Modelled impact of virtual fractional flow reserve in patients undergoing coronary angiography (VIRTU-4).

BACKGROUND: The practical application of 'virtual' (computed) fractional flow reserve (vFFR) based on invasive coronary angiogram (ICA) images is unknown. The objective of this cohort study was to investigate the potential of vFFR to guide the management of unselected patients undergoing ICA. The hypothesis was that it changes management in >10% of cases. METHODS: vFFR was computed using the Sheffield VIRTUheart system, at five hospitals in the North of England, on 'all-comers' undergoing ICA for non-ST-elevation myocardial infarction acute coronary syndrome (ACS) and chronic coronary syndrome (CCS). The cardiologists' management plan (optimal medical therapy, percutaneous coronary intervention (PCI), coronary artery bypass surgery or 'more information required') and confidence level were recorded after ICA, and again after vFFR disclosure. RESULTS: 517 patients were screened; 320 were recruited: 208 with ACS and 112 with CCS. The median vFFR was 0.82 (0.70-0.91). vFFR disclosure did not change the mean number of significantly stenosed vessels per patient (1.16 (±0.96) visually and 1.18 (±0.92) with vFFR (p=0.79)). A change in intended management following vFFR disclosure occurred in 22% of all patients; in the ACS cohort, there was a 62% increase in the number planned for medical management, and in the CCS cohort, there was a 31% increase in the number planned for PCI. In all patients, vFFR disclosure increased physician confidence from 8 of 10 (7.33-9) to 9 of 10 (8-10) (p<0.001). CONCLUSION: The addition of vFFR to ICA changed intended management strategy in 22% of patients, provided a detailed and specific 'all-in-one' anatomical and physiological assessment of coronary artery disease, and was accompanied by augmentation of the operator's confidence in the treatment strategy.

Antithrombotic therapy after heart valve intervention: review of mechanisms, evidence and current guidance.

As the population ages and treatment options for heart valve disease increase, the number of patients with intracardiac valve prostheses is growing rapidly. Although all devices have the potential to cause thrombus formation, the propensity depends on the type of prosthesis as well as risk of the individual patient. Mechanical valve prostheses carry the highest (and persistent) risk of thromboembolism, and these patients require anticoagulation with vitamin K antagonists (warfarin). Required international normalised ratio levels are dependent on the location of the valve (mitral>aortic), type of valve (ball and cage vs bilealfet vs On-X bilealfet) and rhythm. The risk of tissue (biological) prosthesis is highest soon after surgery and is dependent on individual patient risk including age, valve location (mitral>aortic), history of thromboembolic events and rhythm. In patients with no other indication for anticoagulation, there is uncertainty on the benefits of anticoagulation versus antiplatelet therapy in patients with tissue prostheses or repaired native valves. Patients with an a priori indication for anticoagulation with a direct oral anticoagulant can continue taking this class of drug. Patients with transcatheter aortic valve implantation devices and no additional evidence-based indication for dual antiplatelet therapy or anticoagulation can be maintained on aspirin monotherapy. Patients undergoing transcatheter instrumentation in the mitral valve position should be anticoagulated, although there is currently no published evidence for antithrombotic management in this group of patients. Patients with thrombosed devices (commonly mitral mechanical) should preferably be treated surgically. Patients at high risk of thromboembolism (with mechanical prostheses) should undergo bridging therapy when undergoing surgery.

Outpatient management of heart valve disease following the COVID-19 pandemic: implications for present and future care.

The established processes for ensuring safe outpatient surveillance of patients with known heart valve disease (HVD), echocardiography for patients referred with new murmurs and timely delivery of surgical or transcatheter treatment for patients with severe disease have all been significantly impacted by the novel coronavirus pandemic. This has created a large backlog of work and upstaging of disease with consequent increases in risk and cost of treatment and potential for worse long-term outcomes. As countries emerge from lockdown but with COVID-19 endemic in society, precautions remain that restrict 'normal' practice. In this article, we propose a methodology for restructuring services for patients with HVD and provide recommendations pertaining to frequency of follow-up and use of echocardiography at present. It will be almost impossible to practice exactly as we did prior to the pandemic; thus, it is essential to prioritise patients with the greatest clinical need, such as those with symptomatic severe HVD. Local procedural waiting times will need to be considered, in addition to usual clinical characteristics in determining whether patients requiring intervention would be better suited having surgical or transcatheter treatment. We present guidance on the identification of stable patients with HVD that could have follow-up deferred safely and suggest certain patients that could be discharged from follow-up if waiting lists are triaged with appropriate clinical input. Finally, we propose that novel models of working enforced by the pandemic-such as increased use of virtual clinics-should be further developed and evaluated.

Results of mechanical versus tissue AVR: caution in young patients with tissue AVR.

The first aortic valve prosthesis, implanted more than 50 years ago, was a mechanical prosthesis (ball-and-cage design). Over the ensuing decades, tissue prostheses and new mechanical designs were introduced to mitigate the need for anticoagulation with its associated side effects. Tissue and mechanical heart valve prostheses were compared in two head-to-head randomised control trials. Both of these confirmed that mechanical prostheses were durable but patients suffered anticoagulant-related bleeds. Patients who received a tissue prosthesis were more likely to suffer prosthetic dysfunction and require reoperation. This trend was stronger in younger patients. Since the publication of those two trials, several large retrospective studies using data from meta-analyses of published papers or registries have failed to show a survival advantage of either prostheses when implanted in the aortic position in younger patients. This equipoise has been reflected in the heart valve disease guidelines published by European and US societies. In recent years, the primacy of patient choice, the rapid increase in life expectancy of populations, the increased incidence of atrial fibrillation with requirement for anticoagulation, the advent of transcatheter techniques to treat degenerating tissue valves as well as advances in anticoagulant therapy and in new tissue and to a lesser extent mechanical prosthetic design continue to influence choice of aortic valve prosthesis in younger patients undergoing aortic valve replacement.

Sutureless aortic valve prostheses.

Conventional surgical aortic valve replacement (AVR) is the 'gold standard' for treatment of severe or symptomatic aortic valve stenosis. The increasing age of patients and increasing comorbidities has led to the development of procedures to minimise operative time and reduce risks of surgery. One method of reducing operative times is the use of sutureless aortic valves (SU-AVR). We examine the current literature surrounding the use of SU-AVR. Alternatives to AVR are SU-AVR, sometimes referred to as rapid deployment valves, or transcatheter aortic valve implantation (TAVI). TAVI has been demonstrated to be superior over medical therapy in patients deemed inoperable and non-inferior in high and intermediate-risk patients compared with surgical AVR. However, the lack of excision of the calcified aortic valve and annulus raises concerns regarding long-term durability and possibly thromboembolic complications. TAVI patients have increased rates of paravalvular leaks, major vascular complications and pacemaker implantation when compared with conventional AVR. SU-AVR minimises the need for suturing, leading to reduced operative times, while enabling complete removal of the calcified valve. The increase in use of SU-AVR has been mostly driven by minimally invasive surgery. Other indications include patients with a small and/or calcified aortic root, as well as patients requiring AVR and concomitant surgery. SU-AVR is associated with decreased operative times and possibly improved haemodynamics when compared with conventional AVR. However, this has to be weighed against the increased risk of paravalvular leak and pacemaker implantation when deciding which prosthesis to use for AVR.

Improving Medical Students' Application of Knowledge and Clinical Decision-Making Through a Porcine-Based Integrated Cardiac Basic Science Program.

OBJECTIVE: Despite the concerted effort of modern undergraduate curriculum designers, the ability to integrate basic sciences in clinical rotations is an ongoing problem in medical education. Students and newly qualified doctors themselves report worry about the effect this has on their clinical performance. There are examples in the literature to support development of attempts at integrating such aspects, but this "vertical integration" has proven to be difficult. We designed an expert-led integrated program using dissection of porcine hearts to improve the use of cardiac basic sciences in clinical medical students' decision-making processes. To our knowledge, this is the first time in the United Kingdom that an animal model has been used to teach undergraduate clinical anatomy to medical students to direct wider application of knowledge. METHODS: Action research methodology was used to evaluate the local curriculum and assess learners needs, and the agreed teaching outcomes, methods, and delivery outline were established. A total of 18 students in the clinical years of their degree program attended, completing precourse and postcourse multichoice questions examinations and questionnaires to assess learners' development. RESULTS: Student's knowledge scores improved by 17.5% (p = 0.01; students t-test). Students also felt more confident at applying underlying knowledge to decision-making and diagnosis in clinical medicine. An expert teacher (consultant surgeon) was seen as beneficial to students' understanding and appreciation. CONCLUSIONS: This study outlines how the development of a teaching intervention using porcine-based methods successfully improved both student's knowledge and application of cardiac basic sciences. We recommend that clinicians fully engage with integrating previously learnt underlying sciences to aid students in developing decision-making and diagnostic skills as well as a deeper approach to learning.