Non-contact quantification of aortic stenosis and mitral regurgitation using carotid waveforms from skin displacements.

Objective. Early diagnosis of heart problems is essential for improving patient prognosis.Approach. We created a non-contact imaging system that calculates the vessel-induced deformation of the skin to estimate the carotid artery pressure displacement waveforms. We present a clinical study of the system in patients (n= 27) with no underlying condition, aortic stenosis (AS), or mitral regurgitation (MR).Main results. Displacement waveforms were compared to aortic catheter pressures in the same patients. The morphologies of the pressure and displacement waveforms were found to be similar, and pulse wave analysis metrics, such as our modified reflection indices (RI) and waveform duration proportions, showed no significant differences. Compared with the control group, AS patients displayed a greater proportion of time to peak (p= 0.026 andp= 0.047 for catheter and displacement, respectively), whereas augmentation index (AIx)was greater for the displacement waveform only (p= 0.030). The modified RI for MR (p= 0.047 andp= 0.004 for catheter and displacement, respectively) was lower than in the controls. AS and MR were also significantly different for the proportion of time to peak (p= 0.018 for the catheter measurements), RI (p= 0.045 andp= 0.002 for the catheter and displacement, respectively), and AIx (p= 0.005 for the displacement waveform).Significance. These findings demonstrate the ability of our system to provide insights into cardiac conditions and support further development as a diagnostic/telehealth-based screening tool.

Characteristics and Outcomes of Patients With Severe Aortic Stenosis Discussed by the Multidisciplinary "Heart Team" According to Treatment Allocation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an alternative and effective contemporary intervention to surgical aortic valve replacement (SAVR) for patients with severe aortic valve disease at increased surgical risk. Guidelines recommend a multidisciplinary "Heart Team" (MHT) review of patients considered for a TAVI procedure, but this has been little studied. We reviewed the characteristics, treatments and outcomes of such patients reviewed by the MHT at our centre. METHODS: Data on consecutive patients with severe aortic valve stenosis discussed by the Auckland City Hospital MHT from June 2011 to August 2016 were obtained from clinical records. Patient characteristics, treatment and outcomes were analysed using standard statistical methods. RESULTS: Over the 5-year period 243 patients (mean age 80.2 ± 8.0 years, 60% male) were presented at the MHT meeting. TAVI was recommended for 200, SAVR for 26 and medical therapy for 17 patients, with no significant difference in mean age (80.2 ± 8.3, 80.4 ± 6.1, 80.4 ± 7.3 years, respectively) or EuroSCORE II (6.5 ± 4.7%, 5.3 ± 3.6%, 6.7 ± 4.3%, respectively). Over time, there was an increase in the number of patients discussed and treated, with no change in their mean age, but the mean EuroSCORE II significantly decreased (TAVI p = 0.026, SAVR p = 0.004). Survival after TAVI and SAVR was similar to that of the age-matched general population, but superior to medical therapy p = 0.002 (93% (n = 162), 84% (n = 21) and 73% (n = 18) at one year and 85% (n = 149), 84% (n = 21) and 54% (n = 13) at 2 years, respectively). CONCLUSIONS: An increasing number of patients were discussed at the MHT meeting with the majority undergoing TAVI, with a similar age and EuroSCORE II to those allocated SAVR or medical therapy. Survival following TAVI and SAVR was superior to medical therapy and similar to the age-matched general population. These findings suggest that the MHT process is robust, consistent and appropriately allocating a limited treatment resource.

Postdischarge outcome after Takotsubo syndrome compared with patients post-ACS and those without prior CVD: ANZACS-QI 19.

Objective: Takotsubo syndrome (TS) mimics acute coronary syndrome (ACS) but has a distinct pathophysiology. While in-hospital adverse outcomes appear similar to those presenting with an ACS, data on longer term postdischarge risk are conflicting. This study sought to assess the long-term prognosis of patients discharged alive after TS. Methods: The clinical profile and in-hospital and long-term outcomes were prospectively assessed in consecutive patients with TS. Survival in patients with TS was compared with two representative age-matched and gender-matched comparison cohorts: a hospitalised ACS cohort and a community cohort without known cardiovascular disease (CVD). Results: Two hundred and-twenty-five patients with TS (216 women, mean age 63.7±11.8 years) were included. In-hospital mortality was 1.8% and 1.9% for patients with TS and ACS, respectively. Of the 219 patients with TS with postdischarge follow-up, at a mean follow-up of 4.8±3.2 years, there were 19 (8.3%) deaths, 18 of which were from non-cardiac causes. When compared with the cohort without prior CVD, postdischarge patients with TS were at increased mortality risk (HR 2.00, 95% CI 1.26 to 3.17, p=0.003), but mortality in postdischarge patients with ACS was over threefold higher (HR 3.43, 95% CI 2.97 to 3.96, p<0.0001). Conclusions: In-hospital mortality for patients diagnosed with TS and ACS was similar. However, while postdischarge survivors of TS had a long-term survival which was poorer than for a community-based cohort without known CVD, their survival was better than for postdischarge survivors of an ACS event. Late deaths in patients with TS were almost all from non-cardiac causes.

Long and short of optimal stent design.

The ideal stent must fulfil a broad range of technical requirements. Stents must be securely crimped onto the delivery balloon and, in this form, must have a low profile and be sufficiently flexible to facilitate deliverability to the lesion site without distortion or displacement. Following expansion, stents must exert sufficient radial force on the vessel wall to overcome lesion resistance and elastic recoil. To achieve an optimal lumen diameter, the lesion must be uniformly and adequately scaffolded, with minimal tissue prolapse between struts but without compromising side-branch access. Furthermore, the deployed stent must conform to the vessel curvature to minimise vessel distortion, particularly at the stent edges. Radio-opacity is also important to guide safe positioning, adequate deployment and postdilataion and to permit assessment of optimal stent expansion. Equally though, the stent lumen must also be sufficiently visible to allow radiographic assessment of flow dynamics and restenosis. Efforts to optimise one characteristic of stent design may have detrimental effects on another. Thus, currently available stents all reflect a compromise between competing desirable features and have subtle differences in their performance characteristics. Striving to achieve stents with optimal deliverability, conformability and radial strength led to a reduction in longitudinal strength. The importance of this parameter was highlighted by complications occurring in the real-world setting where percutaneous coronary intervention is often undertaken in challenging anatomy. This review focuses on aspects of stent design relevant to longitudinal strength.

Impact of the Everolimus-eluting Bioresorbable Scaffold in Coronary Atherosclerosis.

INTRODUCTION AND OBJECTIVES: The Absorb bioresorbable vascular scaffold has been shown to decrease total plaque areas in the treated segment. However, it is unknown whether plaque size is modified in scaffolded segments only or whether the modification extends to other coronary segments. METHODS: Absorb Cohort A is a single-arm, prospective study, with safety and imaging endpoints, in which 30 patients underwent percutaneous coronary intervention with the first generation Absorb bioresorbable vascular scaffold. Noninvasive multislice computed tomography imaging was performed in 18 patients at 18 months and 5 years of follow-up. The present study was an intrapatient comparison of matched segments (normalized by the segment length) of the scaffolded region with nonintervened segments for lumen volume, vessel volume, plaque volume, plaque burden, and percent change in plaque atheroma volume. RESULTS: All 18 scaffolded segments could be analyzed. In the nonintervened segments, 1 of 72 segments had a motion artifact and was excluded. Serial comparison showed that the scaffolded segments showed no significant change in the mean plaque burden, total atheroma volume, total lumen volume, or vessel volume between 18 months and 5 years. Conversely, the untreated segments showed a significant increase in plaque burden (2.7 ± 6.5%; P < .01) and normalized plaque volumes (8.0 ± 22.8mm(3); P < .01). This resulted in a significant difference in plaque burden between scaffolded and nonintervened segments (P = .03). CONCLUSIONS: In this small series, the Absorb bioresorbable vascular scaffold showed the potential to provide an additional benefit to pharmacological therapy in locally reducing progression of percent plaque burden. These findings need to be confirmed in larger studies.

An independent bench comparison of two bioresorbable drug-eluting coronary scaffolds (Absorb and DESolve) with a durable metallic drug-eluting stent (ML8/Xpedition).

AIMS: We compared the mechanical and physical properties and the safety from strut fracture of side branch and post-dilatation strategies for the Absorb and DESolve bioresorbable scaffolds with the durable metallic drug-eluting XIENCE Xpedition stent using largely independent bench testing. METHODS AND RESULTS: The strut thickness and crossing profile of the polymeric scaffolds was greater than those of the metallic drug-eluting stent. While all three devices recoiled after deployment, the DESolve enlarged between 10 mins and one hour returning to the immediate post-deployment diameter ("self-correction"). In 3.0 mm stents/scaffolds, the main branch post-dilatation safe threshold without fracture for Absorb was 3.8 mm at 20 atm, for DESolve was 5.0 mm at 20 atm whereas the ML8 did not fracture. For side branch dilatation with a 3.0 mm non-compliant balloon, the threshold before the Absorb fractured was 10 atm whereas the DESolve and ML8 did not fracture at 22 atm. The safe threshold for mini-kissing balloon post-dilatation in 3.0 mm scaffolds/stents with 3.0 mm non-compliant balloons was 5 atm for the Absorb whereas the DESolve and ML8 did not fracture up to 20 atm. CONCLUSIONS: The metallic stent has thinner struts, lower profile, and greater radial strength than the polymeric scaffolds. Different safe pressure thresholds exist for different scaffolds/stents. Unlike the others, the DESolve showed "self-correction" or enlargement after initial recoil.

Coronary stent durability and fracture: an independent bench comparison of six contemporary designs using a repetitive bend test.

AIMS: Stent fracture is important because it may cause adverse events. The interventional cardiologist needs independent data to aid stent selection. Stent designers need data to improve stent design. We used a repetitive bend test to compare durability and fracture for different stent designs. METHODS AND RESULTS: Tested were 15 examples of six designs (BioMatrix Flex, Vision, MULTI-LINK 8, Element, Promus PREMIER and Integrity). One end of a nominally deployed stent was mounted on a fixed mandrel. The other end was translated a distance of ±3.5 mm at a rate of 6 Hz until fracture or 10 million cycles completed. The numbers of cycles to fracture for the Vision design (288,411±193,391) and the MULTI-LINK 8 (314,475±239,869) were significantly greater than for the BioMatrix Flex design (38,904±13,160), p<0.001. The difference between Vision and MULTI-LINK 8 was not significant (p=0.79). The Element, PREMIER, and Integrity designs did not fracture. Most fractures were in the curved portions of connectors between hoops. CONCLUSIONS: The stent design which fractured most readily was the BioMatrix Flex. The most flexible designs did not fracture and, in general, stents with three connectors were more likely to fracture than those with two connectors between loops.

Absorb everolimus-eluting bioresorbable scaffolds in coronary bifurcations: a bench study of deployment, side branch dilatation and post-dilatation strategies.

AIMS: To provide bench insights which may predict safety and efficacy of side branch dilatation (SB) and kissing balloon post-dilatation (KBPD) in Absorb everolimus-eluting bioresorbable scaffolds deployed in bifurcations. METHODS AND RESULTS: Stages of deployment and post-dilatation of scaffolds (3.0 and 3.5 mm diameter) in bifurcation phantoms were imaged by fluoroscopy, light microscopy and micro-computed tomography. Dilatation through the scaffold side displaced struts from the side branch (SB) lumen, but caused main branch (MB) malapposition opposite the SB, MB scaffold narrowing beyond the SB, and protrusion of struts into the SB. Scaffold distortion was corrected by MB post-dilatation or by mini-kissing balloon post-dilatation (mini-KBPD). When 3.0 mm diameter balloons were used for SB dilatation or mini-KBPD in 3.0 mm Absorbs, strut fracture did not occur at or below inflation pressures of 10 and 5 atm, respectively. Above these thresholds, the likelihood of strut fracture increased with increasing pressure. Fractures were usually single without malapposition, but mini-KBPD or post-dilatation with high inflation pressures sometimes caused multiple strut fractures and lumen compromise. CONCLUSIONS: SB dilatation of an Absorb caused MB distortion which was corrected by MB post-dilation or low-pressure mini-KBPD without scaffold damage below pressure thresholds. These benchtop insights may help guide the clinical deployment of Absorb scaffolds in bifurcations and might enhance clinical outcomes but need clinical confirmation.

High-sensitivity troponin level pre-catheterization predicts adverse cardiovascular outcomes after primary angioplasty for ST-elevation myocardial infarction.

BACKGROUND: Cardiac troponins are the preferred biomarkers for diagnosing myocardial infarction (MI). High-sensitivity troponin T (hs-TnT) assays have increased sensitivity and enable more rapid diagnosis of infarction. We assessed the prognostic utility of admission hs-TnT to detect outcomes after primary angioplasty for ST-elevation/new left bundle branch block myocardial infarction (STEMI). METHODS: Patients admitted to Auckland City Hospital for acute coronary catheterization with a diagnosis of STEMI between October 2010 and September 2011 were identified, and included if hs-TnT levels were measured at admission. Clinical characteristics and major adverse cardiovascular events (MACE: death, myocardial infarction and revascularization) at 30 days and 1 year were collected from national statistics and electronic medical records. RESULTS: Median admission hs-TnT level in the 173 STEMI patients studied was 59 ng/L (interquartile range (IQR) 19-310). Incidences of MACE at 30 days and 1 year were 10% (n=17) and 18% (n=31), respectively. C-statistics and 95% confidence interval (CI) (95% CI) for hs-TnT on admission at detecting MACE at 30 days and 1 year were 0.800 (0.696-0.904) and 0.750 (0.655-0.845) respectively, with the optimal cut-point of 225 ng/L giving sensitivities/specificities of 76.5%/75.6% and 64.5%/78.2% respectively. Admission log(hs-TnT) independently predicted both MACE at 30 days with hazards ratio 5.16, 95% CI (2.25-11.9) and 1 year with hazards ratio 2.88, 95% CI (1.79-4.63), as did age and cardiogenic shock. Age, Maori or Pacific ethnicity and chronic respiratory disease were independent predictors of hs-TnT>225 ng/L. CONCLUSION: Admission hs-TnT measured in primary angioplasty is strongly prognostic of MACE at 30 days and 1 year, even following adjustment for potential confounding variables.

Stent longitudinal strength assessed using point compression: insights from a second-generation, clinically related bench test.

BACKGROUND: Stent longitudinal distortion, while infrequent, can lead to adverse clinical events. Our first bench comparison of susceptibility of different stent designs to distortion applied force to the entire circumference of the proximal stent hoop. The test increased understanding of stent design and led to recommendations for design change in some. Our second-generation test more closely mimics clinical scenarios by applying force to a point on the proximal hoop of a malapposed stent. METHODS AND RESULTS: Each 3-mm-diameter stent was secured in a test apparatus so that its proximal 5 mm was malapposed in a 3.5-mm tube. An instron applied force to the proximal hoop of each of 5 examples of each of 6 stent designs using a narrow rod so that force applied and distance compressed could be measured. Hoops on the side of the force were pushed together, became malapposed, and obstructed the lumen. In addition, the proximal stent hoop tilted causing malapposition, the contralateral side of the stent from the applied force causing lumen obstruction. CONCLUSIONS: This second-generation, more clinically relevant test showed the Biomatrix Flex was the most resistant to deformation and the Element the most easily deformed. The addition of more connectors between the proximal hoops in the Promus Premier design has reduced the potential for distortion when compared with the Element, so that distortion was similar to the Vision, Multi-Link 8, and Integrity designs. The test also provided insight into the way in which stents are likely to distort in clinical practice.

How to do it?: percutaneous treatment of a severely stenosed and calcified left main stem bifurcation.

CASE SUMMARY: A frail 87 year-old lady presented with rest angina associated with widespread ECG change and troponin release. She failed attempts at medical therapy and therefore was referred for coronary intervention on the basis that she was not a surgical candidate. INVESTIGATION: Coronary angiography demonstrated heavily calcified coronary arteries with critical disease at the distal left main stem bifurcation extending into the proximal segments of both LAD and circumflex. DIAGNOSIS: Acute coronary syndrome with extensive calcific coronary artery disease in the left main stem bifurcation. MANAGEMENT: Sequential rotational atherectomy of the left main stem bifurcation followed by 'Y'-stenting using three Xience Prime drug eluting stents.

Renal denervation for resistant hypertension using an irrigated radiofrequency balloon: 12-month results from the Renal Hypertension Ablation System (RHAS) trial.

AIMS: Renal denervation using the point-by-point application of radiofrequency energy delivered by the first-generation Symplicity system is effective in lowering office blood pressure but may be time-consuming. The OneShot Renal Denervation System with a balloon-mounted spiral electrode potentially shortens and simplifies the procedure. This study is a hypothesis-generating first-in-human study to assess feasibility, and to provide preliminary efficacy and safety data. METHODS AND RESULTS: Eligible patients had a baseline office systolic blood pressure ≥160 mmHg (or ≥150 mmHg for diabetics) and were on two or more antihypertensive medications. Nine patients were enrolled. The primary endpoint, the insertion of the OneShot balloon into each renal artery and the delivery of radiofrequency energy, was achieved in 8/9 (89%) of patients. The one failure (the first patient) was due to generator high-impedance safety shut-off threshold set too low for humans. Adverse events were minor. No patient developed renal artery stenosis. Baseline BP was 185.67 ± 18.7 mmHg and the reductions at 1, 3, 6 and 12 months were 30.1 ± 13.6 (p=0.0004), 34.2 ± 20.2 (p=0.002), 33.6 ± 32.2 (p=0.021) and 30.6 ± 22.0 (p=0.019). CONCLUSIONS: The OneShot renal denervation system successfully delivered radiofrequency energy to the renal arteries in a short and straightforward procedure. Australian New Zealand Clinical Trials Registry - URL: anzctr.org.au. Trial identification: ACTRN12611000987965.