Impact of On-Site Cardiac Surgery on Clinical Outcomes After Transfemoral Transcatheter Aortic Valve Replacement.

OBJECTIVES: This study sought to investigate the outcome of high-risk and inoperable patients with severe symptomatic aortic stenosis undergoing transfemoral transcatheter aortic valve replacement (TAVR) in hospitals with (iOSCS) versus without institutional on-site cardiac surgery (no-iOSCS). BACKGROUND: Current guidelines recommend the use of TAVR only in institutions with a department for cardiac surgery on site. METHODS: In this analysis of the prospective multicenter Austrian TAVI registry, 1,822 consecutive high-risk patients with severe symptomatic aortic stenosis undergoing transfemoral TAVR were evaluated. A total of 290 (15.9%) underwent TAVR at no-iOSCS centers (no-iOSCS group), whereas the remaining 1,532 patients (84.1%) were treated in iOSCS centers (iOSCS group). RESULTS: Patients of the no-iOSCS group had a higher perioperative risk defined by the logistic EuroSCORE (20.9% vs. 14.2%; p < 0.001) compared with patients treated in hospitals with iOSCS. Procedural survival was 96.9% in no-iOSCS centers and 98.6% in iOSCS centers (p = 0.034), whereas 30-day survival was 93.1% versus 96.0% (p = 0.039) and 1-year survival was 80.9% versus 86.1% (p = 0.017), respectively. After propensity score matching for confounders procedural survival was 96.9% versus 98.6% (p = 0.162), 93.1% versus 93.8% (p = 0.719) at 30 days, and 80.9% versus 83.4% (p = 0.402) at 1 year. CONCLUSIONS: Patients undergoing transfemoral TAVR in hospitals without iOSCS had a significantly higher baseline risk profile. After propensity score matching short- and long-term mortality was similar between centers with and without iOSCS.

Optimal determination of steric mass action model parameters for beta-lactoglobulin using static batch experiments.

In this work, parameters of the steric mass-formalism SMA are optimally ascertained for a reliable determination of the adsorption isotherms of beta-lactoglobulin A and B under non-isocratic conditions. For this purpose, static batch experiments are used in contrast to the protocols based on different experimental steps, which use a chromatographic column. It is shown that parameters can already be determined for a small number of experiments by using a systematic procedure based on optimal model-based experimental design and an efficient NLP-solver. The in different works observed anti-Langmuir shape of the isotherm for small concentrations of beta-lactoglobulin A was corroborated. Moreover, we also found indications for a porosity variation with changing protein concentrations.