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 safety, efficacy and cost-effectiveness of stress echocardiography in patients with high pretest probability of coronary artery disease.

OBJECTIVE: In this study, we assess the clinical and cost-effectiveness of stress echocardiography (SE), as well as the place of SE in patients with high pretest probability (PTP) of coronary artery disease (CAD). METHODS: We investigated 257 patients with no history of CAD, who underwent SE, and they had a PTP risk score >61% (high PTP). According to the National Institute for Health and Care Excellence guidance (NICE CG95, 2010), these patients should be investigated directly with an invasive coronary angiogram (ICA). We investigated those patients with SE initially and then with ICA when appropriate. Follow-up data with regard to Major Adverse Cardiac and Cerebrovascular Events (MACCE, defined as cardiovascular mortality, cerebrovascular accident (CVA), myocardial infarction (MI) and late revascularisation for acute coronary syndrome/unstable angina) were recorded for a period of 12 months following the SE. The tariff for SE and ICA is £300 and £1400, respectively. RESULTS: 106 patients had a positive SE (41.2%) and 61 of them (57.5%) had further investigation with ICA. 15 (24.6%) of these patients were revascularised. The average cost per patient for investigations was £654.09. If NICE guidance had been followed, the cost would have been significantly higher at £1400 (p<0.001). Overall, 5 MACCE (2.0%) were recorded; 4 (3.8%) in the group of positive SE (2 CVAs and 2 MIs) and 1 (0.7%) in the group of negative SE (1 CVA). There was no MI and no need for revascularisation in the negative SE group. CONCLUSION: Our approach to investigate patients who present with de novo chest pain and high PTP, with SE initially and subsequently with ICA when appropriate, reduces the cost significantly (£745.91 per patient) with a very low rate of MACCE. However, this study is underpowered to assess safety of SE.

Three-Dimensional Measurement of Aortic Annulus Dimensions Using Area or Circumference for Transcatheter Aortic Valve Replacement Valve Sizing: Does It Make a Difference?

BACKGROUND: The use of transcatheter aortic valve replacement (TAVR) is increasing worldwide. We present our 6-year experience using three-dimensional (3D) transesophageal echocardiography (TEE) and investigate whether different sizing methods of the aortic annulus lead to different prosthesis size that may impact outcome. METHODS: We investigated 262 patients who underwent TAVR and had 3D TEE data sets of the aortic annulus. We have used the area-derived diameter (Darea = 2(area/π)) and the circumference-derived diameter (Dcirc = Circumference/π) to size the prosthesis in separate populations in different time periods. RESULTS: The Dcirc method is correlated with lower incidence of paravalvular aortic regurgitation (PVAR; odds ratio = 0.44, 95% confidence interval, 0.23-0.85; P = .015). Other factors associated with PVAR were the cover index, area-mismatch index, and circumference-mismatch index. Retrospectively, for the purposes of the study, we used the Edwards-Sapien 3 Valve 3D sizing guide in all patients, to predict the hypothetical valve size with each method. In the whole population, the calculated Dcirc was higher in all cases (Dcirc = 23.4 ± 2.3 mm vs Darea = 22.9 ± 2.3 mm; P < .001). The two methods had good agreement in predicting the valve size (kappa = 0.600). In total, 192 (73.3%) patients were assigned for the same prosthesis size, whereas 70 (26.7%) would be eligible for a different size, of which 44 (16.7%) would definitely have had a different valve implanted. CONCLUSION: Using the aortic annulus area or circumference to calculate the annular diameter provides different values. Comparing the two methods, a different prosthesis size could have been implanted in 26.7% of patients. In our series the use of circumference-derived diameter resulted in lower incidence of PVAR. The findings of this study may be independent of the imaging modality and may therefore also apply to computed tomography-based aortic annulus measurements, but this needs to be further investigated.

The prognostic role of stress echocardiography in a contemporary population and the clinical significance of limited apical ischaemia.

INTRODUCTION: In this study, we aim to reassess the prognostic value of stress echocardiography (SE) in a contemporary population and to evaluate the clinical significance of limited apical ischaemia, which has not been previously studied. METHODS: We included 880 patients who underwent SE. Follow-up data with regards to MACCE (cardiac death, myocardial infarction, any repeat revascularisation and cerebrovascular accident) were collected over 12 months after the SE. Mortality data were recorded over 27.02 ± 4.6 months (5.5-34.2 months). We sought to investigate the predictors of MACCE and all-cause mortality. RESULTS: In a multivariable analysis, only the positive result of SE was predictive of MACCE (HR, 3.71; P = 0.012). The positive SE group was divided into 2 subgroups: (a) inducible ischaemia limited to the apical segments ('apical ischaemia') and (b) ischaemia in any other segments with or without apical involvement ('other positive'). The subgroup of patients with apical ischaemia had a significantly worse outcome compared to the patients with a negative SE (HR, 3.68; P = 0.041) but a similar outcome to the 'other positive' subgroup. However, when investigated with invasive coronary angiography, the prevalence of coronary artery disease (CAD) and their rate of revascularisation was considerably lower. Only age (HR, 1.07; P < 0.001) was correlated with all-cause mortality. CONCLUSION: SE remains a strong predictor of patients' outcome in a contemporary population. A positive SE result was the only predictor of 12-month MACCE. The subgroup of patients with limited apical ischaemia have similar outcome to patients with ischaemia in other segments despite a lower prevalence of CAD and a lower revascularisation rate.

Pre-test probability risk scores and their use in contemporary management of patients with chest pain: One year stress echo cohort study.

OBJECTIVES: To compare how patients with chest pain would be investigated, based on the two guidelines available for UK cardiologists, on the management of patients with stable chest pain. The UK National Institute of Clinical Excellence (NICE) guideline which was published in 2010 and the European society of cardiology (ESC) guideline published in 2013. Both guidelines utilise pre-test probability risk scores, to guide the choice of investigation. DESIGN: We undertook a large retrospective study to investigate the outcomes of stress echocardiography. SETTING: A large tertiary centre in the UK in a contemporary clinical practice. PARTICIPANTS: Two thirds of the patients in the cohort were referred from our rapid access chest pain clinics. RESULTS: We found that the NICE risk score overestimates risk by 20% compared to the ESC Risk score. We also found that based on the NICE guidelines, 44% of the patients presenting with chest pain, in this cohort, would have been investigated invasively, with diagnostic coronary angiography. Using the ESC guidelines, only 0.3% of the patients would be investigated invasively. CONCLUSION: The large discrepancy between the two guidelines can be easily reduced if NICE adopted the ESC risk score.

The safety profile of perflutren microsphere contrast echocardiography during rest and stress imaging: results from an Australian multicentre cohort.

BACKGROUND: Contrast enhanced echocardiography (CEE) is utilised when sub-optimal image quality results in non-diagnostic echocardiograms. However, there have been numerous safety notices issued by regulatory authorities regarding rare but potentially serious adverse reactions (AR). This multi-centre, retrospective analysis was performed to assess the short-term safety of CEE in a broad range of indications. METHODS: All CEE performed over 58 months at three institutions were assessed for AR within 30 min. RESULTS: A total of 5956 CEE were performed in 5576 patients. A total of 4903 were stress CEE and 1053 resting CCE. Bolus administration in 5719, infusion in 237 cases; 89.9% of CCE were outpatients. Commonest CEE indication was functional stress testing (82.3%). There were 16 AR related to CEE (0.27%). All AR were mild, transient and all patients made a full recovery. No cases of serious anaphylaxis or death within 30 min of contrast administration. Comparing those with and without an AR, there were no significant differences in age, gender, BMI, LVEF, patient location, exam type or RVSP. There was a slightly increased likelihood of an AR during infusion versus bolus dosing (p = 0.02). CONCLUSION: CEE is a safe investigation in a broad range of indications and clinical scenarios. AR are very rare, mild and transient.

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.

Non-pharmacological therapy for atrial fibrillation: managing the left atrial appendage.

The prevalence of atrial fibrillation (AF) is increasing in parallel with an ageing population leading to increased morbidity and mortality. The most feared complication of AF is stroke, with the arrhythmia being responsible for up to 20% of all ischemic strokes. An important contributor to this increased risk of stroke is the left atrial appendage (LAA). A combination of the LAA's unique geometry and atrial fibrillation leads to low blood flow velocity and stasis, which are precursors to thrombus formation. It has been hypothesized for over half a century that excision of the LAA would lead to a reduction in the incidence of stroke. It has only been in the last 20-25 years that the knowledge and technology has been available to safely carry out such a procedure. We now have a number of viable techniques, both surgical and percutaneous, which will be covered in this paper.