The paradigm that cardiac myocytes are non-proliferating and terminally differentiated cells has recently been challenged by several studies reporting the ability of bone marrow-derived cells (BMC) to transdifferentiate into cardiomyocytes. However, these results are controversial and could not be reproduced by others. Therefore, we studied the contribution and potential transdifferentiation of BMC into different cell types during the remodelling process in mouse hearts with experimental myocardial infarction. Mice (C57BL/6J) were sublethally irradiated, and BM from enhanced green fluorescent protein (eGFP)-transgenic mice was transplanted. Coronary artery ligation was performed 3 months later. The hearts were studied 7 days (n=13) and 21 days (n=12) after infarction. Immunohistochemical staining was performed using antibodies against titin, connexin 43, vimentin, SMemb alpha-smooth muscle actin, CD45, CD34, F4/80, BS-1, CD31, and eGFP. Sections were analyzed using fluorescence and confocal laser microscopy. Success of BM transplantation was confirmed by FACS analysis. Occlusion of the coronary artery resulted in infarct sizes of 41+/-6% of the left ventricle. CD45+/eGFP+ inflammatory cells were found frequently after 7 days and to a lesser degree after 21 days. In 25 examined hearts, only 3 eGFP-positive cardiomyocytes were found. However, numerous BMC-derived fibroblasts and myofibroblasts were found in the infarct area. BMC contributed to scar tissue neoangiogenesis but not to angiogenesis in the periinfarct and remote zones. Transdifferentiation of BMC into viable cardiomyocytes is a negligible event in normal repair processes after myocardial damage. BMC-derived fibroblasts and myofibroblasts as well as neoangiogenesis significantly contribute to post-infarction scar formation and might be important in scar tissue remodelling.

Background: Transcatheter aortic valve implantation (TAVI) has become standard treatment for elderly patients with symptomatic severe aortic valve stenosis. The ACURATE neo AS study evaluates 30-day and 1-year clinical and hemodynamic outcomes in patients treated with the ACURATE neo2 valve. Methods: The primary endpoint of this single-arm multicenter study is 30-day all-cause mortality. Other key endpoints include device performance, echocardiographic measures assessed by an independent core laboratory, and VARC-2 clinical efficacy and safety endpoints through 12 months. Results: The study enrolled 120 patients (mean age 82.1 ± 4.0 years; 67.5% female, mean baseline STS score 4.8 ± 3.8%). The VARC-2 composite safety endpoint at 30 days occurred in 13.3% of patients. All-cause mortality was 3.3% at 30 days and 11.9% at 1 year. The 30-day stroke rate was 2.5% (disabling stroke 1.7%); there were no new strokes between 30 days and 12 months. The rate of permanent pacemaker implantation was 15.0% (18/120) at 30 days and 17.8% (21/120) at 1 year. No patients required re-intervention for valve-related dysfunction and there were no cases of valve thrombosis or endocarditis. Patients demonstrated significant improvement in mean aortic valve gradient (baseline 38.9 ± 13.1 mmHg, 1 year 7.8 ± 3.5 mmHg; P < 0.001 in a paired analysis). In the overall population, paravalvular leak was evaluated at 1 year as none/trace in 60.5%, mild in 37.0%, and moderate in 2.5%; no patients had severe PVL. Conclusions: One-year outcomes from the ACURATE neo AS study support the safety and performance of TAVI with the ACURATE neo2 valve. Graphic

We analysed the number of procedures, complications, and in-hospital mortality rates of all patients undergoing transvascular transcatheter aortic valve implantation (TV–TAVI) in comparison to isolated surgical aortic valve replacement (iSAVR) from 2014 to 2016 in Germany. All aortic valve procedures performed in Germany are mandatorily registered in a quality control program. More than 15 000 TV–TAVI procedures were performed in 2016 in Germany. Especially the number of post-procedural complications declined within the last few years, including new pacemaker implantations (2015: 12.6% vs. 2016: 11.4%, P = 0.002) and vascular complications (2015: 8.5% vs. 2016: 7.1%; P < 0.001). Thus, in 2016 the overall in-hospital mortality rate after TV–TAVI was 2.6%, which is for the first time numerically below that of iSAVR, which was 2.9% (P = 0.19). A stratified analysis according to the German aortic valve score shows a lower observed than expected in-hospital mortality rate for TV–TAVI (O/E 0.68). Additionally, the in-hospital mortality was significantly lower after TV–TAVI than after iSAVR in the very high- (11.3% vs. 23.6%; P < 0.001), in the high- (4.1% vs. 9.2%; P < 0.001), and in the intermediate-risk group (3.0% vs. 4.6%; P = 0.016) and was similar to that of iSAVR in low-risk patients (1.6% vs. 1.4%; P = 0.4). The overall in-hospital mortality after TV–TAVI was numerically lower than after iSAVR in 2016 for the first time. In the low risk group in-hospital mortality was similar, whereas in all other risk groups in-hospital mortality after TV–TAVI was significantly lower than after SAVR. This is likely to contribute to a redefinition of the standard of care in the future.