Unlocking room-temperature bistable spin transition at the nanoscale: the synthesis of core@shell [Fe(NH2trz)3(NO3)2]@SiO2 nanoparticles

In this work, we address the synthesis of stable spin-crossover nanoparticles capable of undergoing a hysteretic spin transition at room temperature. For this purpose, we use the reverse-micelle protocol to prepare naked [Fe(NH2trz)3](NO3)2 and core@shell [Fe(NH2trz)3](NO3)2@SiO2 nanoparticles. Through meticulous adjustment of synthetic parameters, we achieved nanoparticle sizes ranging from approximately 40 nm to 60 nm. Our findings highlight that [Fe(NH2trz)3](NO3)2 presents a modest thermal hysteresis of 7 K, which decreases by downsizing. Conversely, silica-coated nanoparticles with sizes of ca. 60 and 40 nm demonstrate a remarkable hysteretic response of approximately 30 K, switching their spin state around room temperature. Moreover, the presence of a SiO2 shell substantially enhances the nanoparticles' stability against oxidation. In this context, the larger 60 nm [Fe(NH2trz)3](NO3)2@SiO2 hybrid remains stable in water for up to two hours, enabling the observation of an unreported water-induced spin transition after 30 min. Therefore, this work also introduces an intriguing avenue for inducing spin transitions through solvent exchange, underscoring the versatility and potential of these nanoparticles.

First medical contact facility type as a determinant of prognosis in a regional ST elevation myocardial infarction network

Background

Delay in primary percutaneous coronary intervention (PPCI) in ST elevation myocardial infartion (STEMI) is associated with worse prognosis. In our regional STEMI network, the first medical contact (FMC) facility type defines 4 different assistance pathways (i.e. emergency medical services'diagnosis on the field and direct transfer to the catheterization laboratory (cath. lab) of a PCI hospital (EMS group); direct admission to a PCI hospital (PCI-H group); admission to community hospital and transfer to the cath lab of the PCI-H (CH group); diagnosis in a primary care centre and transfer to the cath lab of the PCI-H (PCC group). Each different FMC has been associated with different degrees in reperfusion delay.

Objective

To determine the influence of FMC facility type on 1-year mortality in patients with STEMI in our regional STEMI network.

Methods

This is a retrospective study based on the STEMI network registry, a mandatory registry conducted since its implantation and supervised by the regional health authorities. We included STEMI patients treated with PPCI from January 2010 to December 2020. We analyzed differences in clinical variables, reprefusion times and 1-year all-cause mortality regarding the FMC facility type.

Results

We included 18332 patients (EMS 34.25%, PCI-H 12.28%, CH 33.47%, PCC 20.01%). Initial Killip classes III–IV: EMS 8.43%, PCI-H 7.51%, CH 5.54%, PCC 3.76%; p<0.001. All comorbidities and complications in first medical assistance were more frequent in EMS and PCI-H groups (p<0.05). PCC group had the lowest risk profile regarding comorbidities and first medical assistance complications (p<0.05 for most of variables). The PCI-H group had the shortest system delay (median 82 min, p<0.001), the EMS group had the shortest total ischemic time (median 151 min, p<0.001). Crude 1-year mortality was EMS 8.6%, PCI-H 9.11%, CH 8.25%, and PCC 4.77% (p<0.001). After adjusting for several covariables with a logistic regression model, PCI-H and CH groups were associated with higher 1-year mortality compared to EMS group (OR 1.23 (IC95% 1.01–1.49; p=0.04) and OR 1.16 (IC95% 1.01–1.34; p=0.04) respectively), while PCC group was associated with lower 1-year mortality (OR 0.69 (IC95% 0.57–0.84; p<0.01)).

Conclusions

First medical contact with EMS and direct transfer to the cath lab was associated with lower adjusted 1-year mortality compared to first medical contact with a PCI hospital or a community hospital.

Funding Acknowledgement

Type of funding sources: None.

Long-term clinical outcomes of patients with chronic total coronary occlusion caused by intra-stent re-stenosis

Objectives

In this study we aim 1) at identifying predictors of selecting percutaneous coronary intervention (PCI) to treat chronic total occlusion due to in-stent restenosis (CTO-ISR); and, 2) at comparing long-term clinical outcomes of patients treated with coronary artery by-pass graft (CABG), percutaneous coronary intervention (PCI) or optimal medical therapy (OMT).

Methods

Between June 2010 and January 2014 a total of 1290 CTO were included in a prospective Registry. 86 of those patients presented with CTO-ISR. Clinical follow-up was obtained until April 2019. Major adverse cardiac events (MACE) rate was defined as the composite end-point of cardiac death, acute myocardial infarction or target lesion revascularization (TLR).

Results

A total of 54 patients were treated with PCI (63%), 22 received OMT alone (25%) and the remaining 10 (12%) were treated with CABG. Patients treated with PCI were older and presented higher values of left ventricular ejection fraction than those of the other groups. From the anatomical point of view, calcification and ostial location were more frequently observed in the OMT group, whereas Syntax score was higher in the CABG arm. At multivariate analysis, age and Syntax score were the only independent predictors of selecting PCI. At long-term follow-up (mean 101 months), MACE rate was higher in the CABG arm mainly driven by a higher incidence of TLR.

Conclusions

Percutaneous coronary intervention could be an effective and safe procedure to treat CTO-ISR. Larger prospective trials are required to confirm these clinical results.

Funding Acknowledgement

Type of funding sources: None.

Obesity paradox in 12,381 patients undergoing transfemoral transcatheter aortic valve implantation: from the CENTER-collaboration

Background

Transcatheter aortic valve implantation (TAVI) is a well-established treatment for symptomatic aortic valve stenosis. The majority of patients treated are overweight or obese. Obesity has traditionally been linked to reduced survival and worse cardiovascular outcomes. However, an “obesity paradox” has been described in some diseases, with improved survival of obese patients after invasive and surgical procedures.

Methods

The CENTER-collaboration included data from 10 registries or clinical trials of patients undergoing transfemoral TAVI from 2007 to 2018. Patients were divided in four groups according to body mass index (BMI): underweight: BMI <18.5 kg/m2, normal weight: BMI 18.5 to 24.9 kg/m2, overweight: BMI 25 to 29.9 kg/m2, and obese: BMI ≥30 kg/m2. The primary endpoints of this analysis were differences in 30-day all-cause mortality and stroke after TAVI.

Results

Of the 12,381 patients analysed, 2% (n=205) were underweight, 29% (n=3552) had normal weight, 44% (n=5460) were overweight and 25% (n=3140) obese. Older patients had lower BMI (median of 84 years for underweight and 81 years for obese patients, p<0.001). Cardiovascular risk factors such as hypertension, diabetes mellitus and dyslipidaemia increased progressively with increase of BMI category. As to clinical outcomes, there were no differences for stroke rates across BMI groups. In-hospital mortality was highest in patients who were underweight, namely 8.4%, compared to normal weight, overweight and obese patients (6.2%, 4.3% and 4.6% respectively, p<0.001) as was 30-day mortality (9.8% compared to 6.9%, 5.3% and 5.2% respectively, p=0.001). On the other hand, extremely obese patients (BMI ≥40.0 kg/m2) also had worse prognosis, with a 30-day mortality of 7.6%.

Conclusions

In this global analysis of more than 12 000 patients undergoing transfemoral TAVI, overweight and obese patients had better in-hospital and 30-day survival than normal weight patients, confirming the obesity paradox. There was an inverted J-shaped relationship of body mass index with prognosis, with higher mortality rates for underweight and extremely obese patients.

Mortality and stroke per BMI category

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Dutch Heart Foundation; Netherlands Organisation for Health Research and Development

P3695Predicting adverse outcomes after TAVI procedure - a comparison of two CoreValve generations using real-life outcomes and patient-specific computer simulations

Background and aim

Post-procedure conduction abnormalities (CA) and paravalvular aortic regurgitation (PAR) continue to strain TAVI outcomes. Computer simulations, based on patient-specific anatomy, valve properties, and implantation position, have been validated for prediction of these complications. The new-generation CoreValve Evolut PRO has been shown to have lower levels of PAR and CA than previous generations. The aim was to compare clinical outcomes after Evolut Pro implantation in real-life with outcomes of virtual deployment of the same size, implantation depth adjusted CoreValve Evolut R.

Methods

Patients undergoing Evolut Pro implantation at a single centre were included into the study. Postoperative Doppler echocardiography was assessed to define PAR, the pre- and postoperative 12-lead ECGs for CA, and the postoperative angiograms to measure implantation depth based on annular plane distance from the non-coronary and left coronary aortic valve cusps. Preoperative multislice computed tomography was used to generate patient-specific models of the native aortic root. Implantation of the Evolut R valve and corresponding aortic root deformation was simulated using computational mechanics, whereas blood flow and level of PAR were predicted using computational fluid dynamics. Prediction of CA – new onset left bundle branch block or atrioventricular block type II or III -was based on calculations of contact pressure in a patient-specific region of the aortic root containing the AV conduction system (ROI). Outcomes were predicted in three implantation depth positions - high, medium, low – where the position closest to the real-life implantation depth was chosen for outcome comparisons.

Results

Study diagram is shown in Figure 1. Thirty-three patients (57% female, mean age 82±6 years old) underwent a TAVI intervention with an Evolut PRO valve. Evolut PRO implantation depths were, in general, closest to the lowest modeled Evolut R depth. Comparison demonstrated similar overall incidence of moderate-to-severe PAR. The Evolut R simulation predicted 18 patients without PAR and 2 with PAR. With the Evolute PRO, 1 of the 18 not predicted developed significant PAR, and 1 of the 2 predicted did not develop PAR. CA were notably higher with the Evolut R simulation, where CA were present in 9 out of 12 patients, as compared to the observed 5 out of 12 with the Evolut PRO.

Figure 1

Conclusion

Single-centre outcomes after Evolut Pro implantation in real-life showed a similar overall incidence of moderate-to-severe PAR and a lower incidence of conduction abnormalities as compared to the same size, implantation depth adjusted, patient-specific Evolut R modeled outcomes. As inferred from the results, computer simulations may have high clinical utility in supporting clinical decisions regarding valve choice in TAVI procedures.

Acknowledgement/Funding

Horizon 2020 European Commission Project H2020-MSCA-ITN-2016 (764738)

P1562Outcomes of nonagenarians with ST elevation myocardial infarction

Background

Developed countries are facing a sustained increase in life expectancy. Elderly people represent the fastest growing portion of cardiovascular patients. However, nonagenarians with ST-segment elevation myocardial infarction (STEMI) are often underrepresented in clinical trials as prolonged follow-up may be compromised by limited life expectancy. The aim of this retrospective study is to analyse the clinical presentation, risk factors, co-morbidities, outcomes of nonagenarian patients presenting with STEMI.

Methods

We included all consecutive nonagenarians presenting with STEMI admitted in 2 academic centers between 2007 and 2017. There were no exclusion criteria. We collected demographic, clinical, and procedural data. All-cause mortality was assessed in-hospital, at 6 months and at 1-year follow-up.

Results

A total of 140 patients (mean age 91.6 years [91.3–92]; 59% females) were included. The number of patients increased over the years (from 6.5 cases per year before 2012 to 14.4 cases per year after 2012). One out of 5 patients presented disability or dependence for activities of daily living (ADL). Emergent catheterization was performed in 70% of our patients, and primary percutaneous coronary intervention (pPCI) in 57% (n=80). The use of bare metal stent was preponderant (72%) in this cohort. Successful revascularization of the culprit vessel was achieved in 90% of patients. Dual antiplatelet therapy with aspirin and clopidogrel was used in 97% of patients. Overall, in-hospital mortality was 22%, increased up to 27% at 6 months and up to 34% at 1-year follow-up. In-hospital mortality was lower in pPCI group than in conservative group (13.7% versus 31.6%, adjusted OR: 0.17, 95% CI: 0.04–0.67, P<0.01). One-year mortality was also lower in pPCI group than in conservative group (26% versus 45%, P<0.01). Multivariable analysis identified mechanical complications (adjusted OR: 28.1, 95% CI: 3.18–247.7, P<0.01), Killip class (III/IV) (adjusted OR: 4.19, 95% CI: 3.37–22.3, P<0.01) and pPCI (adjusted OR: 0.40, 95% CI: 0. 16- 0. 95, P<0.05) as independent predictors of all-cause mortality at 1 year.

Conclusions

STEMI in nonagenarians is becoming more and more common. pPCI may be also the preferred strategy in this high-risk cohort. The hemodynamic compromise (Killip class III/IV), the presence of complications related to myocardial infarction and early revascularization may be related to prognosis of these patients.

[Perioperative management of atrial fibrillation]

Atrial fibrillation is a frequent complication in the perioperative period. When it appears there is an increased risk of perioperative morbidity due to stroke, thromboembolism, cardiac arrest, myocardial infarction, anticoagulation haemorrhage, and hospital readmissions. The current article focuses on the recommendations for the management of perioperative atrial fibrillation based on the latest Clinical Practice Guidelines on atrial fibrillation by the European Society of Cardiology and the Spanish Society of Cardiology. This article pays special attention to the preoperative management, as well as to the acute perioperative episode. For this reason, the latest recommendations for the control of cardiac frequency, antiarrhythmic treatment and anticoagulation are included.

Primary immunosuppression and outcome differences after heart transplantation: tacrolimus versus cyclosporine

BACKGROUND

The superiority of tacrolimus (Tac) as primary immunosuppression for heart transplantation (HT) compared with cyclosporine (CsA) is still under debate. Outcomes of comparison studies are not consistent; the duration of these studies has been limited. The aim of this study was to evaluate long-term outcomes of patients undergoing HT based on primary immunosuppression regime.

METHODS AND RESULTS

We analyzed a single-center registry of all HT patients between 1998 and 2009, comparing outcomes based on primary immunosuppressions (Tac or CsA). Patients who died before starting immunosuppression were excluded. A total of 197 patients entered the study; 103 received Tac and 94 CsA. There were no differences between groups in baseline characteristics, United Network for Organ Sharing status 1A or ventricular assist device use, except for ischemia time (195 ± 50 min in Tac group vs 182 ± 55 min in CsA; P = .08) and days on waiting list (164 ± 155 vs 100 ± 73; P < .001). After mean follow-ups of 4.5 ± 2.3 years in the Tac group and 6.3 ± 4.3 years in the CsA group, there were 19 and 36 deaths, respectively. Kaplan-Meier analysis showed increased survival for the Tac group (log rank P = .04). Tac also was significantly superior to CsA regarding mortality (relative risk 0.55; 95% confidence interval, 0.31-0.98; P = .04).

CONCLUSIONS

In our series the use of tacrolimus resulted in improved long-term survival compared with cyclosporine. At 1-year follow-up, there were no differences in acute rejection episodes or the appearance of vasculopathy.