Cecília Andrade Santos

Pulmonary Valve Replacement After Operative Repair of Tetralogy of Fallot: Meta-Analysis and Meta-Regression of 3,118 Patients From 48 Studies

Because the real benefit of pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot who develop pulmonary insufficiency remains unclear, it is necessary to analyze the evidence published around the world. We performed a systematic review of studies that reported data about the effect of PVR in patients with repaired tetralogy of Fallot that developed pulmonary insufficiency, until December 2012. The variables chosen to represent the benefit were both right ventricular (RV) and left ventricular measures, QRS duration, and functional class. The principal summary measures were difference in means with 95% confidence interval and p values (considered statistically significant when p < 0.05). The differences in means were combined across studies with the weighted DerSimonian-Laird random effects model. Meta-analysis, sensitivity analysis, and meta-regression were completed with the software Comprehensive Meta-Analysis (version 2, Biostat, Inc., Englewood, New Jersey). Forty-eight studies involving 3,118 patients met the eligibility criteria. The pooled 30-day mortality was 0.87% (47 studies; 27 of 3,100 patients); the pooled 5-year mortality was 2.2% (24 studies; 49 of 2,231 patients); the pooled 5-year re-PVR was 4.9% (15 studies; 88 of 1,798 patients). The results of this meta-analysis demonstrate that after PVR: 1) the RV experiences improvement of its volumes and function; 2) the left ventricle experiences improvement of its function; 3) QRS duration decreases; 4) symptoms improve; 5) pre-operative RV geometry modulates the effect of PVR; and 6) there is important heterogeneity of the effects among the studies, and few publication biases. In conclusion, PVR seems to be a positive approach in the analyzed scenario.

Risk factors for mediastinitis after coronary artery bypass grafting surgery

OBJECTIVE Mediastinitis is a serious complication of median sternotomy and is associated to significant morbidity and mortality. The aim of this study is to identify risk factors for mediastinitis in patients undergoing coronary artery bypass grafting (CABG), without the use of bilateral internal thoracic artery (ITA), at the Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE. METHODS A retrospective study of 500 consecutive patients operated on between May 2007 and April 2010. Ten preoperative variables, seven intraoperative variables and seven postoperative variables possibly involved in the development of postoperative mediastinitis were evaluated. Univariate and multivariate logistic regression analyses were performed. RESULTS The incidence of mediastinitis was 5.6% (n=28), with a lethality rate of 32.1% (n=9). In multivariate analysis using logistic regression, five variables remained as independent risk factors: obesity (OR 2.60, 95% CI 1.11 to 6.68), diabetes (OR 2.71, 95% CI 1.18 to 6.65), smoking (OR 2.10, 95% CI 1.12 to 4.67), use of pedicled internal thoracic artery (OR 5.17, 95% CI 1.45 to 18.42) and on-pump CABG (OR 2.26, 95% CI 1.14 to 5.85). CONCLUSION This study identified the following independent risk factors for mediastinitis after CABG: obesity, diabetes, smoking, use of pedicled ITA and on-pump CABG.

A symbiotic gas exchange between bioreactors enhances microalgal biomass and lipid productivities: taking advantage of complementary nutritional modes

This paper describes the association of two bioreactors: one photoautotrophic and the other heterotrophic, connected by the gas phase and allowing an exchange of O2 and CO2 gases between them, benefiting from a symbiotic effect. The association of two bioreactors was proposed with the aim of improving the microalgae oil productivity for biodiesel production. The outlet gas flow from the autotrophic (O2 enriched) bioreactor was used as the inlet gas flow for the heterotrophic bioreactor. In parallel, the outlet gas flow from another heterotrophic (CO2 enriched) bioreactor was used as the inlet gas flow for the autotrophic bioreactor. Aside from using the air supplied from the auto- and hetero-trophic bioreactors as controls, one mixotrophic bioreactor was also studied and used as a model, for its claimed advantage of CO2 and organic carbon being simultaneously assimilated. The microalga Chlorella protothecoides was chosen as a model due to its ability to grow under different nutritional modes (auto, hetero, and mixotrophic), and its ability to attain a high biomass productivity and lipid content, suitable for biodiesel production. The comparison between heterotrophic, autotrophic, and mixotrophic Chlorella protothecoides growth for lipid production revealed that heterotrophic growth achieved the highest biomass productivity and lipid content (>22%), and furthermore showed that these lipids had the most suitable fatty acid profile in order to produce high quality biodiesel. Both associations showed a higher biomass productivity (10–20%), when comparing the two separately operated bioreactors (controls) which occurred on the fourth day. A more remarkable result would have been seen if in actuality the two bioreactors had been inter-connected in a closed loop. The biomass productivity gain would have been 30% and the lipid productivity gain would have been 100%, as seen by comparing the productivities of the symbiotic assemblage with the sum of the two bioreactors operating separately (controls). These results show an advantage of the symbiotic bioreactors association towards a cost-effective microalgal biodiesel production.

Skeletonized left internal thoracic artery is associated with lower rates of mediastinitis in diabetic patients

BACKGROUND Mediastinitis is a serious complication of median sternotomy and is associated to significant morbidity and mortality. Diabetes is a feared risk factor for mediastinitis and viewed with caution by cardiovascular surgeons. OBJECTIVE To identify risk factors for mediastinitis in diabetics undergoing CABG surgery with use of unilateral ITA in the Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE. METHODS Retrospective study of 157 diabetics operated between May 2007 and April 2010. Nine preoperative variables, five intraoperative variables and seven postoperative variables possibly involved in the development of postoperative mediastinitis were evaluated. Univariate and multivariate logistic regression analyses were applied. RESULTS The incidence of mediastinitis was 7% (n=11), with a lethality rate of 36.1% (n=4). Variables associated with increased risk of mediastinitis were: use of pedicled ITA (OR 8.25, 95% CI 2.03 to 66.10, P=0.016), postoperative renal complications (OR 5.10, 95% CI 1.03 to 25.62, P=0.049) and re-operation (OR 7.45, 95% CI 1.24 to 42.17, P=0.023). In multivariate analysis using backward logistic regression, only one variable remained as independent risk factor: use of pedicled ITA (OR 7.64, 95% CI 1.95 to 61.6, P=0.048), in comparison to skeletonized ITA. CONCLUSIONS We suggest that diabetics should be considered for strategies to minimize risk of infection. In diabetics that undergo unilateral ITA, the problem seems to be related to how ITA is harvested. Diabetics should always be considered for use of skeletonized ITA.

EuroSCORE and mortality in coronary artery bypass graft surgery at Pernambuco Cardiologic Emergency Medical Services [Pronto Socorro Cardiológico de Pernambuco]

OBJECTIVE The aim of this study is to evaluate the applicability of EuroSCORE in patients undergoing coronary artery bypass graft (CABG) surgery at the Division of Cardiovascular Surgery of Pernambuco Cardiologic Emergency Medical Services--PROCAPE. METHODS A retrospective study involving 500 patients operated between May 2007 and April 2010. The registers contained all the information used to calculate the EuroSCORE. The outcome of interest was death. Univariate analysis and multivariate analysis by backward logistic regression were applied to assess the association between each variable in the EuroSCORE and deaths. The following parameters were calculated: sensitivity, specificity, positive predictive value, and negative predictive value. The power of concordance between the predicted mortality by the EuroSCORE and the observed mortality was measured using the Kappa coefficient. The accuracy of the model was evaluated by the ROC (receiver operating characteristic) curve. RESULTS The incidence of death was 13%. In multivariate analysis, nine variables remained independent predictors of death: chronic obstructive pulmonary disease, creatinine >2,3mg/dL, active endocarditis, preoperative critical state, unstable angina, ejection fraction 30% to 50%, acute myocardial infarction < 90 days, emergency surgery and additional surgery. The score had a sensitivity of 88.4%, specificity of 79.3%, positive predictive value of 40.7%, negative predictive value of 97.7% and 80.6% concordance. The accuracy measured by the area under the ROC curve was 0.892 (95% CI 0.862-0.922). CONCLUSIONS The EuroSCORE proved to be a simple and objective index, revealing a satisfactory discriminator of postoperative evolution in patients undergoing CABG surgery at our institution.

Risk factors for low cardiac output syndrome after coronary artery bypass grafting surgery

OBJECTIVES Low cardiac output syndrome (LCOS) is a serious complication after cardiac surgery and is associated with significant morbidity and mortality. The aim of this study is to identify risk factors for LCOS in patients undergoing coronary artery bypass grafting (CABG) in the Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE (Recife, PE, Brazil). METHODS A historical prospective study comprising 605 consecutive patients operated between May 2007 and December 2010. We evaluated 12 preoperative and 7 intraoperative variables. We applied univariate and multivariate logistic regression analysis. RESULTS The incidence of LCOS was 14.7% (n = 89), with a lethality rate of 52.8% (n = 47). In multivariate analysis by logistic regression, four variables remained as independent risk factors: age > 60 years (OR 2.00, 95% CI 1.20 to 6.14, P = 0.009), on-pump CABG (OR 2.16, 95% CI 1.40 to 7.08, P = 0.006), emergency surgery (OR 4.71, 95% CI 1.34 to 26.55, P = 0.028), incomplete revascularization (OR 2.62, 95% CI 1.32 to 5.86, P = 0.003), and ejection fraction <50%. CONCLUSIONS This study identified the following independent risk factors for LCOS after CABG: age> 60 years of off-pump CABG, emergency surgery, incomplete CABG and ejection fraction <50%.

Enhanced lipidic algae biomass production using gas transfer from a fermentative Rhodosporidium toruloides culture to an autotrophic Chlorella protothecoides culture.

In order to produce single-cell oil for biodiesel, a yeast and a microalga were, for the first time, grown in two separate reactors connected by their gas-phases, taking advantage of their complementary nutritional metabolisms, i.e., respiration and photosynthesis. The yeast Rhodosporidium toruloides was used for lipid production, originating a carbon dioxide-enriched outlet gas stream which in turn was used to stimulate the autotrophic growth of Chlorella protothecoides in a vertical-alveolar-panel (VAP) photobioreactor. The microalgal biomass productivity was 0.015 gL(-1)h(-1), and its lipid productivity attained 2.2 mgL(-1)h(-1) when aerated with the outlet gas stream from the yeast fermenter. These values represent an increase of 94% and 87%, respectively, as compared to a control culture aerated with air. The CO2 bio-fixed by the microalgal biomass reached an estimated value of 29 mgL(-1)h(-1) in the VAP receiving the gas stream from the fermenter, a value 1.9 times higher than that measured in the control VAP.

Validation of MagedanzSCORE as a predictor of mediastinitis after coronary artery bypass graft surgery

OBJECTIVE The aim of this study is to evaluate the applicability of a new score for predicting mediastinitis - MagedanzSCORE - in patients undergoing coronary artery bypass graft (CABG) surgery in the Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE. METHODS Retrospective study involving 500 patients operated between May/2007 and April/2010. The registers contained all the information used to calculate the MagedanzSCORE. The outcome of interest was mediastinitis. We calculated sensitivity, specificity, positive predictive value, negative predictive value, concordance and accuracy. The accuracy of the model was evaluated by ROC (receiver operating characteristic) curve. RESULTS The incidence of mediastinitis was 5.6%, with a lethality rate of 32.1%. In univariate analysis, the five variables of the MagedanzSCORE were predictors of postoperative mediastinitis: chronic obstructive pulmonary disease (OR 6.42; 95.0% CI 2.76-14.96; P<0.001), obesity (OR 3.06; 95.0% CI 1.32-7.09; P=0.009), surgical reintervention (OR 82.40; 95.0% CI 30.40-223.30; P<0.001), multiple transfusion (OR 3.33; 95.0% CI 1.52-7.29; P=0.003) and stable angina class IV or unstable (OR 2.59; 95.0% CI 1.19-7.64; P=0.016) according to Canadian Cardiovascular Society. The score had a sensitivity of 96.4%, specificity of 90.0%, positive predictive value of 36.5%, negative predictive value of 99.8% and 90.4% concordance. The accuracy measured by the area under the ROC curve was 96.2% (95.0% CI 94.5%-97.9%). CONCLUSIONS The MagedanzSCORE proved to be a simple and objective index, revealing a satisfactory predictor of development of postoperative mediastinitis in patients undergoing CABG surgery at our institution.

Predictors of transfusion of packed red blood cells in coronary artery bypass grafting surgery

Objectives: Finding predictors of blood transfusion may facilitate the most efficient approach for the use of blood bank services in coronary artery bypass grafting procedures. The aim of this retrospective study is to identify preoperative and intraoperative patient characteristics predicting the need for blood transfusion during or after CABG in our local cardiac surgical service. Methods: 435 patients undergoing isolated first-time CABG were reviewed for their preoperative and intraoperative variables and analyzed postoperative data. Patients were 255 males and 180 females, with mean age 62.01 ± 10.13 years. Regression logistic analysis was used for identifying the strongest perioperative predictors of blood transfusion. Results: Blood transfusion was used in 263 patients (60.5%). The mean number of transfused blood products units per patient was 2.27 ± 3.07 (0-23) units. The total number of transfused units of blood products was 983. Univariate analysis identified age >65 years, weight <70 Kg, body mass index <25 Kg/m2, hemoglobin ≤ ≤ ≤ ≤ ≤13mg/dL, hematocrit ≤ 40% and ejection fraction <50%, use of cardiopulmonary bypass (CPB), not using an internal thoracic artery as a bypass, and multiple bypasses as significant predictors. The strongest predictors using multivariate analysis were hematocrit ≤ ≤ ≤ ≤ ≤ 40% (OR 2.58; CI 1.62-4.15; P<0.001), CPB use (OR 2.00; CI 1.27-3.17; P=0.003) and multiple bypasses (OR 2.31; CI 1.31-4.08; P=0.036). Conclusions: The identification of these risk factors leads to better identification of patients with a grater probability of using blood, allocation blood bank resources and costeffectiveness use of blood products.OBJECTIVES Finding predictors of blood transfusion may facilitate the most efficient approach for the use of blood bank services in coronary artery bypass grafting procedures. The aim of this retrospective study is to identify preoperative and intraoperative patient characteristics predicting the need for blood transfusion during or after CABG in our local cardiac surgical service. METHODS 435 patients undergoing isolated first-time CABG were reviewed for their preoperative and intraoperative variables and analyzed postoperative data. Patients were 255 males and 180 females, with mean age 62.01 ± 10.13 years. Regression logistic analysis was used for identifying the strongest perioperative predictors of blood transfusion. RESULTS Blood transfusion was used in 263 patients (60.5%). The mean number of transfused blood products units per patient was 2.27 ± 3.07 (0-23) units. The total number of transfused units of blood products was 983. Univariate analysis identified age >65 years, weight <70 Kg, body mass index <25 Kg/m2, hemoglobin <13mg/dL, hematocrit < 40% and ejection fraction <50%, use of cardiopulmonary bypass (CPB), not using an internal thoracic artery as a bypass, and multiple bypasses as significant predictors. The strongest predictors using multivariate analysis were hematocrit < 40% (OR 2.58; CI 1.62-4.15; P<0.001), CPB use (OR 2.00; CI 1.27-3.17; P=0.003) and multiple bypasses (OR 2.31; CI 1.31-4.08; P=0.036). CONCLUSIONS The identification of these risk factors leads to better identification of patients with a greater probability of using blood, allocation blood bank resources and cost-effectiveness use of blood products.

Skeletonized internal thoracic artery is associated with lower rates of mediastinitis in elderly undergoing coronary artery bypass grafting surgery

Background and Objectives: Mediastinitis is a serious complication of median sternotomy and is associated to significant morbidity and mortality. The aim of this study is to identify which option of harvesting internal thoracic artery (ITA), pedicled or skeletonized, is associated with lower rates of mediastinitis after coronary artery bypass grafting surgery (CABG) in elderly, in the Division of Cardiovascular Surgery of PROCAPE. Methods: Retrospective study of 160 elderly who underwent consecutive CABG between May 2007 and June 2011. Eleven preoperative variables, four intraoperative variables and eight postoperative variables possibly involved in the development of postoperative mediastinitis were evaluated between two groups: CABG with skeletonized ITA (n=80) and pedicled ITA (n=80). Univariate and multivariate logistic regression analyses were applied. Results: The incidence of mediastinitis was 6.8% (n=11), with a lethality rate of 54.5% (n=6). The skeletonized ITA group were more exposed than pedicled ITA group to obesity (n=12 vs. n=4; 15% vs. 5%; P=0.035) and multiple transfusions (n=25 vs. n=11; 31.2% vs. 13.7%; P=0.008). The pedicled ITA group presented a greater risk of mediastinitis after CABG than skeletonized ITA group (n=10 vs. n=1; 12.5% vs. 1.2%; Unadjusted OR 11.3; 95% CI 1.4 - 241.5; P=0.008). In multivariate analysis, this difference maintained statistically significant (Adjusted OR 5.2; 95% CI 1.5-495.8; P=0.012), being considered an independent association. Conclusions: We suggest that elderly should be considered for strategies to minimize risk of infection. In elderly that undergo unilateral ITA, the problem seems to be related to how ITA is harvested. Elderly should always be considered for use of skeletonized ITA.BACKGROUND AND OBJECTIVES Mediastinitis is a serious complication of median sternotomy and is associated to significant morbidity and mortality. The aim of this study is to identify which option of harvesting internal thoracic artery (ITA), pedicled or skeletonized, is associated with lower rates of mediastinitis after coronary artery bypass grafting surgery (CABG) in elderly, in the Division of Cardiovascular Surgery of PROCAPE. METHODS Retrospective study of 160 elderly who underwent consecutive CABG between May 2007 and June 2011. Eleven preoperative variables, four intraoperative variables and eight postoperative variables possibly involved in the development of postoperative mediastinitis were evaluated between two groups: CABG with skeletonized ITA (n=80) and pedicled ITA (n=80). Univariate and multivariate logistic regression analyses were applied. RESULTS The incidence of mediastinitis was 6.8% (n=11), with a lethality rate of 54.5% (n=6). The skeletonized ITA group were more exposed than pedicled ITA group to obesity (n=12 vs. n=4; 15% vs. 5%; P=0.035) and multiple transfusions (n=25 vs. n=11; 31.2% vs. 13.7%; P=0.008). The pedicled ITA group presented a greater risk of mediastinitis after CABG than skeletonized ITA group (n=10 vs. n=1; 12.5% vs. 1.2%; Unadjusted OR 11.3; 95% CI 1.4 - 241.5; P=0.008). In multivariate analysis, this difference maintained statistically significant (Adjusted OR 5.2; 95% CI 1.5-495.8; P=0.012), being considered an independent association. CONCLUSIONS We suggest that elderly should be considered for strategies to minimize risk of infection. In elderly that undergo unilateral ITA, the problem seems to be related to how ITA is harvested. Elderly should always be considered for use of skeletonized ITA.