Early safety and feasibility of a first-in-class biomimetic transcatheter aortic valve - DurAVR.

BACKGROUND: TAVI is a widely accepted treatment for patients with severe aortic stenosis (AS). Despite the adoption of diverse therapies, opportunities remain to develop technologies tailored to provide optimal acute and potential long-term benefits, particularly around haemodynamics, flow and durability. AIMS: We aimed to evaluate the safety and feasibility of the DurAVR transcatheter heart valve (THV), a first-in-class biomimetic valve, in the treatment of patients with symptomatic severe AS. METHODS: This was a first-in-human (FIH), prospective, non-randomised, single-arm, single-centre study. Patients with severe, symptomatic AS of any surgical risk and who were eligible for the DurAVR THV prosthesis were recruited; they were assessed at baseline, 30 days, 6 months, and 1 year post-procedure for implant success, haemodynamic performance, and safety. RESULTS: Thirteen patients (73.9±6.4 years old, 77% female) were enrolled. The DurAVR THV was successfully implanted in 100% of cases with no device-related complications. One access site complication, one permanent pacemaker implantation, and one case of moderate aortic regurgitation occurred. Otherwise, no deaths, stroke, bleeding, reinterventions, or myocardial infarction were reported during any of the follow-up visits. Despite a mean annulus size of 22.95±1.09 mm, favourable haemodynamic results were observed at 30 days (effective orifice area [EOA] 2.00±0.17 cm2, and mean pressure gradient [MPG] 9.02±2.68 mmHg) and were sustained at 1 year (EOA 1.96±0.11 cm2, MPG 8.82±1.38 mmHg), resulting in zero patients with any degree of prosthesis-patient mismatch. Additionally, new valve performance measures derived from cardiovascular magnetic resonance displayed restoration of laminar flow, consistent with a predisease state, in conjunction with a mean coaptation length of 8.3±1.7 mm. CONCLUSIONS: Preliminary results from the FIH study with DurAVR THV demonstrate a good safety profile with promising haemodynamic performance sustained at 1 year and restoration of near-normal flow dynamics. Further clinical investigation is warranted to evaluate how DurAVR THV may play a role in addressing the challenge of lifetime management in AS patients.

Outcomes of the First 300 Cases of Transcatheter Aortic Valve Implantation at a High-Volume Australian Private Hospital.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) was first performed in Australia in 2008 with a steady increase in the number of implanting centres from seven in 2008 to 42 in 2018 (24 private and 18 public hospitals). There is limited published data on outcomes from Australian centres and no published data from Australian private hospitals. We describe outcomes of the first 300 cases at Queensland's first TAVI implanting private hospital. METHODS: From July 2015 to August 2018, 300 patients with severe, symptomatic aortic stenosis underwent TAVI at our centre. A heart team assessed all patients as suitable. All patients underwent computed tomography (CT) assessment of valve sizing and peripheral access. RESULTS: Median age was 85 years, 58% male, mean Society of Thoracic Surgeons' score 4.0%, 49% had New York Heart Association Class III/IV, 28% previous coronary artery bypass grafts, 14% peripheral vascular disease and 3.7% renal impairment (creatinine >177 µmol/L). At 30 days mortality was 1%, stroke 1.3%, myocardial infarction (MI) 0.3%, major vascular complication 3.0%, no life-threatening or disabling bleeding and new permanent pacemaker (PPM) requirement was 9.0%. Paravalvular leak was none, trace and mild in 27%, 53% and 20% respectively with 0.3%≥moderate paravalvular leak. At 1 year, mortality was 4.2%, stroke 2.1%, MI 0.3%, no life-threatening bleeding and PPM 11.4%. Lower rates of mortality, stroke, and major vascular complications were observed compared to the well-established TAVI centres in USA and Germany. CONCLUSION: Excellent TAVI clinical outcomes can be achieved in the Australian private hospital setting. Expert heart team assessment and CT guided procedural planning are key to these outcomes.

The effect of X-ray beam distortion on the Edwards Sapien XT(™) trans-catheter aortic valve replacement prosthesis.

INTRODUCTION: Profiling the Aortic root perpendicular to the fluoroscopic image plane will achieve a more successful implant position for trans-catheter aortic valve replacement (TAVR). This study aimed to investigate whether the divergent nature of the X-ray beam from the C-arm altered the appearance of the TAVR device. METHODS: Under bench-top testing, a 23, 26 and 29 mm Edwards Sapien XT valve was positioned coaxially at the bottom of a fluoroscopic image utilising 22 and 32 cm fields of view (FOV). The table was then moved so that the valve was positioned at the top of the image. The valve's appearance was scored using a previously published three tier classification tool (excellent, satisfactory and poor) and quantified with measurements. The number of degrees of C-arm rotation that were required to bring the valve back to a coaxial appearance was recorded. RESULTS: When using the 32 cm FOV, the valve's appearance changes from excellent to satisfactory. When a 22 cm FOV was used, the change is less marked. More C-arm rotation is required to bring the appearance back to coaxial with the 32 cm FOV. CONCLUSION: Not maintaining the valve in the centre of the image can distort the valves appearance. This has the potential to affect the final implantation depth.

Pre-hospital ambulance notification and initiation of treatment of ST elevation myocardial infarction is associated with significant reduction in door-to-balloon time for primary PCI.

BACKGROUND: Mortality in ST elevation myocardial infarction (STEMI) is strongly predicted by the time from first medical contact to reperfusion. The aim of this study was to examine the impact of pre-hospital diagnosis by paramedics in the field on the door-to-balloon (DTB) times of patients with ST elevation myocardial infarction undergoing primary percutaneous intervention. METHODS: Paramedics in the field identified patients with ST elevation myocardial infarction on a 12-lead electrocardiograph, activated the cardiac catheter laboratory team from the field and initiated therapy with anticoagulants and antiplatelet agents in the pre-hospital setting. This cohort of patients was compared to a similar group of patients without pre-hospital diagnosis and notification. The primary outcome measure was DTB times. A secondary end point was mortality at 30 days and mortality at six months. RESULTS: A total of 281 patients, mean age of 61.1±12.9 years underwent primary percutaneous intervention with pre-hospital notification occurring in 63 cases. DTB times were lower in those with pre notification than in those without pre-hospital notification (40.4 vs. 75.6 minutes, p<0.001). This represented a 47.6% shorter DTB time. A non-statistically significant mortality reduction at one month and six months was observed in the pre-hospital notification group (1.6 versus 4.3%, p= 0.307 and 1.6 versus 6.4%, p= 0.203, respectively). CONCLUSION: Pre-hospital intervention at our centre had a powerful effect in reducing the time to reperfusion in patients with STEMI undergoing primary percutaneous intervention.

Early experience of transaortic TAVI--the future of surgical TAVI?

BACKGROUND: Trans-catheter aortic valve implantation (TAVI) is now a well recognised procedure for the high risk surgical patient with native or bioprosthetic aortic valve stenosis. Transfemoral and transapical implantation techniques are well described. With increasing referral of more marginal transapical patients, we describe our experience of a transaortic TAVI approach which we believe reduces the postoperative wound pain, respiratory complications, operative risk and hospital stay. METHODS: Patients referred for surgical TAVI underwent trans-catheter aortic valve implantation via an upper sternotomy and direct cannulation of the ascending aorta. RESULTS: Thirteen patients with a mean age of 81 years underwent transaortic Edwards SAPIEN valve implantation. There was no in hospital mortality in our series. One patient required insertion of a permanent pacemaker for complete heart block. There were no aortic cannulation complications. CONCLUSION: The transaortic TAVI approach provides good exposure of the distal ascending aorta, a familiar cannulation site for cardiac surgeons. Our initial experience demonstrates the approach to be a safe technique with the potential for faster and less complicated recovery in patients undergoing surgical TAVI procedures. With further experience and greater acceptance, the transaortic approach may ultimately become the procedure of choice for patients unsuitable for a transfemoral approach.

Fistula between subclavian arterial graft and oesophagus.

This is the first reported case of an oesophageal fistula arising from a subclavian arterial graft. A 28 year-old woman presented with massive haematemesis in severe haemorrhagic shock, three months after surgery to detach and relocate an aberrant right subclavian artery. Acutely, she was haemodynamically unstable and required transfusion of 45 units of blood. The fistula was identified with angiography (via the right brachial artery) after endoscopic and open visualisation were unsuccessful because of the torrential haemorrhage. The patient was stabilised and the fistula was managed with an endovascular covered stent. She had further surgery subsequently to remove the infected graft and to salvage the right arm.

Impact of optimising fluoroscopic implant angles on paravalvular regurgitation in transcatheter aortic valve replacements - utility of three-dimensional rotational angiography.

AIMS: The clinical value of optimising implant angles during transcatheter aortic valve replacements (TAVR) remains undefined. The Aortic Valve Guide (AVG) is a proprietary software that provides structured analysis of three-dimensional images from rotational angiography (DynaCT). This study compares AVG with preprocedural multislice computed tomography (MSCT) and DynaCT in optimal implant angle prediction for TAVR, and evaluates if an optimised implant angle is associated with reduced paravalvular regurgitation (PVR). METHODS AND RESULTS: One hundred and six consecutive patients were included, comprising three groups. Group 1 (n=19) underwent no preprocedural MSCT or DynaCT (or AVG); Group 2 (n=44) underwent periprocedural DynaCT, without AVG; Group 3 (n=43) had DynaCT with AVG. Implant angles yielded were graded as excellent, satisfactory or poor. Group 3 were more likely than Groups 2 and 1 to have excellent implant angles (83.7% vs. 52.3% vs. 42.1%, respectively, p=0.001). In 100 patients who had 30-day transthoracic echocardiogram follow-up, an excellent implant angle was significantly more likely to be associated with no PVR than a non-excellent angle (41.3% vs. 21.6%, respectively, p=0.045), independent of operator experience and THV used. CONCLUSIONS: Optimising implant angles may be important in reducing PVR. This is significantly more likely to be achieved with AVG rotational angiography.

First Australian transapical mitral valve-in-valve implant for a failed mitral bioprosthesis: how to do it.

Transcatheter aortic valve replacements lower mortality in patients not suitable for surgical valve replacement compared to conservative treatment. Transcatheter valve-in-valve implants have been shown to be feasible in failed bioprostheses in aortic, mitral, pulmonary and tricuspid positions. We report the first Australasian experience of a transapical mitral valve-in-valve placement with an Edwards Sapien(®) transcatheter valve for a failed mitral bioprosthesis, focussing on the technical aspects of this novel procedure. Whilst the evidence for this niche indication is limited currently to case reports and case series, further evaluation of its long term outcomes may justify its use in this particularly high risk group of re-do sternotomy patients.