Multivariate prediction of in-hospital mortality associated with coronary artery bypass graft surgery. Northern New England Cardiovascular Disease Study Group

Clinical prediction models and risk tools for early detection of patients at risk of surgical site infection and surgical wound dehiscence: a scoping review

OBJECTIVE

Despite advances in surgical techniques, intraoperative practice and a plethora of advanced wound therapies, surgical wound complications (SWCs), such as surgical site infection (SSI) and surgical wound dehiscence (SWD), continue to pose a considerable burden to the patient and healthcare setting. Predicting those patients at risk of a SWC may give patients and healthcare providers the opportunity to implement a tailored prevention plan or potentially ameliorate known risk factors to improve patient postoperative outcomes.

METHOD

A scoping review of the literature for studies which reported predictive power and internal/external validity of risk tools for clinical use in predicting patients at risk of SWCs after surgery was conducted. An electronic search of three databases and two registries was carried out with date restrictions. The search terms included 'prediction surgical site infection' and 'prediction surgical wound dehiscence'.

RESULTS

A total of 73 records were identified from the database search, of which six studies met the inclusion criteria. Of these, the majority of validated risk tools were predominantly within the cardiothoracic domain, and targeted morbidity and mortality outcomes. There were four risk tools specifically targeting SWCs following surgery.

CONCLUSION

The findings of this review have highlighted an absence of well-developed risk tools specifically for SSI and/or SWD in most surgical populations. This review suggests that further research is required for the development and clinical implementation of rigorously validated and fit-for-purpose risk tools for predicting patients at risk of SWCs following surgery. The ability to predict such patients enables the implementation of preventive strategies, such as the use of prophylactic antibiotics, delayed timing of surgery, or advanced wound therapies following a procedure.

Machine learning algorithms for population-specific risk score in coronary artery bypass grafting

BACKGROUND

The aim of this study was to develop a new risk prediction score (NH Score) for patients undergoing coronary artery bypass grafting (CABG) specific to the Indian population and compare it to the Society of Thoracic Surgeon (STS) Score and the EuroSCORE II.

METHOD

The baseline features of adult patients who underwent CABG between the years 2015 and 2021 (n = 6703) were taken and split into training data (2015-2020; n = 5561) and validation data (2020-2021; n = 1142). The CatBoost algorithm was trained to predict risk scores (NH score), and the performance was tested on the validation set by Precision-Recall Curve and F1 Score. Model calibration was measured by the Brier Score, Expected Calibration Error and Maximum Calibration Error.

RESULTS

The NH score outperformed both the STS and EuroSCORE II for all outcomes. For mortality, the PR AUC for NH Score was (0.463 [95% confidence interval [CI], 0.28-0.64]) compared to 0.113 [95% CI, 0.04-0.22] for the STS score and 0.146 [95% CI, 0.06-0.31] for the EuroSCORE II (p ≪ 0.0001). With respect to morbidity NH Score was superior to the STS score (0.43 [95% CI, 0.33-0.50]) vs. (0.229 [95% CI, 0.18-0.3, p < 0.0001). The observed to the predicted ratio for NH score was superior to the STS Score and similar to EuroSCORE II. NH Score was also more accurate at predicting the risk of prolonged ventilation compared to the STS Score.

CONCLUSION

NH score shows an excellent improvement over the performance of STS score and EuroSCORE II for modelling risk predictions for patients undergoing CABG in Indian population. It warrants further validation for larger datasets.

Development of a new sternal dehiscence prediction scale for decision making in sternal closure techniques after cardiac surgery

Background

After sternotomy, the spectrum for sternal osteosynthesis comprises standard wiring and more complex techniques, like titanium plating. The aim of this study is to develop a predictive risk score that evaluates the risk of sternum instability individually. The surgeon may then choose an appropriate sternal osteosynthesis technique that is risk- adjusted as well as cost-effective.

Methods

Data from 7.173 patients operated via sternotomy for all cardiovascular indications from 2008 until 2017 were retrospectively analyzed. Sternal dehiscence occurred in 2.5% of patients (n = 176). A multivariable analysis model examined pre- and intraoperative factors. A multivariable logistic regression model and a backward elimination based on the Akaike Information Criterion (AIC) a logistic model were selected.

Results

The model showed good sensitivity and specificity (area under the receiver-operating characteristic curve, AUC: 0.76) and several predictors of sternal instability could be evaluated. Multivariable logistic regression showed the highest Odds Ratios (OR) for reexploration (OR 6.6, confidence interval, CI [4.5–9.5], p < 0.001), obesity (body mass index, BMI > 35 kg/m²) (OR 4.23, [CI 2.4–7.3], p < 0.001), insulin-dependent diabetes mellitus (IDDM) (OR 2.2, CI [1.5–3.2], p = 0.01), smoking (OR 2.03, [CI 1.3–3.08], p = 0.001). After weighting the probability of sternum dehiscence with each factor, a risk score model was proposed scaling from − 1 to 5 points. This resulted in a risk score ranging up to 18 points, with an estimated risk for sternum complication up to 74%.

Conclusions

A weighted scoring system based on individual risk factors was specifically created to predict sternal dehiscence. High-scoring patients should receive additive closure techniques.

EuroScore and IL-6 predict the course in ICU after cardiac surgery

BACKGROUND

Despite modern advances in intensive care medicine and surgical techniques, mortality rates in cardiac surgical patients are still about 3%. Considerable efforts were made to predict morbidity and mortality after cardiac surgery. In this study, we analysed the predictive properties of EuroScore and IL-6 for mortality in ICU, prolonged postoperative mechanical ventilation, and prolonged stay in ICU.

METHODS

We enrolled 2972 patients undergoing cardiac surgery. The patients either underwent aortic valve surgery (AV), mitral valve surgery (MV), coronary artery bypass grafting (CABG), and combined operations of aortic valve and coronary artery bypass grafting (AV + CABG) or of mitral and tricuspid valve (MV + TV). Different laboratory and clinical parameters were analysed.

RESULTS

EuroScore as well as IL-6 were associated with increased mortality after cardiac surgery. Furthermore, a higher EuroScore and elevated levels of IL-6 were predictors for prolonged mechanical ventilation and a longer stay in ICU. Especially, highly significant elevated IL-6 levels and an increased EuroScore showed a strong association. Statistics suggested superiority when both parameters were combined in a single model.

CONCLUSION

Our results suggest that EuroScore and IL-6 are helpful in predicting the course in ICU after cardiac surgery, and therefore, the use of intensive care resources. Especially, the combination of highly elevated levels of IL-6 and EuroScore may prove to be excellent predictors for an unfortunate postoperative course in ICU.

Risk stratification tool for all surgical site infections after coronary artery bypass grafting

OBJECTIVE

To develop a risk score for surgical site infections (SSIs) after coronary artery bypass grafting (CABG).

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENTS

A derivation sample of 7,090 consecutive isolated or combined CABG patients and 2 validation samples (2,660 total patients).

METHODS

Predictors of SSIs were identified by multivariable analyses from the derivation sample, and a risk stratification tool (additive and logistic) for all SSIs after CABG (acronym, ASSIST) was created. Accuracy of prediction was evaluated with C-statistic and compared 1:1 (using the Hanley-McNeil method) with most relevant risk scores for SSIs after CABG. Both internal (1,000 bootstrap replications) and external validation were performed.

RESULTS

SSIs occurred in 724 (10.2%) cases and 2 models of ASSIST were created, including either baseline patient characteristics alone or combined with other perioperative factors. Female gender, body mass index >29.3 kg/m2, diabetes, chronic obstructive pulmonary disease, extracardiac arteriopathy, angina at rest, and nonelective surgical priority were predictors of SSIs common to both models, which outperformed (P < .0001) 6 specific risk scores (10 models) for SSIs after CABG. Although ASSIST performed differently in the 2 validation samples, in both, as well as in the derivation data set, the combined model outweighed (albeit not always significantly) the preoperative-only model, both for additive and logistic ASSIST.

CONCLUSIONS

In the derivation data set, ASSIST outperformed specific risk scores in predicting SSIs after CABG. The combined model had a higher accuracy of prediction than the preoperative-only model both in the derivation and validation samples. Additive and logistic ASSIST showed equivalent performance.

Galectin-3 as a Predictor of Long-term Survival After Isolated Coronary Artery Bypass Grafting Surgery

BACKGROUND

Galectin-3 (Gal-3) is a well-established biomarker of adverse clinical outcomes, but its prognostic value for long-term survival after cardiac surgery is not well understood. Elevated levels of Gal-3 have been found to be remarkably associated with higher risk of death in both acute decompensated and chronic heart failure populations. Its prognostic value for long-term survival after cardiac surgery is not known.

METHODS

A sample of patients contributing to the Northern New England Cardiovascular Disease Study Group Cardiac Surgery Registry from 2004 to 2007 were enrolled in a prospective biomarker cohort (N = 1690). Preoperative Gal-3 levels were measured and categorized by quartile. We used Kaplan-Meier survival analysis and Cox regression models, adjusting for variables in The Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategy probability calculator to evaluate the association between elevated Gal-3 levels and survival to 6 years.

RESULTS

Preoperative Gal-3 levels ranged from 1.72 to 28.89 ng/mL (mean, 8.96 ng/mL; median, 8.06 ng/mL; interquartile range, 5.42-11.08 ng/mL). Crude survival decreased by increasing quartile. After adjustment, serum levels of Gal-3 in the highest quartile of the cohort were associated with significantly decreased survival compared with the lowest quartile (hazard ratio [HR] 2.22; 95% confidence interval [CI], 1.40-3.54; P = .001). No decrease in survival was found for the middle quartiles (HR 1.36; 95% CI, 0.87-2.12; P = .177).

CONCLUSIONS

A substantial association was found between elevated preoperative Gal-3 levels and risk of mortality after isolated coronary artery bypass grafting surgery. An assessment of the relationship between preoperative serum biomarkers and long-term survival can be used for risk stratification or estimating postsurgical prognosis.

Intensity of Glycemic Control Affects Long-Term Survival After Coronary Artery Bypass Graft Surgery

BACKGROUND

A patient's hemoglobin (Hb) A_1c level, regardless of diabetic status, is a measure of glycemic control. Studies have found it is an independent predictor of short-term death in patients undergoing coronary artery bypass grafting (CABG). In this study, we used preoperative HbA_1c to assess whether levels are associated with short-term and long-term survival after CABG.

METHODS

From a regional registry of consecutive cases, we identified 6,415 patients undergoing on-pump isolated CABG from 2008 to 2015 with documented preoperative HbA_1c level. We defined four HbA_1c groups: less than 5.7% (n = 1,713), 5.7% to 6.4% (n = 2,505), 6.5% to 8.0% (n = 1,377), and more than 8% (n = 820). Relationship to in-hospital outcomes and long-term survival was assessed. Outcome rates and hazard ratios were adjusted for patient and disease risk factors using multivariable logistic regression and Cox models.

RESULTS

The study included 3,740 patients (58%) not diagnosed as having diabetes and 2,674 with diabetes. Prediabetes (HbA_1c 5.7% to 6.4%) was documented in 52% (n = 1,933) of nondiabetic patients. Higher HbA_1c values were associated with younger age, female sex, greater body mass index, more comorbid diseases, lower ejection fraction, more 3-vessel coronary disease, and recent myocardial infarction (p < 0.05 trend for all). After adjustment for patient risk, greater HbA_1c values were not associated with higher rates of in-hospital death or morbidity. Long-term survival was significantly worse as HbA_1c increased. Risk of death increased by 13% for every unit increase in HbA_1c (adjusted hazard ratio, 1.13; 95% confidence interval, 1.07 to 1.19; p < 0.001).

CONCLUSIONS

Preadmission glycemic control, as assessed by HbA_1c, is predictive of long-term survival, with higher levels associated with poorer prognosis. Whether this risk can be modified by better glycemic control postoperatively remains to be determined.

Predictive Ability of Novel Cardiac Biomarkers ST2, Galectin-3, and NT-ProBNP Before Cardiac Surgery

BACKGROUND

Current preoperative models use clinical risk factors alone in estimating risk of in-hospital mortality following cardiac surgery. However, novel biomarkers now exist to potentially improve preoperative prediction models. An assessment of Galectin-3, N-terminal pro b-type natriuretic peptide (NT-ProBNP), and soluble ST2 to improve the predictive ability of an existing prediction model of in-hospital mortality may improve our capacity to risk-stratify patients before surgery.

METHODS AND RESULTS

We measured preoperative biomarkers in the NNECDSG (Northern New England Cardiovascular Disease Study Group), a prospective cohort of 1554 patients undergoing coronary artery bypass graft surgery. Exposures of interest were preoperative levels of galectin-3, NT-ProBNP, and ST2. In-hospital mortality and adverse events occurring after coronary artery bypass graft were the outcomes. After adjustment, NT-ProBNP and ST2 showed a statistically significant association with both their median and third tercile categories with NT-ProBNP odds ratios of 2.89 (95% confidence interval [CI]: 1.04-8.05) and 5.43 (95% CI: 1.21-24.44) and ST2 odds ratios of 3.96 (95% CI: 1.60-9.82) and 3.21 (95% CI: 1.17-8.80), respectively. The model receiver operating characteristic score of the base prediction model (0.80 [95% CI: 0.72-0.89]) varied significantly from the new multi-marker model (0.85 [95% CI: 0.79-0.91]). Compared with the Northern New England (NNE) model alone, the full prediction model with biomarkers NT-proBNP and ST2 shows significant improvement in model classification of in-hospital mortality.

CONCLUSIONS

This study demonstrates a significant improvement of preoperative prediction of in-hospital mortality in patients undergoing coronary artery bypass graft and suggests that biomarkers can be used to identify patients at higher risk.

Definition of a Geriatric Depression Scale cutoff based upon quality of life: a population-based study

OBJECTIVES

The cutoff scores for the Geriatric Depression Scale (GDS) commonly adopted in clinical and research settings are based upon other neuropsychological tests. However, any intervention for depression should aim at improving subjective quality of life (QoL). We searched for a GDS cutoff level that might identify a decrease in perceived QoL using a scale that also allows formal cost-effectiveness calculations.

METHODS

Quality of life was assessed by the Health Utilities Index, Mark 3 in all 344 residents of Tuscania (Italy) aged 75 years and above. Mood was assessed by both the 30-item GDS and the derived 15-item GDS. The association of GDS with low QoL was analyzed by multivariable logistic regression. Receiver operating characteristic curve analysis was adopted to estimate the overall predictive value and the best GDS cutoff for poor QoL.

RESULTS

The 30-item GDS score was associated with increased probability of a worse QoL (odds ratio (OR) = 1.07, 95% confidence (CI) = 1.02-1.12, p = 0.003); also, it was a fair predictor of worse QoL (area under the curve (AUC) = 0.72; 95% CI = 0.67-0.76). The best GDS score cutoff for identifying a poor QoL was above 9/30. Results were similar (OR = 1.07, 95% CI = 1.02-1.12, p = 0.003, and AUC = 0.72, 95% CI = 0.67-0.76) for the short GDS form for a cutoff above 5/15.

CONCLUSIONS

Among older subjects, depressive symptoms are associated with reduced QoL; GDS scores above 9/30 or 5/15 best predict poor perceived health-related QoL. These cutoff scores could therefore identify subjects in whom treatment is more likely to improve QoL and to yield a favorable cost-effectiveness ratio. Copyright © 2017 John Wiley & Sons, Ltd.

Modifying risks to improve outcome in cardiac surgery: An anesthesiologist's perspective

Challenging times are here for cardiac surgical and anesthesia team. The interventional cardiologist seem to have closed the flow of ‘good cases’ coming up for any of the surgery,; successful percutaneous interventions seem to be offering reasonable results in these patients, who therefore do not knock on the doors of the surgeons any more. It is a common experience among the cardiac anesthesiologists and surgeons that the type of the cases that come by now are high risk. That may be presence of comorbidities, ongoing medical therapies, unstable angina, uncontrolled heart failure and rhythm disturbances; and in patients with ischemic heart disease, the target coronaries are far from ideal. Several activities such as institution of preoperative supportive circulatory, ventilatory, and systemic disease control maneuvers seem to have helped improving the outcome of these ‘high risk ‘ patients. This review attempts to look at various interventions and the resulting improvement in outcomes. Several changes have happened in the realm of cardiac surgery and several more are en route. At times, for want of evidence, maximal optimization may not take place and the patient may encounter unfavorable outcomes.. This review is an attempt to bring the focus of the members of the cardiac surgical team on the value of preoperative optimization of risks to improve the outcome. The cardiac surgical patients may broadly be divided into adults undergoing coronary artery bypass graft surgery, valve surgery and pediatric patients undergoing repair/palliation of congenital heart ailments. Optimization of risks appear to be different in each genre of patients. This review also brings less often discussed issues such as anemia, nutritional issues and endocrine problems. The review is an attempt to data on ameliorating modifiable risk factors and altering non modifiable ones.

Outcome of cardiac surgery in patients with low preoperative ejection fraction

Background

In patients undergoing cardiac surgery, a reduced preoperative left ventricular ejection fraction (LVEF) is common and is associated with a worse outcome. Available outcome data for these patients address specific surgical procedures, mainly coronary artery bypass graft (CABG). Aim of our study was to investigate perioperative outcome of surgery on patients with low pre-operative LVEF undergoing a broad range of cardiac surgical procedures.

Methods

Data from patients with pre-operative LVEF ≤40 % undergoing cardiac surgery at a university hospital were reviewed and analyzed. A subgroup analysis on patients with pre-operative LVEF ≤30 % was also performed.

Results

A total of 7313 patients underwent cardiac surgery during the study period. Out of these, 781 patients (11 %) had a pre-operative LVEF ≤40 % and were included in the analysis. Mean pre-operative LVEF was 33.9 ± 6.1 % and in 290 patients (37 %) LVEF was ≤30 %. The most frequently performed operation was CABG (31 % of procedures), followed by mitral valve surgery (22 %) and aortic valve surgery (19 %). Overall perioperative mortality was 5.6 %. Mitral valve surgery was more frequent among patients who did not survive, while survivors underwent more frequently CABG. Post-operative myocardial infarction occurred in 19 (2.4 %) of patients, low cardiac output syndrome in 271 (35 %). Acute kidney injury occurred in 195 (25 %) of patients. Duration of mechanical ventilation was 18 (12–48) hours. Incidence of complications was higher in patients with LVEF ≤30 %. Stepwise multivariate analysis identified chronic obstructive pulmonary disease, pre-operative insertion of intra-aortic balloon pump, and pre-operative need for inotropes as independent predictors of mortality among patients with LVEF ≤40 %.

Conclusions

We confirmed that patients with low pre-operative LVEF undergoing cardiac surgery are at higher risk of post-operative complications. Cardiac surgery can be performed with acceptable mortality rates; however, mitral valve surgery, was found to be associated with higher mortality rates in this population. Accurate selection of patients, risk/benefit evaluation, and planning of surgical and anesthesiological management are mandatory to improve outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0271-5) contains supplementary material, which is available to authorized users.

Highest core temperature during cardiopulmonary bypass and rate of mediastinitis

Temperature control during cardiopulmonary bypass (CPB) may be related to rates of bacterial infection. We assessed the relationship between highest core temperature during CPB and rates of mediastinitis in 6955 consecutive isolated coronary artery bypass graft (CABG) procedures in northern New England.

The overall rate of mediastinitis was 1.1%. The association between highest core temperature and mediastinitis was different for diabetics than for nondiabetics. A multivariate model showed that there was a significant interaction between diabetes and temperature in their association with mediastinitis ( p = 0.015). Diabetic patients showed higher rates of mediastinitis as highest core temperature increased, from 0.7% in the ≤37°C group to 3.3% in the ≥38°C group ( ptrend = 0.002). Adjusted rates were similar. Nondiabetic patients did not show this trend ( ptrend = 0.998).

Among diabetic patients, a peak core body temperature > 37.9°C during CPB is a significant risk factor for development of mediastinitis. Avoidance of higher temperatures during CPB may lower the risk of mediastinitis for diabetic patients undergoing CABG surgery.

Profile of Coronary Artery Bypass Surgery in United Arab Emirates: Dubai Hospital Experience

Although coronary artery bypass surgery has become a common procedure, there were no data available regarding this type of surgery in the United Arab Emirates. Therefore, we undertook this retrospective study of the first 522 consecutive patients undergoing coronary artery bypass graft surgery between October 1992 and July 1997. The mean age was 49.1 years at operation with a 97.1% male predominance. Patients of Asian origin accounted for 75.8%, Arabs 22.4%, and Europeans 1.7%. Chronic stable angina was the most frequent presenting symptom (70.4%) and 62.1% patients had at least one prior myocardial infarction. There was a 44.6% incidence of hypertension and 32.9% of patients were diabetic. Other prominent risk factors were smoking (55.7%), hyperlipidemia (53.9%), and family history of ischemic heart disease (10.7%). Left main coronary artery obstruction was evident in 6.5% of patients. An average of 3.4 grafts per patient were performed using reverse saphenous vein and endarterectomies were needed in 2.2%. The early mortality rate in elective cases was 2.4%. This study suggests that in spite of a high incidence of multiple risk factors, our patients tolerated coronary artery bypass surgery well. Our findings highlight the trend towards more urgent operations and the decreasing age of patients with severe coronary artery disease.

Off-Pump Surgery: A Choice in Unstable Angina

The benefit and safety of off-pump coronary artery bypass surgery in patients with unstable angina was assessed retrospectively. From February 1996 to October 2001, 5,306 patients underwent multivessel off-pump coronary artery bypass, of whom 920 (17%) had unstable angina. In these 920 patients, ejection fractions ranged from 15% to 70%, 203 (22%) had an ejection fraction of 20%–35%, and 11 (1%) had an ejection fraction < 20%. Triple-vessel disease was present in 625 patients. Preoperative intraaortic balloon pump support was used in 28 patients. Operative approaches included mid sternotomy (86%), lower partial sternotomy (9%), and left anterior thoracotomy (2%). The number of grafts ranged from 1 to 5 with a mean of 2.43 ± 0.86, and 92.3% of patients received a left internal mammary artery graft. Twenty-two patients need intraoperative intraaortic balloon pumping. Ten patients (1%) suffered perioperative myocardial infarction. The mean hospital stay was 7.8 ± 4.3 days. Hospital mortality was 2/920 (0.22%). Intraaortic balloon pumping was helpful in these cases of unstable angina refractory to medical therapy. Off-pump coronary artery surgery was found to be safe and beneficial in these patients.

Prospective validation of a predictive scoring system for deep sternal wound infection after routine bilateral internal thoracic artery grafting

OBJECTIVES

The Gatti score is a weighted scoring system based on risk factors for deep sternal wound infection (DSWI) that has been specifically created to predict DSWI risk after routine bilateral internal thoracic artery (BITA) grafting. It has not undergone an external validation. The aim of the present study was to perform this validation.

METHODS

BITA grafts were used as skeletonized conduits in 304 (90.7%) of 335 consecutive patients with multivessel coronary artery disease who underwent isolated coronary bypass surgery at the authors' institution between January 2014 and July 2015. Baseline characteristics, operative data and immediate outcomes of every patient were prospectively collected in a computerized data registry. A score was assigned to each patient preoperatively. The goodness-of-fit and the discrimination power of both models, preoperative and combined, of the Gatti score were assessed with the Hosmer-Lemeshow test and the calculation of the area under the receiver-operating characteristic curve, respectively.

RESULTS

Eighteen (5.9%) patients suffered from DSWI. Major differences were found between the original series whence the Gatti score has been derived and the present prospective series. The Gatti score goodness-of-fit was satisfactory for both the preoperative (P = 0.61) and the combined model (P = 0.81). The area under the receiver-operating characteristic curve was 0.82 (95% confidence interval: 0.72-0.91) for the preoperative model and 0.8 (95% confidence interval: 0.71-0.9) for the combined model.

CONCLUSIONS

On the basis of the results of the present prospective study, the Gatti score has proved to be effective in predicting DSWI following BITA grafting despite some differences between the original and the present series of patients. More studies have to be performed in order to strengthen the evidence of this first external validation.

Basics of Stratifying for Severity of Illness

Conventional wisdom suggests that those who assess healthcare processes and outcomes always should stratify cases by severity of illness; however, infection control personnel should analyze each quality assessment tool with and without severity adjustment and determine whether such adjustment is necessary. This article briefly reviews severity adjustments for diseases or procedures involving specific organ systems, as well as those applicable to all diseases, including the commercially available systems. Also discussed is whether and how these various systems for severity adjustment can be compared. Finally, the article will provide selected references for individuals who will use these scoring systems and need more information.

Serum creatinine role in predicting outcome after cardiac surgery beyond acute kidney injury

Serum creatinine is still the most important determinant in the assessment of perioperative renal function and in the prediction of adverse outcome in cardiac surgery. Many biomarkers have been studied to date; still, there is no surrogate for serum creatinine measurement in clinical practice because it is feasible and inexpensive. High levels of serum creatinine and its equivalents have been the most important preoperative risk factor for postoperative renal injury. Moreover, creatinine is the mainstay in predicting risk models and risk factor reduction has enhanced its importance in outcome prediction. The future perspective is the development of new definitions and novel tools for the early diagnosis of acute kidney injury largely based on serum creatinine and a panel of novel biomarkers.

The novel regulations of MEF2A, CAMKK2, CALM3, and TNNI3 in ventricular hypertrophy induced by arsenic exposure in rats

Arsenic is a ubiquitous toxic compound that exists naturally in many sources such as soil, groundwater, and food; in which vast majority forms are arsenite (As(3+)) or arsenate (As(5+)). The mechanism of arsenic detoxification in humans still remains obscured. Epidemiologic studies documented that arsenic pollution caused black foot disease, cardiovascular diseases (hypertension, hypotension, cardiomyopathy), bladder cancer and skin cancer in many countries in which Taiwan is considered as high arsenic exposure country for long time ago. However, the effects of arsenic to cardiac functions still lacked of investigation while some studies mainly focus on inflammatory and cancer mechanisms. In the present study, we found cardiac hypertrophy signaling may be the most significant pathway for up regulated genes in arsenic exposed patients via bioinformatics approach. To verify our bioinformatics prediction, arsenic was fed orally to rats at different concentration based on previous studies in Taiwan. Using hemodynamic method as the main tool to measure the changes in blood pressure, left ventricular pressure and left ventricular contractility index, the findings suggest that highly exposure to arsenic lead to hypertension; elevated left ventricular diastolic pressure and alteration in cardiac contractility which are supposed to be the interaction between arsenic and cardiac nerves activity via the changing in calcium homeostasis. Collectively, based on our real-time PCR and western blot data strongly suggest that calcium homeostasis may also go through MEF2A, TNNI3, CAMKK2, CALM3 and cardiac hypertrophy relative signaling pathway.

Is crystalloid cardioplegia a strong predictor of intra-operative hemodilution?

INTRODUCTION

Complications due to hemodilution (hematocrit value less than 22%) after cardiopulmonary bypass inevitably resulted with significantly greater intensive care requirements, long hospital stays, more operative costs, and increased mortality rates. We tried to identify whether crystalloid cardioplegia is the strongest predictor of intraoperative hemodilution or not.

MATERIALS AND METHODS

One hundred patients were included into this randomized prospective study. Patients were divided into the two groups. Crystalloid cardioplegia were given to the odd-numbered patients (Group 1, n=50 patients) and blood cardioplegia were given to the even-numbered patients (Group 2, n=50 patients). St. Thomas-II solution was used in Group-1 and Calafiore cold blood cardioplegia was in Group-2.

RESULTS

Average intraoperative hematocrit value was 18.4% ± 2.3 in crystalloid group 24.2% ± 3.4 in blood cardioplegia group (p<0.001). The lowest hematocrit value was 15% and 20% in two groups respectively (p<0.001). In crystalloid group average intraoperative packed red blood cell (RBC) transfusion was 2.3 ± 0.41 units, 0.7 ± 0.6 units blood cardioplegia group (p=0.001). Average transfused RBC was 2.7 ± 0.8 units in crystalloid group, 0.9 ± 0.4 units blood cardioplegia group (p<0.001). Multivariate analyses confirmed age (p = 0.005, OR = 3.78), female gender (p = 0.003, OR = 2.91), longer cross-clamp time (>60 minutes) (p = 0.001, OD = 0.97), body surface area <1.6 m2 (p = 0.001, OR = 6.01) and crystalloid cardioplegia (p < 0.001, OR = 0.19) as predictor of intraoperative hemodilution.

CONCLUSION

Crystalloid cardioplegia, compared to blood cardioplegia not only causes much more intra-operative hemodilution but also increases the blood transfusion requirement. Hemodilution and increased transfusion increases the intensive care unit and hospital stay, in the early postoperative period.

Bilateral internal thoracic artery grafting for peripheral arterial disease patients

BACKGROUND

Peripheral arterial disease (PAD) is known to have a poor prognosis. Some reports have also described poor late results after coronary artery bypass grafting (CABG). However, there have been few reports about whether bilateral internal thoracic artery grafting improves the long-term survival of PAD patients after CABG. We performed this study to clarify whether or not this is the case.

METHODS

One hundred and thirty-six PAD patients who underwent elective CABG with two or more grafts were enrolled in this study. Patients were divided into two groups, 71 patients in the bilateral internal thoracic artery (BITA) group and 65 patients in the single internal thoracic artery (SITA) group. The maximum follow-up period was 19 years, with a mean of 5.7 ± 4.4 years.

RESULTS

We investigated the long-term results based on three factors; survival, freedom from cardiac death, and freedom from cardiac events. The 3-, 5- and 10-year survival rates in the BITA group were 83.0, 74.2, and 43.1%, respectively. And those in the SITA group were 79.4, 67.7, and 32.3%, respectively. There were no significant differences between the two groups (p = 0.5843). There were also no statistically significant differences between the two groups in terms of the freedom from cardiac death (p = 0.8589) or in the freedom from cardiac events (p = 0.9445).

CONCLUSION

No long-term advantage was observed for CABG with BITA in comparison to SITA alone in patients with PAD.

The association between perioperative allogeneic transfusion volume and postoperative infection in patients following lumbar spine surgery

BACKGROUND

Perioperative allogeneic red blood cell transfusion is a risk factor for surgical site infection. The purpose of this study was to determine if the volume of perioperative allogeneic red blood cell transfusion influences the risk of surgical site infection following lumbar spine procedures.

METHODS

A retrospective matched case control study was performed by reviewing all patients who had undergone lumbar spine surgery at our institution from 2005 to 2009. Surgical site infections (spinal or iliac crest) were identified, all within thirty days of the procedure. Controls were matched to the infection cohort according to age, sex, body mass index, diabetic status, smoking status, Charlson Comorbidity Index, length of surgery, and procedure. A conditional logistic regression was performed to examine the association between transfusion volume and surgical site infection. The results were summarized by an odds ratio.

RESULTS

A total of 1799 lumbar procedures were identified with an infection rate of 3.1% (fifty-six cases). On the basis of the numbers, there was no significant difference in the matched variables between the infection cohort and the matched controls. The volume of transfusion was significantly associated with surgical site infection (odds ratio, 4.00 [95% confidence interval, 1.96 to 8.15]) after adjusting for both unmatched variables of preoperative hemoglobin level and volume of intraoperative blood loss.

CONCLUSIONS

In this retrospective matched case control study, the association between surgical site infection following lumbar spine surgery and volume of perioperative allogeneic red blood cell transfusion was supported.

Development of the Post Cardiac Surgery (POCAS) prognostic score

Introduction

The risk of mortality in cardiac surgery is generally evaluated using preoperative risk-scale models. However, intraoperative factors may change the risk factors of patients, and the organism functionality parameters determined upon ICU admittance could therefore be more relevant in deciding operative mortality. The goals of this study were to find associations between the general parameters of organism functionality upon ICU admission and the operative mortality following cardiac operations, to develop a Post Cardiac Surgery (POCAS) Scale to define operative risk categories and to validate an operative mortality risk score.

Methods

We conducted a prospective study, including 920 patients who had undergone cardiac surgery with cardiopulmonary bypass. Several parameters recorded on their ICU admission were explored, looking for a univariate and multivariate association with in-hospital mortality (90 days). In-hospital mortality was 9%. Four independent factors were included in the POCAS mortality risk model: mean arterial pressure, bicarbonate, lactate and the International Normalized Ratio (INR). The POCAS scale was compared with four other risk scores in the validation series.

Results

In-hospital mortality (90 days) was 9%. Four independent factors were included in the POCAS mortality risk model: mean arterial pressure, bicarbonate ratio, lactate ratio and the INR. The POCAS scale was compared with four other risk scores in the validation series. Discriminatory power (accuracy) was defined with a receiver-operating characteristics (ROC) analysis. The best accuracy in predicting in-hospital mortality (90 days) was achieved by POCAS. The areas under the ROC curves of the different systems analyzed were 0.890 (POCAS), followed by 0.847 (Simplified Acute Physiology Score (SAP II)), 0.825 (Sepsis-related Organ Failure Assessment (SOFA)), 0.768 (Acute Physiology and Chronic Health Evaluation (APACHE II)), 0.754 (logistic EuroSCORE), 0.714 (standard EuroSCORE) and 0.699 (Age, Creatinine, Ejection Fraction (ACEF) score).

Conclusions

Our new system to predict the operative mortality risk of patients undergoing cardiac surgery is better than others used for this purpose (SAP II, SOFA, APACHE II, logistic EuroSCORE, standard EuroSCORE, and ACEF score). Moreover, it is an easy-to-use tool since it only requires four risk factors for its calculation.

Development of a predictive model for major adverse cardiac events in a coronary artery bypass and valve population

BACKGROUND

Quality improvement initiatives in cardiac surgery largely rely on risk prediction models. Most often, these models include isolated populations and describe isolated end-points. However, with the changing clinical profile of the cardiac surgical patients, mixed populations models are required to accurately represent the majority of the surgical population. Also, composite model end-points of morbidity and mortality, better reflect outcomes experienced by patients.

METHODS

The model development cohort included 4,270 patients who underwent aortic or mitral valve replacement, or mitral valve repair with/without coronary artery bypass grafting, or isolated coronary artery bypass grafting. A composite end-point of infection, stroke, acute renal failure, or death was evaluated. Age, sex, surgical priority, and procedure were forced, a priori, into the model and then stepwise selection of candidate variables was utilized. Model performance was evaluated by concordance statistic, Hosmer-Lemeshow Goodness of Fit, and calibration plots. Bootstrap technique was employed to validate the model.

RESULTS

The model included 16 variables. Several variables were significant such as, emergent surgical priority (OR 4.3; 95% CI 2.9-7.4), CABG + Valve procedure (OR 2.3; 95% CI 1.8-3.0), and frailty (OR 1.7; 95% CI 1.2-2.5), among others. The concordance statistic for the major adverse cardiac events model in a mixed population was 0.764 (95% CL; 0.75-0.79) and had excellent calibration.

CONCLUSIONS

Development of predictive models with composite end-points and mixed procedure population can yield robust statistical and clinical validity. As they more accurately reflect current cardiac surgical profile, models such as this, are an essential tool in quality improvement efforts.

Safety of thromboembolic chemoprophylaxis in spinal trauma patients requiring surgical stabilization

STUDY DESIGN

Retrospective review.

OBJECTIVE

To determine the incidence of thromboembolic events, bleeding complications such as epidural hematomas, and wound complications in patients with spinal trauma requiring surgical stabilization.

SUMMARY OF BACKGROUND DATA

Literature addressing the safety and efficacy of chemoprophylactic agents in postoperative patients with spinal trauma is sparse. As a result, significant variability exists regarding administration of thromboembolic chemoprophylaxis in this population. The risk of bleeding complications is particularly concerning.

METHODS

Patients with spinal trauma who underwent surgical stabilization in 2009 and 2010 at a single level 1 trauma center were retrospectively reviewed. Exclusion criteria included patients who underwent solely decompressive procedures, noninstrumented fusions, kyphoplasty, or had incomplete medical records. Patients who received chemoprophylaxis were compared with patients who did not. Demographical information and injury data were collected. Primary outcome measures were prevalence of thromboembolic events, epidural hematomas, and persistent wound drainage requiring irrigation and debridement.

RESULTS

Two hundred twenty-seven of 373 patients were included (56 in the untreated group, 171 in the treated group). Eight patients in the untreated group (14.3%) and 12 patients in the treated group (7%) developed postoperative thromboembolism (P = 0.096). There was 1 pulmonary embolism in the untreated group (1.8%), and 4 pulmonary embolisms in the treated group (2.3%). Surgical irrigation and debridement for wound drainage was required for 1.8% of patients in the untreated group and for 5.3% of patients in the treated group. No epidural hematomas were noted in either group. The treated group had more spinal levels fused (P = 0.46), higher injury severity scores (0.001), and longer hospitalizations (0.018). Patients who developed postoperative thromboembolism had significantly higher body mass indexes (P = 0.01), injury severity scores (0.001), number of spinal levels fused (P = 0.004), incidence of neurological deficits (0.001), and longer hospitalizations (0.16) compared with those who did not.

CONCLUSION

The use of chemoprophylaxis appears to be safe in at-risk patients in the immediate postoperative period after spinal trauma surgery. No epidural hematomas occurred, and the risk of wound drainage is small. Body mass index, injury severity score, presence of neurological deficits, and number of spinal levels fused should be considered when determining which patients should receive chemoprophylaxis after surgical stabilization.

Hemoglobin and B-type natriuretic peptide preoperative values but not inflammatory markers, are associated with postoperative morbidity in cardiac surgery: a prospective cohort analytic study

Introduction

Risk stratification in cardiac surgery significantly impacts outcome. This study seeks to define whether there is an independent association between the preoperative serum level of hemoglobin (Hb), leukocyte count (LEUCO), high sensitivity C-reactive protein (hsCRP), or B-type natriuretic peptide (BNP) and postoperative morbidity and mortality in cardiac surgery.

Methods

Prospective, analytic cohort study, with 554 adult patients undergoing cardiac surgery in a tertiary cardiovascular hospital and followed up for 12 months. The cohort was distributed according to preoperative values of Hb, LEUCO, hsCRP, and BNP in independent quintiles for each of these variables.

Results

After adjustment for all covariates, a significant association was found between elevated preoperative BNP and the occurrence of low postoperative cardiac output (OR 3.46, 95% CI 1.53–7.80, p = 0.003) or postoperative atrial fibrillation (OR 3.8, 95% CI 1.45–10.38). For the combined outcome (death/acute coronary syndrome/rehospitalization within 12 months), we observed an OR of 1.93 (95% CI 1.00–3.74). An interaction was found between BNP level and the presence or absence of diabetes mellitus. The OR for non-diabetics was 1.26 (95% CI 0.61–2.60) and for diabetics was 18.82 (95% CI 16.2–20.5). Preoperative Hb was also significantly and independently associated with the occurrence of postoperative low cardiac output (OR 0.33, 95% CI 0.13–0.81, p = 0.016). Both Hb and BNP were significantly associated with the lengths of intensive care unit and hospital stays and the number of transfused red blood cells (p < 0.002). Inflammatory markers, although associated with adverse outcomes, lost statistical significance when adjusted for covariates.

Conclusions

High preoperative BNP or low Hb shows an association of independent risk with postoperative outcomes, and their measurement could help to stratify surgical risk. The ability to predict the onset of atrial fibrillation or postoperative low cardiac output has important clinical implications. Our results open the possibility of designing studies that incorporate BNP measurement as a routine part of preoperative evaluation, and this strategy could improve upon the standard evaluation in terms of reducing adverse postoperative events.

Mean platelet volume may predict early clinical outcome after coronary artery bypass grafting

Background

An elevated mean platelet volume is associated with increased platelet activation and thus may predict thrombotic events. The goal of this study was to investigate the association of the mean platelet volume and the major adverse events after coronary artery bypass surgery.

Methods

Baseline clinical details and preoperative hematologic parameters were obtained prospectively in 205 consecutive patients undergoing coronary artery bypass surgery. Postoperative mortality and major adverse events were recorded in the early postoperative period (median of 72 days, interquartile range 58.5-109 days).

Results

Combined adverse events occurred in 37 patients (18.0%) during the early follow-up. The preoperative mean platelet volume and hematocrit levels were found to be associated with postoperative adverse events (p<0.001 for both variables). In multivariate logistic regression models, the preoperative mean platelet volume and hematocrit levels were strong independent predictors of combined adverse events after surgery (respectively OR 1.89, p=0.037; OR 0.87, p=0.011). After receiver-operating-characteristics curve analysis, using a cut-point of 8.75 fL, the preoperative mean platelet volume level predicted adverse events with a sensitivity of 54% and specificity of 70%. In a further model with cut-off points, higher preoperative mean platelet volume levels remained a powerful independent predictor of postoperative myocardial infarction (OR 3.60, p=0.013) and major adverse cardiac events (OR 2.53, p=0.045).

Conclusions

An elevated preoperative mean platelet volume is associated with an adverse outcome after coronary artery bypass grafting. In conclusion, we can say that mean platelet volume is an important, simple, readily available, and cost effective tool and can be useful in predicting the postoperative adverse events in patients undergoing coronary artery bypass grafting.

Urgent endoscopy in elderly patients with non-variceal upper gastrointestinal bleeding

INTRODUCTION

Age of the patient is an important prognostic factor in patients with non-variceal upper gastrointestinal bleeding (UGIB). Despite that fact, current treatment algorithms do not differentiate UGIB management according to the patient's age.

AIM

To compare treatment outcomes in patients below and above 75 years of age, treated for UGIB with urgent endoscopy.

MATERIAL AND METHODS

Prospective analysis of treatment outcomes in 295 patients with non-variceal UGIB divided into two age groups (group A < 75 years of age, group B > 75 years of age). Urgent endoscopy (up to 3 h since admission) was performed in 292 patients. The groups were compared in regards to the duration of symptoms, previous UGIB, presence of factors predisposing to UGIB (NSAIDs, peptic ulcer disease, liver cirrhosis, and previous gastrointestinal surgery), haemodynamic state and haemoglobin (Hb) levels on admission. We analysed the causes of UGIB, severity of UGIB on the Forrest scale, type of endoscopic bleeding control method, and co-morbidities with use of the Charlson Co-morbidity Index (CCI). Treatment outcomes were assessed in regard of mortality rate, UGIB-recurrence rate, duration of hospital stay, amount of transfused blood products and the requirement of intensive therapy unit (ITU) or other departments' admissions. Patients were followed until their discharge home.

RESULTS

Mortality rate was 6.8% (group A vs. B: 3.5% vs. 18.7%; p = 0.001). Upper gastrointestinal bleeding recurrence was noted in 12.2% of patients (group A vs. B: 12.5% vs. 10.9%; p = 0.73). 2.4% of patients required surgery for UGIB (group A vs. B: 1.7% vs. 4.7%; p = 0.16). Patients in group B required ITU admission more frequently (group A vs. B: 1% vs. 4.7%; p < 0.01). The mean hospital stay (4.3 days) and the mean number of transfused packed red blood cells (PRBCs) (2.35 Units) did not differ between the groups. Patients in group B used NSAIDS much more frequently, more often had hypovolaemic shock and had a higher CCI score.

CONCLUSIONS

Urgent endoscopy is an important and broadly accepted method of treatment of UGIB. Despite strict adherence to the modern UGIB-treatment algorithms, mortality remains high in the elderly. Thus, these patients need particular attention. The presented study indicates that the standard management might not be sufficient in elderly patients.

Evaluation of supply-side initiatives to improve access to coronary bypass surgery

Background

Guided by the evidence that delaying coronary revascularization may lead to symptom worsening and poorer clinical outcomes, expansion in cardiac surgery capacity has been recommended in Canada. Provincial governments started providing one-time and recurring increases in budgets for additional open heart surgeries to reduce waiting times. We sought to determine whether the year of decision to proceed with non-emergency coronary bypass surgery had an effect on time to surgery.

Methods

Using records from a population-based registry, we studied times between decision to operate and the procedure itself. We estimated changes in the length of time that patients had to wait for non-emergency operation over 14 calendar periods that included several years when supplementary funding was available. We studied waiting times separately for patients who access surgery through a wait list and through direct admission.

Results

During two periods when supplementary funding was available, 1998–1999 and 2004–2005, the weekly rate of undergoing surgery from a wait list was, respectively, 50% and 90% higher than in 1996–1997, the period with the longest waiting times. We also observed a reduction in the difference between 90th and 50th percentiles of the waiting-time distributions. Forty percent of patients in the 1998, 1999, 2004 and 2005 cohorts (years when supplementary funding was provided) underwent surgery within 16 to 20 weeks following the median waiting time, while it took between 27 and 37 weeks for the cohorts registered in the years when supplementary funding was not available. Times between decision and surgery were shorter for direct admissions than for wait-listed patients. Among patients who were directly admitted to hospital, time between decision and surgery was longest in 1992–1993 and then has been steadily decreasing through the late nineties. The rate of surgery among these patients was the highest in 1998–1999, and has not changed afterwards, even for years when supplementary funding was provided.

Conclusions

Waiting times for non-emergency coronary bypass surgery shortened after supplementary funding was granted to increase volume of cardiac surgical care in a health system with publicly-funded universal coverage for the procedure. The effect of the supplementary funding was not uniform for patients that access the services through wait lists and through direct admission.

Established preoperative risk factors do not predict long-term survival in isolated coronary artery bypass grafting patients

BACKGROUND

Use of isolated coronary artery bypass grafting (CABG) is expected to increase as the population ages. Short-term adverse outcomes models and their application to the decision-making process have greatly increased the safety and effectiveness of CABG. However, similar tools addressing long-term survival have not been developed. We examined the effect of the preoperative risk factors included in short-term outcomes models on long-term survival in patients who survive CABG.

METHODS

A Cox survival model considering preoperative risk factors identified by The Society of Thoracic Surgeons was developed for 8,529 consecutive patients who underwent isolated CABG between January 1, 1997, and August 31, 2010, at Baylor University Medical Center (Dallas, Texas) and were alive 30-days post-CABG.

RESULTS

There were 2,388 (27.9%) deaths during follow-up (≤14 years). Unadjusted survival was 83.8% and 65% at 5 and 10 years, respectively. The Cox model showed that most established preoperative risk factors were significantly associated with survival. Their effect was minimal, however; the variation explained by their cumulative effect in predicting survival was 16.8% (R2=0.168).

CONCLUSIONS

Established operative risk factors may not be good predictors of long-term post-CABG survival. Late mortality may be attributable to many causes, not necessarily related to patients' cardiovascular and general health at the time of operation. Discussions with cardiothoracic surgeons and long-term shared decision making with primary care physicians/cardiologists should therefore not focus solely on patients' preoperative risk profile but should also emphasize the importance of preventing/controlling other diseases through a healthy lifestyle and compliance with disease management protocols.

Computerized prediction of intensive care unit discharge after cardiac surgery: development and validation of a Gaussian processes model

Background

The intensive care unit (ICU) length of stay (LOS) of patients undergoing cardiac surgery may vary considerably, and is often difficult to predict within the first hours after admission. The early clinical evolution of a cardiac surgery patient might be predictive for his LOS. The purpose of the present study was to develop a predictive model for ICU discharge after non-emergency cardiac surgery, by analyzing the first 4 hours of data in the computerized medical record of these patients with Gaussian processes (GP), a machine learning technique.

Methods

Non-interventional study. Predictive modeling, separate development (n = 461) and validation (n = 499) cohort. GP models were developed to predict the probability of ICU discharge the day after surgery (classification task), and to predict the day of ICU discharge as a discrete variable (regression task). GP predictions were compared with predictions by EuroSCORE, nurses and physicians. The classification task was evaluated using aROC for discrimination, and Brier Score, Brier Score Scaled, and Hosmer-Lemeshow test for calibration. The regression task was evaluated by comparing median actual and predicted discharge, loss penalty function (LPF) ((actual-predicted)/actual) and calculating root mean squared relative errors (RMSRE).

Results

Median (P25-P75) ICU length of stay was 3 (2-5) days. For classification, the GP model showed an aROC of 0.758 which was significantly higher than the predictions by nurses, but not better than EuroSCORE and physicians. The GP had the best calibration, with a Brier Score of 0.179 and Hosmer-Lemeshow p-value of 0.382. For regression, GP had the highest proportion of patients with a correctly predicted day of discharge (40%), which was significantly better than the EuroSCORE (p < 0.001) and nurses (p = 0.044) but equivalent to physicians. GP had the lowest RMSRE (0.408) of all predictive models.

Conclusions

A GP model that uses PDMS data of the first 4 hours after admission in the ICU of scheduled adult cardiac surgery patients was able to predict discharge from the ICU as a classification as well as a regression task. The GP model demonstrated a significantly better discriminative power than the EuroSCORE and the ICU nurses, and at least as good as predictions done by ICU physicians. The GP model was the only well calibrated model.

Off-pump surgery is not a contraindication for patients with a severely decreased ejection fraction

BACKGROUND

A severely impaired left ventricular ejection fraction (EF) (30%) increases the risk of surgical myocardial revascularization. We evaluated the safety and feasibility of off-pump coronary artery bypass (OPCAB) surgery in patients with a severely decreased EF.

METHODS

We compared 79 patients with an EF ≤30% (group A) with 863 patients with an EF >30% (group B) who underwent myocardial revascularization between 2003 and 2008. The relationship between EF and outcome after OPCAB was assessed by univariate and logistic regression analyses. A composite end point was constructed from 30-day mortality, renal failure, length of stay in the intensive care unit (ICU) >2 days, neurologic complications, and use of an intra-aortic balloon pump (IABP). Additionally, the completeness of revascularization was assessed.

RESULTS

The mortality rates for groups A and B were comparable (1.3% and 2.0%, respectively; P = .55), and the 2 groups did not differ with regard to serious postoperative complications, such as stroke (2.5% versus 1.4% for groups A and B, respectively; P = .42), peripheral neurologic complications (2.5% versus 0.7%, P = .14), renal failure (0% versus 1.1%, P = 1.00), use of an IABP (1.3% versus 0.8%, P = .50), ICU length of stay >2 days (17.7% versus 19.6%, P = .77). Similarly, groups A and B did not differ with regard to ventilation time (11.2 ± 12.7 hours versus 12.4 ± 15.5 hours, P = .82), indicating similar postoperative courses for the 2 groups of patients. In contrast, the composite end point occurred significantly more frequently in group A (43.0% versus 29.7%, P = .02), a result driven by the increased rate of rethoracotomy for bleeding in that group (11.4% versus 2.9%, P = .001). The 2 groups were similar with respect to the total number of grafts used per patient (3.82 ± 0.89 versus 3.63 ± 1.01, P = .10) and the completeness of revascularization (94% versus 93%, P = .49).

CONCLUSION

A standardized OPCAB approach is safe for patients with a severely decreased EF, and its use does not come at the cost of less complete revascularization.