A Decade of Transapical Aortic Valve Implantation.

BACKGROUND: Transcatheter-based aortic valve procedures have undergone tremendous evolution during the past decade and have led to great changes in the treatment of valvular heart disease. The Hospital of the Johann Wolfgang Goethe University, Frankfurt am Main, Germany is one of the three pioneering centers that started performing transapical transcatheter aortic valve implantation (TA-TAVI) back in 2005, and this study reviews the 10-year institutional experience with this approach. METHODS: From January 2005 through January 2015, 312 consecutive high-risk patients underwent TA-TAVI. Echocardiographic follow-up at discharge, at 6 and 12 months, and yearly thereafter was 100% complete. Structural behavior of the balloon-expandable valves in 11 patients with a mean follow-up time beyond 8 years was additionally evaluated at latest follow-up using computed tomography measurements. RESULTS: The age of the patients in this study was 79.8 ± 5.8 years, and the mean logistic EuroSCORE II and The Society of Thoracic Surgeons score were 23.9% ± 17.2% and 9.8% ± 8.6%, respectively. Perioperative, 30-day, and in-hospital mortality rates were 1.3%, 8.2%, and 9.5%, respectively, with a decrease in 30-day mortality to 4.2% in 2014. The incidence of neurologic complications was 3.2%. Mean length of hospital stay was 8.7 ± 4.3 days. Echocardiographic results demonstrated a significant and persistent increase of effective aortic valve orifice area (preoperative: 0.69 ± 0.1 cm(2) vs. late-follow-up: 1.52 ± 0.2 cm(2); p = 0.04) and a decrease in mean transvalvular gradient (preoperative: 49.5 ± 8.2 mm Hg vs. late-follow-up: 13.8 ± 4.3 mm Hg; p = 0.03) after a mean follow-up time of 4.1 ± 2.3 years. Overall survival rates were 73% ± 2% and 56% ± 6% at 3 and 5 years, respectively. Computed tomography measurements have not shown any signs of stress fracture of balloon-expandable stents up to 8 years of follow-up. CONCLUSIONS: A decade after clinical introduction of TA-TAVI, procedural and technical advances have made it an established alternative to classic aortic valve replacement in high-risk patients with aortic valve stenosis. Despite limited worldwide data on hemodynamic and structural valve behavior beyond 8 years, 11 patients from our early experience who were followed up for 8 years in the current report did not have any signs of structural valve dysfunction.

STR analysis of artificially degraded DNA-results of a collaborative European exercise.

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.