Impact of the indexed effective orifice area on mid-term cardiac-related mortality after aortic valve replacement

Background There has been ongoing controversy as to whether prosthesis-patient mismatch (PPM, defined as indexed effective orifice area (EOAI) <0.85 m(2)/cm(2)) influences mortality after aortic valve replacement (AVR). In most studies, PPM is anticipated by reference tables based on mean EOAs as opposed to individual assessment. These reference values may not reflect the actual in vivo EOAI and hence, the presence or absence of PPM may be based on false assumptions. Objective To assess the impact of small prosthesis EOA on survival after aortic valve replacement AVR. Methods 645 patients had undergone an AVR between 2000 and 2007 entered the study. All patients underwent transthoracic echocardiography for determination of the actual EOAI within 6 months postoperatively. In order to predict time from surgery to death a proportional hazards model for competing risks (cardiac death vs death from other causes) was used. EOAI was entered as a continuous variable. Results PPM occurred in 40% of the patients. After a median follow-up of 2.35 years, 92.1% of the patients were alive. The final Cox regression model showed a significantly increased risk for cardiac death among patients with a smaller EOAI (HR=0.32, p=0.022). The effect of EOAI on the 2-5 year mortality risk was demonstrated by risk plots. Conclusions In contrast to previous studies these EOAI values were obtained through postoperative echocardiography, substantially improving the accuracy of measurement, and the EOAI was modelled as a continuous variable. There was a significantly improved survival for larger EOAIs following AVR. Strategies to avoid PPM should become paramount during AVR

Science fiction and human enhancement: radical life-extension in the movie ‘In Time’ (2011)

The ethics of human enhancement has been a hotly debated topic in the last 15 years. In this debate, some advocate examining science fiction stories to elucidate the ethical issues regarding the current phenomenon of human enhancement. Stories from science fiction seem well suited to analyze biomedical advances, providing some possible case studies. Of particular interest is the work of screenwriter Andrew Niccol (Gattaca, S1m0ne, In Time, and Good Kill), which often focuses on ethical questions raised by the use of new technologies. Examining the movie In Time (2011), the aim of this paper is to show how science fiction can contribute to the ethical debate of human enhancement. In Time provides an interesting case study to explore what could be some of the consequences of radical life-extension technologies. In this paper, we will show how arguments regarding radical life-extension portrayed in this particular movie differ from what is found in the scientific literature. We will see how In Time gives flesh to arguments defending or rejecting radical life-extension. It articulates feelings of unease, alienation and boredom associated with this possibility. Finally, this article will conclude that science fiction movies in general, and In Time in particular, are a valuable resource for a broad and comprehensive debate about our coming future

Exercise hemodynamics of bovine versus porcine bioprostheses: A prospective randomized comparison of the mosaic and perimount aortic valves

ObjectiveThis prospective randomized study compares a porcine with a bovine bioprosthesis in the aortic position with regard to hemodynamic performance during exercise.MethodsBetween August of 2000 and December of 2002, 136 patients underwent aortic valve replacement with the porcine Medtronic Mosaic (n = 66) or the bovine Carpentier-Edwards Perimount (n = 70) bioprosthesis. Transthoracic echocardiography was performed to assess hemodynamic and dimensional data preoperatively and 10 months postoperatively; the latter follow-up included stress echocardiography with treadmill exercise.ResultsAt rest and during exercise (25 and 50 W), there was a significant difference in mean pressure gradient between the bovine and the porcine valves with labeled sizes 21 and 23, with superiority of the Perimount prosthesis. There was no difference in effective orifice area and incidence of patient-prosthesis mismatch among all sizes. The left ventricular mass index decreased significantly within 10 months postoperatively in the size 23 bovine group and the size 25 porcine group.ConclusionsOur data show a significant superiority of pressure gradients for the bovine bioprosthesis, especially with small valve sizes, when compared with the porcine device, which is more distinctive during exercise

An ancestral non-proteolytic role for presenilin proteins in multicellular development of the social amoeba dictyostelium discoideum

Mutations in either of two presenilin genes can cause familial Alzheimer's disease. Presenilins have both proteolysis-dependent functions, as components of the γ-secretase complex, and proteolysis-independent functions in signalling. In this study, we investigate a conserved function of human presenilins in the development of the simple model organism Dictyostelium discoideum. We show that the block in Dictyostelium development caused by the ablation of both Dictyostelium presenilins is rescued by the expression of human presenilin 1, restoring the terminal differentiation of multiple cell types. This developmental role is independent of proteolytic activity, because the mutation of both catalytic aspartates does not affect presenilin ability to rescue development, and the ablation of nicastrin, a γ-secretase component that is crucial for proteolytic activity, does not block development. The role of presenilins during Dictyostelium development is therefore independent of their proteolytic activity. However, presenilin loss in Dictyostelium results in elevated cyclic AMP (cAMP) levels and enhanced stimulation-induced calcium release, suggesting that presenilins regulate these intracellular signalling pathways. Our data suggest that presenilin proteins perform an ancient non-proteolytic role in regulating intracellular signalling and development, and that Dictyostelium is a useful model for analysing human presenilin function

Transcatheter Aortic Valve Replacement Using Transaortic Access

OBJECTIVES The Registry of the Utilization of the TAo-TAVR approach using the Edwards SAPIEN Valve (ROUTE) was established to assess the effectiveness and safety of the use of transaortic (TAo) access for transcatheter aortic valve replacement (TAVR) procedures (NCT01991431). BACKGROUND TAVR represents an alternative to surgical valve replacement in high-risk patients. Whereas the transfemoral access route is used commonly as the first-line approach, transapical access is an option for patients not suitable for transfemoral treatment mainly due to anatomic conditions. TAo-TAVR has been shown to be a viable alternative surgical access route; however, only limited data on its effectiveness and safety has been published. METHODS ROUTE is a multicenter, international, prospective, observational registry; data were collected from 18 centers across Europe starting in February 2013. Patients having severe calcific aortic stenosis were documented if they were scheduled to undergo TAo-TAVR using an Edwards SAPIEN XT or a SAPIEN 3 valve. The primary endpoint was 30-day mortality. Secondary endpoints were intraprocedural or in hospital and 30-day complication rates. RESULTS A total of 301 patients with a mean age of 81.7 +/- 5.9 years and an Society of Thoracic Surgeons score of 9.0 +/- 7.6% were included. Valve success was documented in 96.7%. The 30-day mortality was 6.1% (18/293) (procedure-related mortality: 3.1%; 9 of 293). The Valve Academic Research Consortium-2 defined complications included myocardial infarction (1.0%), stroke (1.0%), transient ischemic attack (0.3%), major vascular complications (3.4%), life-threatening bleeding (3.4%), and acute kidney injury (9.5%). In 3.3% of patients, paravalvular regurgitation was classified as moderate or severe (10 of 300). Twenty-six patients (8.8%) required permanent pacemaker implantation. CONCLUSIONS TAo access for TAVR seems to be a safe alternative to the transapical procedure. (C) 2016 by the American College of Cardiology Foundation.Peer reviewe

Balloon-expandable transaortic transcatheter aortic valve implantation with or without predilation

Objective: It has been reported that balloon aortic valvuloplasty immediately before transfemoral or transapical transcatheter aortic valve implantation has mostly little to no clinical value. We aimed to provide data on the need for balloon aortic valvuloplasty in patients undergoing transaortic transcatheter aortic valve implantation. Methods: Patients undergoing transaortic transcatheter aortic valve implantation with the Edwards SAPIEN XT (Nyon, Switzerland) or 3 transcatheter heart valve were prospectively included at 18 sites across Europe. In the present analysis, we compare the periprocedural and 30-day outcomes of patients undergoing conventional (thorn balloon aortic valvuloplasty) versus direct (-balloon aortic valvuloplasty) transaortic transcatheter aortic valve implantation. Results: Of the 300 patients enrolled, 222 underwent conventional and 78 underwent direct transaortic transcatheter aortic valve implantation. Peak and mean transvalvular gradients were improved in both groups with no significant difference between groups. Procedural duration, contrast agent volume, and requirement for postdilation were also comparable. A trend toward fewer periprocedural complications was evident in the direct group (3.9% vs 11.3%; P = .053), with significantly lower rates of permanent pacemaker implantation (0% vs 5.0%; P = .034). Balloon aortic valvuloplasty omission had no significant effect on any of the 30-day safety and efficacy outcomes, including Valve Academic Research Consortium-2 composite end points (early safety events: 22.7% vs 17.4%, odds ratio, 1.17, 95% confidence interval, 0.53-2.62; clinical efficacy events: 20.5% vs 18.7%, odds ratio, 1.14, 95% confidence interval, 0.51-2.55). Conclusions: For many patients, balloon aortic valvuloplasty predilation seems to have little clinical value in transaortic transcatheter aortic valve implantation using a balloon expandable transcatheter valve and may result in a higher rate of periprocedural complications, particularly in terms of permanent pacemaker implantation.Peer reviewe

Transaortic transcatheter aortic valve implantation as a first-line choice or as a last resort? An analysis based on the ROUTE registry

OBJECTIVES: Transaortic transcatheter aortic valve implantation (TAo-TAVI) is a recently developed alternative to transapical (TA) or transfemoral (TF) TAVI. We aimed to analyse the effectiveness and safety of TAo-TAVI as a first line approach and to compare it to patients receiving TAo-TAVI as a last resort, which is current practice. METHODS: ROUTE is a prospective, multicentre registry to assess the clinical outcomes of TAo-TAVI. Patients without contraindications for TA-and TF-TAVI (TAo-first) were compared to patients with contraindications for both of these access routes (TAo-last). Outcome analysis was based on VARC II defined clinical end-points. RESULTS: Three hundred and one patients were included, of which 224 patients met TAo-first and 77 TAo-last criteria. The valve was delivered and catheter retrieved successfully in all patients. In the TAo-first group, rates of conversion to open surgery and requirement for a second valve were low and not different compared to TAo-last patients (1% vs. 3%, P = 0.46 and 1% vs. 3%, P = 0.46, respectively). This was also true for the rate of paravalvular regurgitation (>= moderate: 4% vs. 3%). All-cause mortality at 30-days was 6% vs. 5% (P = 0.76), rates of stroke 2% vs. 0% (P = 0.24), pacemaker implantation (11% vs. 4%, P = 0.093), and life-threatening bleeding 4% vs. 3% (P = 0.70). Valve safety (both 85%, P = 0.98) and clinical efficacy (80% vs. 82%; P = 0.73) did not differ between groups. CONCLUSIONS: Although comparative data to TA and TF procedures were not available in the present analysis, findings suggest that TAo may be considered not only as a last resort strategy when classical access routes are deemed unfeasible, but also as a potential first-line option, with only low rates of paravalvular regurgitation and permanent pacemaker implantation.Peer reviewe

Biological Contamination Prevention for Outer Solar System Moons of Astrobiological Interest: What Do We Need to Know?

To ensure that scientific investments in space exploration are not compromised by terrestrial contamination of celestial bodies, special care needs to be taken to preserve planetary conditions for future astrobiological exploration. Significant effort has been made and is being taken to address planetary protection in the context of inner Solar System exploration. In particular for missions to Mars, detailed internationally accepted guidelines have been established. For missions to the icy moons in the outer Solar System, Europa and Enceladus, the planetary protection requirements are so far based on a probabilistic approach and a conservative estimate of poorly known parameters. One objective of the European Commission-funded project, Planetary Protection of Outer Solar System, was to assess the existing planetary protection approach, to identify inherent knowledge gaps, and to recommend scientific investigations necessary to update the requirements for missions to the icy moons