An electro-responsive hydrogel for intravascular applications: an in vitro and in vivo evaluation

There is a growing interest in using hydrogels for biomedical applications, because of more favourable characteristics. Some of these hydrogels can be activated by using particular stimuli, for example electrical fields. These stimuli can change the hydrogel shape in a predefined way. It could make them capable of adaptation to patient-specific anatomy even post-implantation. This is the first paper aiming to describe in vivo studies of an electro-responsive, Pluronic F127 based hydrogel, for intravascular applications. Pluronic methacrylic acid hydrogel (PF127/MANa) was in vitro tested for its haemolytic and cytotoxic effects. Minimal invasive implantation in the carotid artery of sheep was used to evaluate its medium-term biological effects, through biochemical, macroscopic, radiographic, and microscopic evaluation. Indirect and direct testing of the material gave no indication of the haemolytic effects of the material. Determination of fibroblast viability after 24 h of incubation in an extract of the hydrogel showed no cytotoxic effects. Occlusion was obtained within 1 h following in vivo implantation. Evaluation at time of autopsy showed a persistent occlusion with no systemic effects, no signs of embolization and mild effects on the arterial wall. An important proof-of-concept was obtained showing biocompatibility and effectiveness of a pluronic based electro-responsive hydrogel for obtaining an arterial occlusion with limited biological impact. So the selected pluronic-methacrylic acid based hydrogel can be used as an endovascular occlusion device. More importantly it is the first step in further development of electro-active hydrogels for a broad range of intra-vascular applications (e.g. system to prevent endoleakage in aortic aneurysm treatment, intra-vascular drug delivery)

Avoiding oversizing in sutureless valves leads to lower transvalvular gradients and less permanent pacemaker implants postoperatively.

peer reviewed[en] OBJECTIVES: The aim of this study was to evaluate the impact of changing the sizing strategy in aortic valve replacement using the Perceval sutureless prosthesis on haemodynamic outcomes and postoperative pacemaker implantation. METHODS: Retrospective analysis of patients implanted with the Perceval valve between 2007 and 2019 was performed by comparing patients implanted before the modification of sizing strategy (OLD group) and after (NEW group). The outcome parameters evaluated were the implanted prosthesis size, haemodynamical profile and postoperative pacemaker implantation. RESULTS: The entire patient cohort (784 patients) consisted of 52% female patients, with a mean age of 78.53 [standard deviation (SD): 5.8] years and a mean EuroSCORE II of 6.3 (range 0.7-76). In 55.5% of cases, surgery was combined. The NEW cohort had more male patients (54.6% vs 43.4%) (P = 0.002). Mean implanted valve size, corrected for body surface area, was significantly lower in the NEW cohort (13.1, SD: 1.4 vs 13.5, SD: 1.4 mm/m2, P < 0.001). The 30-day mortality was 3.4%. Peak and mean transvalvular gradients at discharge were significantly lower in the NEW versus OLD groups: 24.4 mmHg (SD: 9.2) versus 28.4 mmHg (SD: 10.3) (P < 0.001) and 13.6 mmHg (SD: 5.3) versus 15.5 mmHg (SD: 6.0) (P < 0.001). The mean effective opening area and the indexed effective opening area, respectively, increased from 1.5 cm2 (SD: 0.5) and 0.85 cm2/m2 (SD: 0.27) in the OLD group to 1.7 cm2 (SD: 0.5) and 0.93 cm2/m2 (SD: 0.30) in the NEW group (P < 0.001). No difference was found in paravalvular leakage ≥1/4. Centrovalvular leakage ≥1/4 significantly decreased from 18% to 7.9% (P < 0.001). With the new sizing, the new postoperative pacemaker implantation rate decreased significantly from 11% to 6.1% (P = 0.016). CONCLUSIONS: Correct sizing of sutureless aortic valves is crucial to obtain the best possible haemodynamics and avoid complications

Durability of bioprosthetic aortic valve replacement in patients under the age of 60 years - 1-year follow-up from the prospective INDURE registry.

OBJECTIVES We report 1-year safety and clinical outcomes in patients <60 years undergoing bioprosthetic surgical aortic valve intervention. METHODS The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, multicentre registry to assess clinical outcomes of patients <60 years. Patients with planned SAVR with or without concomitant replacement of the ascending aorta and/or coronary bypass surgery were included. Time-related valve safety, haemodynamic performance, and quality of life (QoL) at 1 year were assessed. RESULTS 421 patients were documented with a mean age of 53.5 years, 76.5% being male, and 27.2% in NYHA class III/IV. Outcomes within 30 days included cardiovascular-related mortality (0.7%), time-related valve safety (VARC-2; 5.8%), thromboembolic events (1.7%), valve-related life-threatening bleeding (VARC-2; 4.3%), and permanent pacemaker implantation (3.8%). QoL was significantly increased at 6 months and sustained at 1 year. Freedom from all-cause mortality at 1 year was 98.3% (95%CI 97.1;99.6) and 81.8% were NYHA I vs. 21.9% at baseline. No patient developed structural valve deterioration Stage 3 (VARC-3). Mean aortic pressure gradient was 12.6 mmHg at 1 year and effective orifice area was 1.9 cm2. CONCLUSIONS The 1-year data from the INSPIRIS RESILIA valve demonstrate good safety and excellent haemodynamic performance as well as an early QoL improvement. CLINICALTRIALS NUMBER NCT03666741

European registry of type A aortic dissection (ERTAAD) - rationale, design and definition criteria

Correction: Volume16 Issue1 Article Number225 DOI10.1186/s13019-021-01606-8Background: Acute Stanford type A aortic dissection (TAAD) is a life-threatening condition. Surgery is usually performed as a salvage procedure and is associated with significant postoperative early mortality and morbidity. Understanding the patient's conditions and treatment strategies which are associated with these adverse events is essential for an appropriate management of acute TAAD. Methods: Nineteen centers of cardiac surgery from seven European countries have collaborated to create a multicentre observational registry (ERTAAD), which will enroll consecutive patients who underwent surgery for acute TAAD from January 2005 to March 2021. Analysis of the impact of patient's comorbidities, conditions at referral, surgical strategies and perioperative treatment on the early and late adverse events will be performed. The investigators have developed a classification of the urgency of the procedure based on the severity of preoperative hemodynamic conditions and malperfusion secondary to acute TAAD. The primary clinical outcomes will be in-hospital mortality, late mortality and reoperations on the aorta. Secondary outcomes will be stroke, acute kidney injury, surgical site infection, reoperation for bleeding, blood transfusion and length of stay in the intensive care unit. Discussion: The analysis of this multicentre registry will allow conclusive results on the prognostic importance of critical preoperative conditions and the value of different treatment strategies to reduce the risk of early adverse events after surgery for acute TAAD. This registry is expected to provide insights into the long-term durability of different strategies of surgical repair for TAAD.Peer reviewe

Durability of bioprosthetic aortic valves in patients under the age of 60 years - Rationale and design of the international INDURE registry

Background: There is an ever-growing number of patients requiring aortic valve replacement (AVR). Limited data is available on the long-term outcomes and structural integrity of bioprosthetic valves in younger patients undergoing surgical AVR. Methods: The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, open-label, multicentre, international registry with a follow-up of 5 years to assess clinical outcomes of patients younger than 60 years who undergo surgical AVR using the INS

Sex-related Differences among Patients Undergoing Surgical Aortic Valve Replacement - A Propensity Score Matched Study.

OBJECTIVES We investigated the sex-related difference in characteristics and 2-year outcomes after surgical aortic valve replacement (SAVR) by propensity-score matching (PSM). METHODS Data from two prospective registries, INDURE and IMPACT, were merged, resulting in a total of 933 patients: 735 males and 253 females undergoing first-time SAVR. PSM was performed to assess the impact of sex on the SAVR outcomes, yielding 433 males and 243 females with comparable baseline characteristics. RESULTS Females had a lower body mass index (BMI; median 27.1 vs 28.0 kg/m2; p = 0.008), fewer bicuspid valves (52% vs 59%; p = 0.036), higher EuroSCORE II (mean 2.3 vs 1.8%; p < 0.001) and STS score (mean 1.6 vs 0.9%; p < 0.001), were more often in NYHA class III/IV (47% vs 30%; p < 0.001) and angina CCS III/IV (8.2% vs 4.4%; p < 0.001), but had a lower rate of myocardial infarction (1.9% vs 5.2%; p = 0.028) compared to males. These differences vanished after PSM, except for EuroSCORE II and STS scores, which were still significantly higher in females. Furthermore, females required smaller valves (median diameter 23.0 vs 25.0 mm, p < 0.001). There were no differences in the length of hospital stay (median 8 days) or ICU stay (median 24 vs 25 hours) between both sexes. At two years, post-SAVR outcomes were comparable between males and females, even after PSM. CONCLUSIONS Despite females presenting with a significantly higher surgical risk profile, 2-year outcomes following SAVR were comparable between males and females

Formal consensus study on surgery to replace the aortic valve in adults aged 18-60 years

Objective: There is uncertainty about surgical procedures for adult patients aged 18-60 years undergoing aortic valve replacement (AVR). Options include conventional AVR (mechanical, mAVR; tissue, tAVR), the pulmonary autograft (Ross) and aortic valve neocuspidisation (Ozaki). Transcatheter treatment may be an option for selected patients. We used formal consensus methodology to make recommendations about the suitability of each procedure. Methods: A working group, supported by a patient advisory group, developed a list of clinical scenarios across seven domains (anatomy, presentation, cardiac/non-cardiac comorbidities, concurrent treatments, lifestyle, preferences). A consensus group of 12 clinicians rated the appropriateness of each surgical procedure for each scenario on a 9-point Likert scale on two separate occasions (before and after a 1-day meeting). Results: There was a consensus that each procedure was appropriate (A) or inappropriate (I) for all clinical scenarios as follows: mAVR: total 76% (57% A, 19% I); tAVR: total 68% (68% A, 0% I); Ross: total 66% (39% A, 27% I); Ozaki: total 31% (3% A, 28% I). The remainder of percentages to 100% reflects the degree of uncertainty. There was a consensus that transcatheter aortic valve implantation is appropriate for 5 of 68 (7%) of all clinical scenarios (including frailty, prohibitive surgical risk and very limited life span). Conclusions: Evidence-based expert opinion emerging from a formal consensus process indicates that besides conventional AVR options, there is a high degree of certainty about the suitability of the Ross procedure in patients aged 18-60 years. Future clinical guidelines should include the option of the Ross procedure in aortic prosthetic valve selection

Nanoelectronic COupled problems solutions - nanoCOPS: modelling, multirate, model order reduction, uncertainty quantification, fast fault simulation

The FP7 project nanoCOPS derives new methods for simulation during development of designs of integrated products. It covers advanced simulation techniques for electromagnetics with feedback couplings to electronic circuits, heat and stress. It is inspired by interest from semiconductor industry and by a simulation tool vendor in electronic design automation. The project is on-going and the paper presents the outcomes achieved after the first half of the project duration