BACKGROUND:Median sternotomy infection and bony nonunion are two commonly described complications which occur in 0.4-5.1% of cardiac procedures. Although relatively infrequent, these complications can lead to significant morbidity and mortality. The aim of this retrospective study is to evaluate the initial experience of a transverse plate fixation system following wound complications associated with sternal dehiscence with or without infection following cardiac surgery.METHODS:A retrospective chart review of 40 consecutive patients who required sternal wound reconstruction post sternotomy was performed. Soft tissue debridement with removal of all compromised tissue was performed. Sternal debridement was carried using ronguers to healthy bleeding bone. All patients underwent sternal fixation using three rib plates combined with a single manubrial plate (Titanium Sternal Fixation System®, Synthes). Incisions were closed in a layered fashion with the pectoral muscles being advanced to the midline. Data were expressed as mean±SD, Median (range) or number (%). Statistical analyses were made by using Excel 2003 for Windows (Microsoft, Redmond, WA, USA).RESULTS:There were 40 consecutive patients, 31 males and 9 females. Twenty two patients (55%) were diagnosed with sternal dehiscence alone and 18 patients (45%) with associated wound discharge. Thirty eight patients went on to heal their wounds. Two patients developed recurrent wound infection and required VAC therapy. Both were immunocompromised. Median post-op ICU stay was one day with the median hospital stay of 18 days after plating.CONCLUSION:Sternal plating appears to be an effective option for the treatment of sternal wound dehiscence associated with sternal instability. Long-term follow-up and further larger studies are needed to address the indications, benefits and complications of sternal plating.

Patients report changes in their perception of food tastes following cardiac surgery. This study was designed to explore changes in taste sensitivity following coronary artery bypass graft (CABG) surgery. Detection and recognition thresholds for sweet (sucrose), salty (sodium chloride), sour (citric acid), and bitter (quinine hydrochloride) were determined using the multiple forced-choice ascending concentration series method at baseline (presurgical), discharge, 5 weeks, and 16 weeks post-CABG. Demographic and gastrointestinal data were also obtained. Mixed-model analyses for repeated measures were performed using the baseline scores as reference. Thirty-three patients (mean age=61.8±8 years), consented to participate in the study between January 2003 and January 2006, with 13 completing all visits. Detection and recognition thresholds for sweet were significantly lower at discharge compared with baseline (1.7±1.2 vs 2.43±1.4 and 5.1±1.8 vs 5.5±1.3, respectively; P<0.05). This difference remained significant 4 months after surgery. Detection and recognition thresholds for salt also declined with time, with significant differences at 4 months post-surgery (2.3±2.0 vs 1.8±1.5; P<0.001 and 5.3±1.3 vs 4.2±2.2; P<0.05, respectively). The same trends were noted for the detection of sour and the recognition of bitter. Patients undergoing CABG demonstrated stable or improved taste sensitivity during the recovery period. Further studies aimed at clarifying the relationships between the biological state, taste sensitivity, reported taste changes, and food intake will help to clarify the clinical impact of taste changes and subsequently to guide clinical nutrition care.

AbstractBackgroundPreoperative patients' characteristics can predict the need for perioperative blood component transfusion in cardiac surgical operations. The aim of this prospective observational study is to identify perioperative patient characteristics predicting the need for allogeneic packed red blood cell (PRBC) transfusion in isolated primary coronary artery bypass grafting (CABG) operations.Patients and Methods105 patients undergoing isolated, first-time CABG were reviewed for their preoperative variables and followed for intraoperative and postoperative data. Patients were 97 males and 8 females, with mean age 58.28 ± 10.97 years. Regression logistic analysis was used for identifying the strongest perioperative predictors of PRBC transfusion.ResultsPRBC transfusion was used in 71 patients (67.6%); 35 patients (33.3%) needed > 2 units and 14 (13.3%) of these needed > 4 units. Univariate analysis identified female gender, age > 65 years, body weight ≤ 70 Kg, BSA ≤ 1.75 m2, BMI ≤ 25, preoperative hemoglobin ≤ 13 gm/dL, preoperative hematocrit ≤ 40%, serum creatinine > 100 μmol/L, Euro SCORE (standard/logistic) > 2, use of CPB, radial artery use, higher number of distal anastomoses, and postoperative chest tube drainage > 1000 mL as significant predictors. The strongest predictors using multivariate analysis were CPB use, hematocrit, body weight, and serum creatinine.ConclusionThe predictors of PRBC transfusion after primary isolated CABG are use of CPB, hematocrit ≤ 40%, weight ≤ 70 Kg, and serum creatinine > 100 μmol/L. This leads to better utilization of blood bank resources and cost-efficient targeted use of expensive blood conservation modalities.

BACKGROUND:Diffuse microvascular bleeding remains a common problem after cardiac procedures. Systemic use of antifibrinolytic reduces the postoperative blood loss. The purpose of this study was to examine the effectiveness of local application of tranexamic acid to reduce blood loss after coronary artery bypass grafting (CABG).METHODS:Thirty eight patients scheduled for primary isolated coronary artery bypass grafting were included in this double blind, prospective, randomized, placebo controlled study. Tranexamic acid (TA) group (19 patients) received 1 gram of TA diluted in 100 ml normal saline. Placebo group (19 patients) received 100 ml of normal saline only. The solution was purred in the pericardial and mediastinal cavities.RESULTS:Both groups were comparable in their baseline demographic and surgical characteristics. During the first 24 hours post-operatively, cumulative blood loss was significantly less in TA group (median of 626 ml) compared to Placebo group (median of 1040 ml) (P = 0.04). There was no significant difference in the post-op Packed RBCs transfusion between both groups (median of one unit in each) (P = 0.82). Significant less platelets transfusion required in TA group (median zero unit) than in placebo group (median 2 units) (P = 0.03). Apart from re-exploration for excessive surgical bleeding in one patient in TA group, no difference was found in morbidity or mortality between both groups.CONCLUSION:Topical application of tranexamic acid in patients undergoing primary coronary artery bypass grafting led to a significant reduction in postoperative blood loss without adding extra risk to the patient.

Background Sternal instability with mediastinitis is a very serious complication after median sternotomy. Biomechanical studies have suggested superiority of rigid plate fixation over wire cerclage for sternal fixation. This study tests the hypothesis that sternal closure stability can be improved by adding plate fixation in a human cadaver model. Methods Midline sternotomy was performed in 18 human cadavers. Four sternal closure techniques were tested: (1) approximation with six interrupted steel wires; (2) approximation with six interrupted cables; (3) closure 1 (wires) or 2 (cables) reinforced with a transverse sternal plate at the sixth rib; (4) Closure using 4 sternal plates alone. Intrathoracic pressure was increased in all techniques while sternal separation was measured by three pairs of sonomicrometry crystals fixed at the upper, middle and lower parts of the sternum until 2.0 mm separation was detected. Differences in displacement pressures were analyzed using repeated measures ANOVA and Regression Coefficients. Results Intrathoracic pressure required to cause 2.0 mm separation increased significantly from 183.3 ± 123.9 to 301.4 ± 204.5 in wires/cables alone vs. wires/cables plus one plate respectively, and to 355.0 ± 210.4 in the 4 plates group (p < 0.05). Regression Coefficients (95% CI) were 120 (47–194) and 142 (66–219) respectively for the plate groups. Conclusion Transverse sternal plating with 1 or 4 plates significantly improves sternal stability closure in human cadaver model. Adding a single sternal plate to primary closure improves the strength of sternal closure with traditional wiring potentially reducing the risk of sternal dehiscence and could be considered in high risk patients.

Participants will understand the components of an aggressive dietary strategy that can be used by patients to reduce cardiovascular risk factors.

INTRODUCTION: Endothelial cell apoptosis, in response to inflammatory, ischemic and hypoxic stressors, has been identified as an essential target for therapies aimed at improving graft patency. BRCA1 is a tumor suppressor gene which functions primarily to promote DNA repair, and afford protection against various genotoxic stimuli, including immunosuppressant and chemotherapeutic regimens often employed post-transplantation. We hypothesized that BRCA1 is a novel target to limit inflammation-induced endothelial cell apoptosis and to restore endothelial function. METHODS AND RESULTS: In the first series of studies, we used a gain-of-function approach by adenoviral BRCA1 overexpression in human umbilical vein endothelial cells (HUVECs). Ad-BRCA1-expressing HUVECs exhibited profound protection against TNFα (20 ng/ml)-induced apoptosis, as assessed by flow cytometry, DNA laddering, COMET assay and cleaved procaspase 3 (P < 0.01). This response was mediated by complete prevention of TNFα-induced increases in endothelial ROS production (P < 0.001, vs. Ad-BRCA1). Furthermore, Ad-BRCA1 overexpression prevented TNFα-induced reduction in key indices of endothelial function, namely capillary-like tube formation (P < 0.01) and cell migration (P < 0.01). The protective effects of BRCA1 were not mediated by changes in total or phosphorylated p53 (P = 0.1) but were associated with a significant 6-fold upregulation in eNOS (P < 0.05). A loss-of-function strategy with BRCA1 gene silencing reversed the effects on endothelial apoptosis, ROS production and eNOS phosporylation. CONCLUSIONS: BRCA1 protects endothelial cells against inflammation-induced apoptosis, through a mechanism that involves up-regulation of eNOS and reduced ROS production, and is a novel candidate gene to limit aberrant vascular remodeling. These data also suggest that patients with BRCA1 mutations or cancer syndromes may be at an exaggerated risk of native and transplant atherosclerosis and graft dysfunction, particularly in the setting of DNA damaging immunosuppressants.

BACKGROUND AND AIM:We evaluated the impact of triple nutrient supplementation (TNS: carnitine, taurine and coenzyme Q(10)) vs. carnitine alone (CARN) or placebo on survival, infarct size, cardiac function and metabolic gene expression using a model of myocardial infarction (MI) in rats. METHODS AND RESULTS:Male Wistar rats were randomized to three groups divided in two independent studies prior to ligation of the left anterior descending coronary artery (LAD): TNS vs. Placebo and TNS vs. CARN. Nutrient supplementation [L-carnitine (300 mg/day), coenzyme Q(10) (15 mg/kg body weight/day) and taurine (0.1M)] was administered daily for four weeks prior to and for 10 days after MI. At that time, cardiac function and infarct size were measured. Metabolic gene (mRNA) expression in the peri-infarct tissue of left ventricle from TNS, placebo or corresponding time-control rats (TNS or placebo without LAD ligation) was measured 10 days after MI. When compared to placebo, TNS significantly improved survival (60% vs. 34%, p<0.02), cardiac function, and reduced infarct size (30+/-7% vs. 42+/-9%, p<0.001). Although CARN improved survival like TNS (45% vs. 50%, not significant), it did not reduce infarct size (32+/-14% vs. 19+/-10%, p<0.05) or delay myocardial remodeling. In the placebo group, MI was associated with a significantly altered pattern of metabolic gene expression (glucose transporter 1, liver carnitine palmitoyl transferase 1, medium-chain acyl-CoA dehydrogenase; p<0.01 for all three) in the left ventricle peri-infarct tissue. In contrast, gene expression was normalized in the group receiving TNS. CONCLUSIONS:Our results support the potential cardioprotective impact of TNS during myocardial ischemia. In contrast to carnitine supplementation alone, TNS improved survival as well as cardiac function, gene expression and delayed remodeling.

The healthy heart relies primarily upon the oxidation of fatty acids for energy, with the remaining coming from the oxidation of glucose and lactate. Changes in energy requirements are met by altering the balance of fuels depending upon the hormonal milieu as well as upon the availability of oxygen and substrates. The use of carbohydrates for fuel is metabolically more efficient and may improve the coupling between glycolysis and pyruvate oxidation. Therefore, promoting a shift in metabolic fuel substrate use during times of reduced oxygen availability may represent a cardioprotective strategy. Subsequently, there has been interest in pharmacologic strategies such insulin or drugs like ranolazine and dichloroacetate that stimulate carbohydrate oxidation either by enhancing oxidation at the pyruvate dehydrogenase complex or by limiting fatty acid oxidation. There is evidence that nutrients may also be able to stimulate carbohydrate oxidation. Previous studies by our group suggest that a combination of nutrients (carnitine, coenzyme Q10, and taurine) may work together, resulting in pleiotropic cardioprotective effects. Our current studies are investigating the potential of nutrients as both a preventative and adjunctive treatment before and after an ischemic event. These investigations will determine the role of nutritional supplementation in the care of patients with ischemic injury.

Background Congestive heart failure depletes the myocardium of carnitine, coenzyme Q10 (CoQ10), and taurine—substances known to influence mitochondrial function and cell calcium. We hypothesized that feeding patients a nutritional supplement that contained carnitine, CoQ10, and taurine would result in higher myocardial levels of these nutrients and improve left ventricular function. Methods Forty-one patients who underwent aortocoronary artery bypass with an ejection fraction ≤40% at referral were randomly assigned to a double-blind trial of supplement or placebo. Radionuclide ventriculography was performed at randomization and before surgery. Surgical myocardial biopsies, adjusted for protein content, were analyzed for carnitine, CoQ10, and taurine levels. Results The groups were well matched. Minor exceptions were supplement group versus placebo group for digoxin use (7 vs 0, respectively; P =.009) and age (62 ± 11 years vs 69 ± 5 years, respectively; P =.04). There were significantly higher levels in the treated group compared with the placebo group for myocardial levels of CoQ10 (138.17 ± 39.87 nmol/g wet weight and 56.67 ± 23.08 nmol/g wet weight; P =.0006), taurine (13.12 ± 4.00 μmol/g wet weight and 7.91 ± 2.81 μmol/g wet weight; P =.003), and carnitine (1735.4 ± 798.5 nmol/g wet weight and 1237.6 ± 343.1 nmol/g wet weight; P =.06). The left ventricular end-diastolic volume fell by −7.5 ± 21.7 mL in the supplement group and increased by 10.0 ± 19.8 mL in the placebo group (P =.037). Conclusions Supplementation results in higher myocardial CoQ10, taurine, and carnitine levels and is associated with a reduction in left ventricular end-diastolic volume in patients with left ventricular dysfunction before revascularization. Because the risk of death for surgical revascularization is related to preoperative left ventricular end-diastolic volume, supplementation could improve outcomes. (Am Heart J 2002;143:1092-100.)