Coronary vessel geometry can create disturbed blood flow that is associated with adverse haemodynamics and atherosclerotic risk. Patient-specific haemodynamic assessments have led to some insights, however population assessments of adverse shape characteristics are lacking. Twenty patient-specific left main geometries (15 females, 5 males, 55 ± 9 years) were analysed for shape features and compared to haemodynamic simulations. Significant shape variation was present (angle A 129.9° ± 20.7°; inflow angle 15.9° ± 24.3°; angle B 75.3° ± 21.3°; radii 1.74 ± 0.64 mm, 1.42 ± 1.07 mm, 1.59 ± 0.46 mm, and tortuosity 1.09 ± 0.13, 1.02 ± 0.06 and 1.46 ± 0.68 for LM, LAD and LCx, respectively). A principal component analysis (PCA) showed that the bifurcations varied primarily in size, and secondly in curvature and angle. Geometric differences of larger radii and higher LAD tortuosity were found in patients with hypertension, and variations in LM shape were also evident across age groups. Interestingly, we found that an obtuse angle B is only unfavourable in combination with an acute LM inflow angle, which was shown to be a more dominant factor in local haemodynamics. An acute angle B (<60°) was also found adverse. Similarly, both radii and tortuosity appeared to have an optimal range with adverse haemodynamic effects outside that range. This demonstrates the potential of shape feature analysis combined with haemodynamic assessment and highlights the value of vessel shape as a clinical biomarker for adverse haemodynamics and atherosclerotic risk.

Objective: Safety and preliminary effectiveness evaluation of non-invasive ultrasound (US) renal denervation system in patients who were previously treated with catheter-based radiofrequency renal denervation. Design and method: The Surround Sound system delivers therapeutic US non-invasively to create a field of energy around the renal artery. This mode of delivery is very different from other catheter-based systems which deliver (radiofrequency) energy at concentrated ablation spots. Pre-clinical animal data showed no discernible effects on the renal artery in a repeated treatment model even at doses much higher than used in the clinic. The hypothesis underpinning these data was that the Surround Sound treatment could be safely applied to patients with prior denervation and is potentially well suited for repeated treatments. Eleven patients with uncontrolled hypertension who were previously treated with catheter based renal denervation were treated with the Surround System at 4 centres [U.K (5), Czech Republic (3), Poland (1) and New Zealand (2). Treatment criteria were: office systolic blood pressure (SBP) >160 mm, 24 hour ambulatory SBP > 135 mm Hg, and patients were required to be taking three antihypertensive medications. The patients may or may not have responded to prior renal denervation treatment but all met entry BP criteria. Results: There were no mortality or major adverse events, no significant device related AEs including significant back pain, change in renal function, renal artery stenosis, or other events. At 3 months (11 patients), the average office SBP change was −27.4 mm Hg. At one year (8 patients), the average change in office SBP was −33.4 mm Hg. Average ambulatory SBP change at 6 months (8 patients) was −21.5 mm Hg and −17.2 mm Hg at 1 year (5 patients). Conclusions: These clinical data serve as the initial pilot safety data for redo US renal denervation. Larger randomized trials are needed in this patient population to assess efficacy as well as a treatment regimen in a treatment naïve patient cohort in which planned denervation with the Surround Sound system is studied.

This chapter discusses coronary artery flow assessment for atherosclerosis investigations. The overall goal is to foster the reader's understanding of coronary flow assessment with CFD and experimental MRI, including advantages, shortcomings, and potential for clinical applicability. In Section 1, we begin by introducing coronary artery disease and how it links to local blood flow and hemodynamic parameters, before introducing strategies to investigating coronary flow for risk assessment—computational modeling and experimental studies. Both of these need the artery geometry and embedded stents to be retrieved first, as detailed in Section 2. Section 3 details the concepts of computational coronary flow modeling with computational fluid dynamics (CFD) including the governing equations, mesh discretization, and boundary and initial conditions. Section 4 introduces experimental approaches using in vitro flow sensitive magnetic resonance imaging (MRI), including dynamic scaling for steady or transient state considerations, creation of phantom, consideration of vessel compliance and motion, non-Newtonian blood properties, and the design of an experimental circuit. Postprocessing, analysis, and comparison of both methods are explained in Section 5, before discussion of the accuracy and reliability of the results in Section 6. Finally, current developments, particularly patient-specific profiling, are discussed in Section 7.

Computational fluid dynamics (CFD) comparison between two common stent designs regarding hemodynamic optimisation and minimising adverse flow induced vessel wall stresses.

Background: Transcatheter aortic valve implantation (TAVI) is a treatment option for patients with severe aortic stenosis (AS) at increased risk for surgical aortic valve replacement (SAVR). Timely and appropriate multidisciplinary triage of patients with AS to either SAVR, TAVI, or medical treatment is important. This study audited the workflow for the Auckland region. Methods: The study population was those with severe AS ± coronary artery disease (CAD) presented at the weekly regional Cardiosurgical Conference (CSC) in 2014. Some patients were subsequently discussed at a high risk SAVR/ TAVI multidisciplinary group meeting. Results: 178/666 (26%) patients discussed at CSC had severe AS ± CAD. Of these 121(68%) were accepted for SAVR, 23 (12%) were recommended for continued medical management, and 36 (20%) referred to the high risk SAVR/TAVI conference, at which 31 were accepted for TAVI, 4 for SAVR, and 1 declined. The waiting time in days (range) was:Tabled 1CSC to SAVRCSC to SAVR/TAVI conferenceSAVR/TAVI conference to interventionTotal CSC to intervention post SAVR/TAVI conference50 (1-346)27 (13-161)64 (13-161)91 (20-216) Open table in a new tab Those having TAVI waited significantly longer than those having SAVR (p<0.0001). 2 patients died waiting for intervention (1 for TAVI and 1 for SAVR). Conclusion: Patients with severe AS are a major contributor to the CSC workload. Of those discussed, 70% have SAVR, and only 17% are listed for TAVI. The current two-stage decision process adds a significant delay in patients with severe AS, who are at high risk of dying without intervention, receiving TAVI.

A Statistical Model of the Main Bifurcation of the Left Coronary Artery using Coherent Point Drift

One hundred forty-six hypertensive patients were treated with bipolar radiofrequency balloon-based renal denervation. Significant office blood pressure (BP) reductions were sustained through 2 years of follow-up, with few patients experiencing related serious adverse events. Although confirmatory randomised controlled trials with designs to minimise confounding factors are needed, long-term follow-up after renal denervation continues to support procedure safety and suggests that it may have a lowering effect on BP.

Background: Many patients with severe aortic stenosis (AS) are high-risk for SAVR due to comorbidity, frailty and anatomical limitations. TAVI is an attractive alternative solution; however, there are perceptions that it is high-cost. Policy-makers fear that expansion of TAVI will impact detrimentally upon the public healthcare budget, but savings from reduced resource utilisation may offset the high trans-catheter valve cost. Methods: We compare index-admission cost and clinical data for 201 patients who received TAVI across NZ in the public system with 99 intermediate-high risk SAVR patients (using EuroSCORE-II>4) from Auckland and Waikato. Variables include age, gender, weight, EuroSCORE-II, renal function, left-ventricular function, previous sternotomy, total cost, cost-breakdown and length of stay (LOS). Initial Results: EuroSCORE-II independently correlates with cost. Mean EuroSCORE-II was 10.2±7.7 (TAVI) compared with 7.2±3.3 (SAVR) (p=0.055). Mean cost of TAVI was $48,536±$14,173 vs. $68,970±$37,902 for SAVR (p=0.0001). The main cost-driver for TAVI is the valve (58% cost). Average LOS for TAVI was half that of SAVR patients. Mean ICU cost was $4,762±4,724 (TAVI) compared to $15,471±$19,516 (SAVR). TAVI cost varies between centres ($53,332-Auckland, $46,985-Waikato, $48,688-Christchurch) despite similar pre-procedural clinical risk (p=0.0005). Between centres the mean SAVR cost (Auckland=$69,560 vs Waikato=$67,394) is not statistically different (p=0.59) with comparable clinical risk (Auckland EuroSCORE-II=7.3±3.4 vs Waikato EuroSCORE-II=6.8±3.0). Conclusion: TAVI appears cost-saving using index-admission cost in intermediate-high risk patients requiring aortic valve replacement in NZ, due to reduced use of hospital resource and LOS. These data have implications for future fund allocations for treating severe AS in this country.

Background: Lipoprotein (a) (Lp(a)) level is genetically determined. The relationship between Lp(a), family history (FHx) and coronary calcium score (CACS) has not been fully defined. Methods: 2234 consecutive patients without known CHD had Lp(a) levels measured and Framingham risk score (FRS) calculated as part of a prospective audit of CACS. A CACS of > 100 units and Lp(a) > 300 mg/L were chosen a priori as representing significant atheroma burden and elevated Lp(a). SAS (v9.3) was used to calculate odds ratios (OR), and AUC for ROC curves. Results: Median age was 56 yrs (SD 8.9), 59% were male. A positive Fhx of CHD was not predictive of a CACS > 100 units, however those with Lp(a) > 300mg/l had a significantly increased likelihood of elevated CACS in the high (>20%) and intermediate (10-20%) risk band. In those at highest 5year CHD risk Lp(a) > 300 mg/l was synergistic to family history of CHD (table)Tabled 1FRSOdds of CACS > 100AUC ROC Curve (95% CI)nPositive FHxLp(a) > 300 mg/LPositive FHx v Distant or noneLp(a) >300 v < 300 mg/LFHxLp(a)FHx + Lp(a)0-10%1148410 (36%)376 (33%)0.8 (0.6, 1.1)1.2 (0.9, 1.6)0.52 (0.49, 0.55)0.52 (0.49, 0.56)0.53 (0.49, 0.57)10-20%892383 (43%)316 (35%)0.8 (0.6, 1.1)1.4 (1.1, 1.9)*0.52 (0.49, 0.55)0.54 (0.51, 0.57)*0.55 (0.52, 0.59)*20%+19475 (39%)78 (40%)1.5 (0.9, 2.8)2.0 (1.1, 3.6)*0.55 (0.54, 0.57)*0.58 (0.57, 0.60)*0.60 (0.59, 0.67)*^*P < 0.05. ^ Significant improvement in AUC over FHx alone Open table in a new tab *P < 0.05. ^ Significant improvement in AUC over FHx alone Conclusions: In patients at intermediate or high CVD risk, stratification by Lp(a) > 300 mg/L provided additional independent discrimination in predicting an elevated CACS, whereas a family history of CHD did not. Lp(a) measurement should be considered in addition to standard risk factor screening and family history to predict coronary atherosclerotic burden.

The Vessix Renal Denervation System (Boston Scientific, Natick, MA) consists of a radiofrequency generator and a balloon catheter mounted with a bipolar radiofrequency electrode array. The objective of the REDUCE-HTN Clinical Study is to evaluate the performance of the Vessix System in treating

Long-term clinical follow-up of new drug-eluting stents is essential to ensure continued safety in patients treated with these DES in clinical practice. Two clinical trials of the MiStent SES are currently in long-term follow-up; the DESSOLVE I clinical trial, a first-in-human study of 30 patients

Background and aims: Bioresorbable vascular scaffolds represent an exciting advance in percutaneous coronary intervention (PCI), providing an initial coronary scaffold which are eventually resorbed by the body. The DESolve Nx BCSS is a novel drug eluting bioresorbable vascular scaffold that combines a PLLA-based scaffold coated with a biodegradable polylactide-based polymer and the drug Novolimus, a macrocyclic lactone mTOR inhibitor which has demonstrated potent anti-proliferative properties in previous clinical trials using Elixir's metallic Novolimus-eluting coronary stents. The drug dose is 5 mcg per mm of scaffold length and is available in three diameters (3.0, 3.25 and 3.5) and two lengths (14 and 18 mm). The DESolve NX study is a prospective, multicenter evaluation of the safety and efficacy of the DESolve™ Nx Novolimus-Eluting Bioresorbable Coronary Scaffold (BCSS) in patients with single de novo native coronary artery lesions through clinical endpoints and multiple imaging modalities.Methods and results: 126 patients with single, de novo coronary artery lesions were enrolled in this prospective, multi-center, single-arm study. Those patients receiving the study device are being analysed for multiple clinical endpoints including: Device and Procedure Success; Major Adverse Cardiac Events (MACE), a composite endpoint of cardiac death, target vessel MI, or clinically-indicated target lesion revascularization (CI-TLR); Clinically-indicated Target Lesion and Target Vessel Revascularization, (CI-TVR) and Stent Thrombosis assessed at 1, 6 and 12 months and annually to 5 years. All patients underwent angiographic assessment at 6 months and a subset of patients underwent IVUS and OCT assessment at 6 months. Additional imaging analyses will be conducted in the subset of patients at 12 months using MSCT and at 24 months using Angiography, IVUS and OCT to assess the long-term scaffold, lesion and vessel characteristics. Device Success and Procedure Success were 95.2% and 100% respectively demonstrating the feasibility and initial safety of this novel device.Conclusion: The DESolve™ Nx Novolimus-Eluting BCSS demonstrated initial safety and efficacy in this study. A first report of the principal clinical and imaging outcomes through 6 months will be presented.

Background: CVS risk assessment is a blunt tool better suited to populations than individuals. Calcium scores of >100 Agatston units are strongly predictive of a CVS event, however CVS risk assessment does not routinely include calcium scoring. We examined the calcium scores of patients stratified by bands of CVS risk from the New Zealand guidelines group adjusted Framingham risk score. Methods: Using a prospectively acquired, comprehensive database we audited 3600 pts consecutive pts to undergo a 64-slice computed tomographic (CT) cardiac angiogram with a calcium score or a calcium score alone (GE Light Speed, Mercy Hospital, Auckland). Pts with previous MI (n = 123) were excluded. Results: The mean pt age was 57 (SD 9) years; 44% pts were female, 88% pts were Caucasian, with current or previous smokers (43%), history of hypertension (36%), hyperlipidaemia (54%), diabetes mellitus (6%) pts. Most (51%) pts were at low (<10%) five year risk yet 373 (22%) of these had importantly elevated calcium scores. Intriguingly, 184 (26%) of pts at >15% risk of a CVS event in five years had a calcium score of zero. Conclusion: 22% of low CVS risk pts, as assessed by the traditional Framingham equation, have a markedly increased calcium score and hence a significantly increased risk of a CVS event. Clinicians managing individual pts, rather than populations, may consider a calcium score as a valuable, focussed, additional tool to the standard risk assessment.

Background: Primary percutaneous coronary intervention (PPCI) is the optimal strategy for patients (pts) presenting with a ST elevation myocardial infarction (STEMI). Guidelines indicate that the door-to-reperfusion time (DTRT) of ≤90 min is the target time and ≤60 min is the optimal time. PPCI became the preferred STEMI pt management at Auckland City Hospital (ACH) in 2006. We compare our 2006–2007 and 2012 experiences. Method: Data on all STEMI pts admitted to ACH between 1/6/2006 to 31/7/2007 and 1/1/2012 to 31/12/2012 was obtained from prospective databases, which included the DTRT. The 2006–2007 CCU database recorded 97 (49%) PPCI pts and 99 (51%) medically managed pts; the 2012 catheter laboratory database only recorded PPCI pts. Only pts from the ACH catchment area (468,000 ADHB Annual Plan 2012/13) were selected for this analysis. Results:Tabled 12006–20072012Duration of audit13 months12 monthsNumber ACH PPCI97149Number "Clear-cut" PPCI52 (54%)125 (84%)DTRT median(IQR)92 (74–104)79 (62–94)DTRT ≤ 90 min25 (48%)87 (70%)DTRT ≤ 60 min8 (15%)25 (20%) Open table in a new tab Conclusions: In 2012, STEMI pts receiving PPCI, had a significantly improved DTRT of ≤90 min (48% vs 70%; P = 0.0099) compared to PPCI STEMI pts in 2006–7. Ongoing improvements in the DTRT will further improve pt care, and the optimal goal of a DTRT of ≤60 min may be more often achieved.

Background: Primary percutaneous coronary intervention (PPCI) is the optimal management for ST segment elevation myocardial infarction (STEMI) patients (pts). We reviewed the largest PPCI regional service in New Zealand: the Auckland/Northland service based (out of hours) at Auckland City Hospital (ACH).

Aims: To evaluate the long term safety and efficacy of the Elixir DESyneTM Novolimus-Eluting Coronary Stent System (CSS) compared to the Endeavor Zotarolimus-Eluting CSS through assessment of clinical, angiographic, and IVUS endpoints through 3 years. Method and results: 210 patients were randomized 2:1 either to the DESyne CSS loaded with 5mcg per mm of stent length of Novolimus, a sirolimus metabolite, eluted via a durable methacrylate polymer, or to the Endeavor CSS loaded with 10mcg per mm of stent length of Zotarolimus eluted via a durable phosphoryl choline polymer. All patients were analyzed for the primary endpoint of late lumen loss (LLL) assessed by QCA at 9 months. All patients also underwent evaluation for secondary endpoints which included a Device-orientated Composite Endpoint (DoCE) defined as: cardiac death, MI not clearly attributable to a non-intervention vessel, and clinically-indicated target lesion revascularization (TLR); clinically-indicated Target Vessel Revascularization (TVR); and stent thrombosis all evaluated at 1, 6, 9, and 12 months and annually through 5 years. Table 1: 9-month Angiographic, IVUS and Conclusion: The study met the non-inferiority endpoint and also demonstrated superiority of the DESyne CSS as compared to control (Endeavor). Long term clinical results through 3 years and a review of angiographic and IVUS results will be presented.

Purpose: Fully bioresorbable scaffolds (BS) provide temporary vascular scaffold- ing with drug delivery capability to prevent vessel recoil and minimize restenosis. By recovering several aspects related to vascular biology and physiology, BS has the potential to reduce late stent thrombosis and need for dual anti-platelet ther-apy. The DESolve is a PLLA-based myolimus-eluting BS that is programmed to be fully absorbed within 1-2 years. We aim to present the optical coherence tomography (OCT) results of the first-in-human evaluation of this novel BS. Methods: The DESolve FIM trial enrolled 15 pts, treated with a single 3.0x14mm DESolve at 3 centers. Serial (baseline and 6-month follow-up) OCT was avail- able for 10 pts. All images were analyzed by an independent core laboratory. At baseline, scaffold expansion and apposition were assessed. Scaffold structural discontinuity was qualitatively defined as the presence of ≥ 2 struts overhanging each other in the same angular sector of the lumen, or by isolated struts floating inside the lumen in complete misalignment with the surrounding struts. At follow-up, serial changes in lumen and scaffold dimensions were assessed as well as the degree of neointimal hyperplasia (NIH)formation. Frequency ofcovered struts and NIH thickness on top of each strut were also examined. Scaffold and strut malapposition were serially assessed at the cross-section level and strut-level respectively. Results: At baseline, an overall positive scaffold expansion (12.7%) was ob- tained. Malapposition was seen in 8 (80%) scaffolds, but it was in average very small (0.03 ± 0.04 stents Objective: The aim of this study was to evaluate mid-term angiographic and clin- ical outcomes about each stents of sirolimus (SES),paclitaxel (PES),zotarolimus (ZES), biolimus (BES), and everolimus (EES) eluting stent. Methods: We analyzed consecutive 2688 patients underwent angioplasty with any DES implanted from October 2008 to December 2012 in our hospital. Angio- graphical follow-up was performed in 704 patients (937 lesions) with SES (n =67), PES (n=210), ZES (n=199), BES (n=68), EES (n=393). Results: Restenosis rate was lower in BES and EES group compared with first generation DES (4.4%, 4.8% vs 9.0%, P=0.21, < 0.05). However, there was no significant difference between ZES group and first generation DES (9.5% vs 9.0%, P=0.85).

Background: In the DES era, stent mechanical and physical properties continue to influence clinical outcomes, and independent benchtop data may aid optimal stent selection. This study compares recoil after deployment and post-dilatation in 12 contemporary DES platforms.