Anomalous enhancement of thermoelectric power factor in multiple two-dimensional electron gas system

Toward drastic enhancement of thermoelectric power factor, quantum confinement effect proposed by Hicks and Dresselhaus has intrigued a lot of researchers. There has been much effort to increase power factor using step-like density-of-states in two-dimensional electron gas (2DEG) system. Here, we pay attention to another effect caused by confining electrons spatially along one-dimensional direction: multiplied 2DEG effect, where multiple discrete subbands contribute to electrical conduction, resulting in high Seebeck coefficient. The power factor of multiple 2DEG in GaAs reaches the ultrahigh value of ~100 μWcm-1 K-2 at 300 K. We evaluate the enhancement rate defined as power factor of 2DEG divided by that of three-dimensional bulk. The experimental enhancement rate relative to the theoretical one of conventional 2DEG reaches anomalously high (~4) in multiple 2DEG compared with those in various conventional 2DEG systems (~1). This proposed methodology for power factor enhancement opens the next era of thermoelectric research.

Quantitative characterization of built-in potential profile across GaAs p-n junctions using Kelvin probe force microscopy with qPlus sensor AFM

The electrostatic potential distribution in materials and devices plays an important role in controlling the behaviors of charge carriers. Kelvin probe force microscopy (KPFM) is a powerful technique for measuring the surface potential at a high spatial resolution. However, the measured surface potential often deviates from the potential deep in the bulk owing to certain factors. Here, we performed KPFM measurements across the p-n junction, in which such factors were eliminated as much as possible by selecting the sample, force sensor, and measurement mode. The measured surface potential distribution agrees well with the line shape of the simulated bulk potential. Our results demonstrate that KPFM is capable of quantitatively characterizing potential distributions whose changes occur on the order of 10 nm.

Low Dark Current Operation in InAs/GaAs(111)A Infrared Photodetectors: Role of Misfit Dislocations at the Interface

We demonstrate an extended short-wave infrared (e-SWIR) photodetector composed of an InAs/GaAs(111)A heterostructure with interface misfit dislocations. The layer structure of the photodetector consists simply of an n-InAs optical absorption layer directly grown with a thin undoped-GaAs spacer layer on n-GaAs by molecular beam epitaxy. The lattice mismatch was abruptly relaxed by forming a misfit dislocation network at the initial stage of the InAs growth. We found high-density threading dislocations (1.5 × 10⁹ cm^-2) in the InAs layer. The current-voltage characteristics of the photodetector at 77 K had a very low dark current density (<1 × 10^-9 A cm^-2) at a positive applied voltage (electrons flow from n-GaAs to n-InAs) of up to ∼+1 V. Simulation of the band structure revealed that the direct connection of GaAs and InAs and the formation of interfacial states by the misfit dislocations play significant positive roles in suppressing dark current. Under illumination with e-SWIR light at 77 K, a clear photocurrent signal was observed with a 2.6 μm cutoff wavelength, which is consistent with the bandgap of InAs. We also demonstrated e-SWIR detection at room temperature with a 3.2 μm cutoff wavelength. The maximum detectivity at 294 K exceeds 2 × 10⁸ cm Hz^0.5 W^-1 for the detection of e-SWIR light at 2 μm.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Non-vitamin K antagonist oral anticoagulants in adult congenital heart disease: a single-center study

Introduction

Adults with congenital heart disease (ACHD) are at an increased risk for thromboembolic events and atrial arrhythmias are common in this population. Non-vitamin K anatagonist oral anticoagulants (NOACs) prescription is increasing, however data on efficacy and safety in ACHD is unclear, particularly in patients (P) with complex CHD. The aim of the study was to review the use of NOACs in various types of ACHD and assess its safety and efficacy.

Methods

Evaluation of consecutive ACHD P started on NOAC therapy from 2014 to 2020. P were followed-up for bleeding or thromboembolic events and mortality. CHA2DS2-VASc and HASBLED scores were calculated and risk factors for bleeding were identified.

Results

93 ACHD P were included, mean age 52±15 years, 58% female, 44% with complex CHD (3.2% with Fontan circulation), with diagnosis of: 22.2% atrial septal defect, 20% tetralogy of Fallot, 11.1% transposition of the great arteries, 10% Ebstein's anomaly, 8.9% ventricular septal defect, 7.8% pulmonary stenosis, 5.6% ductus arteriosus, 4.4% AV septal defect, 3.4% univentricular heart, 3.4% coarctation of aorta, 2.2% supra-aortic stenosis and 1% with Uhl disease.

Most P were anticoagulated with rivaroxaban (43%), followed by edoxaban (24%), apixaban (20%), and dabigatran (13%). The indications for anticoagulation were: atrial arrhythmias (81%), pulmonary embolism (PE) (6.3%), atrial thrombi (4.3%), thromboprophylaxis in Fontan circulation (3.2%), deep vein thrombosis (3.2%) and stroke (2%). 66% of P had a CHA2DS2-VASc score ≥2 and 82% HASBLED score ≤2.

In a mean follow-up of 41±21 months (400.4 patient-years), there were embolic events in 2P (1 splenic infarction and 1 PE) albeit both were in the context of oral anticoagulation interruption. The cardiovascular mortality was 2% and allcause mortality 5%, however with no relation to thrombosis or bleeding events.

6 P (6.5%) suffered a minor and 3 P (3.2%) suffered a major bleeding, a median time of 12 (IQR 15) months after starting NOAC therapy. The annual risk for bleeding was 2.2%/patient/year. P with bleeding events showed no significant difference regarding age (55±16 vs 52±15 years, p=0.587), gender (13% female vs 5.1% male, p=0.295) or CHD type (p=0.582). 8.6% of P required dose reduction, mostly for bleeding (3.2%) or renal impairment (2.2%).

Renal disease was a strong risk factor for major bleeding (HR 14.6 [95% CI 1.23–73.6], p=0.033 and multivariate analysis showed that an increased HASBLED score was an independent predictor of minor (adjusted HR 3.44 [95% CI 1.13–10.52], p=0.030) and major (adjusted HR 5.29 [95% CI 1.14–24.45], p=0.033) bleeding complications.

Conclusion

Anticoagulation with NOACs is a safe and effective option for selected ACHD P, although bleeding complications were not negligible, particularly in P with renal disease. Larger scale research studies are required, especially regarding complex CHD such as P with Fontan circulation.

Funding Acknowledgement

Type of funding sources: None.

Virtual fractional flow reserve derived from coronary angiography – artery and lesion specific correlations

Introduction

Virtual Fractional flow reserve (vFFR) from standard non-hyperaemic invasive coronary angiography (ICA) has emerged as a promising non-invasive test to assess hemodynamic severity of coronary artery disease (CAD).

Purpose

To investigate the difference in vFFR analysis between vessels and specific lesions.

Methods

Retrospective analysis of consecutive patients (pts) who underwent invasive functional assessment (iFA) in a tertiary center between 2019 and 2020. vFFR was calculated using dedicated software (CAAS Workstation 8.4) based on coronary angiograms of the acquired in ≥2 different projections, by operators blinded to iFA results. Diagnostic performance of vFFR was evaluated and correlated with iFA, according to coronary vessel, vessel diameter at stenosis, diameter stenosis and area stenosis at lesion. vFFR was considered positive when &lt;0.80. FFR &lt;0.8 and iFR/RFR &lt;0.90 were classified as positive according to current clinical standards.

Results

106 coronary arteries of 95 pts (78% male, mean age 67.8±9.7 years) underwent vFFR evaluation. ICA indications were chronic coronary syndrome in 63% or acute coronary syndrome (non-culprit lesion) in the remaining pts. VFFR accuracy was good (AUC 0.839 (p&lt;0.001) and Pearson's correlation coefficient 0.533 (p&lt;0.001) when vFFR was measured in the distal vessel segment. The correlation improved when vFFR were assessed at lesion site (r=0.631, p&lt;0.001) or up to 1cm below the stenosis (0.610, p&lt;0.001). Binary concordance of 89% were observed in RCA and LAD (Sensibility -S 68%, Specificity-Sp 96%, False positive -FP 3.8%, False negative - FN 31%, predictive positive value-PPV 87%, predictive negative value- PNV 89%), while in the circumflex coronary artery binary concordance were of 77% (S 50%; Sp 82%; FP 18%; FN 50%; PPV 33% and PNV 90%). Correlation between vFFR and iFA was higher in vessels ≥2mm (r=0.730, p&lt;0.001). and in lesions in the extremes of the severity spectrum (Table 1).

Conclusion

vFFR has a moderate to high linear correlation to iFA, depending on the artery and type of lesion studied. The higher correlation was found when vFFR were measured at lesion site, in non-circumflex artery stenosis, in vessels ≥2mm and in vessels with mild or severe stenosis.

Funding Acknowledgement

Type of funding sources: None.

Quantification of epicardial fat with cardiac CT and association with cardiovascular risk factors and obstructive coronary disease

Introduction

Recent studies advocate epicardial fat (EF) as a biologically active organ that influence coronary atherosclerosis development through endocrine and paracrine pathways. We aim to study the relations between EF, thoracic adipose tissue (TAT), cardiovascular risk factors (CRF) and obstructive coronary disease (OCD).

Methods

Retrospective analysis of patients (pts) referred to 64-multislice cardiac computed tomography (CT) in one center. The authors underwent a standardized protocol for quantification of EAT, TAT (subcutaneous and visceral), abdominal visceral fat, coronary calcium score and angiography.

Results

Total of 178 pts: male 99 (56%), mean age 65.9±12.9 years. Indications for performing CT were coronary disease (76%), valvular heart disease (15%), atrial fibrillation (6%) and congenital heart disease (2%). Regarding CRF, EF was only significant higher in patients with diabetes (115±60 vs 95±47, p=0.018), in male gender (114±60 vs 91±42, p=0.04) and was linear correlated with age (p=0.004). The authors also found that EF volume is significant higher in patients with typical angina (p=0.02) and with coronary atherosclerosis: non-obstructive (p=0.0049) and OCD (p=0.001) – Graphic 1. ROC analysis of EF (AUC 0.659, p=0.0039) and EF/TAT relation (AUC 0.704, p=0.003) allowed to estimate that EF&gt;100 ml and EF/TAT &gt;0.06 had a sensibility to predict OCD of 53% and 58%, respectively, and specificity of 66% and 60%. We did not find a correlation between EF, EF/TAT or TAT and coronary calcium score.

Conclusion

EF is higher in patients with diabetes and coronary atherosclerosis. EF and EF/TAT relation had moderate sensibility and specificity to predict OCD, irrespective of calcium score. EF and EF/TAT are promising atherosclerotic markers that could be routinely use in the near future.

Funding Acknowledgement

Type of funding sources: None.

Trends in mortality of adult congenital heart disease patients in the last 4 decades

Introduction

Medical, surgical, and technological advances over the past decades increased the life expectancy of congenital heart disease (CHD) patients (pts), with &gt;90% reaching adulthood. Nonetheless, mortality for adults with CHD (ACHD) is still higher than for the general population.

Purpose

To analyse trends in mortality and causes of death of ACHD.

Methods

Retrospective analysis of pts followed in an ACHD outpatient clinic, in one tertiary center, who died between 1980 and December 2020. Data relating to the cardiac diagnosis, symptoms, interventions, comorbidities, and causes of death were analysed.

Results

During a median follow-up of 8.9 years (IQR 2.2–17), 251 pts of 3725 (6.7%) died during the study period: 127 males (51%), mean age at death 44.9±18.1 years, 54% with severe CHD. The majority of these death was CHD-related (171 pts – 68.1%) with no statistically significant differences over the years vs non-cardiovascular death (Table 1). However, a paradigm shift was noticed: in the first years the main cardiac cause was sudden-death that was replaced by heart failure in the last decade. Also, the mean age at death increased over the years (33±14.9 years until 2000 vs 52.3±17 years after the year 2010, p&lt;0.001) as the number of implantable devices (4 vs 20, p=0.05).

Conclusion

Causes of death of ACHD patients are in the majority still CHD-related. However, in the last decade, according to the increase in life expectancy, heart failure became the leading cause of death.

Funding Acknowledgement

Type of funding sources: None.

Malignant cardiac tumors: a single-centre 25-year review

Background

Primary cardiac tumors are extremely rare and are usually diagnosed late due to the nonspecific symptoms. Surgery is the main treatment option, and despite chemotherapy, the prognosis remains poor. Cardiac invasion by metastatic tumors, while more common, also entails an unsatisfactory outcome. The aim of this study was to review patients (P) with malignant cardiac tumors that were diagnosed by transthoracic echocardiogram (TTE) or transoesophageal echocardiogram (TOE) in a tertiary center between 1995 and 2020.

Methods

Retrospective analysis of clinical data, echocardiographic assessment of tumor location and morphology, histology results and survival outcomes.

Results

A total of 44 malignant cardiac tumors were diagnosed: 12 primary tumors (A) and 32 metastatic tumors (B). A: Regarding primary cardiac tumors, the most common types were angiosarcomas (6), undifferentiated pleomorphic sarcomas (2), fibrosarcomas (2), myxofibrosarcoma (1) and primary cardiac lymphoma (1). The mean age of P at time of diagnosis was 43±15 years, 50% male. The most frequent presentation was heart failure symptoms (50%) followed by arrhythmias (20%). 1 P presented with pruritus and polyarthralgias. On TTE, the most prevalent tumor location was in the right-heart chambers (70%) – mostly the right atrium (50%), with mean dimensions of 40±18x27±11 mm. 85% of P had preserved biventricular systolic function and there was severe pericardial effusion in 38%. The most frequent metastatic involvement at diagnosis was pulmonary (33%) and hepatic (33%). 50% of P were submitted to tumor resection and 40% to chemotherapy. Regarding angiosarcomas, the most common immunohistochemical markers were vimentin, CD31 and CD34. The authors found a mortality rate of 10P (83%) in P with primary cardiac tumors, with a median time to mortality of 5.5 (IQR 2–10) months (Figure 1), in a median follow-up of 6.2 (IQR 2.5–15) months (minimum of 20 days and maximum of 19 years). In the latter case, the P was submitted to heart transplantation after diagnosis of a fibrosarcoma and is still alive and well.

B: Regarding secondary cardiac invasion, there was a diagnosis of the following primary tumor sites: 12 lung carcinomas, 7 thymomas, 4 lymphomas, 3 hepatocellular carcinomas, 2 bladder carcinomas, 1 parathyroid carcinoma, 1 soft tissue sarcoma, 1 uterine sarcoma and 1 melanoma. The mean age of P was 57±19 years, 57% male. On TTE/TOE the authors found a right-sided chambers predominance (12 P, 38%) vs left-sided chambers in (8 P, 25%), with pericardial metastasis also present in 13 P (41%). Cardiac tamponade occurred in 6P (19%). The mortality rate was 75% (24P), with a median time to mortality of 1.1 (IQR 0.6–3.8) months (minimum of 7 days, maximum of 44 months), in a median follow-up of 2.3 (IQR 0.8–14) months.

Conclusion

Cardiac malignant tumors generally present in a late stage with a dismal prognosis. When possible, heart transplantation can be an option with a favourable outcome.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Kaplan-Meier analysis

What are the predictors of heart failure in patients admitted with acute coronary syndrome? Data from a large national registry

Background

Heart failure (HF) is a serious and frequent complication of acute myocardial infarction with important impact in outcome. Early treatment according to contemporaneous guidelines is essential to avoid that complication. Previous ischemic heart disease and HF are important predictors. Our objective is to identify additional predictors of HF in patients admitted with acute coronary syndrome (ACS).

Methods

Analysis of all consecutive patients prospectively included in a large national registry of ACS. Patients with a previous history of ACS, myocardial revascularization or heart failure were excluded from the analysis. The group that developed HF was compared with the group without HF and multivariate logistic regression analysis was performed to identify independent predictors of HF during hospitalization (Killip class &gt;1).

Results

A total of 19,248 patients were included, and 17.3% developed HF during hospitalization. Patients with HF were older, less often males and smokers, and more often with hypertension and diabetes, as well as other comorbidities (p&lt;0.001). ST elevation myocardial infarction (STEMI), atrial fibrillation, mechanical and electrical complications are also more frequent. Patients that developed HF have higher in-hospital mortality (0.9% vs. 12.1%). Independent predictors of HF are female gender (OR 1.64, 95% CI 1.15–2.33), age (1.42, 1.25–1.62, per 10-year increase) diabetes (1.97, 1.44–2.69), atrial fibrillation (2.65,1.66–4.23), STEMI (2.30, 1.70–3.10), multivessel disease (1.52, 1.13–2.05) and initial admission in a hospital without catheterization laboratory as a protective factor (0.71, 0.52–0.96). In STEMI patients, anterior location is also an independent predictor.

Conclusions

In patients admitted with a first ACS and without previous ischemic heart disease or heart failure, female gender, increasing age, diabetes, atrial fibrillation, STEMI and multivessel disease are the main predictors of worst outcome and these patients should be treated more aggressively to avoid HF development.

Funding Acknowledgement

Type of funding sources: None.

Fetal and maternal outcomes in patients with tetralogy of Fallot

Introduction

Women with tetralogy of Fallot (TOF) have an increased risk of adverse cardiac and neonatal events during pregnancy. The aim was to assess fetal and maternal outcomes in patients (pts) with uncorrected and corrected TOF.

Methods

Retrospective analysis of cardiological and obstetric data in women with TOF followed at our institution. Pregnancy and neonatal outcomes were compared in patients (pts) submitted to corrective surgery vs pts with no previous intervention and in pts with or without cyanosis.

Results

51 women (median age 27 years; median number of previous interventions of 2), 22% with cyanosis, who experienced 126 pregnancies resulting in 73 live births A previous corrective surgery was found in 78% (40 pts), while 4% (2 pts) had previous palliative surgery and 18% (9 pts) no previous procedure. We found that women that were not submitted to previous intervention had a significant higher incidence of preterm birth (56% vs 17.5%, p=0.029), spontaneous abortion (56% vs 10%, p=0.006) and stillbirth (22% vs 0%). No difference was found for obstetric complications between groups. Cyanotic pts also demonstrated higher incidence of low birth weight (LBW) (36% vs 7.5%, p=0.031), preterm birth (54% vs 17.5%, p=0.021), spontaneous abortion (55% vs 10%, p=0.004) and stillbirth (18% vs 0%). There were no cardiac complications during pregnancy nor evident deterioration on cardiac status. Congenital heart disease was reported in 2 infants (3% of live births).

Conclusions

Pregnancy is well tolerated in pts with TOF. In our population, even in uncorrected TOF and in pts with cyanosis, there were no cardiac complications during pregnancy, although those pts had worse fetal outcomes. An explanation for the low incidence of cardiac events may be less severe forms of the disease, allowing survival into adulthood without intervention.

Funding Acknowledgement

Type of funding sources: None.

Myocardial Work and long-term prognosis in patients after ST-segment elevation acute myocardial infarction

Background

Left ventricular (LV) global longitudinal strain has demonstrated incremental prognostic value over LV ejection fraction (LVEF) in patients with ST-segment-elevation acute myocardial infarction. However, LV global longitudinal strain (GLS) does not take into consideration the effect of afterload. Myocardial work (MW) by speckle-tracking echocardiography integrates blood pressure measurements (afterload) with LV GLS and it has been recently demonstrated that Global Work Efficiency (GWE) is associated with long-term all-cause mortality. It remains to be demonstrated if MW indices are associated with hard cardiovascular endpoints. The present study aimed to investigate the prognostic value of global LV MW obtained from pressure-strain loops with echocardiography in patients with ST-segment-elevation myocardial infarction.

Methods

A total of 100 consecutive ST-segment-elevation myocardial infarction patients (mean age, 61±12 years; 75% men) that survived to discharge were retrospectively analysed. LVEF, GLS and all LVMW indices were measured by transthoracic echocardiography before discharge (4.6±2.0 days after admission). All patients had at least a two-year follow-up (mean follow-up of 833±172 days). Outcomes: all-cause mortality, major acute cardiovascular events (a composite of cardiovascular mortality, myocardial infarction, stroke, unplanned cardiovascular admission) and heart failure hospitalization.

Results

In the two-year follow-up, 6 patients died, there were 17 patients with MACE, and 3 patients were hospitalized with heart failure. We confirmed that for all-cause mortality, GWE showed higher discrimination, compared to GLS (Table 1), with a cut-off of 83% (log-rank &lt;0,001). For MACE, the performance of all methods is suboptimal, with an AUC &lt;0.65 for all variables, except for GLS. For heart failure admission, performance is slightly better, but GLS is still the better parameter to predict this event.

Conclusions

LVGWE is a better predictor of all-cause mortality compared to GLS, but MW indices failed to demonstrate a prognostic impact in long-term cardiovascular events. Prospective studies are warranted to confirm this finding.

Funding Acknowledgement

Type of funding sources: None. Table 1

Direct comparison of bioabsorbable and biodurable polymer everolimus-eluting stent in neointimal stent coverage and in-stent thrombus using high-resolution angioscope

Background/Introduction

Although second-generation drug eluting stent (DES) employing biodurable polymer drastically shortened the duration of dual antiplatelet therapy (DAPT), previous reports raised concerns that switching from DAPT to single antiplatelet therapy increased rates of subsequent stent thrombosis with time. Third-generation DES employing bioabsorbable polymer has been introduced so as not to hinder the healing process of the vessel wall, however, at present, both DES with bioabsorbable polymer and those with biodurable polymer are used in parallel. It means there is no conclusive evidence regarding pros and cons of these two types of polymers.

Purpose

This study aims to clarify how bioabsorbable polymer and biodurable polymer act on the human coronary artery by observing neointimal stent coverage (NIC) and in-stent thrombus by comparing the third-generation DES with bioabsorbable-polymer cobalt-platinum everolimus-eluting stent (BP CoPt-EES), and the second-generation DES with biodurable-polymer cobalt-chromium everolimus-eluting stent (DP CoCr-EES).

Methods

This is a multicenter observational study including 11 hospitals. We investigated 70 stents (BP CoPt-EES: 40, DP CoCr-EES: 30) of 60 cases, who underwent stent implantation followed by simultaneous observation by coronary angiography, IVUS and angioscopy within 6 to 12 months. For angioscopy, we used a recently available, high-resolution angioscope with a pixel count of 9,000 which realized both stent coverage analysis and planar thrombus detection precisely. Neointimal stent coverage was graded from G0: non coverage to G3: full coverage, and heterogeneity value of neointima was measured as the difference between maximum and minimum NIC grade.

Results

A strong relationship was observed between NIC grade and in-stent thrombus in all stents (p=0.0011), and between the heterogeneity value and stent thrombus (p=0.012). There was no statistical difference in NIC grade between BP CoPt-EES vs. DP CoCr-EES; grade 0: 0 (0.0%) vs. 2 (6.7%), grade 1: 13 (32.5%) vs. 11 (36.7%), grade 2: 6 (15.0%) vs. 6 (20.0%), grade 3: 21 (52.5%) vs. 11 (36.7%), p=0.17) and neither in the heterogeneity value of neointima (p=0.49). The ratio of stent thrombus did not reach statistical difference; 16 (40.0%) in BP CoPt-EES vs. 17 (56.7%) in DP CoCr-EES (p=0.23).

Conclusion

The existence of stent thrombus was associated with the neointimal stent coverage. There was no significant difference both in neointimal stent coverage and stent thrombus between bioabsorbable polymer cobalt-platinum EES and biodurable polymer cobalt-chromium EES after 6 to 12 months following stent deployment.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific JapanOvalis ltd

Feasibility of virtual fractional flow reserve derived from coronary angiography and its correlation with invasive functional assessment

Introduction

Invasive functional assessment (iFA) of coronary artery disease (CAD) needs expensive devices, has potential procedure-related complications and is still underutilized. Virtual Fractional Flow Reserve (vFFR) derived from invasive coronary angiography (ICA) has the potential to overcome these limitations.

Purpose

To investigate the feasibility of vFFR analysis and its correlation with iFA (iFR, RFR or FFR).

Methods

Retrospective analysis of consecutive patients (pts) who underwent iFA in a tertiary center between 2019 and 2020. vFFR was calculated using a dedicated software (CAAS Workstation 8.4) based on standard non-hyperaemic coronary angiograms acquired in ≥2 different projections, by operators blinded to iFA results. Diagnostic performance and accuracy of vFFR were evaluated. vFFR was considered positive when &lt;0.80. FFR &lt;0.8 and iFR/RFR &lt;0.90 were classified as positive according to current clinical standards.

Results

Out of 113 coronary arteries of 102 pts, vFFR was successfully analysed in 106 (94%). Reasons for vFFR analysis failure were: vessel projection overlap (48%), &lt;2 angiographic projections (28%) and table movement while acquisition (24%). From 106 coronary arteries of 95 pts with analysable vFFR (78% male, mean age 67.8±9.7 years), 90 (85%) showed agreement with the respective iFA result. The vFFR predicted which lesions were physiologically significant and which were not with accuracy, sensitivity, specificity, positive and negative predictive values of 73%, 73%, 83%, 53%, and 92% respectively. The mean difference between vFFR and iFA were −0.0484±0.096 and Pearson's correlation coefficient was 0.533 (p&lt;0.001). The ROC area under the curve was 0.839 (0.751–0.928, p&lt;0.001).

Conclusion

FFR were feasible in 94% of cases analysed retrospectively. As compared to gold-standard iFA, vFFR had an overall moderate accuracy in detecting ischemia-producing lesions and a negative predictive value &gt;90%. vFFR has the potential to substantially simplify physiological coronary lesion assessment and thus improve its current uptake.

Funding Acknowledgement

Type of funding sources: None. Bland-Altman plot between vFFR and IFA

Peripheral Blood BRCA1 Methylation Positively Correlates with Major Alzheimer's Disease Risk Factors

BACKGROUND

Recent biomarker studies demonstrated that the central nervous system (CNS) environment can be observed from peripherally-derived samples. In a previous study, we demonstrated significant hypomethylation of the BRCA1 promoter region in neuronal cells from post-mortem brains of Alzheimer's disease patients through neuron-specific methylome analysis. Thus, we investigate the methylation changes in the BRCA1 promoter region in the blood samples.

OBJECTIVES

To analyze the methylation level of the BRCA1 promoter in peripheral blood from AD patients and normal controls.

DESIGN, SETTING, PARTICIPANTS

Genomic DNA samples from peripheral blood were obtained from the J-ADNI repository, and their biomarker data were obtained J-ADNI from the National Bioscience Database Center. Genomic DNA samples from an independent cohort for validation was obtained from Niigata University Hospital (Niigata, Japan). Amyloid positivity was defied by visual inspection of amyloid PET or a CSF Aβ42 value ≤ 333 pg/mL at the baseline.

MEASUREMENTS

Methylation level of the BRCA1 promoter was analyzed by pyrosequencing.

RESULTS

Compared to normal controls, methylation of the BRCA1 promoter in AD patients was not significantly changed; however, in AD patients, it showed a positive correlation with AD risk factors.

CONCLUSIONS

Our data confirmed the importance of cell-type specific methylome analysis and also suggested that environmental changes in the CNS can be detected by observing the peripheral blood, implying that the peripheral BRCA1 methylation level can be a surrogate for AD.

Eigenmode symmetry assignment of triangular-lattice photonic crystal slabs and their Dirac cones materialized by effective degeneracy in the mid-infrared region

We measured angle-resolved reflection spectra of triangular-lattice photonic crystal slabs fabricated in a silicon-on-insulator wafer in the mid-infrared region. We achieved a high angle-resolution measurement by means of our homemade optical setup integrated in the sample chamber of an FT-IR spectrometer. By examining the reflection peak frequency as a function of the lateral component of the wave vector of the incident light and applying the selection rules expected from the spatial symmetry of electromagnetic eigenmodes in C_6v-symmetric structures, we successfully obtained the dispersion relation and the mode symmetry of the photonic crystal slabs, which agreed well with numerical calculations by the finite element method. We also found the redistribution of diffraction loss between A₁- and E₁-symmetric modes, which was caused by the Dirac-cone formation due to their effective degeneracy.

Cardiopulmonary exercise testing in repaired tetralogy of Fallot: a valuable tool for pulmonary regurgitation severity assessment

Funding Acknowledgements

Type of funding sources: None.

Introduction and purpose

The optimal timing for pulmonary valve replacement (PVR) in asymptomatic patients with repaired tetralogy of Fallot (TOF) and pulmonary regurgitation (PR) remains uncertain but is often guided by imaging characterization of the right ventricle. As cardiopulmonary exercise testing (CPET) performance is an accessible prognostic indicator, we assessed which CPET parameters best correlate with pulmonary regurgitation severity to potentially improve identification of high-risk patients.

Methods

A retrospective chart review was done from 2009 to 2018 on adult patients with repaired TOF who underwent maximal effort cardiopulmonary exercise testing with cycle ergometry and with concurrent pulmonary function testing. Demographics, standard measures of CPET interpretation, and major cardiovascular outcomes were collected.

Results

Cardiopulmonary exercise testing was performed in 54 adult repaired TOF patients (59% male), with a mean follow-up of 60 ± 33 months. The mean age was 34 ± 9 years. 30 patients (56%) had severe pulmonary regurgitation and 26 patients (48%) were submitted to PVR, with a 0% mortality rate. PVR was performed a mean 28 ± 7 years after TOF repair surgery. There was moderate to severe right ventricular dysfunction in 11 patients (20%). 12 patients (22%) had a hospitalization for heart failure. Arrhythmic events occurred in 9 patients (17%), mainly atrial fibrillation or atrial flutter (67%). 2 patients (4%) received an implantable cardioverter-defibrillator for secondary prevention of sudden cardiac death.

Peak VO2 consumption (pVO2) showed no statistically significant correlation with severity of pulmonary regurgitation (HR 0.26, 95% CI 0.879-1.036, p= 0.262) or PVR (HR 0.92, 95% CI 0.829-1.028, p = 0.914), while percent of predicted pVO2 significantly correlated with severity of pulmonary regurgitation (HR 0.95, 95% CI 0.918-0.993, p = 0.020) and PVR (HR 0.94, 95% CI 0.886-0.992, p = 0.025).

VE/VCO2 slope was not a significant predictor of severity of pulmonary regurgitation (HR 1.03, 95% CI 0.929-1.130, p = 0.622) or PVR (HR 1.04, 95% CI 0.952-1.128, p = 0.414) or) and neither cardiorespiratory optimal point (HR 0.94, 95% CI 0.786-1.120, p = 0.480) nor maximum end-tidal carbon dioxide pressure (PETCO2) (HR 0.93, 95% CI 0.846-1.037, p = 0.213) correlated with severity of pulmonary regurgitation or PVR.

Conclusion

Percent of predicted peak VO2 had the highest predictive power of all CPET parameters analysed in adult repaired TOF patients. Preoperative CPET could be an accessible way to identify high-risk patients earlier for PVR and should therefore be included in the routine assessment of these patients.

Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy

We provide an extensive and systematic investigation of exciton dynamics in droplet epitaxial quantum dots comparing the cases of (311)A, (001), and (111)A surfaces. Despite a similar s-shell exciton structure common to the three cases, the absence of a wetting layer for (311)A and (111)A samples leads to a larger carrier confinement compared to (001), where a wetting layer is present. This leads to a more pronounced dependence of the binding energies of s-shell excitons on the quantum dot size and to the strong anti-binding character of the positive-charged exciton for smaller quantum dots. In-plane geometrical anisotropies of (311)A and (001) quantum dots lead to a large electron-hole fine interaction (fine structure splitting (FSS) ∼100 μeV), whereas for the three-fold symmetric (111)A counterpart, this figure of merit is reduced by about one order of magnitude. In all these cases, we do not observe any size dependence of the fine structure splitting. Heavy-hole/light-hole mixing is present in all the studied cases, leading to a broad spread of linear polarization anisotropy (from 0 up to about 50%) irrespective of surface orientation (symmetry of the confinement), fine structure splitting, and nanostructure size. These results are important for the further development of ideal single and entangled photon sources based on semiconductor quantum dots.

Patchwork metasurface quantum well photodetectors with broadened photoresponse

Complex lightwave manipulation such as broadband absorption has been realized with metasurfaces based on laterally arranged metal-dielectric-metal cavities with different geometries. However, application of these metasurfaces for optoelectronic devices by incorporating functional dielectrics remains challenging. Here, we integrate a quantum well infrared photodetector (QWIP) with a metasurface made of a patchwork of square cavities with different dimensions arranged in a subwavelength unit cell. Our detector realizes wideband photoresponse approaching the entire responsivity spectrum of the QWIP-single-sized square cavities can utilize only 60% of the possible bandwidth-and external quantum efficiencies of up to 78% at 6.8 µm. Our highly flexible design scheme enables integration of photodetectors and metasurfaces with arbitrary arrangements of cavities selectively responding to incidence with a specific wavefront.

Cohort-Specific Optimization of Models Predicting Preclinical Alzheimer's Disease, to Enhance Screening Performance in the Middle of Preclinical Alzheimer's Disease Clinical Studies

BACKGROUND

Models that can predict brain amyloid beta (Aβ) status more accurately have been desired to identify participants for clinical trials of preclinical Alzheimer's disease (AD). However, potential heterogeneity between different cohorts and the limited cohort size have been the reasons preventing the development of reliable models applicable to the Asian population, including Japan.

OBJECTIVES

We aim to propose a novel approach to predict preclinical AD while overcoming these constraints, by building models specifically optimized for ADNI or for J-ADNI, based on the larger samples from A4 study data.

DESIGN AND PARTICIPANTS

This is a retrospective study including cognitive normal participants (CDR-global = 0) from A4 study, Alzheimer Disease Neuroimaging Initiative (ADNI), and Japanese-ADNI (J-ADNI) cohorts.

MEASUREMENTS

The model is made up of age, sex, education years, history of AD, Clinical Dementia Rating-Sum of Boxes, Preclinical Alzheimer Cognitive Composite score, and APOE genotype, to predict the degree of amyloid accumulation in amyloid PET as Standardized Uptake Value ratio (SUVr). The model was at first built based on A4 data, and we can choose at which SUVr threshold configuration the A4-based model may achieve the best performance area under the curve (AUC) when applied to the random-split half ADNI or J-ADNI subset. We then evaluated whether the selected model may also achieve better performance in the remaining ADNI or J-ADNI subsets.

RESULT

When compared to the results without optimization, this procedure showed efficacy of AUC improvement of up to approximately 0.10 when applied to the models "without APOE;" the degree of AUC improvement was larger in the ADNI cohort than in the J-ADNI cohort.

CONCLUSIONS

The obtained AUC had improved mildly when compared to the AUC in case of literature-based predetermined SUVr threshold configuration. This means our procedure allowed us to predict preclinical AD among ADNI or J-ADNI second-half samples with slightly better predictive performance. Our optimizing method may be practically useful in the middle of the ongoing clinical study of preclinical AD, as a screening to further increase the prior probability of preclinical AD before amyloid testing.

Pregnancy outcomes in women with mechanical heart valves

Background

Mechanical heart valves (MHV) and their absolute need for adequate anticoagulation poses a challenge for pregnancy, either due to warfarin fetotoxicity or an increased risk of maternal thromboembolism. This represents a unique patient (P) group where data is scarce and maternal and fetal risks and benefits must be carefully weighed.

Purpose

To assess maternal and perinatal outcomes in women with MHV on different anticoagulant regimens and compare them with patients with other types of valvular heart disease (VHD).

Methods

A retrospective analysis of 131 pregnancies in 83 women with VHD (mean age 26.5±5.6 years) was carried out in a tertiary referral centre from 2000 to 2019. 92 pregnancies with VHD, including 11 with biological prosthetic valves, and 39 pregnancies in 22 P with MHV were identified. The main outcome measures were major maternal complications and perinatal outcome.

Results

MHV implanted were in mitral position (89.7%), aortic (2.6%), or both (7.7%). History of rheumatic heart disease was identified in 16 P (72.7%) and a congenital etiology was present in 2 P (9.1%). 9 P (40.9%) were on warfarine and 13 P (59.1%) on acenocumarol. Regarding anticoagulation strategy, 21 P (65.6%) remained on oral anticoagulation and 10 P (31.3%) had been switched to some form of heparin during part or the entire pregnancy. Mechanical valve thrombosis complicated pregnancy in 4 patients (10.2%), all cases on heparin, and resulted in maternal death in 1 P. MHV P had more hemorrhagic complications (15.4 vs 2.2%, p=0.004) requiring transfusion or surgical revision. MHV P tended to experience more NHYA class worsening demanding initiation or intensification of cardiac medication (17.9 vs 5.4%, p=0.023). Also in the MHV group there was a higher incidence of miscarriage (46.2 vs 12.0%, p≤0.0005), comprising spontaneous abortion (31.6 vs 7.6%, p&lt;0.0005) and fetal malformations (18.4 vs 5.4%, p=0.028), including warfarin embryopathy (10.3 vs 1.1%, p=0.012). The live birth rate was higher in women on heparin compared with those on warfarin (85.9 vs 79.2%, p=0.002). The presence of multivalve disease (p=0.04), mechanical protheses (p&lt;0.001), ACO (p&lt;0.001) and previous impaired LVEF (p=0.02) were related to miscarriage. In multivariate analysis, ACO was the unique independent predictor of unsuccessful pregnancy (p=0.01). Only 29% of the patients with an MHV had a pregnancy free of serious adverse events compared with other types of VHD (81.5%, p&lt;0.0005).

Conclusions

MHV remains a challenging condition for pregnancy with only 29% chance of experiencing an uncomplicated pregnancy with a live birth. The increased morbimortality warrant extensive prepregnancy counseling with prosthesis type discussion,centralization of care and further larger studies to come up with evidence-based recommendations.

Funding Acknowledgement

Type of funding source: None

Role of tilt-table testing in syncope diagnosis and management: analysis of patients referred to a syncope unit

Introduction

Head-up tilt-testing (HUT) enables the reproduction of reflex syncope in a laboratory setting. Despite being used to confirm the diagnosis of this syncope, there is some concerns regarding the best protocol to use and recent studies with implantable loop recorders have called the value of HUT into question.

Aim

To characterize the population undergoing HUT according to the modified Italian protocol, type of response to HUT and subsequent management at our center in the last 4 years.

Methods

Retrospective analysis of consecutive P who underwent HUT between 2015 and 2018. Descriptive analysis of patients (P) demographics and medical history, indication for HUT, type of response to HUT and management.

Results

A total of 419P (55.1% female) were included with a mean age of 62 years. The majority (n=302, 72.1%) had comorbidities (structural heart disease – 55%, cardiac dysrhythmias – 57.6%, hypertension – 48.3%, diabetes – 15.6%, depression – 15.9%, cerebrovascular disease –10.6%) or was under medication (n=220, 52.5%) with a potential hypotensive or bradycardic effect (44.1% ACEI/ARA, 29.1% beta-blocker, 27.7% diuretic, 23.6% antidepressant, 22.7% calcium channel blocker, 19.1% benzodiazepines). Syncope/presyncope episodes accounted for 56.1% of the HUT, with falls and disequilibrium accounting for 52%. In 21 cases (5%) suspected dysautonomia or other non-specified reasons were the indication for HUT. HUT were ordered according to the guidelines in 136P (84.6% – indication level I, 3.6% – level IIa, 11.8% – level IIb). HUT was positive in 292P (69.7%) – 77.1% after nitroglycerin administration (vasodepressor – 170P, cardioinhibitory – 53P, mixed – 62P and dysautonomic – 7P). Cardioinhibitory (CI) response predominated in the younger, and vasodepressor in the older P. Of the P with CI response, 41.5% had asystole (median of 41.4s, minimum 7.5s, maximum 115s). All P were instructed in the need to avoid triggering factors and perform counterpressure maneuvers. A pacemaker was implanted in 24P (5.7% of all population, due to long sinus pauses and asystole). Twenty-four P (5.7%) completed a tilt training program.

Conclusion

Most of the HUT were requested for syncope/presyncope, frequently according to the guidelines. There was a high rate of positive tests, with a predominance of vasodepressive response, particularly in the elderly.

Funding Acknowledgement

Type of funding source: None

Impact of diabetes mellitus on the early phase arterial healing after drug-eluting stent implantation: a multicenter coronary angioscopic study

Background

Diabetes mellitus (DM) is a strong risk factor for major cardiac and cerebrovascular events. In particular, coronary artery disease with DM is often complicated with complex lesions. Drug-eluting stents (DES) are mainly used for these lesions, and dual-antiplatelet therapy (DAPT) has been used to prevent stent thrombosis. Early arterial healing after DES implantation may enable short DAPT strategy. However, the impact of DM on the arterial healing in the early phase has not been elucidated to date.

Purpose

We evaluated the arterial healing in the early phase after DES implantation using coronary angioscopy (CAS) and compared the findings between DM and non-DM patients.

Methods

This study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients which were evaluated 3 to 5 months after DES implantation. Patients were divided into two groups: DM (149 lesions in 118 patients) versus non-DM groups (188 lesions in 152 patients). We assessed neointimal coverage (NIC) grades (maximum, minimum and dominant), thrombus adhesion and maximum yellow color of plaque underneath the stent. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as follows: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

Results

Minimum NIC coverage grade was lower in DM group than in non-DM group (P=0.002, Figure), while maximum and dominant NIC coverage grades were similar between them (P=0.94 and P=0.59, respectively). Thrombus adhesion (44.3% versus 38.8%, P=0.32) and maximum yellow color grade (P=0.78) were also similar between DM and non-DM groups. Even after the adjustment by the confounding factors such as follow-up duration and primary disease of acute coronary syndrome, DM was an independent factor predicting grade 0 of minimum NIC (odds ratio [OR] 1.83 [95% confidence interval 1.11–3.03], P=0.019).

Conclusion

DM patients showed less covered struts than non-DM patients 3 to 5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applicable to DM patients.

Minimum neointimal coverage grade

Funding Acknowledgement

Type of funding source: None

Prognostic impact of suspected cardiac amyloidosis in aortic stenosis patients referred for transcatheter aortic valve implantation

Background

The prevalence of cardiac amyloidosis (CA) and aortic stenosis (AS) both increase with age. Transcatheter aortic valve implantation (TAVI) expands the number of patients (P) eligible for treatment of AS, emphasizing the need to understand the prevalence of CA in AS and its prognostic associations. Echocardiography with speckle tracking has emerged as a useful method to enhance the clinical suspicion and to provide prognostic information.

Purpose

To estimate the prevalence of CA in P with severe AS referred for TAVI and to evaluate the impact of concomitant CA in prognosis.

Methods

94 consecutive AS P who underwent TAVI with maximum left ventricular wall thickness (LVWT)&gt;12 mm were retrospectively identified. Clinical data, pre TAVI echocardiographic parameters and follow up (FU) data regarding all-cause mortality and MACE (including all-cause mortality, admission for heart failure, pacemaker implantation and stroke) were analysed. We registered apical sparing pattern in bull's eye plots (ASPB), calculated relative apical longitudinal strain formula (RALS) [average apical LS/(average basal LS + mid-LS)] and ejection fraction/global longitudinal strain (EF/GLS) ratio.

Results

Mean age was 82.2±5.8 years (Y), with 43 men (45.7%). 27.7% were in NYHA functional class II, 64.9% in functional class III and 7.4% in functional class IV. Median EF was 57±15% and 26.6% presented EF&lt;50%. Suspected CA evaluated by ASPB was found in 39 P (41.5%) and RALS &gt;1 was identified in 22 P (23.4%). An EF/GLS ratio &gt;4.1 was obtained in 53 P (56.4%). Over a median follow-up of 13.4±25.8 months, 28 deaths (29.8%) and 31 MACEs (33.0%) occurred.

The presence of ASPB was associated with increased all-cause mortality (33.3% vs. 5.6%, p=0.002) and MACE (48.7% vs 22.2%, p=0.01). RALS&gt;1 correlated also with all-cause mortality (31.8% vs. 12.5%, p=0.04) and with new bundle branch block and indication for pacemaker implantation (46.2% vs 37.0%, p=0.05). P with GLS&gt;−14.8% and ASPB had significantly worse prognosis regarding all-cause mortality (p=0.003) and MACE (p=0.007). Kaplan–Meier survival analysis showed that survival was significantly worse for P with ASPB (log-rank 0.002). With multivariate Cox regression analysis, ASPB was independently associated with all-cause mortality (HR=4.49, p=0.039).

Conclusions

Suspected CA appears prevalent among patients with AS and associates with all-cause mortality. The importance of screening for CA in older AS patients and optimal treatment strategies in those with CA warrant further investigation, especially in the era of transcatheter aortic valve implantation.

Funding Acknowledgement

Type of funding source: None

New onset atrial fibrillation after dual chamber pacemaker implantation: long term predictors

Background

Preserving atrioventricular synchrony has been accepted as a significant advantage of atrial and dual-chamber (DDD) pacing. However, little is known about the incidence of atrial fibrillation (AF) after DDD implantation and its prognostic predictors in long term.

Purpose

To determine the incidence of new AF episodes and to identify risk factors and prognostic predictors for new-onset AF and all-cause mortality after implantation of dual-chamber pacemakers.

Population and methods

713 consecutive patients (P) who underwent colocation of DDD pacemaker, due to AV block (AVB) or sinus node disease (SND), with no prior history of AF, from 2011 to 2015. Through periodic PM interrogation, occurrence of AF (“automatic mode switch” episodes with documented AF), switch to ventricular pacing (VVIR), pacing site (apical or septal) and cumulative right ventricular (RV) pacing % were analysed.

Results

Follow-up data was available for 669 patients (93.8%) for a mean follow-up (FU) time of 47.8±22.7 months. Mean age was 72.9±10.8 years with 60.1% male. New occurrence of AF was observed in 345 P (51.6%) during the FU period; 45.7% of them were consequently anticoagulated (59.0% with NOACs). Median time to 1st AF episode since implantation was 21.6 months and in 50.9% of the cases it lasted ≥1h. In univariate analysis, 1st AF episode lasting more than 1 hour and existence of at least one episode longer than 24 hours were directly related to switch to VVIR (p&lt;0.0005; p&lt;0.0005; p&lt;0.0005) as well as prescription of anticoagulation (p=0.001; p=0.011; p&lt;0.0005).

Compared to non-AF P, those with AF were older (74.0±9.9 vs. 71.8±11.7 years; p=0.008), had higher prevalence of SND (50.0% vs 40.20%; p=0.015), had superior % of RV pacing (65.9±39.3% vs. 58.3±44.3%; p=0.021) and more frequently had RV apical pacing (70.1% vs 57.3%; p=0.001). The prevalence of hypertension, diabetes mellitus and dyslipidemia were similar in the two groups. With multivariable Cox-regression, age (HR 1.02; p=0.017), SND (HR 1.49; p=0.010), admission for HF (HR 1.55; p=0.012) and % RV pacing (HR 1.01; p=0.003) were significantly associated with the incidence of FA. Predictors of all-cause mortality in Cox regression were the occurrence of AF in 1st of FU (HR 1.67; p=0.018) and % RV pacing (HR 1.01; p=0.043).

Conclusions

New onset AF is a frequent finding after DDD pacemaker implantation and is associated with all-cause mortality in long term. Age, admission for heart failure, sinus node disease and % of RV pacing were independent predictors for AF during follow-up.

Funding Acknowledgement

Type of funding source: None

Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A-Oriented Substrates

Droplet epitaxy allows the efficient fabrication of a plethora of 3D, III–V-based nanostructures on different crystalline orientations. Quantum dots grown on a (311)A-oriented surface are obtained with record surface density, with or without a wetting layer. These are appealing features for quantum dot lasing, thanks to the large density of quantum emitters and a truly 3D lateral confinement. However, the intimate photophysics of this class of nanostructures has not yet been investigated. Here, we address the main optical and electronic properties of s-shell excitons in individual quantum dots grown on (311)A substrates with photoluminescence spectroscopy experiments. We show the presence of neutral exciton and biexciton as well as positive and negative charged excitons. We investigate the origins of spectral broadening, identifying them in spectral diffusion at low temperature and phonon interaction at higher temperature, the presence of fine interactions between electron and hole spin, and a relevant heavy-hole/light-hole mixing. We interpret the level filling with a simple Poissonian model reproducing the power excitation dependence of the s-shell excitons. These results are relevant for the further improvement of this class of quantum emitters and their exploitation as single-photon sources for low-density samples as well as for efficient lasers for high-density samples.

Angle-resolved reflection spectra of Dirac cones in triangular-lattice photonic crystal slabs

The dispersion relation and the angle-resolved reflection spectra of triangular-lattice photonic crystal slabs of the C_6v symmetry were examined by the finite element method. The Dirac-cone dispersion relation on the Γ point of the reciprocal space was confirmed. The reflection spectra showed unique selection rules that agreed with the analytical calculation by the k · p perturbation theory. The distortion of the liner dispersion relation of the Dirac cones due to diffraction loss was also reproduced well by the numerical calculation, while we found distortion-free Dirac cones materialized with E₂-symmetric modes.

Strain relaxation in InAs heteroepitaxy on lattice-mismatched substrates

Strain relaxation processes in InAs heteroepitaxy have been studied. While InAs grows in a layer-by-layer mode on lattice-mismatched substrates of GaAs(111)A, Si(111), and GaSb(111)A, the strain relaxation process strongly depends on the lattice mismatch. The density of threading defects in the InAs film increases with lattice mismatch. We found that the peak width in x-ray diffraction is insensitive to the defect density, but critically depends on the residual lattice strain in InAs films.

Mid-IR Dirac-cone dispersion relation materialized in SOI photonic crystal slabs

We materialized the isotropic Dirac-cone dispersion relation in the mid-infrared range by fabricating photonic crystal slabs of the C_4v symmetry in SOI (silicon-on-insulator) wafers by electron beam lithography. The dispersion relation was examined by the angle-resolved reflection spectra with our home-made high-resolution apparatus, which showed a good agreement with the dispersion relation and the reflection spectra calculated by the finite element method. The reflection spectra also agreed with the selection rules derived from the spatial symmetry of the Dirac-cone modes, which proved to be a powerful tool for the mode assignment.

Synchronously wired infrared antennas for resonant single-quantum-well photodetection up to room temperature

Optical patch antennas sandwiching dielectrics between metal layers have been used as deep subwavelength building blocks of metasurfaces for perfect absorbers and thermal emitters. However, for applications of these metasurfaces for optoelectronic devices, wiring to each electrically isolated antenna is indispensable for biasing and current flow. Here we show that geometrically engineered metallic wires interconnecting the antennas can function to synchronize the optical phases for promoting coherent resonance, not only as electrical conductors. Antennas connected with optimally folded wires are applied to intersubband infrared photodetectors with a single 4-nm-thick quantum well, and a polarization-independent external quantum efficiency as high as 61% (responsivity 3.3 A W⁻¹, peak wavelength 6.7 μm) at 78 K, even extending to room temperature, is demonstrated. Applications of synchronously wired antennas are not limited to photodetectors, but are expected to serve as a fundamental architecture of arrayed subwavelength resonators for optoelectronic devices such as emitters and modulators.

Applications of metasurfaces for optoelectronic devices require wiring to each isolated antenna for biasing and current flow. Here, the authors report optimal wire interconnects design for controlling the optical properties and present antenna-enhanced mid-infrared photodetection incorporating a single quantum well.

P1433 Antiarrhythmic effects of sacubitril-valsartan therapy assessed by mechanical dispersion index

Introduction

Sacubitril/Valsartan (LCZ696) significantly reduced sudden cardiac death in the PARADIGM-HF trial. However, there is little published data regarding the possible explanations for the antiarrhythmic effects found with LCZ696 therapy.

Previous trials have shown that mechanical dispersion by strain echocardiography can predict arrhythmic events in Heart Failure (HF) patients.

The aim of this study was to compare electrocardiographic (ECG) parameters and mechanical dispersion index with left ventricular (LV) global longitudinal strain (GLS) analysis before and after LCZ696 therapy.

Methods

Prospective evaluation of chronic HF patients with LV ejection fraction ≤ 40% despite optimized standard of care therapy, in which LCZ696 therapy was started and no additional HF treatment was expected to change.

ECG and transthoracic echocardiographic data were gathered in the week before starting LCZ696 therapy and 6 months after therapy. A semiautomated analysis of LV GLS was made and mechanical dispersion index was defined as the standard deviation from the 16 time intervals corresponding to each LV segment.

Results

Of the 42 patients, 35 (83.3%) completed the 6 months of follow-up, since 2 (4.8%) patients died and 5 (11.9%) discontinued treatment for adverse events. Mean age was 58.6 ± 11.1 years.

QTc interval (451.9 vs 426.0msec, p &lt; 0.001) and QRS interval (125.1 vs 120.8msec, p = 0.033) were reduced after 6 months of LCZ696 therapy. Mechanical dispersion index (88.4 vs 78.1msec, p = 0.036) was also significantly reduced after therapy.

Conclusion

LCZ696 therapy is associated with antiarrhythmic effects with a reduction in QTc and QRS intervals in ECG and a reduction in mechanical dispersion index as assessed by LV GLS.

Abstract P1433 Figure.

P715 When "wait and see" is the best option: a case report of a spontaneous coronary artery dissection

Introduction

Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome and is now being identified more frequently, in part because of increased awareness.

Case report

We present the case of a 63-year-old female, without cardiovascular risk factors or relevant past medical history. She complained of atypical chest pain in the last year. The patient was admitted due to acute chest pain at rest, hemodynamically stable, with unremarkable physical examination, including absence of heart failure signs. The EKG revealed a dynamic ST depression in leads V4-V6. The peak of high sensitivity troponin I was 13744pg/mL (ULN&lt; 15.6) and CK 874U/l (ULN &lt;168). The echocardiogram showed preserved left ventricular ejection fraction and hypokinesia of mid-apical segments of anterior wall. Considering the diagnosis of NSTEMI the patient underwent coronary angiography that revealed luminal narrowing of 70% in left main artery, 70% in proximal anterior descending artery (LAD) and 99% in first obtuse marginal. Given the absence of cardiovascular risk factors, the smooth angiographic appearance of coronary lesions and absence of calcium, we suspected of spontaneous dissection or vasculitis. Considering the absence of angina revascularization was delayed. A first coronary angio-CT confirmed the luminal narrowing and suggested a spontaneous dissection. Two weeks later the coronariography and the angio-CT were repeated with a significant improvement, showing only intermediate stenosis of proximal LAD. The additional imaging study revealed a 45mm ascending aortic dilation and a left primitive carotid stenosis without other vascular territory alterations, excluding fibromuscular dysplasia. The auto-immune study was unremarkable. With all these results it was assumed the diagnosis of a spontaneous coronary artery dissection and the patient was discharged asymptomatic under single antiplatelet therapy and Rivaroxaban. Three months later a new coronary angio-CT showed no significant coronary artery stenosis and the patient was asymptomatic.

Discussion and conclusion

The recognition of spontaneous coronary artery dissection is essential to the correct management of these cases because, unlike acute coronary syndrome due to atherosclerotic disease, the results of revascularization in these patients are suboptimal and conservative management is probably the best option.

Abstract P715 Figure. angio-CT

1185 Three-dimensional speckle tracking echocardiography for the global and regional assessment of myocardial deformation in breast cancer patients submitted to anthracyclines

Introduction

Serial echocardiographic assessment of 2D/3D left ventricular ejection fraction (LVEF) and 2D global longitudinal strain (GLS) is the gold standard for screening for cancer therapeutics-related cardiac dysfunction (CTRCD). Although 3D speckle tracking echocardiography (STE) has several technical advantages, is more reproducible, and has a better correlation to magnetic resonance than 2D STE, it is still not currently used in this setting. We aimed to investigate the usefulness of 3D STE in evaluating left ventricle mechanics and its relation to CTRCD.

Methods

Prospective study of female breast cancer patients submitted to anthracycline chemotherapy who underwent one transthoracic echocardiography (ETT) before and at least one ETT during/after chemotherapy. Standard ETT parameters and 3D volumetric measurements were assessed. STE was used to estimate 2D GLS – average and 18 segments – and 3D GLS, global circumferential strain (GCS), global radial strain (GRS) and global area strain (GAS) – average and 17 segments. CTRCD was defined as an absolute decrease in 2D or 3D LVEF &gt;10% to a value &lt;54% or a relative decrease in 2D GLS &gt;15%.

Results

105 patients (mean age 53.8 ± 12.5 years, 52.4% immunotherapy, 77.2% radiotherapy, 2.8 echocardiograms/patient) were included. During a mean follow-up of 12.1 months, 24 patients (22.9%) developed CTRCD. During anthracycline therapy, there was a significant worsening of 2D LVEF (65.6 vs. 57.8), 3D LVEF (61.5 vs. 54.4), 2D GLS (-21.1 vs. -18.0), 3D GLS (-15.6 vs. -10.9), 3D GCS (-14.0 vs. -11.0), 3D GRS (42.0 vs. 28.5) and 3D GAS (-27.0 vs. -20.0) [all p &lt;0.001]. More than 73% of patients presented 3D global strain values below the limits of normal during chemotherapy. On 3D strain regional analysis, impaired contractility was observed in the anterior, inferior and septal walls. Logistic regression analysis showed that 3D GRS and 3D GCS were associated with a higher incidence of CTRCD. In the multivariate model, 3D GRS remained the only independent predictor of CTRCD. The receiver operating curve analysis showed a good calibration and discrimination of 3D GCS and 3D GRS in predicting CTRCD with areas under de curve of 0.748 and 0.719, with the optimal cut-off values being 0.342 for GCS and 0.344 for GRS. These variations were observed a median of 45 days and 22.5 days before the diagnosis of CTRCD, respectively.

Conclusion

3D strain parameters worsened during anthracycline therapy, with predominant involvement of septal, anterior and inferior walls. Variations of 3D GCS and GRS were predictive of subsequent CTRCD, and thus can be considered an earlier sign of CTRCD, with added value over the currently recommended 2D/3D LVEF and 2D GLS. Routine application of this technique should be considered in order to offer targeted monitoring and timely initiation of cardioprotective treatment.

P1256 Salvage mitraclip implantation for postmyocardial infarction mitral regurgitation: 2 case reports

Introduction

Acute mitral regurgitation (MR) secondary to AMI is associated with a poor clinical outcome. The role of MitraClip implantation (MCI) in this population is still not well established. We report two successful cases of salvage MCI in acute ischaemic MR.

Case Report 1: A 66-year-old diabetic woman was admitted to our institution due to extensive anterior STEMI with cardiogenic shock. Urgent cardiac catheterization (CC) revealed 100% occlusion of the left anterior descending and critical stenosis of the obtuse marginal artery, with successful PCI of both vessels and implantation of an intra-aortic balloon pump. Early transthoracic echocardiogram (TTE) revealed a dilated left ventricle with severe systolic dysfunction (LVEF – 35%), apical and anterior wall akinesia and functional grade IV MR (EROA - 40mm2 and regurgitant volume - 45mL), that was later confirmed by transesophageal echocardiography (TEE). 48h after AMI, the patient developed an arrhythmic storm requiring multiple shocks and a prolonged period of mechanical ventilation. Due to an extremely slow clinical improvement, with the need for prolonged inotropic support and refractory pulmonary congestion (NYHA IV), she was submitted to MCI, resulting in post-procedural grade I MR (EROA 7mm2 and regurgitant volume 11mL) and a marked clinical and hemodynamic improvement. An ICD for secondary prevention was implanted. At the 3 month follow-up the patient presented in NYHA II functional class without congestive symptoms.

Case Report 2: An 82-year old female patient was admitted with an inferior STEMI, with CC documenting severe 3 vessel disease with a calcified occlusion of the right coronary artery, not amenable to PCI, so the patient was submitted to emergent CABG. There was a prolonged period of post-operatory mechanical ventilation with an extremely difficult weaning process, including the need for re-intubation due to acute pulmonary edema. TTE revealed LVEF of 39% with a large inferobasal aneurysm and severe eccentric MR due to tendinous cord rupture. The patient was submitted to MCI with immediate significant improvement of the MR, allowing successful extubation 36 hours after the procedure. In the end of first month of follow-up, the TTE revealed a well-positioned clip with mild-to-moderate MR (EROA – 21.5mm2 and regurgitant volume – 38mL) with the patient being completely asymptomatic.

Conclusion

Treatment of acute MR following AMI with MCI may be a safe and effective approach in critically ill patients. In our experience, it can lead to a rapid clinical recovery and resolution of cardiogenic shock.

P1260 Chagas disease, a new challenge to the old continent

Case Report

A 53-year-old female patient from the North Region of Brazil with a past medical history of Chagas Disease (CD) with esophageal involvement and permanent atrial fibrillation (AF) presented to the Emergency Department (ED) due to complaints of retrosternal discomfort and dizziness. The patient reported multiple recent syncopal episodes and had performed a recent 24-hour Holter monitoring revealing AF with predominantly slow ventricular rate and frequent ventricular premature beats. Her sister had recently been diagnosed with obstructive hypertrophic cardiomyopathy. During the ED stay, the patient developed a syncopal monomorphic ventricular tachycardia, requiring synchronized electrical cardioversion. Post cardioversion EKG revealed a sinus rhythm with a right bundle branch block, left anterior fascicular block and 1st degree AV block. The patient was admitted in the Cardiology Department for further investigation. Transthoracic echocardiogram revealed a dilated left ventricle with a reduced systolic function (LVEF of 38%, GLS of -7.1%), with an aneurysm of the basal inferior and posterior walls and a markedly dilated left atrium (68mL/m2). Cardiac magnetic resonance imaging showed a marked dilation of both atriums and ventricles, with biventricular systolic dysfunction, hypertrabeculation of the left ventricular wall and the presence of diffuse intramural and subepicardic fibrosis. These features were compatible with chagasic cardiomyopathy. Due to biventricular systolic dysfunction, the documentation of AV conduction disturbance, the natural history of the disease and the need for antiarrhythmic therapy, the patient underwent cardiac resynchronization therapy–defibrillator implantation. 1 week after the procedure, the patient experienced an arrhythmic storm with a total of 6 CRT-D shocks. Amiodarone was initiated and beta-blocker was titulated to the maximum tolerated dose, with no recurrence of ventricular tachycardia. On the 3 month follow-up visit the patient denied symptoms of congestive heart failure. Device interrogation revealed a high percentage of biventricular pacing and no arrhythmic events.

Conclusion

This case describes the most remarkable and characteristic features of chagasic cardiomyopathy. It is almost always progressive and is associated with a worse outcome comparing with other cardiomyopathies. The prevalence of CD is growing in traditionally nonendemic areas and its timely recognition is fundamental.

P1262 If anything can go wrong, it will: management of a pericardial effusion in a young patient

Case Report

A 25 year-old male patient with an unremarkable past medical history presented to the Emergency Department due to a hemodynamically stable wide complex tachycardia at 260bpm with no response to adenosine, which was successfully treated with synchronized electrical cardioversion. Post cardioversion EKG revealed a pre excitation pattern and the transthoracic echocardiogram showed a large pericardial effusion with diastolic right atrial collapse. The patient was admitted in the Cardiology Department for emergent pericardiocentesis and further investigation. A total of 800 mL of bloody pericardial fluid was removed, compatible with an exudate, but fluid culture and cytology were inconclusive. Due to a rapid reaccumulation of pericardial fluid, the patient underwent a pericardial window, after which he developed an intractable pleuritic thoracalgia, refractory to the combination of ibuprofen, colchicine and oral steroid, despite the resolution of the pericardial effusion. He was also submitted to an electrophysiologic study with successful ablation of a right sided accessory pathway. Analysis of the pericardial fluid and biopsy were inconclusive once again, including a low level of adenosine deaminase and negative acid-fast bacilli test and nucleic acid amplification test for Mycobacterium tuberculosis. The patient was afebrile and denied any constitutional symptoms or relevant epidemiological context. The remainder etiological study was unremarkable, with the exception of fluctuating antibody titers for adenovirus, Borrelia burgdorferi and Mycoplasma pneumoniae, which were interpreted as a result of cross-reactivity. Nevertheless, a course of 21 days of doxycycline was tried without any significant improvement. Thoracic-abdominal-pelvic CT and PET scan were normal. Direct inoculation in guinea pig led to positive results for Mycobacterium tuberculosis and antituberculous therapy was started. Despite pathogen directed antibiotic treatment, there was no clinical improvement and the pericardial effusion gradually relapsed, evolving to cardiac tamponade requiring emergent drainage. Histologic examination of pericardial fragments finally revealed massive infiltration by an undifferentiated malignant tumor compatible with a malignant epithelioid hemangioendothelioma. Due to the patient’s poor performance status and rapidly deteriorating clinical course, it was decided not to start chemotherapy. The patient eventually died, 6 months after his admission to the ED and 2 weeks after the neoplasm’s diagnosis.

Conclusion

In regions with a high Tuberculosis incidence, there should be a high degree of suspicion for tuberculous pericarditis, especially in cases of recurrent pericardial effusion. Immunosuppressed individuals, such as oncologic patients, are at an increased risk for tuberculosis. The management of relapsing pericardial effusion remains a diagnostic challenge as described in this clinical case.

P1429 B-Type natriuretic peptide prediction of right catheterization parameters in the first year after heart transplant

Introduction

Despite being the gold-standard for hemodynamic assessment, right heart catheterization (RHC) was overcome by plasma B-Type Natriuretic Peptide (BNP) levels in daily clinical routine. However, in the first year after heart transplantation (HT), the relationship between BNP and adverse hemodynamics have yielded conflicting results.

Purpose

The aim of this study was to evaluate whether BNP values can be used to estimate adverse hemodynamics in the first year after HT.

Methods

Prospective study of consecutive RHC performed in the first year after HT (according to the endomyocardial biopsies program). Plasma BNP levels were measured at the same day.

The area under the curve (AUC) was analysed to find the BNP values with higher sensitivity and specificity to detect adverse hemodynamics.

Results

From 2017 to 2018, 50 RHC were performed. Mean age was 48.7 ± 8.3 years, with mean BNP value of 964.4 ± 1114.7pg/ml.

Prediction of adverse hemodynamics by AUC results are represented in the table. BNP values were significantly increased in patients with pulmonary capillary wedge pressure (PCWP) &gt;12mmHg (p &lt; 0.001), cardiac index &lt;2.5L/min/m2 (p = 0.001), mean pulmonary artery pressure (mPAP) ≥25mmHg (p &lt; 0.001), pulmonary vascular resistance &gt; 1,5WU (p = 0.044) and right atrial pressure &gt;5mmHg (p = 0.003).

BNP &gt;500pg/ml had a sensitivity of 78.3% and 87.5% and a specificity of 76.0% and 67.7% to detect PCWP &gt;12mmHg and mPAP ≥25mmHg, respectively.

Conclusion Significant associations were found between BNP values and adverse hemodynamics in RHC, supporting the clinical utility of BNP in the first year after HT.

BNP prediction AUC values SR HEMODYNAMIC PARAMETERS AUC p 95% CI Best BNP value Sensitivity Specificity Pulmonary capillary wedge pressure (PCWP) &gt; 12mmHg 0.798 &lt;0.001 0.671-0.925 &gt; 500pg/ml 78.3% 76.0% Mean pulmonary artery pressure (mPAP) ≥ 25mmHg 0.830 &lt;0.001 0.714-0.946 &gt; 500pg/ml 87.5% 67.7% Cardiac output &lt; 4L/min 0.833 0.002 0.667-1.000 &gt; 1500pg/ml 77.8% 87.5% Cardiac index (CI) &lt; 2.5L/min/m2 0.810 0.001 0.663-0.957 &gt; 1150pg/ml 76.9% 86.1% Pulmonary vascular resistance (PVR) &gt; 1,5WU 0.678 0.044 0.509-0.848 &gt; 200pg/ml 83.3% 47.1% Right atrial pressure (RAP) &gt; 5mmHg 0.744 0.003 0.607-0.880 &gt; 500pg/ml 70.8% 65.4% BNP prediction

P354 Right heart catheterization parameters, echocardiography parameters and B-Type natriuretic peptide prediction of acute cellular rejection in the first year after heart transplant

Introduction

Since the mid-1970s, the diagnosis of acute cellular rejection (ACR) has been made by endomyocardial biopsy (EMB). Whether B-Type Natriuretic Peptide (BNP), transthoracic echocardiography (TTE) parameters and right heart catheterization (RHC) parameters can detect rejection in heart transplant (HT) patients have yielded conflicting results and did not overcome the use of EMB in the first year after HT.

Purpose

The aim of this study was to evaluate whether BNP, TTE and RHC parameters can be used to detect ACR in the first year after HT.

Methods

Prospective study of consecutive EMB performed in the first year after HT. Plasma BNP levels, TTE and RHC were performed at the same day.

Clinical significant ACR was defined as ≥ 2R, according to the ISHLT 2004 grading. The area under the curve (AUC) was analysed for statistically significant associations to detect ACR.

Results

From 2017 to 2018, 50 EMB were performed with the following results: 2R - 5 (10.0%); 1R- 29 (58.0%); 0 – 16 (32%). Mean age was 48.7 ± 8.3 years, with mean BNP value of 964.4 ± 1114.7pg/ml.

AUC results of BNP and several TTE and RHC parameters for the prediction of ACR are represented in the table. Right atrial pressure (RAP) value (p = 0.027) was the only significantly predictor of ACR, while isovolumic relaxation time measured by TTE revealed a borderline significant trend (p = 0.076).

RAP &gt; 10mmHg had a sensitivity of 60.0% and a specificity of 84.4% for detecting ACR.

Conclusion

Detecting ACR without EMB remains a clinical challenge, but RAP measured by RHC was a significant predictor of ACR in the first year after HT, while BNP values did not correlate with ACR.

AUC values PARAMETERS AUC p 95% CI BNP 0.658 0.251 0.405-0.911 Troponin I 0.591 0.507 0.260-0.923 Left ventricular ejection fraction 0.416 0.541 0.218-0.614 E/A 0.480 0.895 0.282-0.678 Deceleration time 0.463 0.463 0.161-0.765 Isovolumic relaxion time 0.745 0.076 0.427-1.000 Cardiac index 0.595 0.488 0.346-0.845 Pulmonary capillary wedge pressure 0.628 0.401 0.329-0.926 Mean pulmonary artery pressure 0.684 0.181 0.511-0.857 Right atrial pressure 0.804 0.027 0.631-0.978 AUC values

P175 Cardiac device infection: to extract or not to extract, that is the question

Introduction

The incidence of infectious complications related to intracardiac devices has been increasing in recent year and is associated with a poor prognosis, which is determined not only by the infectious process but also by the severity of the underlying cardiac pathology and the spectrum of comorbidities presented. Appropriate antibiotic therapy and extraction of the devices are fundamental in the management of these patients.

Case report

We describe the case of a 66-year-old patient on a waiting list for transplantation due to non-ischemic dilated cardiomyopathy with poor left ventricular systolic function (LVEF of 10%), with severe functional mitral regurgitation and severe pulmonary hypertension, who received a CRT-D for secondary prevention (non-responder). He was admitted for decompensated heart failure (NYHA functional class IV and "dry-cold" profile) requiring inotropic support becoming dependent on dobutamine. During hospitalization, there was a progressive increase in inflammatory markers accompanied by recurrent febrile peak and inflammatory signs of the central venous catheter, with catheter-tip and serial hemocultures positive for Morganella morganii. Piperacillin / tazobactam was started. Due to the lack of response to pathogen directed antibiotic therapy, he underwent a transesophageal echocardiogram (TEE) that revealed several filiform images associated with the electrodes, with no image of valvular vegetations, which led to the association of gentamicin and device extraction (DE), according to the Pisa technique, that occurred without complications. On the 7th day after DE, there was a progressive clinical deterioration in spite of increasing doses of inotropes and vasopressors. It was considered that patient would not be candidate for cardiac transplantation or mechanical ventricular assist, and died on the 118th day of hospitalization in refractory cardiogenic shock.

Conclusion

Device endocarditis is a class I indication for intracardiac DE and TEE is fundamental in its diagnosis. Despite being a considered a non-responder to cardiac resynchronization therapy based on clinical and echocardiographic criteria, this case illustrates how the loss of cardiac resynchronization may have contributed to the patient’s hemodynamic deterioration and have played a fundamental role in the clinical outcome.

P4704The efficacy of intravascular ultrasound for patients with peripheral artery diseases presenting aorto-iliac artery disease

Background

The use of intravascular ultrasound (IVUS) promotes better clinical outcomes for intervention in complex lesions. However, the data demonstrating whether use of IVUS improves primary patency following stenting for aorto-iliac lesions in patients with peripheral artery disease (PAD) are limited.

Purpose

The purpose of the current study was to investigate the impact of IVUS use on primary patency 12 months after stent implantation for aorto-iliac lesions.

Methods

We analyzed a clinical database of the OMOTENASHI registry (Observational prospective Multicenter registry study on Outcomes of peripheral arTErial disease patieNts treated by AngioplaSty tHerapy in aortoIliac artery), registering symptomatic PAD patients (Rutherford category 2, 3, or 4) undergoing endovascular therapy for aorto-iliac lesions between January 2014 and April 2016 in Japan. The current study analyzed 803 patients who underwent self-expandable stent implantation at 61 centers with the institutional volume known. The primary endpoint was 12-month restenosis, defined as ≥50% stenosis on computed tomography or angiography, or a peak systolic velocity ratio ≥2.5 on duplex ultrasound. When treatment strategies, endovascular procedures and clinical outcomes were compared between the patients treated with IVUS use and those treated without IVUS use, the propensity score matching was performed to minimize the inter-group difference in baseline characteristics.

Results

A total of 545 patients (67.9%) underwent IVUS-supported stent implantation. Patients treated with IVUS use had a lower prevalence of regular dialysis, whereas they had a higher prevalence of TASC II class D and chronic total occlusion. In patients treated with IVUS use, carbon dioxide contrast agent were more often used, and 0.035-inch guidewire was less frequently selected. Implanted stents in these patients were longer and smaller in diameter. The propensity score matching extracted 138 pairs, with no remarkable intergroup difference in baseline characteristics. Procedure time ≤1 hour was less frequent in patients treated with IVUS use; their radiation time was longer. Endovascular strategies, as well as postoperative medication were not significantly different between patients with and without IVUS use. The 12-month restenosis risk was not significantly different between patients with and without IVUS use (10.2% [6.9 to 14.9%] versus 10.3% [5.4 to 18.6%], P=0.99).

Conclusion

IVUS use in aorto-iliac stenting for patients with PAD was not associated with primary patency at 12 months.

Acknowledgement/Funding

None

P2516Cardiac rehabilitation program - experience and outcomes in a tertiary center

Introduction

Cardiac rehabilitation (CR) programs are effective in improving functional capacity and reducing mortality. The level of adherence to them seems to be less than the ideal, and some factors can predict non-compliance with impact on outcomes.

Purpose

The aim was to characterize the population of the cardiac rehabilitation (CR) appointment, determine factors predictive of compliance with the standard CR exercise program and evaluate the benefits of the program.

Methods

Retrospective analysis of patients in a CR appointment at a single center between 2014 and 2017. Patients (P) were divided into two groups: compliance >80% of the program (GI) and non-compliance (GII). We assessed clinical, laboratory, and echocardiographic characteristics and determined predictors for compliance and compared the follow-up to date.

Results

270P (83% men) were included, with a mean age of 57 years. The P had a median follow up of 35 months, with an interquartil interval of 28 months. The majority (92.5%) had at least one cardiovascular risk factor (25.1% diabetes, 57.1% hypertension, 72.8% dyslipidemia, 75.8% obesity or weight excess, with mean body mass index (BMI) 27.3±3.46, 16.7% family history, 19.8% acute myocardial infarction (AMI), 48.2% smoking). 99% of the patients were medicated (93.7% acetylsalicylic acid, 67.3% clopidogrel, 24.1% ticagrelor, 95.6% beta-blocker, 93.7% ACEI/ARB, 95.5% statin). 144P (53.3%) were not from Lisbon. Most patients (77%) were referred after AMI, 8.9% with heart failure (HF), 8.5% with stable or unstable coronary disease and 1.9% with valvulopathy. 69P (25.6%) attended >80% of the CR program. Death occurred in 4.4% of the P (71.4% cardiovascular causes) and 27% had at least 1 hospitalization. Age, sex, economic insufficiency and residence local (Lisbon or non-Lisbo) were not predictors of non-compliance (p=0.859, p=0.656, p=0.914 and p=0.515 respectively). Predictors of non-compliance were higher IMC (CC=-0.141, p=0.014), higher cholesterol (CC=-0.140, p=0.016), higher C reactive protein (CC=-0.120, p=0.043), higher HbA1c (CC=-0.170, p=0.008) and CR for heart failure (HF) (OR = 0.715, IC [0.659–0.775], p=0.002). Of these, higher HbA1C (p=0.018) and CR for HF (p=0.034) were independent predictors. Compliance with>80% of the program was associated with lower overall mortality (OR = 0.732, IC [0.679–0.788], p=0.037), but not as an independent factor (p=0.378). The only independent predictor of mortality were BNP (p<0.0001).

Conclusion

Of the patients referred to the CR consultation one fourth concludes the program. Several factors can predict non-compliance, with higher HbA1c and CR for HF being independent predictors. Compliance with the CR program is associated with lower overall mortality.

P4711The prognostic impact of infrapopliteal arterial calcification on wound healing in patients with critical limb ischemia

Background

Critical limb ischemia (CLI) is the most progressed manifestation of peripheral artery disease. Although patients with CLI commonly complicate with severely calcified lesions in infrapopliteal lesions, the prognostic impact of infrapopliteal arterial calcification on wound healing in patients with CLI has not been systematically studied.

Purpose

The aim of current study was to elucidate the prognostic impact of infrapopliteal arterial calcification on wound healing in CLI undergoing endovascular therapy (EVT).

Methods

This study enrolled 639 CLI patients with tissue loss (age 74±10 years, male 62%, diabetes 69%, hemodialysis 57%, Rutherford class 5 77%, class 6 23%) primarily treated with EVT for the infrapopliteal lesions between April 2010 and December 2015. Arterial calcification was assessed by high intensity fluoroscopy and classified into 3 groups as follows; 1) none, 2) unilateral and 3) bilateral calcification. The primary outcome measure was complete wound healing. The predictors of the outcome were evaluated by Cox proportional hazards regression analysis.

Results

During a mean follow-up period of 22±19 months, 1-year wound healing rate were 59.0%. In Kaplan-Meier analysis, 1-year wound healing rate was worse in patients with bilateral calcification than in those with unilateral or none calcification (Figure, 46.2% versus 55.1% versus 67.8%, P<0.001). After multivariate analysis, the predictors of wound healing were non-ambulatory status (hazard ratio (HR) 0.67 [95% confidential interval (CI) 0.53–0.85], P=0.001) and bilateral calcification (HR 0.75 [95% CI 0.47–0.98], versus none or unilateral calcification, P=0.036).

Figure 1

Conclusion

Infrapopliteal Arterial calcification as well as non-ambulatory status was associated with wound healing in patients with CLI.

P2510Cardiorespiratory optimal point as a predictor of outcomes in patients enrolled in a cardiac rehabilitation program

Introduction

The cardiopulmonary exercise test (CEPT) allows the evaluation of peak and sub-maximal tolerance to the effort, giving us relevant information for clinical decisions. Evidence has emerged that Cardiorespiratory Optimal Point (COP)>30, calculated as the minimum ratio between ventilation and oxygen (VE/VO2) may be a good predictor of events.

Purpose

The aim was to characterize the population of the cardiac rehabilitation (CR) appointment that performed CEPT, evaluate COP as a predictor of events and determine the best cut off for our population.

Methods

Retrospective analysis of CR appointment patients who performed CEPT between 2014 and 2017 in a single center. We compared the mortality and hospitalizations according to COP and COP>30. We established the appropriate Cut Off for our population and compared the same with the occurrence of events.

Results

207Patients (P) (83.6% men) were included, with a mean age of 57 years. The mean COP was 23.6±5.8 (IC [24.06–25.66]). 15.9% P had COP >30 and 33.8% had COP<22. The majority (96.6%) had a cardiovascular disease or risk factors and 99% were medicated. The majority (87.9%) was referred for CR with isquemic cardiopathy (AMI or stable or unstable coronary disease), 9.2% with heart failure (HF) and 9.2% with valvulopathy. 6.9% P died from any cause, 33.8% had an hospitalization (78.6% from a cardiovascular reason). Higher COP values correlated with higher number of all causes hospitalizations (H) (CC = 0.123, p=0.032), cardiovascular H (CC = 0.123, p=0.032), heart failure H (CC = 0.189, p=0.001) and device placement H (CC = 0.173, p=0.003). COP did not correlate with mortality (p=0.453). The cut off of 30 only correlated with HF hospitalization in this population (OR = 5, IC [1.429–17.494] p=0.006). In our population, COP was a good predictor for all cause H and heart failure H (AUC = 0.8 in both). A cut off of 25 had a sensitivity (S) of 78% with a specificity (E) of 70% for all cause hospitalization and S 73% and E 68% for heart failure H. Values above this cut off correlate with more all cause H (OR = 1,928, IC [1.06–3.507], p=0.031) and heart failure H (OR = 5.63, IC [1,44–21.94]), p=0.006). COP was an independent predictor of all-cause H (p=0.018) and heart failure H (p<0.0001). Other independent predictors of HF hospitalization are BNP (p=0.0011) and ejection fraction (p<0.0001).

Conclusion

COP was a good independent predictor of all-cause hospitalizations and HF hospitalization. In our population the cut off 25 for COP had the greatest S and E for predicting events. In our population this factor was not a good predictor of mortality.