Cem Alhan

Coronary Artery Bypass Grafting vs Percutaneous Coronary Intervention and Long-term Mortality and Morbidity in Multivessel Disease Meta-analysis of Randomized Clinical Trials of the Arterial Grafting and Stenting Era

IMPORTANCE Recent trials of percutaneous coronary intervention (PCI) vs coronary artery bypass grafting (CABG) for multivessel disease were not designed to detect a difference in mortality and therefore were underpowered for this outcome. Consequently, the comparative effects of these 2 revascularization methods on long-term mortality are still unclear. In the absence of solid evidence for mortality difference, PCI is oftentimes preferred over CABG in these patients, given its less invasive nature. OBJECTIVES To determine the comparative effects of CABG vs PCI on long-term mortality and morbidity by performing a meta-analysis of all randomized clinical trials of the current era that compared the 2 treatment techniques in patients with multivessel disease. DATA SOURCES A systematic literature search was conducted for all randomized clinical trials directly comparing CABG with PCI. STUDY SELECTION To reflect current practice, we included randomized trials with 1 or more arterial grafts used in at least 90%, and 1 or more stents used in at least 70% of the cases that reported outcomes in patients with multivessel disease. DATA EXTRACTION Numbers of events at the longest possible follow-up and sample sizes were extracted. DATA SYNTHESIS A total of 6 randomized trials enrolling a total of 6055 patients were included, with a weighted average follow-up of 4.1 years. There was a significant reduction in total mortality with CABG compared with PCI (I2 = 0%; risk ratio [RR], 0.73 [95% CI, 0.62-0.86]) (P < .001). There were also significant reductions in myocardial infarction (I2 = 8.02%; RR, 0.58 [95% CI, 0.48-0.72]) (P < .001) and repeat revascularization (I2 = 75.6%; RR, 0.29 [95% CI, 0.21-0.41]) (P < .001) with CABG. There was a trend toward excess strokes with CABG (I2 = 24.9%; RR, 1.36 [95% CI, 0.99-1.86]), but this was not statistically significant (P = .06). For reduction in total mortality, there was no heterogeneity between trials that were limited to and not limited to patients with diabetes or whether stents were drug eluting or not. Owing to lack of individual patient-level data, additional subgroup analyses could not be performed. CONCLUSIONS AND RELEVANCE In patients with multivessel coronary disease, compared with PCI, CABG leads to an unequivocal reduction in long-term mortality and myocardial infarctions and to reductions in repeat revascularizations, regardless of whether patients are diabetic or not. These findings have implications for management of such patients.

Highly positive intraoperative fluid balance during cardiac surgery is associated with adverse outcome.

Hemodilution and increase in capillary permeability occurring with cardiopulmonary bypass (CPB) impose a risk for tissue edema and blood transfusion that may result in an increased complication rate after coronary artery bypass grafting (CABG). Of the 1280 consecutive patients undergoing isolated on-pump CABG, total fluid balance at the end of the operation was less than or equal to 500 mL in 1155 (Group 1) and more than 500 mL in 125 (Group 2). During CPB, blood was added to the reservoir only when the hematocrit fell to 17% or less and crystalloid solution only when the pump flow index fell below 2.0 L/min/m2. Anesthetic, surgical, and postoperative management and diagnoses were the same in all patients, and a single surgical and anesthesia team performed all operations. No patient was excluded from the study. Results: Hypertension, diabetes, chronic obstructive pulmonary disease, New York Heart Association (NYHA) Class III - IV, use of angiotensin converting enzyme (ACE) inhibitors, chronic renal failure, and female gender were the significant preoperative risk factors for increased volume replacement during CPB. The groups were similar in body mass index, preoperative hematocrit values, total fluid balance in the intensive care unit (ICU), and total chest tube output. However, red blood cells’ transfusion rate, readmission rate to the ICU and length of hospital stay were significantly higher in Group 2 patients. Multiple logistic regression revealed that age < 70 years (p < 0.001, Odds Ratio (OR): 2, 95% CI: 1.4 - 2.8), and total fluid balance > 500 mL at the end of the operation (p < 0.01, OR: 2.2, 95% CI: 1.5-3.2) were the predictors of increased length of stay. For transfusion of red blood cells, age > 70 years (p < 0.0001, OR: 2.3, 95% CI: 1.6-3.3), and total fluid balance > 500 mL at the end of the operation (p < 0.001, OR: 2, 95% CI: 1.3-2.9) were the only significant risk factors. This study suggests that intraoperative volume overload increases blood transfusion and length of hospital stay in patients undergoing CABG.

Lactic acidosis after cardiac surgery is associated with adverse outcome.

BACKGROUND The accurate identification of patients who have the potential to further deteriorate after cardiac surgery is difficult. Elevated serum lactate level after cardiac surgery is an indicator of systemic hypoperfusion and tissue hypoxia. The aim of this study was to investigate the effect of increased serum lactate on outcome after on-pump coronary artery bypass grafting. METHODS Serum lactate level was measured in 776 patients within half an hour after surgery. Lactate level was less than or equal to 2 mmol/L in 534 patients (low lactate group) and more than 2 mmol/L in 242 patients (high lactate group). Continuous variables were analyzed with the Student t test. The chi 2 test and Fisher exact test were used to compare categorical variables. RESULTS Demographic characteristics and details of surgery were similar in both groups. Increased cross-clamp and cardiopulmonary bypass times and highly positive fluid balance at the end of surgery were associated with a significant rise in postoperative lactate levels, which leads to increased need for intraaortic balloon pump support (odds ration [OR], 5.9, P =.006), increased likelihood of >24 h intensive care unit stay (OR, 3.4, P =.0001), greater need for red blood cell transfusion (OR, 1.6, P =.002), increased length of hospital stay, and higher mortality rates (OR, 5.6, P =.04). CONCLUSIONS This study has demonstrated that elevated blood lactate level is associated with adverse outcome, and monitoring the blood lactate level during and after cardiac surgery is a valuable tool in identifying the patients who have the potential to deteriorate.

Efficiency of antibacterial suture material in cardiac surgery: a double-blind randomized prospective study.

OBJECTIVE Postoperative surgical site infections (SSI) still greatly affect mortality and morbidity in cardiovascular surgery. SSI may be related to the suture material. In this prospective, randomized, controlled, and double-blinded study, the effect of antibacterial suture material on SSI in cardiac surgical patients was investigated. METHODS We randomly allocated 510 patients into 2 groups. Antibacterial suture materials were used for wound closure in 170 patients (triclosan-coated suture group), and routine suture materials were used in 340 patients (noncoated suture group). All patients were evaluated for SSI on days 10, 20, and 30 following cardiac surgery. RESULTS Preoperative risk factors and laboratory findings were comparable for the 2 groups. Sternal infection occurred in 4 (2.4%) of the patients in the triclosan-coated suture group and in 3.5% of the noncoated suture group (P > .05). Leg wound infection occurred in 5 (3.5%) of the patients in the triclosan-coated suture group and in 3.8% of the noncoated suture group (P > .05). Only diabetes mellitus was an independent predictor of SSI. CONCLUSION Both noncoated and triclosan-coated suture materials are safe. Larger studies may be needed to show the benefit and cost-effectiveness, if any, of triclosan-coated materials over noncoated materials.

Fast track recovery of high risk coronary bypass surgery patients

OBJECTIVE Fast track recovery protocols on younger, low risk patients result in shorter hospital stays and decreased costs. However, data is lacking on the impact of these protocols on high risk patients based on an objective scoring system. METHODS In this study, a high risk cohort of patients (EuroSCORE >or=6, n=158) was compared with a low risk cohort of patients (EuroSCORE <6, n=1004) to define the safety and efficacy of fast track recovery among high risk patients. A standard perioperative data is collected prospectively for every patient. RESULTS Time to extubation was longer in the high risk group (299+/-253 vs. 232+/-256min; P=0.003), but intensive care unit (ICU) stay (25.6+/-28.7 vs. 21.5+/-9.4h; P=ns), and postoperative length of stay (5.8+/-2.4 vs. 5.6+/-2.7 days; P=ns) was similar when compared with the low risk group. Of the high risk patients 81% were extubated within 6h, 87% were discharged from the intensive care unit within 24h, and 67% were discharged from the hospital within 5 days. Multiple regression analysis showed that any red blood cell transfusion (P=0.02), and cross clamp time >60min (P=0.03) were the predictors of delayed extubation (>or=6h) in the high risk group. The predictors of extended ICU stay were any red blood cell transfusion (P=0.0001), and peripheral vascular disease (P=0.05). Any red blood cell transfusion was the only predictor for mortality (P=0.02) and readmission to the hospital within the first 30 days (P=0.02) in this cohort of patients. CONCLUSIONS This study confirms the safety and efficacy of fast track recovery protocol among high risk patients undergoing coronary artery bypass surgery. All patients are basically suitable for fast track recovery and the preoperative risk factors are poor predictors of prolonged ventilation, increased ICU and hospital stay. Red blood cell transfusion is associated with delayed extubation and discharge from the ICU, and increased mortality and hospital readmission rate.

The impact of allogenic red cell transfusion and coated bypass circuit on the inflammatory response during cardiopulmonary bypass: a randomized study

OBJECTIVES This study is designed to determine and compare the effects of transfusion and coated circuits on the inflammatory response during cardiopulmonary bypass. METHODS Forty patients were randomized into two groups according to the type of extracorporeal circuit used and later prospectively enrolled into two subgroups according to the need for red cell transfusion during CPB (leading to 4 groups--10 patients per group; group 1: with no transfusion and standard oxygenator, group 2: with transfusion and standard oxygenator, group 3: with no transfusion and coated oxygenator, group 4: with transfusion and coated oxygenator). Serum lactate, interleukin 6, human tumor necrosis factor alpha (TNF-alpha), D-dimer and CRP levels were measured at three time points (T1: start of CPB, T2: before removal of aortic cross-clamp, T3: 45 min after the completion of proximal anastomoses). Protein adsorption of oxygenator fibers was measured. Outcome parameters were recorded. RESULTS Interleukin 6, TNF-alpha, D-dimer and lactate levels increased at T2 and T3 in all groups (P<0.05 within groups). The increase in interleukin 6 was significant at T2 in group 2 when compared to group 1 (8.0+/-3.9 vs. 4.4+/-1.8, P=0.03). The increase in TNF-alpha was higher at T2 in group 1 when compared to group 3 (16.0+/-4.2 vs. 11.7+/-2.8, P=0.05) and in group 2 when compared to group 3 at T2 and T3 (15.3+/-4.6 vs. 11.7+/-2.8, P=0.06; 17.6+/-5.0 vs. 13.7+/-3.9, P=0.06). Protein adsorption was higher in group 1 and group 2 (group 1 vs. group 3, 2.2+/-0.8 vs. 1.4+/-0.3, P=0.01; group 2 vs. group 3, 2.4+/-0.7 vs. 1.4+/-0.3, P=0.02; group 2 vs. group 4, 2.4+/-0.7 vs. 1.8+/-0.3, P=0.04), it was also higher at group 4 when compared to group 3 (1.8+/-0.3 vs. 1.4+/-0.3, P=0.03). CONCLUSIONS Allogenic red cell transfusion enhances inflammatory response during CPB; coated circuit systems have a limiting effect on this inflammatory reaction.

Validation of the EuroSCORE risk models in Turkish adult cardiac surgical population

OBJECTIVE The aim of this study was to validate additive and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) models on Turkish adult cardiac surgical population. METHODS TurkoSCORE project involves a reliable web-based database to build up Turkish risk stratification models. Current patient population consisted of 9443 adult patients who underwent cardiac surgery between 2005 and 2010. However, the additive and logistic EuroSCORE models were applied to only 8018 patients whose EuroSCORE determinants were complete. Observed and predicted mortalities were compared for low-, medium-, and high-risk groups. RESULTS The mean patient age was 59.5 years (± 12.1 years) at the time of surgery, and 28.6% were female. There were significant differences (all p<0.001) in the prevalence of recent myocardial infarction (23.5% vs 9.7%), moderate left ventricular function (29.9% vs 25.6%), unstable angina (9.8% vs 8.0%), chronic pulmonary disease (13.4% vs 3.9%), active endocarditis (3.2% vs 1.1%), critical preoperative state (9.0% vs 4.1%), surgery on thoracic aorta (3.7% vs 2.4%), extracardiac arteriopathy (8.6% vs 11.3%), previous cardiac surgery (4.1% vs 7.3%), and other than isolated coronary artery bypass graft (CABG; 23.0% vs 36.4%) between Turkish and European cardiac surgical populations, respectively. For the entire cohort, actual hospital mortality was 1.96% (n=157; 95% confidence interval (CI), 1.70-2.32). However, additive predicted mortality was 2.98% (p<0.001 vs observed; 95%CI, 2.90-3.00), and logistic predicted mortality was 3.17% (p<0.001 vs observed; 95%CI, 3.03-3.21). The predictive performance of EuroSCORE models for the entire cohort was fair with 0.757 (95%CI, 0.717-0.797) AUC value (area under the receiver operating characteristic, AUC) for additive EuroSCORE, and 0.760 (95%CI, 0.721-0.800) AUC value for logistic EuroSCORE. Observed hospital mortality for isolated CABG was 1.23% (n=75; 95%CI, 0.95-1.51) while additive and logistic predicted mortalities were 2.87% (95%CI, 2.82-2.93) and 2.89% (95%CI, 2.80-2.98), respectively. AUC values for the isolated CABG subset were 0.768 (95%CI, 0.707-0.830) and 0.766 (95%CI, 0.705-0.828) for additive and logistic EuroSCORE models. CONCLUSION The original EuroSCORE risk models overestimated mortality at all risk subgroups in Turkish population. Remodeling strategies for EuroSCORE or creation of a new model is warranted for future studies in Turkey.

Readmission to the intensive care unit after fast-track cardiac surgery: an analysis of risk factors and outcome according to the type of operation.

INTRODUCTION In the present study, we investigated risk factors for intensive care unit (ICU) readmission after fasttrack cardiac surgery and analyzed outcome data according to the type of surgical procedure. METHODS Between 1999 and 2008, we prospectively enrolled 4270 consecutive patients who underwent isolated coronary artery bypass grafting (CABG) (CABG group, n = 3754), isolated valve surgery (valve group, n = 353), or combined CABG and valve surgery (CABG + valve group, n = 163) in the study. RESULTS Ninety-eight patients (2.2%) were readmitted to the ICU. Of these patients, 73 were in the CABG group (1.9% of this group), 16 were in the valve group (4.5%), and 9 were in the CABG + valve group (5.5%). The main reason for ICU readmission in all groups was respiratory distress. A multivariate analysis showed that the independent risk factors for ICU readmission in the CABG group were an age >65 years (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.5-5.4; P = .001), peripheral arterial disease (OR, 2.7; 95% CI, 1.2-6.1; P = .016), and drainage >500 mL (OR, 2.5; 95% CI, 1.2-5.1; P = .009). The independent risk factors for the valve group included only preoperative congestive heart failure (OR, 3.9; 95% CI, 1.3-11.7; P = .01). No independent risk factor was defined for the CABG + valve group. Mortality was significantly higher among the readmitted patients in all groups. CONCLUSIONS The risk factors for readmission after cardiac surgery with fast-track recovery may differ according to the type of operation. A strict control of volume balance and blood transfusion may further help prevent the occurrence of the most frequent cause of readmission, respiratory failure.

Is it the patient or the physician who cannot tolerate anemia? A prospective analysis in 1854 non-transfused coronary artery surgery patients.

Background and objective: Low hematocrit level and transfusion may coexist during cardiopulmonary bypass and the actual impact of one on the outcome parameters may be counfounded or masked by the other. This study aims to determine the impact of the lowest hematocrit level during cardiopulmonary bypass on outcome parameters in non-transfused patients. Methods: Two thousand six hundred and thirty-two consecutive patients who underwent isolated coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass were evaluated prospectively:1854 (70.4%) patients who did not receive any red blood cells during hospital stay were included in the study. Perioperative data and outcome parameters were recorded. Outcomes were evaluated in 2 groups according to the lowest level of hematocrit (>21%: high hematocrit group, n= 1680, (91.6%) and ≤21%: low hematocrit group, n=174, (9.4%)) during cardiopulmonary bypass. Results: Overall mean lowest hematocrit level of patients was 27.7±4.4% (19.7±1.9% in the low hematocrit group, 28.5±4.1% in the high hematocrit group). The comparison of outcome parameters regarding the time on ventilator, duration of intensive care unit stay, intensive care unit re-admission, hospital re-admission, reoperation for bleeding or tamponade, low cardiac output, postoperative atrial fibrillation, stroke, creatinine level at hospital discharge, new onset renal failure, mediastinitis, pulmonary complication and mortality rates were similar in both groups. Conclusions: Our findings suggest that a lowest hematocrit level of ≤21% during cardiopulmonary bypass has no adverse impact on outcome after isolated coronary surgery in non-transfused patients.

Adjusting Oxygen Fraction to Avoid Hyperoxemia during Cardiopulmonary Bypass

Although an adverse influence of hyperoxemia during cardiopulmonary bypass is well documented, there is a wide range of oxygen settings during cardiopulmonary bypass, based mostly on trial and error. The aim of this study was to determine the optimal inspired oxygen fraction during cardiopulmonary bypass. Ninety patients undergoing isolated coronary artery bypass operations were randomly allocated to one of 3 groups of 30 each. In group 1, cardiopulmonary bypass was started with an inspired oxygen fraction of 0.40, increased to 0.60 during rewarming. These settings were 0.40 and 0.50 in group 2, and 0.35 and 0.45 in group 3. Samples for blood gas analysis were collected at defined time periods during the operation. PaO2 was significantly higher in groups 1 and 2 compared to group 3. All patients in group 1 and 88% of patients in group 2 suffered at least one episode of hyperoxemia during cardiopulmonary bypass, compared to 30% of patients in group 3. The differences were significant, and we concluded that to avoid hyperoxemia, inspired oxygen fraction should be kept at 0.35 during cardiopulmonary bypass and increased to 0.45 during rewarming.