ECG Changes after CABG: The Role of the Surgical Technique

Objective: The purpose of this study was to determine whether coronary artery bypass grafting (CABG) surgery on the beating heart (BH) is associated with reduction of R-wave potentials on the precordial leads on the surface electrocardiogram (ECG) as previously shown for CABG with cardiopulmonary bypass. Methods: Fifty-four patients undergoing CABG surgery at a single tertiary care university hospital were analyzed. Patients suffering a postoperative cardiac event (myocardial infarction) or nonspecific ECG changes were excluded. ECG results were recorded at arrival in the intensive care unit, after 4 and 18 hours postoperatively; simultaneously, myocardial cell damage biomarkers (CK-MB and cTnI) were assayed. A control group of 31 patients undergoing mitral valve repair was also evaluated. Results: Patients operated with the BH (OPCABG) technique did not show any decrease of R-wave amplitude at 0, 4, and 18 hours postoperatively; whereas those operated with CPB, both for coronary artery surgery and for mitral repair, had a similar extent and pattern of R-wave reduction. The release of myocardial necrosis markers was significantly lower in coronary artery patients operated with BH than in those operated with CPB; however, no statistically significant correlation between the ECG changes and release of myocardial cell damage markers was observed in any of the groups. Conclusions: The findings indicate, for the first time, that CABG surgery on the BH is not followed by any reduction of R-wave amplitude on precordial leads and confirms that the BH technique is associated with a lower release of myocardial cell damage markers. © 2004 Elsevier Inc. All rights reserved

Cardiac Biomarker Release after CABG with Different Surgical Techniques

Objective: To investigate the release of cardiac biomarkers (troponin I and CK-MB) in patients undergoing coronary artery bypass graft (CABG) with or without cardiopulmonary bypass (CPB). Design: Prospective study, Setting: University tertiary hospital. Participants: Sixty-five consecutive patients undergoing coronary artery bypass grafting (â\u89¥2 vessel disease, ejection fraction â\u89¥0.35%, elective procedure). Interventions: Cardiac biomarkers were measured before surgery, at intensive care unit arrival, 4 and 18 hours after the end of the procedure. Measurements and Main Results: Cardiac biomarker release was higher in on-pump than in off-pump patients at every time point. On multivariate analysis, CPB (p â\u89¤ 0.0001), number of distal grafts (p = 0.005), and hypertension treatment (p = 0.03) were the only independent predictors of peak cardiac troponin release. Conclusions: Cardiac troponin I release after multivessel CABG is associated with the technique. Different values for the normal range should be considered. OPCABG is minimally invasive for the heart as far as myocardial marker release is concerned. © 2004 Elsevier Inc. All rights reserved

“Clickable” bacterial poly(gamma-glutamic acid)

Poly(gamma-glutamic acid) (gamma-PGA) is one of the few bacterial polymers in nature; as such, it possesses the added value of a “green birth” (fermentation) and “green death” (biodegradability), which is ideal for sustainable macromolecular platforms. Efficient functionalization strategies are required in order to transform the native bacterial biopolymer into a material with tailored properties for bulk scale or biomedical applications. We report on a novel approach to the facile functionalization of bacterial gamma-PGA, realized with several levels of control: (a) the modulation of the molecular weight through sonication, and the solubilization in organic solvents through counterion exchange with suitable quaternary ammonium salts, (b) the introduction of reactive functionalities through reactions in homogeneous conditions in organic solvents, to afford homo- or copolymers; (c) a second tier functionalization using copper(I)-catalyzed alkyne–azide cycloaddition (CuAAC) click chemistry.Peer ReviewedPostprint (published version

Biocompatible graft copolymers from bacterial poly(gamma-glutamic acid) and poly(lactic acid)

We report a novel approach for the modular and convergent construction of biocompatible graft copolymers starting from bacterial poly(¿-glutamic acid)(¿-PGA) and incorporating poly(lactic acid) (PLA). This synthesis strategy is controlled at different levels: (a) the choice of a suitable initiator for the ring-opening polymerization of lactide; (b) the chemical elaboration of the polylactic fragments; and (c) their convergent “grafting to” functionalization of bacterial ¿-PGA propargyl ester using copper(I)-catalyzed alkyne–azide cycloaddition (CuAAC) click chemistry. The graft copolymers are characterized in terms of their thermal and macromolecular properties, their conformational preferences through molecular modelling, and their cytotoxicity.Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesPostprint (author's final draft