Aims: Elevated gradients have been proposed to be associated with haemodynamic structural valve deterioration (SVD) after transcatheter aortic valve implantation (TAVI); however, data regarding their characterisation remain scarce. This study sought to investigate the prevalence and predictors of moderate or greater SVD and the prevalence of valve thrombosis during follow-up after TAVI with balloon-expandable valves.Methods and results: A total of 691 patients undergoing transfemoral TAVI were enrolled. The primary endpoint was moderate or severe haemodynamic SVD during 12-month follow-up after TAVI, defined as (I) mean transvalvular gradient ≥20 mmHg or (II) mean transvalvular gradient increase ≥10 mmHg. The primary endpoint was observed in 10.3% after TAVI. Use of a 20 mm valve, valve-in-valve procedure and absence of oral anticoagulation (OAC) were independently associated with haemodynamic SVD, whereas valve-in-valve procedure and absence of OAC were the only significant variables after accounting for death as a competing event. Absence of OAC was significantly associated with haemodynamic SVD (RR 8.65; p=0.004) and death (RR 3.57; p=0.06), whereas valve-in-valve procedure was only associated with haemodynamic SVD (RR 52.76; p<0.001). Valve thrombosis was present in 0.87% (6/691) of the patients. Conclusions:The prevalence of moderate or greater haemodynamic SVD during the first 12 months after TAVI is 10.3%. Procedural factors and pharmacotherapy seem to play a key role during manifestation. Future studies should focus on the underlying mechanisms.

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In many developing countries no infrastructure for providing people with microbiological safe drinking water exists. This demands for decentralized water disinfection that is inexpensive and requires no consumables. The casualties are often recommended the application of SODIS for drinking water treatment. There are numerous scientific studies on this disinfection method, which however are still leaving questions on the mode of functioning which is often reduced to the effect caused by the UV part of the solar radiation and there is almost no discussion in the literature what happens to the disinfected water after the SODIS treatment.In this paper disinfection experiments with Escherichia coli in isotonic saline solutions and real surface water are performed for a set of realistic conditions for UVA irradiation and for heating but separated from each other. The results confirm that SODIS is based on the combined effect of UVA radiation and increased temperature. Further experiments lead to the recommendation that once disinfected water should be consumed without a large delay, otherwise the germ concentration rises again.

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