Background-To evaluate initial multicenter results with minimally invasive transapical aortic valve implantation (TAP-AVI) for high risk patients with aortic stenosis. Methods and Results-TAP-AVI was performed via a small anterolateral minithoracotomy with or without femorofemoral extracorporeal circulation (ECC) on the beating heart. A pericardial xenograft fixed within a stainless steel, balloon expandable stent (Edwards SAPIEN THV, Edwards Lifesciences) was used. Fifty-nine consecutive patients (81Ϯ6 years, 44 female) were operated on from 02/06 until 10/06 at 4 centers using fluoroscopic and echocardiographic visualization. Average EuroSCORE predicted risk for mortality was 27Ϯ14%. TAP valve positioning was performed successfully in 53 patients, 4 required early conversion to sternotomy. Implantation (23-mm valves in 19 and 26-mm valves in 40 patients) was performed on the beating heart during brief periods of rapid ventricular pacing. Thirty-one patients were operated on without cardiopulmonary bypass. Neither coronary artery obstruction nor migration of the prosthesis was observed, and all valves had good hemodynamic function. Echocardiography revealed minor paravalvular leakage in 26 patients (trace in 11, mild in 12, and severe in 3). Eight patients died in-hospital (13.6%) without any valve dysfunction. Actuarial survival was 75.7Ϯ5.9% at a follow-up interval of 110Ϯ77 days (range 1 to 255 days). Conclusions-TAP-AVI can be performed safely with good early results in high risk patients. Long-term valve performance as well as broader based applications of this promising approach will need to be studied.
Background-Porcine bone marrow-derived mesenchymal stem cells (MSCs) were stably transfected with a lentiviral vector for transgene expression of the trifusion protein renilla luciferase, red fluorescent protein and herpes simplex truncated thymidine kinase (LV-RL-RFP-tTK; positron emission tomography [PET] reporter gene) for in vivo noninvasive tracking of the intramyocardially delivered MSC fate. Methods and Results-A closed-chest, reperfused myocardial infarction was created in farm pigs. Sixteen days after myocardial infarction, LV-RL-RFP-tTK-MSCs were injected intramyocardially using electromechanical mapping guidance in the infarct border zone (nϭ7). PET-computed tomographic metabolic and perfusion imaging was performed after an intravenous injection of 10 mCi [18F]-FHBG and 13N-ammonia PET at 30Ϯ2 hours and 7 days after LV-RL-RFP-tTK-MSC treatment.
Fusion imaging of the [18F]-FHBG PET-computed tomography with MRI was used to determine the myocardial location of the injected LV-RL-RFP-tTK-MSCs. Seven days after injections, [18F]-FHBG PET showed a decreased cardiac uptake with a mild increased pericardial and pleura uptake in the treated animals, which was confirmed by the measurement of luciferase activity. At 10 days, infarct size by MRI in the LV-RL-RFP-tTK-MSC-treated animals was smaller than controls (nϭ7
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