Impact of the COVID-19 Pandemic on Global TAVR Activity: The COVID-TAVI Study.

BACKGROUND: The COVID-19 pandemic adversely affected health care systems. Patients in need of transcatheter aortic valve replacement (TAVR) are especially susceptible to treatment delays. OBJECTIVES: This study sought to evaluate the impact of the COVID-19 pandemic on global TAVR activity. METHODS: This international registry reported monthly TAVR case volume in participating institutions prior to and during the COVID-19 pandemic (January 2018 to December 2021). Hospital-level information on public vs private, urban vs rural, and TAVR volume was collected, as was country-level information on socioeconomic status, COVID-19 incidence, and governmental public health responses. RESULTS: We included 130 centers from 61 countries, including 65,980 TAVR procedures. The first and second pandemic waves were associated with a significant reduction of 15% (P < 0.001) and 7% (P < 0.001) in monthly TAVR case volume, respectively, compared with the prepandemic period. The third pandemic wave was not associated with reduced TAVR activity. A greater reduction in TAVR activity was observed in Africa (-52%; P = 0.001), Central-South America (-33%; P < 0.001), and Asia (-29%; P < 0.001). Private hospitals (P = 0.005), urban areas (P = 0.011), low-volume centers (P = 0.002), countries with lower development (P < 0.001) and economic status (P < 0.001), higher COVID-19 incidence (P < 0.001), and more stringent public health restrictions (P < 0.001) experienced a greater reduction in TAVR activity. CONCLUSIONS: TAVR procedural volume declined substantially during the first and second waves of the COVID-19 pandemic, especially in Africa, Central-South America, and Asia. National socioeconomic status, COVID-19 incidence, and public health responses were associated with treatment delays. This information should inform public health policy in case of future global health crises.

Hemostatic Profiles of Patients Who Underwent Transcatheter Versus Surgical Aortic Valve Replacement Versus Percutaneous Coronary Intervention.

Guidelines for transcatheter aortic valve replacement (TAVR) antithrombotic prophylaxis are extrapolated predominantly from percutaneous coronary intervention (PCI) data. Here, we examined temporal coagulation changes occurring in the early perioperative period to determine the pathobiologic validity of this supposition. This was a prospective observational study of consecutive patients who underwent transfemoral TAVR (n = 27), PCI (n = 12), or surgical aortic valve replacement (SAVR) requiring cardiopulmonary bypass and cross-clamping (n = 12). Blood samples were taken at 4 time points: T1 (baseline), after general anesthesia or sedation; T2, after heparin administration; T3, at the end of the procedure; and T4, 6 hours after the procedure. The samples were assessed concurrently using standard laboratory coagulation tests and viscoelastic tests of whole blood clotting, including the latest generation thromboelastometry (ROTEM sigma) and thromboelastometry (TEG 6s). Patients in the TAVR cohort were older and a had lower baseline hemoglobin level than patients in the PCI and SAVR cohorts. The baseline platelet function was similar between the TAVR and PCI cohorts and impaired in the SAVR cohort Figure S1. The baseline hemostatic measures were comparable among cohorts. Regarding the per-patient change from baseline, the TAVR cohort showed an overall more prothrombotic state than the other cohorts, with the most marked differences from the SAVR cohort after intraoperative heparin administration and from the PCI cohorts 6 hours after the procedure. In addition, the ROTEM and TEG parameters were well correlated but not interchangeable. In conclusion, patients who underwent TAVR have a more prothrombotic hemostatic profile than PCI and SAVR patients. These findings question the current guidelines that extrapolate antithrombotic regimens from PCI to TAVR settings.

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.

Evaluation of latest viscoelastic coagulation assays in the transcatheter aortic valve implantation setting.

BACKGROUND: Point of care viscoelastic measures with thromboelastography (TEG; Haemonetics Corporation, Switzerland) and thromboelastometry (ROTEM, Tem Innovations GmbH, Germany) now supersede laboratory assays in the perioperative assessment and management of coagulation. To the best of our knowledge, this sophisticated coagulation assessment has not been performed to characterise thrombotic changes in the transcatheter aortic valve implantation (TAVI) setting, nor have the two latest iteration cartridge-based systems been directly compared in the elective perioperative period. METHODS: Patients undergoing TAVI were prospectively recruited. Samples (n=44) were obtained at four timepoints (postinduction of anaesthesia, postheparin (100 IU/kg), postprotamine (1 mg/100 IU heparin) and 6 hours postoperatively). Each sample was concurrently assessed with standard laboratory tests (prothrombin time/international normalised ratio, activated partial thromboplastin time, thrombin clotting time, platelet count and direct fibrinogen, ROTEMSigma and TEG6s). RESULTS: Clot strength showed a statistically significant increase postheparin/TAVI deployment. When considering the subgroup of samples taken following the administration heparin, the heparinase channel of the TEG6s did not yield clotting strength results in 55% of samples and clotting time exceeded the upper limit of normal in 70% of samples. It was retrospectively recognised that the arachidonic acid channel of the TEG6s Platelet Mapping Cartridge had been decommissioned prohibiting assessment of aspirin effect. CONCLUSIONS: This study demonstrated a small intraprocedural prothrombotic change of uncertain clinical importance during the transcatheter aortic valve procedure. Further comparison with percutaneous coronary intervention and aortic valve replacement cohorts are needed to assess the merits of current antithrombotic guidelines, which are extrapolated from the PCI setting. The heparin effect was more consistently quantified by ROTEM.

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.

Early Changes of Myocardial Function After Transcatheter Aortic Valve Implantation Using Multilayer Strain Speckle Tracking Echocardiography.

Transcatheter aortic valve implantation (TAVI) is an effective therapeutic option for severe symptomatic aortic valve stenosis (AS) with intermediate or high surgical risk. The purpose of this study was to examine the effects of TAVI on left ventricular (LV) mechanics using multilayer global longitudinal strain (GLS) by 2D speckle-tracking echocardiography. A total of 119 patients (mean age 83 ± 7.0 years, male 54%) with severe symptomatic AS and normal LV ejection fraction (LVEF) underwent echocardiography at baseline and 1 month after TAVI. Global longitudinal strain was measured from the endocardial layer (GLSendo), mid-ventricular layer (GLSmyo), epicardial layer (GLSepi) and full thickness of myocardium (GLSwhole). There was significant improvement in all 3 layers of GLS after TAVI compared with baseline, but there was no significant change in LVEF. The relative % increment in GLS in each layer strain were 11.2 ± 23.4% (GLSendo), 13.4 ± 33.0% (GLSmyo) and 18.0 ± 46.6% (GLSepi) with significant difference between GLSendo and GLSepi (p < 0.05). In conclusion, multilayer GLS is more sensitive than conventional LVEF to detect early improvement in LV systolic function after TAVI in patients with severe AS. There is a disproportional improvement in different layers with least improvement in the endocardium. Multilayer strain analysis may provide new insights into understanding mechanics of AS.

Pulmonary Artery Pseudoaneurysms in the Setting of Gout Polyarthropathy: A Case Report.

Pulmonary artery pseudoaneurysm is a dangerous pathology often missed as a differential and on imaging. With a 50% mortality rate early detection and intervention are critical to patient outcome, rendering diagnosis based on clinical grounds to be of paramount importance. A high index of suspicion should be placed on patients presenting with unprovoked hemoptysis, hemorrhage or hemothorax. Knowledge of the common causes of pulmonary artery pseudoaneurysms is also important; however, it is integral to note spontaneous occurrences in patients with no known risk factors. Herein, we report a case of an unprovoked pulmonary artery pseudoaneurysm in a 72-year-old male with no known risk factors or causes for the pathology. Additionally, we review the pathophysiology behind the potential association of polyarthritic gout as a cause of pulmonary artery pseudoaneurysms. To the best of our knowledge this is the first reported link between the two diseases, providing grounds to widen literature and increase diagnoses of pulmonary artery pseudoaneurysms.

Transcatheter mitral valve intervention: an emerging treatment for mitral regurgitation.

Mitral regurgitation (MR) is a valvular heart disease associated with significant morbidity and mortality. Transcatheter mitral valve intervention (TMVI) repairs or replaces the mitral valve through small arterial and venous entry sites and so avoids risks associated with open heart surgery. Transcatheter devices targeting components of the mitral apparatus are being developed to repair or replace it. Numerous challenges remain including developing more adaptable devices and correction of multiple components of the mitral annulus to attain durable results. The mitral valve apparatus is a complex structure and understanding of the mechanisms of MR is essential in the development of TMVI. There will likely be a complementary role between surgery and TMVI in the near future.

Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality. METHODS: Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed. RESULTS: Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity. CONCLUSION: Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

Palliative embolisation for intrapulmonary shunting in lepidic predominant adenocarcinoma of the lung.

Lepidic predominant adenocarcinoma (LPA) (formerly known as bronchioalveolar carcinoma) has rarely been reported to cause refractory hypoxia with intrapulmonary shunting [1-7]. We describe a case who underwent the palliative strategy of intravascular right lower pulmonary artery embolisation with an 18 mm Amplatzer II vascular plug to reduce intrapulmonary shunting. This is the first report we are aware of using this minimally invasive procedure to treat this condition.

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.

Transcatheter valve-in-valve replacement of degenerated bioprosthetic aortic valves: a single Australian Centre experience.

BACKGROUND: Patients with degenerated surgical bioprosthetic valves may be at high risk for further surgery because of age, comorbidities and the difficulties of repeat procedures. Percutaneous valve-in-valve implantation offers what may be a simpler and safer procedure. METHODS: From May 2009 to March 2014 at the Prince Charles Hospital 1625 patients underwent surgical aortic valve replacement while 262 underwent transcatheter aortic valve implantation. Twelve patients had valve-in-valve implants for degenerated bioprosthetic aortic valves. RESULTS: These implants were deployed successfully without major valvular or paravalvular regurgitation. There were no periprocedural deaths, myocardial infarcts, neurological events or major vascular complications. Two patients died after 1624 and 1319days. Median survival for the remainder is 581days; they are stable with New York Heart Association class I/II functional status although 4 have a degree of patient-prosthesis mismatch, one has moderate aortic regurgitation and one required surgery for a late aortic dissection. CONCLUSION: Transcatheter valve-in-valve implantation is safe and effective treatment for patients with failed bioprosthetic aortic valves for whom reoperation is considered to be hazardous.

Percutaneous revascularization of a chronic total occlusion of the left lower pulmonary vein.

Pulmonary vein stenosis occurs in 1.3% of patients undergoing pulmonary vein isolation procedures for atrial fibrillation. Complete occlusion can occur and is often associated with symptoms including dyspnea and chest pain. Percutaneous intervention with angioplasty and stenting is frequently performed for pulmonary vein stenosis, but management of pulmonary vein occlusion remains challenging. We report the case of a 47-year-old female who presented with dyspnea and history of two previous radiofrequency ablation procedures for paroxysmal atrial fibrillation. Initial imaging with a ventilation/perfusion scan showed absent perfusion of the lower one-third of the left lung, and occlusion of the left lower pulmonary vein was confirmed by computed tomography (CT). Under sedation, with transesophageal echocardiographic and fluoroscopic guidance, the left atrium was accessed via the right femoral vein and a transseptal puncture. Initially, hydrophilic coronary guidewires were not able to cross the occlusion, but antegrade wire-escalation strategies usually reserved for coronary chronic total occlusion (CTO) cases were successful. The lesion was successfully stented, with prompt resolution of symptoms and stent patency demonstrated at follow-up.

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.

The demographic profile of young patients (<45 years-old) with acute coronary syndromes in Queensland.

BACKGROUND: There is little data regarding the demographic profile of young (<45 years) Australian acute coronary syndrome patients. The aim of this study was to compare baseline characteristics, risk factor profile and outcomes of young patients compared with their older counterparts referred to two metropolitan Queensland hospitals. METHODS: Over a four-year period, data on acute coronary syndrome patients referred to The Prince Charles and Royal Brisbane Hospitals were retrospectively analysed. Three major groups were identified: <45 years, 45-60 years and those >60 years. Age, sex, body mass index, risk factor profile, degree of coronary disease, left ventricular dysfunction, mode of presentation, initial pharmacological therapy and mortality data were compared between the three groups. RESULTS: 4549 patients were analysed of whom, 277 were less than 45 years old. Younger patients tended to be male, more overweight and present more commonly with ST segment elevation myocardial infarction compared to their older counterparts. Smoking, family history and dyslipidaemia tended to occur more frequently in younger patients as compared to those >45 years. Those patients >45 years tended to present with non-ST segment elevation myocardial infarction and have a higher degree of ischaemic burden and left ventricular dysfunction. No patients <45 years died in their index admission at 30 days or at one year. CONCLUSIONS: Although young patients <45 years make up the minority (6.1%) of patients presenting with acute coronary syndrome and generally have a favourable prognosis, this paper highlights the need for aggressive risk factor modification, with particular attention to smoking and dyslipidaemia, before the onset of overt clinical disease.

Using DynaCT for the assessment of ilio-femoral arterial calibre, calcification and tortuosity index in patients selected for trans-catheter aortic valve replacement.

Adequate vascular access for femoral trans-catheter aortic valve replacement is fundamental to the success of the procedure. Assessment of vascular calibre, tortuosity and calcification is performed by angiography and multi-slice computed tomography (MSCT). Can DynaCT provide the same information as MSCT? 15 Patients underwent MSCT, angiography and DynaCT. Vessel diameter measurements were taken in three positions of the left and right ilio-femoral arteries. Tortuosity was assessed using an index of the direct distance and the distance taken by the artery between two points. Calcification was assessed in MSCT and DynaCT using a simple scoring system. Concordance correlation coefficient of arterial calibre between angiography and MSCT was 0.96 (95 % CI 0.94-0.97). DynaCT and angiography was 0.94 (95 % CI 0.91-0.96) and Dyna CT and MSCT, 0.95 (95 % CI 0.92-0.97). Bland-Altman tests demonstrate a mean difference between the angiogram and the MSCT of 0.06 mm (+0.97, -1.42), angiogram and DynaCT, 0.13 mm, (+1.00, -0.87), DynaCT and MSCT, 0.2 mm, (+1.15, -0.76). Tortuosity comparisons gave a median tortuosity index for MSCT 1.29 and DynaCT 1.23 (p = 0.472). Calcification comparisons of MSCT and DynaCT using correlation coefficients demonstrate a correlation of 0.245 (p = 0.378). Effective radiation doses were: DynaCT; 3.63 ± 0.65 mSv and angiography; 0.57 ± 0.72 mSv, MSCT; 7.15 ± 2.58 mSv. DynaCT is equal to MSCT and angiography in assessing femoral artery calibre. Like MSCT, it can assess tortuosity and can produce 3D images but is inferior in the assessment of calcification.