The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Nov 2014
Diabetic hearts have lower basal urocortin levels that fail to increase after cardioplegic arrest: association with increased apoptosis and postsurgical cardiac dysfunction.
The present study investigated the cardioprotective role of urocortin (Ucn) and its relationship with protein kinase C (PKC)ε and PKCδ in patients with (DMPs) and without (NDMPs) diabetes mellitus after on-pump cardiac surgery (OPCS). The molecular mechanisms responsible for the reported worse outcomes of DMP after OPCS remain unknown. ⋯ Cardioplegic arrest failed to induce in DMPs myocyte overexpression of Ucn or PKCε but was associated with induction and mitochondrial relocation of PKCδ, resulting in apoptosis. Failure to overexpress Ucn in the DMPs was associated with apoptosis and cardiac dysfunction and, thus, might contribute to worse postoperative outcomes.
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J. Thorac. Cardiovasc. Surg. · Nov 2014
Targeted imaging of matrix metalloproteinase activity in the evaluation of remodeling tissue-engineered vascular grafts implanted in a growing lamb model.
The clinical translation of tissue-engineered vascular grafts has been demonstrated in children. The remodeling of biodegradable, cell-seeded scaffolds to functional neovessels has been partially attributed to matrix metalloproteinases. Noninvasive assessment of matrix metalloproteinase activity can indicate graft remodeling and elucidate the progression of neovessel formation. Therefore, matrix metalloproteinase activity was evaluated in grafts implanted in lambs using in vivo and ex vivo hybrid imaging. Graft growth and remodeling was quantified using in vivo x-ray computed tomography angiography. ⋯ Matrix metalloproteinase activity remained elevated in tissue-engineered grafts 6 months after implantation and could indicate remodeling. Optimization of in vivo imaging to noninvasively evaluate matrix metalloproteinase activity could assist in the serial assessment of vascular graft remodeling.
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J. Thorac. Cardiovasc. Surg. · Nov 2014
Repeat sternotomy for surgical aortic valve replacement in octogenarian patients with aortic valve stenosis and previous coronary artery bypass graft operation: what is the operative risk?
There are limited data defining the risk of repeat sternotomy for surgical aortic valve replacement in octogenarian patients with aortic valve stenosis and previous coronary artery bypass graft operation. Our study assesses the risk of operation. ⋯ Repeat sternotomy and surgical aortic valve replacement can be done with low risk in octogenarian patients with previous coronary artery bypass graft operation.
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J. Thorac. Cardiovasc. Surg. · Nov 2014
Timing of valve repair for severe degenerative mitral regurgitation and long-term left ventricular function.
Current guidelines recommended surgery for patients with severe degenerative mitral regurgitation (MR) when specific left ventricular (LV) dimensions or ejection fraction (EF) are reached, based on previous postoperative survival studies. The aim of this study was to evaluate the incidence and predictors of long-term postoperative LV dysfunction, and investigate the preoperative parameters necessary to maintain or recover long-term LV function in the era of mitral valve (MV) repair. ⋯ Early MV repair with LVEF greater than 63% and LVESD less than 39 mm preserved long-term postoperative LV function well, and smaller preoperative LVESD was associated with long-term LV function recovery, even in patients with preoperative LV dysfunction.
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J. Thorac. Cardiovasc. Surg. · Nov 2014
Lung injury after simulated cardiopulmonary bypass in an isolated perfused rat lung preparation: Role of mitogen-activated protein kinase/Akt signaling and the effects of theophylline.
Lung deflation and inflation during cardiac surgery with cardiopulmonary bypass contributes to pulmonary dysfunction postoperatively. Theophylline treatment for lung diseases has traditionally been thought to act by phosphodiesterase inhibition; however, increasing evidence has suggested other plausible mechanisms. We investigated the effects of deflation and reinflation on signaling pathways (p38-mitogen-activated protein kinase [MAPK], extracellular signal-regulated kinase 1 and 2 [ERK1/2], and Akt) and whether theophylline influences the deflation-induced lung injury and associated signaling. ⋯ Lung deflation and reinflation stimulates differential p38-MAPK, ERK1/2, and Akt activation, suggesting a role in lung injury during cardiopulmonary bypass. However, p38-MAPK was not involved in the compromised compliance. A supratherapeutic theophylline dose protected lungs against deflation-induced injury and was associated with inhibition of phosphoinositide 3-kinase/Akt rather than phosphodiesterase.