redesign the year-one medical curriculum at the Imperial College School of Medicine. However, inherent to such partnerships can be imbalanced power dynamics, which may pose a barrier and prevent the project from achieving its potential. The sources and impacts of these power dynamics are complex and the solutions multi-faceted. In our project, these imbalances of power were mitigated because the correct steps were taken both by the educators, as well as by the organisation. We produced outputs that led to significant change in the curriculum, in the short space of 2 weeks. I attribute this largely to the careful management of power dynamics throughout. In the current milieu of COVID-19, student-staff collaboration will be a valuable source of research; mitigating the impacts of power dynamics will undoubtedly improve productivity and motivation.