Patients with severe asymptomatic carotid artery stenosis do not have a higher risk of stroke and mortality after coronary artery bypass surgery.

BACKGROUND AND PURPOSE: Stroke development is a major concern in patients undergoing coronary artery bypass grafting (CABG). Whether asymptomatic severe carotid artery stenosis (CAS) contributes to the development of stroke and mortality in such patients remains uncertain. METHODS: A retrospective analysis of 878 consecutive patients with documented carotid duplex ultrasound who underwent isolated CABG in our institution from January 2003 to December 2009 was performed. Patients with severe CAS (n=117) were compared with those without severe CAS (n=761) to assess the rates of stroke and mortality during hospitalization for CABG. The 30-day mortality rate was also assessed. RESULTS: Patients with severe CAS were older and had a higher prevalence of peripheral arterial disease and heart failure. Patients with severe CAS had similar rates of in-hospital stroke (3.4% versus 3.6%; P=1.0) and mortality (3.4% versus 4.2%; P=1.0) compared with patients without severe CAS. The 30-day rate of mortality was also similar between the 2 cohorts (3.4% versus 2.9%; P=0.51). CONCLUSIONS: Severe CAS alone is not a risk factor for stroke or mortality in patients undergoing CABG. The decision to perform carotid imaging and subsequent revascularization in association with CABG must be individualized and based on clinical judgment.

Early readmission of low-risk patients after coronary surgery.

BACKGROUND: Early readmission after coronary artery bypass grafting (CABG) is an expensive adverse outcome. Although the perioperative experience of high-risk CABG patients has been studied extensively, little attention has been paid to low-risk CABG patients. The primary goal of this study was to identify the preoperative characteristics and to define risk predictors of readmission and preventive factors for readmission in low-risk isolated-CABG patients. METHODS: We identified 2157 patients who underwent CABG between January 2000 and December 2005 at Washington Hospital Center, Washington, DC, and defined as low risk patients who had a Parsonnet bedside risk score lower than the 25th percentile. Patients who were rehospitalized within 30 days after surgery were compared with those who were not rehospitalized during this period. RESULTS: The overall readmission rate for this study cohort was 6.3%. Compared with non-readmitted patients, early-readmitted patients were more likely to have diabetes mellitus (27.94% versus 20.88%, P = .05) and less likely to have hypertension (42.65% versus 51.36%, P = .05). Blood product transfusion (P < .01), postoperative length of intensive care unit stay (P = .01), and length of hospital stay (P = .05) were all significantly increased in the readmitted patients. The use of beta-blockers (P = .03) and angiotensin-converting enzyme inhibitors (P = .04) was significantly lower at discharge in this group of patients; however, multivariate regression analysis demonstrated diabetes (odds ratio, 1.59; 95% confidence interval, 1.08-2.42) to be the only independent predictor of early readmission. CONCLUSIONS: For low-risk CABG patients, diabetes mellitus is the risk predictor of early readmission. Early discharge was not associated with early readmission.

Effect of clopidogrel premedication in off-pump cardiac surgery: are we forfeiting the benefits of reduced hemorrhagic sequelae?

BACKGROUND: Premedication with clopidogrel has reduced thrombotic complications after percutaneous coronary revascularization procedures. However, because of the enhanced and irreversible platelet inhibition by clopidogrel, patients requiring surgical revascularization have a higher risk of bleeding complications and transfusion requirements. A principal benefit of surgical coronary revascularization without cardiopulmonary bypass is its lower hemorrhagic sequelae. The purpose of this study was to evaluate the effect of preoperative clopidogrel administration in the incidence of hemostatic reexploration, blood product transfusion rates, morbidity, and mortality in patients undergoing off-pump coronary artery bypass graft surgery using a large patient sample and a risk-adjusted approach. METHODS AND RESULTS: Two hundred eighty-one patients (17.9%) did and 1291 (82.1%) did not receive clopidogrel before their surgery, for a total of 1572 patients undergoing isolated off-pump coronary artery bypass graft surgery between January 2000 and June 2002. Risk-adjusted logistic regression analyses and a matched pair analyses by propensity scores were used to assess the association between clopidogrel administration and reoperation as a result of bleeding, intraoperative and postoperative blood transfusions received, and the need for multiple transfusions. Hemorrhage-related preoperative risk factors identified in the literature and those found significant in a univariate model were used. The clopidogrel group had a higher likelihood of hemostatic reoperations (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.47 to 10.47; P<0.01) and an increased need in overall packed red blood cell (OR, 2.6; 95% CI, 1.94 to 3.60; P<0.01), multiple unit (OR, 1.6; 95% CI, 1.07 to 2.48; P=0.02), and platelet (OR, 2.5; 95% CI, 1.77 to 3.66; P<0.01) transfusions. Surgical outcomes and operative mortality (1.4% versus 1.4%; P=1.00) were not statistically different. CONCLUSIONS: Clopidogrel administration in the cardiology suite increases the risk for hemostatic reoperation and the requirements for blood product transfusions during and after off-pump coronary artery bypass graft surgery.

Chronologic distribution of stroke after minimally invasive versus conventional coronary artery bypass.

OBJECTIVES: We sought to investigate whether the chronologic distribution of the onset of stroke occurring after coronary artery bypass graft surgery (CABG) without cardiopulmonary bypass (off-pump CABG) is different from the conventional on-pump approach (CABG with cardiopulmonary bypass). BACKGROUND: Off-pump CABG has been associated with a lower stroke rate, compared with conventional on-pump CABG. However, it is unknown whether the chronologic distribution of the onset of stroke is different between the two approaches. METHODS: We evaluated the chronologic distribution of postoperative stroke in patients undergoing CABG from June 1996 to August 2001 (n = 10,573). Preoperative risk factors for stroke were identified using the Northern New England preoperative estimate of stroke risk. Multivariate logistic regression analysis was used to determine the independent predictors of early stroke and to delineate the association between the surgical approach and the chronologic distribution of the onset of stroke. RESULTS: Stroke occurred in 217 patients (2%, n = 10,573). A total of 44 (20%) and 173 (80%) of these patients had stroke after off-pump CABG and on-pump CABG, respectively. The median time for the onset of stroke was two days (range 0 to 11 days) after on-pump CABG versus four days (range 0 to 14 days) after off-pump CABG (p < 0.01). On-pump CABG was associated with a higher risk of early stroke (odds ratio 5.3, 95% confidence interval 2.6 to 10.9; p < 0.01) compared with off-pump CABG. CONCLUSIONS: Compared with off-pump CABG, on-pump CABG is associated with an earlier onset of postoperative stroke during the recovery phase, suggesting different mechanisms in the pathogenesis of stroke between the two surgical approaches.

Stroke after conventional versus minimally invasive coronary artery bypass.

BACKGROUND: Postoperative stroke is a serious complication after coronary artery bypass grafting with cardiopulmonary bypass (on-pump), and portends higher morbidity and mortality. It is unknown whether an off-pump cardiopulmonary bypass (OPCAB) approach may yield a lower stroke rate over conventional on-pump coronary artery bypass grafting. METHODS: From June 1994 to December 2000, OPCAB was performed in 2,320 patients and compared with 8,069 patients who had on-pump coronary artery bypass grafting, during the same period of time. The patients undergoing OPCAB were randomly matched to on-pump patients by propensity score. A logistic regression model was used to test the difference in the postoperative stroke rate between OPCAB and on-pump procedures controlling for the correlation between matched sets. A multiple logistic regression model predicting the risk of stroke adjusted by stroke risk factors and operation type was also computed. RESULTS: Matches by propensity score were found for 72% of the patients undergoing OPCAB. Patients undergoing on-pump coronary artery bypass grafting were 1.8 (95% confidence interval 1.0 to 3.1, p = 0.03) times more likely to suffer a stroke postoperatively than OPCAB patients after controlling for preoperative risk factors through matching. Independent predictors of stroke identified from the multiple logistic model included on-pump operation (versus OPCAB operation), female gender, 4 to 6 vessels grafted (versus <4 grafts), hypertension, history of previous cerebrovascular accident, carotid artery disease, chronic obstructive pulmonary disease, and depressed ejection fraction. CONCLUSIONS: Off-pump cardiopulmonary bypass avoids the risks of cardiopulmonary bypass and atrial trauma. A substantially lower stroke rate suggests that OPCAB is a neurologically safe treatment option for revascularization.

Operative mortality after conventional versus coronary revascularization without cardiopulmonary bypass.

OBJECTIVE: Off-pump coronary artery bypass (CABG) is a safe revascularization option with comparable or superior results to the conventional on-pump CABG. However, comparative analysis of the type of surgical approach on the mortality rate is largely unknown. This study sought to investigate whether CABG without cardiopulmonary bypass (off-pump CABG) is associated with lower operative mortality than the conventional on-cardiopulmonary bypass (on-pump) approach. METHODS: From October 1998 to June 2001, off-pump CABG was performed on 2477 patients and on-pump CABG was performed on 3077 patients. The patients undergoing off-pump CABG were randomly matched to on-pump patients via propensity score. Seventy-four percent of the off-pump CABG patients were matched with on-pump patients via propensity scores. A logistic regression model was used to test the difference in the postoperative mortality rate between off-pump CABG and on-pump CABG, controlling the correlation between matched sets. A multiple logistic regression model predicting the risk of mortality adjusted by risk factors of mortality and operation type was computed. RESULTS: Results from the general estimating equation showed that patients who had on-pump CABG were 1.6 (95% confidence intervals (CI)=1.2-2.0, P<0.01) times more likely to die during the first 30 days after surgery than patients who had off-pump CABG. Independent predictors of 30-day mortality identified from the multiple logistic model included on-pump CABG (versus off-pump CABG), advanced age, female gender, carotid artery disease, chronic renal failure, depressed ejection fraction, reoperative CABG, preoperative intraaortic balloon counterpulsation, and recent myocardial infarction. CONCLUSION: Excellent clinical results and a lower operative mortality rate can be achieved with the off-pump CABG technique compared with the conventional on-pump approach.

Clinical outcomes of coronary revascularization without cardiopulmonary bypass.

OBJECTIVE: Coronary artery bypass without cardiopulmonary bypass (OPCAB) eliminates the complications related to cardiopulmonary bypass. However, the long-term outcomes of this procedure are largely unknown. METHODS: We sought to investigate the rates of late mortality, stroke, acute myocardial infarction, and target vessel reintervention after OPCAB in a consecutive series of 857 patients who underwent OPCAB between May 1987 and March 1999. RESULTS: Long-term follow-up was obtained for 86% of eligible patients. Actuarial and event-free survival was 89% and 76%, respectively, for a median follow-up period of 2.2 years (range, 0-13.3 years). Risk factors for late mortality were identified with Cox regression analysis. In the multivariate analysis, patient age >75 years (odds ratio, 1.1; 95% confidence interval, 1.0-1.1; P =.01) and an ejection fraction <35% (odds ratio, 2.7; 95% confidence interval, 1.2-6.2; P =.02) emerged as independent predictors of late mortality. CONCLUSION: OPCAB is associated with a low mortality and clinical event rate. Advanced age and depressed ejection fraction may increase mortality after OPCAB.

Association of body mass index with new-onset atrial fibrillation after coronary artery bypass grafting operations.

BACKGROUND: Postoperative atrial fibrillation (AF) frequently complicates coronary artery bypass grafting (CABG) operations. As the frequency of obesity has increased in the United States, the number of obese patients undergoing CABG has kept pace. This study sought to define the association between body mass index (BMI) and postoperative AF. METHODS: We studied 12,367 consecutive patients with no history of AF who underwent isolated CABG operations. BMI was stratified according to Centers for Disease Control and Prevention criteria, and differences in baseline clinical and operative characteristics were adjusted through multivariate logistic regression models. RESULTS: The unadjusted incidence of new-onset postoperative AF demonstrated a U-shape with regard to BMI. The highest incidence (34%) was found in the "lean" stratum (BMI<18.5 kg/m2), followed by 32% in the "severely obese" (BMI≥40 kg/m2) stratum. Lower incidences were found in the "normal" stratum (30%), in the "obese" stratum (28%), and the lowest incidence (26%) was in the overweight stratum. Observed incidence was 50% greater than the expected incidence in the "severely obese" stratum (32% vs 21%). In multivariate regression analysis adjusted for age and other covariates, BMI remains a strong risk factor for new-onset postoperative AF. Compared with normal BMI, obesity (odds ratio, 1.24; 95% confidence interval, 1.08 to 1.42) and severe obesity (odds ratio, 2.00; 95% confidence interval, 1.54 to 2.57) both emerged as strong risk factors for postoperative AF. No association was found between a lean BMI and postoperative AF (odds ratio, 1.14; 95% confidence interval, 0.66 to 1.98). CONCLUSIONS: After adjusting for potential confounders, obesity, as reflected by the body mass index, remains an independent predictor of postoperative AF.

Comparison of frequency of atrial fibrillation after coronary artery bypass grafting in African Americans versus European Americans.

In the general population, African Americans experience atrial fibrillation (AF) less frequently than European Americans. This difference could also exist in the incidence of this arrhythmia after cardiac surgery, but this possibility has been insufficiently examined. To test the association of such an ethnic difference, we compared the incidence of postoperative AF in a consecutive series of 2,312 African Americans and 6,054 European Americans who underwent isolated coronary artery bypass grafting from July 2000 to June 2007. Raw differences between the cohorts in the incidence of new AF were adjusted to take into account the baseline differences. Postoperatively, new-onset AF developed in 504 (22%) of 2,312 African-American patients and in 1,838 (30%) of 6,054 European-American patients (p <0.01). After adjustment with logistic regression analysis for numerous baseline differences, African Americans remained less likely to develop AF (odds ratio 0.63, 95% confidence interval 0.55 to 0.72; p <0.001). Risk was also adjusted using propensity matching. In that analysis, 457 (22%) of 2,059 African-American patients had postoperative AF, as did 597 (29%) of 2,059 matched European-American patients (p <0.01). In conclusion, AF was significantly less common among African-American patients than among European-American patients after coronary artery bypass grafting.

Is cardiac surgery safe in extremely obese patients (body mass index 50 or greater)?

BACKGROUND: We investigated the impact of extreme obesity (body mass index [kg/m(2)] 50 or greater) on short-term clinical outcomes and report 1-year mortality. METHODS: Fifty-seven patients were found to have a body mass index of 50 or greater among 14,449 patients who underwent cardiac surgery between July 2000 and June 2007. Multivariable logistic regression analyses were used to assess the independent influence of extreme obesity on the major outcomes. RESULTS: Of the 57 patients, the mean age was 58 +/- 11 years, mean body mass index was 55.1, and 63% of the patients were women. Forty patients underwent elective surgery. Forty-one patients had isolated coronary artery bypass graft surgery. The overall operative mortality was 9%; the mortality was 5% in isolated coronary artery bypass graft surgery and 5% in elective surgery. Fifteen patients had nonelective isolated coronary artery bypass graft surgery, and 2 patients had emergent active endocarditis surgery. Off-pump coronary artery bypass graft surgery was performed on 23 patients (23 of 41, 54%). After adjusting for known preoperative and operative risk factors through a multivariate logistic model, extreme obesity did not emerge as a significant risk factor for operative mortality (odds ratio, 1.75; p = 0.47) and other adverse outcomes (p > 0.05) after elective surgery; however, extreme obesity was marginally associated with increased mortality (odds ratio, 2.69; p = 0.05) and was a risk predictor for longer intensive care unit stays (odds ratio, 2.43; p = 0.01) in overall surgery. The 1-year survival rate was 82.5%. CONCLUSIONS: Extreme obesity is not a contraindication to elective cardiac surgery. Studies stratifying the risk factors of mortality for nonelective surgery in extremely obese patients may be warranted.

Comparison of the quality of life after conventional versus off-pump coronary artery bypass surgery.

PURPOSE: Numerous studies have focused on off-pump coronary artery bypass graft (off-pump CABG) morbidity and mortality outcomes, but few looked at the patient's perception of the technique and its effect on postoperative quality of life (QOL). We investigated and compared postoperative QOL in patients who had undergone either conventional or off-pump CABG myocardial revascularization. METHODS: During a six-month period, 191 patients who underwent CABG surgery were prospectively studied through preoperative and six-month postoperative short-form 36 (SF-36) general health status surveys. One hundred-sixteen (60.7%) off-pump CABG patients and 75 (39.3%) conventional on-pump CABG patients were enrolled. RESULTS: Sixteen (13.8%) off-pump patients reported improvement in physical score QOL, 84 (72.4%) reported no change, and 16 (13.8%) reported a decrease. In comparison, 20 (80.0%) patients in the on-pump CABG group reported an improvement in QOL, 42 (56.0%) were unchanged, and 13 (17.3%) reported deterioration (p = 0.28). For postoperative change in mental score, 19 (16.4%) off-pump patients reported an improvement, 85 (73.3%) stayed unchanged, and 12 (10.3%) reported a decrease compared with 8 (10.7%) conventional CABG patients reporting improvement, 60 (80.0%) showing no change, and 7 (9.3%), having a score decline (p = 0.52). In multivariate logistic regression analysis, hypertension (odds ratio [OR] 2.2, 95% confidence intervals [CI], 1.08 to 4.40, p = 0.03) and multivessel coronary artery disease (OR 2.1, 95% CI, 1.11 to 4.13, p = 0.02) emerged as independent predictors of worse physical score component score. Diabetes was associated with an improved physical score component score after CABG (OR 0.4, 95% CI, 0.17 to 0.76, p = 0.01), regardless of the surgical approach. CONCLUSION: This prospective study reveals no significant differences in the expected QOL at six months after either on-pump or off-pump CABG. Patients with hypertension and multivessel coronary artery disease were more likely to have worse, while patients with diabetes have improved physical score component scores six months after CABG.

Coronary revascularization without cardiopulmonary bypass versus the conventional approach in high-risk patients.

BACKGROUND: The premise of coronary revascularization without cardiopulmonary bypass (off-pump coronary artery bypass graft [CABG]) proposes that patient morbidity and, potentially, mortality can be reduced without compromising the excellent results of conventional revascularization techniques (on-pump CABG). High-risk patients may benefit the most from off-pump CABG. The aim of this study was to compare early and mid-term clinical outcomes after off-pump CABG with on-pump CABG in a subset of high-risk patients. METHODS: Between January 1, 2000 and December 31, 2000, 513 high-risk patients with a Parsonnet's risk scores of 20 or higher underwent CABG; 38.6% (n = 198) underwent on-pump CABG, and 61.4% (n = 315) had off-pump CABG. Logistic regression was used to calculate the probability of being selected for on-pump CABG given a set of preoperative risk factors. Propensity scores or the probability of being selected for on-pump CABG were computed. Relative risks, heterogeneity among strata, and interactions between surgery type and the propensity score were assessed by a multivariate Cox proportional-hazards regression for the outcomes mortality and major adverse cardiac events (death, acute myocardial infarction, stroke, reoperative CABG, percutaneous coronary intervention). RESULTS: Operative mortality was lower after off-pump versus on-pump CABG between the two groups after controlling for preoperative risk factors using the propensity score (odds ratio = 2.10; 95% confidence intervals = 1.02 to 4.36, p = 0.04). In the Cox-regression analysis, off-pump CABG was associated with an improved survival rate compared with on-pump CABG (p = 0.03). Off-pump CABG was associated with a comparable event-free survival (p = 0.14) compared with on-pump CABG. CONCLUSIONS: Off-pump CABG can be performed with a reasonably low morbidity and lower early and late mortality in high-risk patients. Off-pump CABG may be a better operative strategy in this subset of patients.

Clopidogrel administration prior to coronary artery bypass grafting surgery: the cardiologist's panacea or the surgeon's headache?

AIMS: Thrombotic complications after percutaneous coronary intervention procedures have decreased in past years mainly due to the use of clopidogrel antiplatelet therapy. However, the risk of bleeding due to enhanced and irreversible platelet inhibition in patients who will require surgical coronary revascularization instead has not been adequately addressed in the literature. The purpose of this study was to evaluate the effect of pre-operative clopidrogel exposure in haemorrhage-related re-exploration rates, peri-operative transfusion requirements, morbidity, and mortality in patients undergoing coronary artery bypass grafting (CABG) surgery. METHODS AND RESULTS: A study population of 2359 patients undergoing isolated CABG between January 2000 and June 2002 was reviewed. Of these, 415 (17.6%) received clopidogrel prior to CABG surgery, and 1944 (82.4%) did not. A risk-adjusted logistic regression analysis was used to assess the association between clopidogrel pre-medication (vs. no) and haemostatic re-operation, intraoperative and post-operative blood transfusion rates, and multiple transfusions received. Haemorrhage-related pre-operative risk factors identified from the literature and those found significant in a univariate model were used. Furthermore, a sub-cohort, matched-pair by propensity scores analysis, was also conducted. The clopidogrel group had a higher likelihood of haemostatic re-operation [OR = 4.9, (95% CI, 2.63-8.97), P < 0.01], an increase in total packed red blood cell transfusions [OR = 2.2, (95% CI, 1.70-2.84), P < 0.01], multiple unit blood transfusions [OR = 1.9, (95% CI, 1.33-2.75), P < 0.01] and platelet transfusions [OR = 2.6, (95% CI, 1.95-3.56), P < 0.01]. Surgical outcomes and operative mortality [OR = 1.5, (95% CI, 0.36-6.51), P = 0.56] were not significantly different. CONCLUSION: Pre-operative clopidogrel exposure increases the risk of haemostatic re-operation and the requirements for blood and blood product transfusion during, and after, CABG surgery.

Beating heart surgery in a patient with dextrocardia and complete situs inversus.

We present a 65-year-old female patient with dextrocardia and situs inversus who underwent successful coronary artery bypass without cardiopulmonary bypass. Vessels revascularized included right internal mammary artery to the left anterior descending artery and a saphenous vein graft to the first obtuse marginal branch. The procedure was performed on a beating heart through a median sternotomy with the use of a compression epicardial stabilizer. The patient was discharged to her home after an uneventful recovery. Only 12 similar cases of myocardial revascularization in patients with dextrocardia have been reported so far, and this is one of the first procedures, in patients with dextrocardia, performed off pump.

The impact of aortic manipulation on neurologic outcomes after coronary artery bypass surgery: a risk-adjusted study.

BACKGROUND: Cerebral embolization of atherosclerotic plaque debris caused by aortic manipulation during conventional coronary artery bypass grafting (CABG) is a major mechanism of postoperative cerebrovascular accidents (CVA). Off-pump CABG (OPCABG) reduces stroke rates by minimizing aortic manipulation. Consequently, the effect of different levels of aortic manipulation on neurologic outcomes after CABG surgery was examined. METHODS: From January 1998 to June 2002, 7,272 patients underwent isolated CABG surgery through three levels of aortic manipulation: full plus tangential (side-biting) aortic clamp application (on-pump surgery; n = 4,269), only tangential aortic clamp application (OPCABG surgery; n = 2,527) or an "aortic no-touch" technique (OPCABG surgery; n = 476). A risk-adjusted logistic regression analysis was performed to establish the likelihood of postoperative stroke with each technique. Preoperative risk factors for stroke from the literature, and those found significant in a univariable model were used. RESULTS: A significant association for postoperative stroke correspondingly increasing with the extent of aortic manipulation was demonstrated by the univariable analysis (CVA incidence respectively increasing from 0.8% to 1.6% to a maximum of 2.2%, p < 0.01). In the logistic regression model, patients who had a full and a tangential aortic clamp applied were 1.8 times more likely to have a stroke versus those without any aortic manipulation (95% confidence interval: 1.15 to 2.74, p < 0.01) and 1.7 times more likely to develop a postoperative stroke than those with only a tangential aortic clamp applied (95% confidence interval: 1.11 to 2.48, p < 0.01). CONCLUSIONS: Aortic manipulation during CABG is a contributing mechanism for postoperative stroke. The incidence of postoperative stroke increases with increased levels of aortic manipulation.