Comparative analysis of the patency of the internal thoracic artery in the CABG of left anterior descending artery: 6-month postoperative coronary CT angiography evaluation

Objective

To assess the patency of the pedicled right internal thoracic artery with an anteroaortic course and compare it to the patency of the left internal thoracic artery , in anastomosis to the left anterior descending artery in coronary artery bypass grafting by using coronary CT angiography at 6 months postoperatively.

Methods

Between December 2008 and December 2011, 100 patients were selected to undergo a prospective coronary artery bypass grafting procedure without cardiopulmonary bypass. The patients were randomly divided by a computer-generated list into Group-1 (G-1) and Group-2 (G-2), comprising 50 patients each, the technique used was known at the beginning of the surgery. In G-1, coronary artery bypass grafting was performed using the left internal thoracic artery for the left anterior descending and the free right internal thoracic artery for the circumflex, and in G-2, coronary artery bypass grafting was performed using the right internal thoracic artery pedicled to the left anterior descending and the left internal thoracic artery pedicled to the circumflex territory.

Results

The groups were similar with regard to the preoperative clinical data. A male predominance of 75.6% and 88% was observed in G-1 and G-2, respectively. Five patients migrated from G-1 to G-2 because of atheromatous disease in the ascending aorta. The average number of distal anastomoses was 3.48 (SD=0.72) in G-1 and 3.20 (SD=0.76) in G-2. Coronary CT angiography in 96 re-evaluated patients showed that all ITAs, right or left, used in situ for the left anterior descending were patent. There were no deaths in either group.

Conclusion

Coronary artery bypass grafting surgery involving anastomosis of the anteroaortic right internal thoracic artery to the left anterior descending artery has an outcome similar to that obtained using the left internal thoracic artery for the same coronary site.     

The cardiac implications of breast reconstruction using the internal mammary artery as the recipient vessel

BACKGROUND:

Microsurgical breast reconstruction is a popular choice in breast reconstruction. Recipient vessel use for these autologous tissue reconstructions has shifted from the thoracodorsal to the internal mammary vessels. Coronary artery bypass (CAB) surgery remains the optimal revascularization strategy in patients with significant, diffuse coronary artery disease. The conduits of choice for coronary revascularization are the internal mammary arteries (IMA) because of their superior long-term graft patency rate and improved patient survival.

OBJECTIVE:

To review the cardiac risk factors in the breast reconstruction population, and to report the incidence of postoperative cardiac events at the London Health Sciences Centre, London, Ontario. The authors present the index cases illustrating cardiac complications following the use of internal mammary vessels.

METHOD:

A retrospective, single-centre, cumulative audit of breast reconstruction practice from 2005 to 2009 was conducted. A total of 81 patients undergoing autologous breast reconstruction were reviewed. Two women were noted to have experienced postoperative myocardial infarction requiring intervention. Both were noted to have triple-vessel disease, an indication for CAB; however, during the breast reconstruction, their IMAs had been utilized. As a result, both women subsequently underwent triple-vesssel percutaneous intervention, with one woman later requiring CAB without IMA because of recurrent ischemia.

CONCLUSION:

While there is limited overlap with the breast reconstruction and cardiac disease population, there can be significant cardiac health implications in the postoperative status (both short and long term) of women undergoing autologous breast reconstruction using the IMAs as recipient vessels.     

Anomalous origin of coronary artery: taxonomy and clinical implication

Objective

Anomalous origin of coronary artery is uncommon. The taxonomies of anomalous origin of coronary artery are inconsistent and complex. Conceptual and therapeutic debates remain. The aim of the present study is to reappraise the concept of anomalous origin of coronary artery and to discuss the potential hazards and treatment rationale of this anomaly on basis of literature review.

Methods

A comprehensive literature review was made in terms of the taxonomies including “simple”, “multiple” and “complex” types of anomalous origin of coronary artery.

Results

Anomalous origin of coronary artery can be simply categorized according to the ectopically originated coronary artery. There are a couple of complex anatomical variants: “multiple” type, involving more than one coronary artery or branch, which can be subdivided into 2 subtypes, A) more than one coronary arteries or branches arising from one place; and B) two coronary arteries/branches arising from separate ectopic sites; and “complex” type, associated with acquired heart disease, or congenital heart defects.

Conclusion

Sudden cardiac death in anomalous origin of coronary artery is associated with the anatomical features including abnormal coursing, acute angle take-off and ostial abnormalities. Atherosclerosis is prone to be in the right-sided ectopic and retroaortic coursing coronary artery. Surgical treatment is a definitive therapy. Simple coronary artery bypass grafting is not recommended due to the potential hazards of coronary steal phenomenon and poor patency of mammary arterial grafts, and modified maneuvers such as coronary ostial reimplantation, impinged coronary segment unroofing and coronary stent deployment are advocated instead.     

Effect of using pump on postoperative pleural effusion in the patients that underwent CABG

Objective

The present study investigated effect of using pump on postoperative pleural effusion in patients who underwent coronary artery bypass grafting.

Methods

A total of 256 patients who underwent isolated coronary artery bypass grafting surgery in the Cardiovascular Surgery clinic were enrolled in the study. Jostra-Cobe (Model 043213 105, VLC 865, Sweden) heart-lung machine was used in on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting was performed using Octopus and Starfish. Proximal anastomoses to the aorta in both on-pump and off-pump techniques were performed by side clamps. The patients were discharged from the hospital between postoperative day 6 and day 11.

Results

The incidence of postoperative right pleural effusion and bilateral pleural effusion was found to be higher as a count in Group 1 (on-pump) as compared to Group 2 (off-pump). But the difference was not statistically significant [P>0.05 for right pleural effusion (P=0.893), P>0.05 for bilateral pleural effusion (P=0.780)]. Left pleural effusion was encountered to be lower in Group 2 (off-pump). The difference was found to be statistically significant (P<0.05, P=0.006).

Conclusion

Under the light of these results, it can be said that left pleural effusion is less prevalent in the patients that underwent off-pump coronary artery bypass grafting when compared to the patients that underwent on-pump coronary artery bypass grafting.     

The risk of cerebrovascular accident in patients with asymptomatic critical carotid artery stenosis who undergo open-heart surgery

Objective

To investigate whether the presence of asymptomatic critical carotid stenosis (ASCCS) increases the risk of perioperative stroke during open-heart surgery, which carries a well-established risk of cerebrovascular accidents.

Design

A case series.

Setting

A university-affiliated hospital that is a major referral centre for cardiovascular surgery.

Patients

Forty-six patients with ASCCS who underwent open-heart surgery between January 1992 and January 1996. Of this group, 27 had bilateral and 19 had unilateral critical carotid artery stenosis.

Interventions

Various cardiac procedures were performed on the 46 patients: 33 underwent coronary bypass grafting, 12 had valve replacement and 1 had heart transplantation.

Main outcome measure

Neurologic deficit.

Results

None of the patients had any perioperative neurologic deficit up to the date of discharge.

Conclusions

Cardiac procedures, without prior carotid artery surgery, can be done in patients with AS-CCS with no significant added risk of stroke. To achieve this, blood pressure should be kept stable intraoperatively, at slightly higher than normal pressure.     

Incidence of postoperative atrial fibrillation in patients undergoing on-pump and off-pump coronary artery bypass grafting

Objective

To determine the incidence of postoperative atrial fibrillation in patients undergoing on-pump and off-pump coronary artery bypass grafting.

Methods

A retrospective study with analysis of 230 medical records between January 2011 and October 2013 was conducted.

Results

Fifty-six (24.3%) out of the 230 patients were female. The average age of patients undergoing on-pump coronary artery bypass grafting was 59.91±8.62 years old, and off-pump was 57.16±9.01 years old (P=0.0213). The average EuroSCORE for the on-pump group was 3.37%±3.08% and for the off-pump group was 3.13%±3% (P=0.5468). Eighteen (13.43%) patients who underwent off-pump coronary artery bypass grafting developed postoperative atrial fibrillation, whereas for the onpump group, 19 (19.79%) developed this arrhythmia, with no significant difference between the groups (P=0.1955).

Conclusion

Off-pump coronary artery bypass grafting did not reduce the incidence of atrial fibrillation in the postoperative period. Important predictors of risk for the development of this arrhythmia were identified as: patients older than 70 years old and presence of atrial fibrillation in perioperative period in both groups, and non-use of beta-blockers drugs postoperatively in the on-pump group.     

Risk factors for mortality of patients undergoing coronary artery bypass graft surgery

Introduction

Coronary artery bypass grafting is a safe procedure performed worldwide with low rates of mortality and morbidity in general population.

Objective

To investigate risk factors for mortality of patients undergoing coronary artery bypass grafting coronary artery bypass grafting surgery.

Methods

A total of 1,628 consecutive patients undergoing on-pump coronary artery bypass grafting were retrospectively studied from December 1999 to February 2012. Data analysis involved paired Student t test, Mann-Whitney test and Fisher’s exact test for the categorical data. Logistic regression, Odds Ratio and 95%CI were used for definition of risk factors for mortality.

Results

Of a total of 1,628 patients undergoing on-pump coronary artery bypass grafting, 141 (8.7%) died. The following risk factors for mortality were identified after logistic regression: dialysis (OR=7.61; 95%CI 3.58-16.20), neurologic dysfunction type I (OR=4.42; 95%CI 2.48-7.81), use of IABP (OR=3.38; 95%CI 1.98-5.79), cardiopulmonary bypass time (OR=3.09; 95%CI 2.04-4.68), serum creatinine on admission and peak values > 0.4mg/dL (OR=2.67; 95%CI 1.79-4.00), age > 65 years (OR=2.31; 95%CI 1.55-3.44), and time between hospital admission and and surgical procedure (OR=1.53; 95%CI 1.03-2.27).

Conclusion

Dialysis, type I neurologic dysfunction, use of IABP, cardiopulmonary bypass time (> 115 minutes), serum creatinine on admission and peak values>0.4mg/dL, age > 65 years and time between hospital admission and surgical procedure were considered as risk factors for mortality in patients undergoing on-pump coronary artery bypass grafting surgery.     

Successful use of the Impella Recover LP 5.0 device for circulatory support during off-pump coronary artery bypass grafting

INTRODUCTION

Surgical coronary revascularization is being performed with ever increasing frequency in patients at high surgical risk. Off-pump coronary artery bypass grafting (OPCABG) is particularly appealing in such subjects, but may limit the options for concomitant mechanical circulatory support.

PRESENTATION OF CASE

We hereby report an original case of mechanical circulatory support with the Impella Recover LP 5.0 device during OPCABG in a 61-year-old gentleman with multiple comorbidities and severe left ventricular systolic dysfunction. Specifically, the soft tipped device did not impede surgical manipulation of the heart during the surgical procedure, providing uninterrupted circulatory support to the patient.

DISCUSSION

This clinical vignette supports the feasibility, safety and efficacy of the Impella Recover LP 5.0 device in patients undergoing OPCABG.

CONCLUSION

Pending further studies, use of the Impella Recover LP 5.0 device can be envisioned safely for OPCABG.     

On-pump beating-heart versus conventional coronary artery bypass grafting for revascularization in patients with severe left ventricular dysfunction: early outcomes

Background

We sought to evaluate the effects of on-pump beating-heart versus conventional coronary artery bypass grafting techniques requiring cardioplegic arrest in patients with coronary artery disease with left ventricular dysfunction.

Methods

We report the early outcomes associated with survival, morbidity and improvement of left ventricular function in patients with low ejection fraction who underwent coronary artery bypass grafting between August 2009 and June 2012. Patients were separated into 2 groups: group I underwent conventional coronary artery bypass grafting and group II underwent an on-pump beating-heart technique without cardioplegic arrest.

Results

In all, 131 patients underwent coronary artery bypass grafting: 66 in group I and 65 in group II. Left ventricular ejection fraction was 26.6% ± 3.5% in group I and 27.7% ± 4.7% in group II. Left ventricular end diastolic diameter was 65.6 ± 3.6 mm in group I and 64.1 ± 3.2 mm in group II. There was a significant reduction in mortality in the conventional and on-pump beating-heart groups (p < 0.001). Perioperative myocardial infarction and low cardiac output syndrome were higher in group I than group II (both p < 0.05). Improvement of left ventricular function after the surgical procedure was better in group II than group I.

Conclusion

The on-pump beating-heart technique is the preferred method for myocardial revascularization in patients with left ventricular dysfunction. This technique may be an acceptable alternative to the conventional technique owing to lower postoperative mortality and morbidity.     

Graft pathology at the time of harvest: impact on long-term survival

Objective

This study aims to present the graft pathology at the time of harvest and its impact on long-term survival.

Methods

The remnants of the bypass grafts from 66 consecutive patients with coronary artery disease receiving a coronary artery bypass grafting were investigated pathologically, and pertinent predictive risk factors and survival were analyzed.

Results

Medial degenerative changes with or without intimal proliferation were present in 36.8%, 37.8% and 35.6% of left internal mammary artery (IMA), radial artery and saphenous vein grafts. There were 2 (3.0%) hospital deaths and 9 (14.1%) late deaths. Multinomial logistic regression revealed left IMA pathological changes, dyslipidemia, history of percutaneous transluminal coronary angioplasty/stent deployment and Y-graft were significant predictive risk factors negatively influencing the patients’ long-term survival. Kaplan-Meier survival analysis revealed that the long-term survival of patients with left IMA pathological changes were significantly reduced compared with those without (74.1% vs. 91.4%, P=0.002); whereas no differences were noted in long-term survivals between patients with and without pathological changes of the radial arterial or saphenous vein grafts.

Conclusion

Pathological changes may be seen in the bypass graft at the time of harvest. The subtle ultrastructural modifications and the expressions of vascular tone regulators might be responsible for late graft patency. The pathological changes of the left IMA at the time of harvest rather than those of the radial artery or saphenous vein graft affect significantly longterm survival. Non-traumatic maneuver of left IMA harvest, well-controlled dyslipidemia and avoidance of using composite grafts can be helpful in maintaining the architecture of the grafts.     

Magnesium in cardioplegia: Is it necessary?

Objective

To study the effectiveness of magnesium in cardioplegic solution in preventing postoperative arrhythmias and perioperative ischemia.

Design

Randomized, control study.

Setting

The cardiovascular surgery division of a major referral centre for the maritime provinces of Canada.

Patients

Fifty patients scheduled to undergo coronary artery bypass who had a normal ejection fraction, normal preoperative serum magnesium level and no history of atrial or ventricular arrhythmia were randomized into two groups of 25 patients. One group received magnesium sulfate (15 mmol/L) in the cardioplegic solution (group 1), the other (control) group did not receive magnesium sulfate in the cardioplegic solution (group 2).

Intervention

Coronary artery bypass grafting during which myocardial protection was provided by intermittent cold blood cardioplegia.

Outcome Measures

Postoperative serum magnesium levels, cardiac-related death, infarction and arrhythmias.

Results

All group 2 patients had a lower postoperative serum magnesium level than group 1 patients. There were no cardiac-related deaths in either group. More group 2 patients had ischemic electrocardiographic changes than group 1 patients (p < 0.03). Non-Q-wave myocardial infarction occurred in two patients (one in each group). Eight patients in group 2 had atrial fibrillation compared with five patients in group 1. Ventricular ectopia occurred significantly (p < 0.01) more frequently in group 2 than in group 1.

Conclusion

The addition of magnesium to the cardioplegic solution is beneficial in reducing the incidence of perioperative ischemia and ventricular arrhythmia in patients who undergo coronary bypass grafting.     

Relationship between pre-extubation positive endexpiratory pressure and oxygenation after coronary artery bypass grafting

Introduction

After removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological.

Objective

The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting.

Methods

A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cmH₂O (n=32); Group B, 8 cmH₂O (n=26); and Group C, 10 cmH₂O (n=20). Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05.

Results

Groups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization.

Conclusion

In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.     

Cardiopulmonary bypass increases the risk of vasoplegic syndrome after coronary artery bypass grafting in patients with dialysis-dependent chronic renal failure

Objective

Coronary artery bypass grafting is currently the best treatment for dialysis patients with multivessel coronary artery involvement. Vasoplegic syndrome of inflammatory etiology constitutes an important postoperative complication, with highly negative impact on prognosis. Considering that these patients have an intrinsic inflammatory response exacerbation, our goal was to evaluate the incidence and mortality of vasoplegic syndrome after myocardial revascularization in this group.

Methods

A retrospective, single-center study of 50 consecutive and non-selected dialysis patients who underwent myocardial revascularization in a tertiary university hospital, from 2007 to 2012. The patients were divided into 2 groups, according to the use of cardiopulmonary bypass or not (off-pump coronary artery bypass). The incidence and mortality of vasoplegic syndrome were analyzed. The subgroup of vasoplegic patients was studied separately.

Results

There were no preoperative demographic differences between the cardiopulmonary bypass (n=20) and off-pump coronary artery bypass (n=30) group. Intraoperative data showed a greater number of distal coronary arteries anastomosis (2.8 vs. 1.8, P<0.0001) and higher transfusion rates (65% vs. 23%, P=0.008) in the cardiopulmonary bypass group. Vasoplegia incidence was statistically higher (P=0.0124) in the cardiopulmonary bypass group (30%) compared to the off-pump coronary artery bypass group (3%). Vasoplegia mortality was 50% in the cardiopulmonary bypass group and 0% in the off-pump coronary artery bypass group. The vasoplegic subgroup analysis showed no statistically significant clinical differences.

Conclusion

Cardiopulmonary bypass increased the risk for developing postoperative vasoplegic syndrome after coronary artery bypass grafting in patients with dialysis-dependent chronic renal failure.     

Alternative Physical Therapy Protocol Using a Cycle Ergometer During Hospital Rehabilitation of Coronary Artery Bypass Grafting: a Clinical Trial

OBJECTIVE

To compare the efficacy of a cycle ergometer-based exercise program to a standard protocol on the increment of the maximum distance walked during the six-minute walk test in the postoperative rehabilitation of patients submitted to coronary artery bypass grafting.

METHODS

A controlled clinical trial pilot, blinded to the outcome, enrolled subjects who underwent coronary artery bypass grafting in a hospital from Southern Brazil. Subjects were designated for the standard physical rehabilitation protocol or to an alternative cycle ergometer-based protocol through simple random sampling. The primary outcome was the difference in the maximum distance walked in the six-minute walk test before and after the allocated intervention.

RESULTS

Twenty-four patients were included in the analysis, 10 in the standard protocol and 14 in the alternative protocol group. There was an increment in the maximum distance walked in both groups, and borderline superiority in the intervention group comparing to the control group (312.2 vs. 249.7; P=0.06).

CONCLUSION

There was an increase in the maximum distance walked in the alternative protocol compared to the standard protocol. Thus, it is postulated that the use of a cycle ergometer can be included in physical rehabilitation in the hospital phase of postoperative coronary artery bypass grafting. However, randomized studies with larger sample size should be conducted to assess the significance of these findings.     

Autologous bone marrow cell transplantation combined with off-pump coronary artery bypass grafting in patients with ischemic cardiomyopathy

Background

Clinical studies have demonstrated that intracoronary or intramyocardial transplantation of bone marrow mononuclear cells (BMMNCs) into ischemic myocardium improves cardiac function. The objective of the present study was to evaluate the safety and feasibility of intramyocardial BMMNC transplantation into nongraftable areas in combination with off-pump coronary artery bypass grafting in patients with ischemic cardiomyopathy.

Methods

Five male patients with myocardial infarction lasting for more than 1 month and with nongraftable myocardium received autologous mononuclear cell transplantation during off-pump coronary artery bypass grafting. Autologous bone marrow was aspirated from the iliac crest. BMMNCs (mean 1.6, standard error [SE] 0.3 × 10⁹) including CD34-positive cells (mean 6.8, SE 1.1 × 10⁶) and AC133-positive cells (mean 3.1, SE 1.7 × 10⁶) were injected into the nongraftable ischemic myocardium. Heart function was evaluated with the use of echocardiography, and myocardial perfusion was examined with single photon emission computed tomography technetium-99mTc sestamibi scans.

Results

Two months after cell transplantation, the mean ejection fraction had increased by 7.4%, SE 1.9% (p = 0.016) compared with that before cell transplantation and off-pump coronary artery bypass grafting. The increase in ejection fraction was not correlated with the number of transplanted total mononuclear cells, CD34-positive cells and AC133-positive cells. Myocardial perfusion at the cell-transplanted area increased after cell transplantation and off-pump coronary artery bypass grafting. No arrhythmia was observed.

Conclusion

The present clinical study suggests that intramyocardial transplantation of autologous BMMNCs into the ischemic area during off-pump coronary artery bypass grafting is both feasible and safe and has beneficial effects on cardiac function.     

Impact of body mass index on outcome in patients undergoing coronary artery bypass grafting and/or valve replacement surgery

Objective

This study aimed to analyze the impact of body mass index on outcomes of 101 patients undergoing coronary artery bypass grafting, valve replacement, or combined valve/ coronary artery bypass grafting surgery in a private hospital in Belo Horizonte, Brazil.

Methods

This was a prospective cross-sectional study of patients undergoing cardiac surgery from May 2009 to December 2012. All patients were followed up from the first day of admission until discharge or death. Patients were divided into three groups according to BMI: normal weight, overweight, and obese. The main outcome measure was the association between BMI and postoperative morbidities and mortality.

Results

Multivariate analysis identified obesity as an independent predictor of increased risk of surgical reintervention (odds ratio [OR] 13.6; 95%CI 1.1 - 162.9; P=0.046) and reduced risk of bleeding (OR 0.05; 95% CI 0.09 - 0.69; P=0.025). Univariate analysis showed that obesity was associated with increased frequency of wound dehiscence (P=0.021). There was no association between BMI and other complications or mortality in univariate analysis. There was also no association between body mass index and duration of cardiopulmonary bypass, aortic clamping, mechanical ventilation, and intensive care unit or hospital stay.

Conclusion

Obese individuals undergoing coronary artery bypass grafting, valve replacement, or combined surgery have a higher postoperative risk of surgical reintervention and lower chances of bleeding.     

Myocardial protection with prophylactic oral metoprolol during coronary artery bypass grafting surgery: evaluation by troponin I

Introduction

Biochemical markers of myocardial injury are frequently altered after cardiac surgery. So far there is no evidence whether oral beta-blockers may reduce myocardial injury after coronary artery bypass grafting.

Objective

To determine if oral administration of prophylactic metoprolol reduces the release of cardiac troponin I in isolated coronary artery bypass grafting, not complicated by new Q waves.

Methods

A prospective randomized study, including 68 patients, divided in 2 groups: Group A (n=33, control) and B (n=35, beta-blockers). In group B, metoprolol tartrate was administered 200 mg/day. The myocardial injury was assessed by troponin I with 1 hour and 12 hours after coronary artery bypass grafting.

Results

No significant difference between groups regarding pre-surgical, surgical, complication in intensive care (15% versus 14%, P=0.92) and the total number of hospital events (21% versus 14%, P=0.45) was observed. The median value of troponin I with 12 hours in the study population was 3.3 ng/ml and was lower in group B than in group A (2.5 ng/ml versus 3.7 ng/ml, P<0,05). In the multivariate analysis, the variables that have shown to be independent predictors of troponin I release after 12 hours were: no beta-blockers administration and number of vessels treated.

Conclusion

The results of this study in uncomplicated coronary artery bypass grafting, comparing the postoperative release of troponin I at 12 hours between the control group and who used oral prophylactic metoprolol for at least 72 hours, allow to conclude that there was less myocardial injury in the betablocker group, giving some degree of myocardial protection.     

Epidemiology of coronary artery bypass grafting at the Hospital Beneficência Portuguesa,S?o Paulo

Introduction

The knowledge of the prevalence of risk factors and comorbidities, as well as the evolution and complications in patients undergoing coronary artery bypass graft allows comparison between institutions and evidence of changes in the profile of patients and postoperative evolution over time.

Objective

To profile (risk factors and comorbidities) and clinical outcome (complications) in patients undergoing coronary artery bypass graft in a national institution of great surgical volume.

Methods

A retrospective cohort study of patients undergoing coronary artery bypass graft in the hospital Beneficência Portuguesa de São Paulo, from July 2009 to July 2010.

Results

We included 3,010 patients, mean age of 62.2 years and 69.9% male. 83.8% of patients were hypertensive, 36.6% diabetic, 44.5% had dyslipidemia, 15.3% were smokers, 65.7% were overweight/obese, 29.3% had a family history of coronary heart disease. The expected mortality calculated by logistic EuroSCORE was 2.7%. The isolated CABG occurred in 89.3% and 11.9% surgery was performed without cardiopulmonary bypass. The most common complication was cardiac arrhythmia (18.7%), especially acute atrial fibrillation (14.3%). Pneumonia occurred in 6.2% of patients, acute renal failure in 4.4%, mediastinites in 2.1%, stroke in 1.8% and AMI in 1.2%. The in-hospital mortality was 5.4% and in isolated coronary artery bypass graft was 3.5%. The average hospital stay was 11 days with a median of eight days (3-244 days).

Conclusion

The profile of patients undergoing coronary artery bypass graft surgery in this study is similar to other published studies.     

Oxidative stress in coronary artery bypass surgery

Objective

The aim of this prospective study was to assess the dynamics of oxidative stress during coronary artery bypass surgery with cardiopulmonary bypass.

Methods

Sixteen patients undergoing coronary artery bypass grafting were enrolled. Blood samples were collected from the systemic circulation during anesthesia induction (radial artery - A1), the systemic venous return (B1 and B2) four minutes after removal of the aortic cross-clamping, of the coronary sinus (CS1 and CS2) four minutes after removal of the aortic cross-clamping and the systemic circulation four minutes after completion of cardiopulmonary bypass (radial artery - A2). The marker of oxidative stress, malondialdehyde, was measured using spectrophotometry.

Results

The mean values of malondialdehyde were (ng/dl): A1 (265.1), B1 (490.0), CS1 (527.0), B2 (599.6), CS2 (685.0) and A2 (527.2). Comparisons between A1/B1, A1/CS1, A1/B2, A1/CS2, A1/A2 were significant, with ascending values (P<0.05). Comparisons between the measurements of the coronary sinus and venous reservoir after the two moments of reperfusion (B1/B2 and CS1/CS2) were higher when CS2 (P<0.05). Despite higher values ​​after the end of cardiopulmonary bypass (A2), when compared to samples of anesthesia (A1), those show a downward trend when compared to the samples of the second moment of reperfusion (CS2) (P<0.05).

Conclusion

The measurement of malondialdehyde shows that coronary artery bypass grafting with cardiopulmonary bypass is accompanied by increase of free radicals and this trend gradually decreases after its completion. Aortic clamping exacerbates oxidative stress but has sharper decline after reperfusion when compared to systemic metabolism. The behavior of thiobarbituric acid species indicates that oxidative stress is an inevitable pathophysiological component.