Trends in isolated coronary artery bypass grafting: An analysis of the Society of Thoracic Surgeons adult cardiac surgery database

Duration and magnitude of blood pressure below cerebral autoregulation threshold during cardiopulmonary bypass is associated with major morbidity and operative mortality

OBJECTIVES

Optimizing blood pressure using near-infrared spectroscopy monitoring has been suggested to ensure organ perfusion during cardiac surgery. Near-infrared spectroscopy is a reliable surrogate for cerebral blood flow in clinical cerebral autoregulation monitoring and might provide an earlier warning of malperfusion than indicators of cerebral ischemia. We hypothesized that blood pressure below the limits of cerebral autoregulation during cardiopulmonary bypass would be associated with major morbidity and operative mortality after cardiac surgery.

METHODS

Autoregulation was monitored during cardiopulmonary bypass in 450 patients undergoing coronary artery bypass grafting and/or valve surgery. A continuous, moving Pearson's correlation coefficient was calculated between the arterial pressure and low-frequency near-infrared spectroscopy signals and displayed continuously during surgery using a laptop computer. The area under the curve of the product of the duration and magnitude of blood pressure below the limits of autoregulation was compared between patients with and without major morbidity (eg, stroke, renal failure, mechanical lung ventilation >48 hours, inotrope use >24 hours, or intra-aortic balloon pump insertion) or operative mortality.

RESULTS

Of the 450 patients, 83 experienced major morbidity or operative mortality. The area under the curve of the product of the duration and magnitude of blood pressure below the limits of autoregulation was independently associated with major morbidity or operative mortality after cardiac surgery (odds ratio, 1.36; 95% confidence interval, 1.08-1.71; P = .008).

CONCLUSIONS

Blood pressure management during cardiopulmonary bypass using physiologic endpoints such as cerebral autoregulation monitoring might provide a method of optimizing organ perfusion and improving patient outcomes from cardiac surgery.

Trends and outcomes of tricuspid valve surgery in North America: an analysis of more than 50,000 patients from the Society of Thoracic Surgeons database

BACKGROUND

This study evaluated trends and outcomes of tricuspid valve surgery (TVS) in North America over the past decade.

METHODS

Adults undergoing TVS between 2000 and 2010 were identified in The Society of Thoracic Surgeons (STS) National Database. Trends were evaluated using linear regression. Multivariable logistic regression analysis was conducted using covariates from the STS valve risk model to identify significant predictors of operative mortality.

RESULTS

A total of 54,375 patients underwent TVS during the study period. The majority of cases were repairs (89%; n = 48,322) and were performed concomitant with another major procedure (86%; n = 46,593). The proportion of TVS that were repairs increased from 84.6% in 2000 to 89.8% in 2010 (p = 0.01). Trend analysis revealed significant changes in patient characteristics with time, including increasing age, a higher comorbidity burden, and a higher proportion of emergency cases. Despite worsening risk factors, unadjusted operative mortality for TVS declined from 10.6% in 2000 to 8.2% in 2010 (p < 0.001), and this trend persisted after risk adjustment. In the multivariable model, concomitant procedures involving multiple valves or coronary artery bypass grafting were associated with an increased risk of mortality compared with isolated TVS, although other factors including renal failure, congestive heart failure, nonelective presentation, reoperation, and tricuspid valve replacement exerted equal or stronger effects.

CONCLUSIONS

During the past decade, repair rates for TVS have increased significantly. Although patients undergoing TVS have demonstrated worsening risk factors, unadjusted and adjusted operative mortalities have declined. Finally, the data suggest that tricuspid valve repair when technically feasible, together with early elective surgical intervention, should be emphasized as potential candidates for continued outcome improvement.

Preoperative atrial fibrillation and long-term survival after open heart surgery in a rural tertiary heart institute

BACKGROUND

Preoperative atrial fibrillation (AF) is associated with increased morbidity and mortality after open heart surgery. However, the impact of preoperative AF on long-term survival after open heart surgery has not been widely examined in rural populations. Patients from rural regions are less likely to receive treatment for cardiac conditions and to have adequate medical insurance coverage.

OBJECTIVE

To examine the influence of preoperative AF on long-term survival following open heart surgery in rural eastern North Carolina.

METHODS

Long-term survival was compared in patients with and without preoperative AF after coronary artery bypass grafting (CABG) and CABG plus valve (CABG + V) surgery between 2002 and 2011. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model.

RESULTS

The study population consisted of 5438 patients. A total of 263 (5%) patients had preoperative AF. Preoperative AF was an independent predictor of long-term survival (open heart surgery: adjusted HR = 1.6, 95% CI = 1.3-2.0; CABG: adjusted HR = 1.6, 95% CI = 1.3-2.1; CABG + V: adjusted HR = 1.6, 95% CI = 1.1-2.3).

CONCLUSION

Preoperative AF is an important predictor of long-term survival after open heart surgery in this rural population.

Systematic review of robotic-assisted, totally endoscopic coronary artery bypass grafting

BACKGROUND

Advancements in surgical robotic technology over the last two decades have enabled coronary artery bypass grafting to be performed totally endoscopically, and have the potential to significantly change clinical practice in the future.

METHODS

A systematic review of studies reporting clinical outcomes of total endoscopic coronary artery bypass grafting (TECABG) was performed.

RESULTS

14 appraised studies included 880 beating heart TECABGs, 360 arrested heart TECABGs, 633 one-vessel operations and 357 two-vessel operations. Patients were generally low-risk. There was a significant learning curve. The weighted means for short-term beating heart and arrested heart TECABG results respectively were: intraoperative exclusion rate of 5.7% and 1.9%, intraoperative conversion rate of 5.6% and 15.0%, all-cause mortality of 1.2% and 0.4%, stroke of 0.7% and 0.8%, myocardial infarction of 0.8% and 1.8%, new onset atrial fibrillation of 10.7% and 5.1% and post-operative reintervention rate of 2.6% and 2.3%. The overall rate of short term postoperative graft patency for beating heart and arrested heart TECABG was 98.3% and 96.4% respectively.

CONCLUSIONS

Appropriate patient selection was important in minimizing the risk of intraoperative and postoperative complications. Short-term outcomes of both beating and arrested heart TECABG were acceptable, but results so far have been heterogeneous. There were fewer studies reporting intermediate to long-term outcomes, but results were encouraging, and further investigation and development of the procedure is warranted.

A meta-analysis comparing bilateral internal mammary artery with left internal mammary artery for coronary artery bypass grafting

BACKGROUND

Increasing evidence continues to demonstrate a survival advantage for bilateral internal mammary artery (BIMA) over left internal mammary artery (LIMA) for coronary artery bypass grafting (CABG). We performed an updated meta-analysis of published studies comparing BIMA versus LIMA in CABG operations and assessed differences in long-term survival.

METHODS

Electronic searches for studies comparing BIMA versus LIMA were performed using three databases from 1972 to December 2012. Studies with at least four years of follow-up and at least 100 patients in each group were included for review. We used a random-effect model and pooled hazard ratios from across all included studies.

RESULTS

No randomized controlled trials and 27 observational studies totaling 79,063 patients (19,277 BIMA, 59,786 LIMA) were included for final analysis. The BIMA group demonstrated significantly better long-term survival than the LIMA group [hazard ratio, 0.78; confidence interval, 0.72-0.84; P<0.00001].

CONCLUSIONS

In an updated meta-analysis, we demonstrate an increase in long-term survival in patients receiving BIMA as a primary grafting strategy over those receiving a LIMA. Although no randomized controlled trials were included in this meta-analysis, the survival benefit seen with a BIMA cannot be overlooked when determining which operation to perform in CABG patients. Until the long-term results of the ART trial are published, we offer best available evidence in favor of BIMA over LIMA for CABG surgery.

A contemporary cost analysis of postoperative morbidity after coronary artery bypass grafting with and without concomitant aortic valve replacement to improve patient quality and cost-effective care

BACKGROUND

The financial burden of postoperative morbidity after cardiac operations remains ill defined. This study evaluated the costs associated with the performance of coronary artery bypass grafting (CABG) with and without aortic valve replacement (AVR) and determined the incremental costs associated with major postoperative complications.

METHODS

A total of 65,534 regional patients undergoing CABG (n = 55,167) ± AVR (n = 10,367) were evaluated from 2001 to 2011. Patient-related, hospital-related, and procedure-related cost data were analyzed by use of Medicare-based cost reports. Hierarchical multivariable regression modeling was used to estimate risk-adjusted incremental cost differences in postoperative complications.

RESULTS

The mean age was 64 years, and women accounted for 31% of patients. CABG + AVR patients had higher rates of overall complication (40% vs 35%, p < 0.001) and operative mortality (5% vs 3%, p < 0.001) than did CABG patients. CABG + AVR patients also accrued increased median postoperative lengths of stay (7 vs 5 days, p < 0.001) and total costs ($26,527 vs $24,475, p < 0.001). After mortality risk adjustment, significant positive relationships existed between total costs and major postoperative complications. Interestingly, the highest incremental costs among CABG patients included newly instituted hemodialysis ($71,833), deep sternal wound infection ($56,003), and pneumonia ($50,025). Among CABG + AVR patients, these complications along with perioperative myocardial infarction ($68,917) dominated costs.

CONCLUSIONS

Postoperative complications after CABG ± AVR are associated with significantly increased incremental costs. The most costly complications include newly instituted hemodialysis, infectious complications, and perioperative myocardial infarction. Identification of the most common and the most costly complications provides opportunities to target improvement in patient quality and the delivery of cost-effective care.

Diagnosis of MI after CABG with high-sensitivity troponin T and new ECG or echocardiogram changes: relationship with mortality and validation of the universal definition of MI

AIMS

Criteria for diagnosing myocardial infarction (MI) after coronary artery bypass grafting (CABG) are controversial. Uncertainties remain around the optimal threshold for biomarker elevation and the need for associated criteria. There are no studies of high-sensitivity troponin (hs-TnT) after CABG. We assessed whether using hs-TnT to define MI after CABG was associated with 30-day and medium-term mortality and evaluated the utility of adding to the troponin criteria new Q-waves or imaging evidence of new wall motion abnormality as suggested in the Universal Definition of MI.

METHODS

Isolated CABG was performed in 818 patients from July 2010 to June 2012 and hs-TnT was measured 12-24 hours after CABG. Patients with rising baseline or missing troponins (n=258) were excluded. Thresholds of 140 ng/l (10-times 99th percentile upper reference limit) and 500 ng/l (10-times coefficient of variation of 10% for fourth-generation troponin T applied to hs-TnT) were prespecified.

RESULTS

Mean follow up was 1.8±0.6 years. On multivariate analyses, isolated hs-TnT rise >140 ng/l (n=360) or >500 ng/l (n=162) were not associated with mortality. Additional ECG and/or echocardiographic criteria plus hs-TnT >140 ng/l was associated with 30-day mortality (hazard ratio, HR, 4.92, 95% CI 1.34-18.1; p=0.017) and medium-term mortality (HR 3.44, 95% CI 1.13-10.5; p=0.030), whereas ECG and/or echocardiographic abnormalities with hs-TnT >500 ng/l was not (p=0.281 and p=0.123 for 30-day and medium-term mortality, respectively).

CONCLUSIONS

A definition for MI following CABG using hs-TnT with a cut point of 10-times 99th percentile upper reference limit and ECG and/or echocardiographic criteria predicts 30-day and medium-term mortality. These findings validate the Third Universal Definition of type 5 MI.

Fractional flow reserve-guided coronary artery bypass grafting: can intraoperative physiologic imaging guide decision making?

OBJECTIVES

Fractional flow reserve-guided coronary artery bypass grafting is emerging in cardiac surgery, in which the nature (anatomic and functional characteristics) of the target vessel epicardial coronary artery stenosis is important in graft site selection. The nature of the stenosis might determine a different physiologic response to bypass grafting. We report our recent experience using near infrared fluorescence complex angiography and perfusion analysis to identify the nature of stenoses in the target vessel by imaging the physiologic response to grafting.

METHODS

In 167 patients who underwent consecutive multivessel coronary artery bypass grafting cases (63% off-pump coronary artery bypass grafting) with traditional anatomy-based revascularization, we imaged and analyzed 359 grafts (53% arterial). This platform provides angiographic data of both the target vessel epicardial coronary artery and graft simultaneously (to assess the imaged competitive flow); and because a change in fluorescence intensity is proportional to the change in blood flow and perfusion, the quantified change (if any) in regional myocardial perfusion surrounding the grafted target vessel epicardial coronary artery.

RESULTS

The patient outcomes in our series were excellent. All 359 grafts were widely patent by angiography, and 24% of the arterial and 22% of the saphenous vein grafts showed no regional myocardial perfusion change in response to bypass grafting. In 165 in situ internal mammary artery grafts to the left anterior descending artery (>70% stenosis), 40 had no change in regional myocardial perfusion, and 32 of the 40 had competitive flow imaged.

CONCLUSIONS

An important number of angiographically patent bypass grafts demonstrated no change in regional myocardial perfusion, suggesting anatomic, but nonfunctional, stenoses in those target vessel epicardial coronary arteries. In in situ arterial grafts, imaged competitive flow is associated with nonfunctional stenoses in the target vessel epicardial coronary artery. Imaging these physiologic responses to target vessel revascularization might be useful in the emerging fractional flow reserve-guided era.

Bilateral internal mammary arteries: evidence and technical considerations

Bilateral internal mammary artery (BIMA) grafts are used for coronary revascularisation by only a minority of surgeons, despite a growing body of evidence suggesting improved survival when compared to use of only one internal mammary artery with additional saphenous vein grafts. Herein we review the evidence supporting revascularisation with BIMA and suggest reasons why the majority of surgeons use only one internal mammary artery. We discuss technical considerations, various graft combinations and the use of BIMA to facilitate anaortic off-pump coronary artery bypass (OPCAB).

The European Association for Cardio-Thoracic Surgery (EACTS) database: an introduction

OBJECTIVES

Continuous monitoring of surgical outcomes through benchmarking and the identification of best practices has become increasingly important. A structured approach to data collection, coupled with validation, analysis and reporting, is a powerful tool in these endeavours. However, inconsistencies in standards and practices have made comparisons within and between European countries cumbersome. The European Association for Cardio-Thoracic Surgery (EACTS) has established a large international database with the goals of (i) working with other organizations towards universal data collection and creating a European-wide repository of information on the practice of cardio-thoracic surgery, and (ii) disseminating that information in scientific, peer-reviewed articles. We report on the process of data collection, as well as on an overview of the data in the database.

METHODS

The EACTS Database Committee met for the first time in Monaco, September 2002, to establish the ground rules for the process of setting up the database. Subsequently, data have been collected and merged by Dendrite Clinical Systems Ltd.

RESULTS

As of December 2008, the database included 1,074,168 patient records from 366 hospitals located in 29 countries. The latest submission from the years 2006-08 included 404,721 records. The largest contributors were the UK (32.0%), Germany (20.9%) and Belgium (7.3%). Isolated coronary bypass surgery was the most frequently performed operation; the proportion of surgical workload that comprised isolated coronary artery bypass grafting varied from country to country: 30% in Spain and almost 70% in Denmark. Isolated valve procedures constituted 12% of all procedures in Norway and 32% in Spain. Baseline demographics showed an increase in the mean age and the percentage of patients that were female over time. Remarkably, the mortality rates for all procedures declined over the period analysed, to 2.2% (95% confidence interval [CI] 2.2-2.3%) for isolated coronary bypass, 3.4% (95% CI 3.3-3.5%) for isolated valve and 6.2% (95% CI 6.0-6.5%) for bypass + valve procedures.

CONCLUSION

The EACTS database has proven to be an important step forward in providing opportunities for monitoring cardiac surgical care across Europe. As the database continues to expand, it will facilitate research projects, establish benchmarking standards and identify potential areas for quality improvements.

Off-pump versus on-pump coronary artery bypass grafting in octogenarians: comparison of short-term outcomes and long-term survival

Off-pump coronary artery bypass (OPCAB) has gained increasing acceptance with potential benefits for high-risk elderly patients. We report a surgeon's operative outcomes in octogenarians with an OPCAB program. Retrospective, intention-to-treat analysis of 97 consecutive octogenarians who underwent coronary bypass by a single surgeon between 1997 and 2001 before and after initiation of a multi-vessel OPCAB program was performed. OPCAB was attempted in all octogenarians. The OPCAB cohort had higher serum creatinine (OPCAB vs. pre-OPCAB: 1.30 ± 0.79 mg/dl vs. 1.08 ± 0.27, p = 0.04) and ejection fractions (52 ± 14% vs. 45 ± 11%, p = 0.02) than the pre-OPCAB cohort. The OPCAB group was more likely to require urgent/emergency surgery (63 vs. 40%, p = 0.04) and to have chronic renal insufficiency (18 vs. 3%, p = 0.05). After programmatic change to OPCAB, significant postoperative improvements were observed in the length of hospital stay (17 ± 19 vs. 8 ± 4 days, p < 0.01), duration of inotropic requirement (47 ± 70 vs. 18 ± 39 h, p < 0.04), duration of ventilator support (51 ± 54 vs. 16 ± 27 h, p < 0.01) and incidence of tracheostomy (16 vs. 3%, p < 0.02). In-hospital mortalities (3.2 vs. 2.7%), strokes (3 per group) and 5-year survival did not differ significantly (57 vs. 67%, p = 0.50, NS). Despite some higher preoperative risks, the OPCAB program demonstrated clinical benefits in octogenarians but no advantage in hospital-mortality or long-term survival.

Simple adaptations of surgical technique to critically reduce the risk of postoperative sternal complications in patients receiving bilateral internal thoracic arteries

OBJECTIVES

Limited blood supply to the thoracic chest wall is a known risk factor for sternal wound complications after CABG. Therefore, bilateral internal thoracic arteries are still rarely utilized despite their proven superior graft patency. The aim of our study was to analyse whether modification of the surgical technique is able to limit the risk of sternal wound complications in patients receiving bilateral internal thoracic artery grafting.

METHODS

All 418 non-emergent CABG patients receiving bilateral internal thoracic artery CABG procedures (BITA) from January 2001 to January 2012 were analysed for sternal wound complications. Surgical technique together with known risk factors and relevant comorbidity were analysed for their effect on the occurrence of sternal wound complications by means of multivariate logistic regression analysis.

RESULTS

Sternal wound complications occurred in 25 patients (5.9%), with a sternal dehiscence rate of 2.4% (10 patients). In multivariate analysis, diabetes (odds ratio [OR]: 4.8, 95% CI: 1.9-11.7, P=0.001), but not obesity (OR: 1.6, 95% CI: 0.7-4.2, P=0.28) or chronic obstructive pulmonary disease (OR: 2.2, 95% CI: 0.87-5.6, P=0.1) was a relevant comorbid condition for sternal complications. Skeletonization of ITA grafts (OR: 0.17, 95% CI: 0.06-0.5, P=0.001) and the augmented use of sternal wires (OR: 0.24, 95% CI: 0.06-0.95, P=0.04) were highly effective in preventing sternal complications. The use of platelet-enriched-fibrin glue (PRF) sealant, however, was associated with more superficial sternal infections (OR: 3.7, 95% CI: 1.3-10.5, P=0.02).

CONCLUSIONS

Adjusted for common risk factors, skeletonization of BITA grafts together with augmented sternal wires is effective in preventing sternal complications. The use of PRF sealant, however, increased the risk for superficial wound complications.

Impact of major non-cardiac complications on outcome following cardiac surgery procedures: logistic regression analysis in a very recent patient cohort

OBJECTIVES

In this study, we sought to analyse the incidence of major non-cardiac complications and their impact on survival following cardiac surgery procedures in a contemporary patient cohort. We further determined independent predictors of perioperative mortality and created a logistic regression model for prediction of outcome after the occurrence of these complications.

METHODS

Prospectively collected data of 5318 consecutive adult patients (mean age 68.9±11.0 years; 29.3% [n=1559] female) undergoing cardiac surgery from January 2009 to May 2012 were retrospectively analysed. Outcome measures were six major non-cardiac complications including respiratory failure, dialysis-dependent renal failure, deep sternal wound infection (DSWI), cerebrovascular accident (CVA), gastrointestinal complications (GIC) and sepsis and their impact on perioperative mortality and hospital length of stay using multivariate regression models. The discriminatory power was evaluated by calculating the area under the receiver operating characteristic curves (C statistic).

RESULTS

A total of 1321 complications were observed in 846 (15.9%) patients: respiratory failure (n=432; 8.1%), dialysis-dependent renal failure (n=295; 5.5%), GIC (n=154; 2.9%), CVA (n=151; 2.8%), DSWI (n=146; 2.7%) and sepsis (n=143; 2.7%). Perioperative mortality was 17.0% in patients with at least one major non-cardiac complication and correlated with the number of complications (single, 9.7%; n=53/549; double, 24.0%; n=44/183; ≥3, 41.2%; n=47/114, P<0.001). Six preoperative and four postoperative independent predictors of operative mortality were identified (age (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.4), peripheral vascular disease (OR 2.6; 95% CI 1.6-4.2), pulmonary hypertension (OR 2.7; 95% CI 1.5-4.9), atrial fibrillation (OR 1.5; 95% CI 1.0-2.3), emergency (OR 5.0; 95% CI 3.4-7.2), other procedures than CABG (OR 1.5; 95% CI 1.0-2.1), postoperative dialysis (OR 4.0; 95% CI 2.6-6.1), sepsis (OR 3.4; 95% CI 2.0-5.6), respiratory failure (OR 3.2; 95% CI 2.2-4.9), GIC (OR 3.2; 95% CI 1.9-5.3)) and included in the logistic model, which accurately predicted outcome (C statistic, 0.892; 95% CI 0.868-0.916). Length of hospital stay was significantly increased according to the number of complications (single: median 15 (IQR 10-24) days, double: 16 (IQR 8-28) days, ≥3: 20 (IQR 13-39) days, P<0.001).

CONCLUSIONS

With a worsening in the risk profile of patients undergoing cardiac surgery, an increasing number of patients develop major complications leading to increased length of stay and mortality, which is correlated to the number and severity of these complications. Our predictive model based on preoperative and postoperative variables allowed us to determine with accuracy the perioperative mortality in critically ill patients after cardiac surgery.

Bilateral internal mammary artery grafts, mortality and morbidity: an analysis of 1 526 360 coronary bypass operations

OBJECTIVES

The objective of this study was to investigate the impact of bilateral internal mammary artery (BIMA) on early outcomes after coronary artery bypass grafting.

DESIGN

Retrospective database analysis.

SETTING

US hospitals.

PATIENTS

1 526 360 patients (mean age 65 years, 73% male) from the Nationwide Inpatient Sample from 2002-2008 who underwent isolated coronary artery bypass grafting with at least one internal mammary artery.

INTERVENTIONS

Single versus BIMA bypass grafting.

MAIN OUTCOME MEASURES

Inhospital mortality, deep sternal wound infection (DSWI).

RESULTS

The rate of BIMA use was 3.9%. Use of BIMA was independently associated with slightly lower inhospital mortality (unadjusted rate 1.1% vs 1.7%, adjusted OR 0.86, 95% CI 0.79 to 0.93). The DSWI rate was 1.4%. The independent predictors of DSWI were female gender (OR 1.06), congestive heart failure (OR 6.22), chronic pulmonary disease (OR 1.57), obesity (OR 1.17), diabetes mellitus (OR 1.04; OR 1.51 with chronic complication) and chronic renal failure (OR 2.13; OR 2.63 with dialysis). The use of BIMA was not an independent predictor of DSWI (OR 1.03, 95% CI 0.96 to 1.10). BIMA was associated with higher incidence of DSWI in patients with chronic complications of diabetes mellitus (OR 1.90, 95% CI 1.51 to 2.41).

CONCLUSIONS

BIMA grafting is associated with increased risk of DSWI only in patients with severe, chronic diabetes. The incremental morbidity and mortality of DSWI does not justify denial of BIMA in the majority of patients.

Almanac 2012: adult cardiac surgery: the national society journals present selected research that has driven recent advances in clinical cardiology

This review covers the important publications in adult cardiac surgery in the last few years, including the current evidence base for surgical revascularisation and the use of off-pump surgery, bilateral internal mammary arteries and endoscopic vein harvesting. The changes in conventional aortic valve surgery are described alongside the outcomes of clinical trials and registries for transcatheter aortic valve implantation, and the introduction of less invasive and novel approaches of conventional aortic valve replacement surgery. Surgery for mitral valve disease is also considered, with particular reference to surgery for asymptomatic degenerative mitral regurgitation.

Cerebral near-infrared spectroscopy monitoring and neurologic outcomes in adult cardiac surgery patients: a systematic review

BACKGROUND

Near-infrared spectroscopy is used during cardiac surgery to monitor the adequacy of cerebral perfusion. In this systematic review, we evaluated available data for adult patients to determine (1) whether decrements in cerebral oximetry during cardiac surgery are associated with stroke, postoperative cognitive dysfunction (POCD), or delirium; and (2) whether interventions aimed at correcting cerebral oximetry decrements improve neurologic outcomes.

METHODS

We searched PubMed, Cochrane, and Embase databases from inception until January 31, 2012, without restriction on languages. Each article was examined for additional references. A publication was excluded if it did not include original data (e.g., review, commentary) or if it was not published as a full-length article in a peer-reviewed journal (e.g., abstract only). The identified abstracts were screened first, and full texts of eligible articles were reviewed independently by 2 investigators. For eligible publications, we recorded the number of subjects, type of surgery, and criteria for diagnosis of neurologic end points.

RESULTS

We identified 13 case reports, 27 observational studies, and 2 prospectively randomized intervention trials that met our inclusion criteria. Case reports and 2 observational studies contained anecdotal evidence suggesting that regional cerebral O(2) saturation (rSco(2)) monitoring could be used to identify cardiopulmonary bypass cannula malposition. Six of 9 observational studies reported an association between acute rSco(2) desaturation and POCD based on the Mini-Mental State Examination (n = 3 studies) or more detailed cognitive testing (n = 6 studies). Two retrospective studies reported a relationship between rSco(2) desaturation and stroke or type I and II neurologic injury after surgery. The observational studies had many limitations, including small sample size, assessments only during the immediate postoperative period, and failure to perform risk adjustments. Two randomized studies evaluated the efficacy of interventions for treating rSco(2) desaturation during surgery, but adherence to the protocol was poor in one. In the other study, interventions for rSco(2) desaturation were associated with less major organ injury and shorter intensive care unit hospitalization compared with nonintervention.

CONCLUSIONS

Reductions in rSco(2) during cardiac surgery may identify cardiopulmonary bypass cannula malposition, particularly during aortic surgery. Only low-level evidence links low rSco(2) during cardiac surgery to postoperative neurologic complications, and data are insufficient to conclude that interventions to improve rSco(2) desaturation prevent stroke or POCD.

Anaortic, total-arterial, off-pump coronary artery bypass surgery: why bother?

Coronary artery bypass grafting (CABG) remains the standard of care for multi-vessel coronary disease. However, the increased rate of peri-operative stroke reported after surgery compared to percutaneous coronary intervention (PCI) remains of concern. Anaortic, total-arterial, off-pump coronary artery bypass (OPCAB) grafting is a technique that offers the main advantages of surgical revascularisation with a rate of stroke that is equivalent to that of PCI. Some recent trials comparing conventional on-pump CABG with OPCAB have questioned the efficacy of the off-pump technique - these are most often performed with manipulation of the ascending aorta. We review the potential benefits of the anaortic, total-arterial OPCAB technique to explain why it is being employed by an increasing number of surgeons.

Angiographic outcomes of radial artery versus saphenous vein in coronary artery bypass graft surgery: a meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of coronary artery bypass graft (CABG) surgery for patients with ischemic heart disease is dependent on the patency of the selected conduit. The left internal thoracic artery is considered to be the best conduit for CABG. However, the preferred conduit between the radial artery (RA) and saphenous vein (SV) remains controversial. The present meta-analysis aims to establish the current level IA evidence on patency outcomes comparing the RA and SV.

METHODS

Electronic searches were performed using 6 databases from their inception to March 2012. Two reviewers independently identified all relevant randomized controlled trials (RCTs) comparing patency outcomes of RA and SV grafts after CABG. Data were extracted and meta-analyzed according to angiographic end points at specified follow-up intervals.

RESULTS

Five relevant RCTs were identified for inclusion in the present meta-analysis. Angiographic results indicated that the RA was significantly more likely to be completely patent and less likely to be associated with graft failure or complete occlusion at 4 years' follow-up and beyond. However, the RA was significantly more likely to be associated with string sign at 1 year of follow-up.

CONCLUSIONS

While acknowledging the limitations of heterogeneous surgical techniques, results from the present meta-analysis suggest potential superiority of the RA compared with the SV at midterm angiographic follow-up. However, the increased incidence of string sign associated with the RA is of potential clinical concern. Further research should be directed at correlating angiographic findings of string sign and graft failure to clinical symptoms and major adverse cardiac and cerebrovascular events at long-term follow-up.