Cell therapy trials using cardiac-resident progenitor cells (CPCs) and bone marrow-derived mesenchymal stem/progenitor cells (BMCs) in patients after myocardial infarction have provided encouraging results. Exosomes, nanosized extracellular vesicles of endosomal origin, figure prominently in the bioactivities of these cells. However, a head-to-head comparison of exosomes from the two cell types has not been performed yet. CPCs and BMCs were derived from cardiac atrial appendage specimens and sternal bone marrow, respectively, from patients (n = 20; age, 69.9 ± 10.9) undergoing heart surgery for aortic valve disease and/or coronary artery disease. Vesicles were purified from cell conditioned media by centrifugation/filtration and ultracentrifugation. Vesicle preparations were predominantly composed of exosomes based on particle size and marker expression (CD9, CD63, CD81, Alix, and TSG-101). CPC-secreted exosomes prevented staurosporine-induced cardiomyocyte apoptosis more effectively than BMC-secreted exosomes. In vivo, CPC-secreted exosomes reduced scar size and improved ventricular function after permanent coronary occlusion in rats more efficiently than BMC-secreted exosomes. Both types of exosomes stimulated blood vessel formation. CPC-secreted exosomes, but not BMC-derived exosomes, enhanced ventricular function after ischaemia/reperfusion. Proteomics profiling identified pregnancy-associated plasma protein-A (PAPP-A) as one of the most highly enriched proteins in CPC vs. BMC exosomes. The active form of PAPP-A was detected on CPC exosome surfaces. These vesicles released insulin-like growth factor-1 (IGF-1) via proteolytic cleavage of IGF-binding protein-4 (IGFBP-4), resulting in IGF-1 receptor activation, intracellular Akt and ERK1/2 phosphorylation, decreased caspase activation, and reduced cardiomyocyte apoptosis. PAPP-A knockdown prevented CPC exosome-mediated cardioprotection both in vitro and in vivo. These results suggest that CPC-secreted exosomes may be more cardioprotective than BMC-secreted exosomes, and that PAPP-A-mediated IGF-1 release may explain the benefit. They illustrate a general mechanism whereby exosomes may function via an active protease on their surface, which releases a ligand in proximity to the transmembrane receptor bound by the ligand.

Left ventricular (LV) endocardial pacing may address the limitations in the selection of an LV pacing site and provide improvements in cardiac resynchronization therapy (CRT) effectiveness. We report on the feasibility, the safety, and the short-term outcome of a leadless ultrasound-based technology for LV endocardial resynchronization in heart failure (HF) patients enroled into the Wireless Stimulation Endocardially for CRT (WiSE-CRT) study. Seventeen HF patients were enroled and categorized as: (i) patients in whom attempted coronary sinus lead implantation for CRT had failed (n = 7); (ii) patients with a previously implanted CRT device, not responding to CRT (n = 2); and (iii) patients with previously implanted pacemakers or implantable cardioverter-defibrillator and meeting the standard indications for CRT (n = 8). System implantation was achieved in 13 patients (76.5%); mean R-wave amplitude was 5.6 ± 3.2 mV and the mean pacing threshold was 1.6 ± 1.0 V, respectively. In one patient, no sufficient pacing thresholds were found; in three patients pericardial effusion occurred. Biventricular pacing was recorded in 83% and 92% of the patients at 1 month and 6 months, respectively. QRS duration was shorter during biventricular pacing compared with right ventricular pacing at 1 month (−41 ms; P = 0.0002) and 6 months (−42 ms; P = 0.0011), respectively. At the 6-month follow-up, two-thirds of the patients had at least one functional class change. Left ventricular ejection fraction significantly increased (P < 0.01) by 6 points at the 6-month follow-up. The feasibility of providing an endocardial stimulation for CRT with a leadless technology was successfully demonstrated. Despite the promising results for a novel technology, further study is required to definitively conclude the safety and the performance of the system. NCT01294527.

Anatomical features of the aortic arch such as its steepness, the take‐off angles and the distances between its supra‐aortic branches can influence the feasibility and difficulty of interventional and/or surgical maneuvers. These anatomical characteristics were assessed by means of 3D multiplanar reconstruction of thoracic angio‐computed tomography scans of 92 living patients (79 males, 13 females, mean age 69.4 ± 9.9 years) carried out for various indications (gross pathology of the thoracic aorta excluded). There was a significant variation of all measured parameters between the subjects – a standard aortic arch (i.e. with all measured parameters within 2 SD) does not seem to exist. There were no significant differences between genders but some of the parameters correlated significantly to age.

The occurrence of severe graft failure after lung transplantation which appears refractory to conventional treatment represents a difficult situation with regard to the therapeutic strategies available. Of 17 patients undergoing single lung transplantation at our center, 2 developed early graft failure. In both, temporary artificial cardiopulmonary support by means of extracorporeal membrane oxygenation became necessary as a bridge to retransplantation. Both patients were successfully retransplanted after 8 h and 232 h, respectively, of extra-corporeal support. Postoperatively, there was a variety of complications. The first patient completely recovered from temporary severe cerebral dysfunction diagnosed as "locked-in syndrome". She was discharged from hospital on the 93rd postoperative day and remains alive and well 10 months after her operation. The other patient recovered well early after retransplantation. Later, however, airway problems developed, requiring the implantation of endotracheal stents. Cachexia and several episodes of viral pneumonia contributed to the progressive deterioration of her clinical status. She finally died after being hospitalized for 5 months after the original operation. These two cases illustrate the feasibility of using extracorporeal membrane oxygenation as a bridge to pulmonary transplantation.