Birkmeyer NJ, Charlesworth DC, Hernandez F, Leavitt BJ, Marrin CA, Morton JR, Olmstead EM, O’Connor GT: Obesity and risk of adverse outcomes associated with coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group

Department of Surgery, Dartmouth Medical School, Hanover, NH, USA.
Circulation (Impact Factor: 14.43). 05/1998; 97(17):1689-94. DOI: 10.1161/01.CIR.97.17.1689
Source: PubMed


Obesity is frequently cited as a risk factor for adverse outcomes of major surgery. The results of prior studies of the relationship between obesity and risk of adverse outcomes of coronary artery bypass grafting (CABG) have been contradictory because of insufficient power to assess relatively infrequent outcomes or data to adjust for confounding factors.
Data on patient age, sex, height, weight, medical history, current clinical status, and treatment factors were assessed prospectively among 11101 consecutive patients undergoing CABG. Body mass index (BMI) was used as the measure of obesity and was categorized as nonobese (1st to 74th percentiles), obese (75th to 94th percentiles), or severely obese (95th to 100th percentiles). Adverse outcomes occurring in-hospital, including mortality, intraoperative/postoperative cerebrovascular accident (CVA), postoperative bleeding, and sternal wound infection, were defined prospectively. Associations between obesity and postoperative outcomes were assessed by use of logistic regression to adjust for potentially confounding variables. Although obesity was not associated with increased mortality (adjusted odds ratio [OR], 1.16; P=.261) or postoperative CVA (adjusted OR, 1.06; P=.765), risks of sternal wound infection were substantially increased in the obese (adjusted OR, 2.10; confidence interval [CI], 1.45 to 3.06; P<.001) and severely obese (adjusted OR, 2.74; CI, 1.49 to 5.02; P=.001). On the other hand, rates of postoperative bleeding were significantly lower in the obese (adjusted OR, 0.66; CI, 0.49 to 0.90; P=.009) and severely obese (adjusted OR, 0.40; CI, 0.20 to 0.81; P=.011).
With the exception of sternal wound infection, the perception among clinicians that obesity predisposes to various postoperative complications with CABG is not supported by these data. Further work is needed to understand the apparent protective effect of obesity on risks of postoperative bleeding.

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Available from: Felix Hernandez, Mar 31, 2014
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    • "Indeed in our study, the incidence of stroke was 2-fold greater in the severe obesity group than in the control group but this difference was not significant. Most of the publications report similar results in obese patients undergoing cardiac surgery regarding the incidence of postoperative stroke in obese patients [9] [11] [14] [18] [20] [24] [25] [43]. But as in our study, several limitation as the samples size or the BMI categorization may mask the relationship between BMI and the risk of stroke. "
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    ABSTRACT: Background Obesity is suggested to reduce postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) but perioperative hemostasis variations have not been studied. Therefore, we investigated the effects of severe obesity (body mass index [BMI] ≥ 35 kg/m2) on chest tube output (CTO) and hemostasis in patients undergoing cardiac surgery with CPB. Materials and Methods We prospectively investigated 2799 consecutive patients who underwent coronary and/or valve surgery using CPB between 2008 and 2012. 204 patients (7.3%) presented a severe obesity. Results In the severe obesity group, the 6-h and 24-h CTO were significantly reduced by -21.8% and -14.8% respectively (P < 0.0001) compared with the control group. A significant reduction of the mean number of red blood cell units transfused at 24 h was observed in the severe obesity groups (P = 0.01). On admission to the intensive care unit, a significant increase of platelet count (+ 9.2%; P < 0.0001), fibrinogen level (+ 12.2%; P < 0.0001) and prothrombin time (+ 4.1%; P < 0.01) and a significant decrease of the activated partial thromboplastin time (-4.2%; P < 0.01) were observed in the severe obesity group compared with the control group. In multivariate analysis, severe obesity was significantly associated to a decreased risk of excessive bleeding (24-h CTO > 90th percentile; Odds ratio: 0.37, 95% CI: 0.17 to 0.82). No significant differences were observed regarding postoperative thromboembolic events between the two groups. Conclusions Severe obesity is associated with a prothrombotic postoperative state that leads to a reduction of postoperative blood loss in patients undergoing cardiac surgery with CPB.
    Thrombosis Research 08/2014; 134(2):346–353. · 2.45 Impact Factor
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    • "It has been associated with the development of diabetes mellitus, hypertension, cardiovascular disease and heart failure [21], [22]. The relation between BMI and surgical outcomes is complex [23].Recent studies have described “obesity paradox” phenomena [11], [24]–[29]. Despite the association of obesity with chronic disease that lead to early death, improved survival has been observed in obese patients with heart failure and following CABG surgery [30], [31]. "
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    ABSTRACT: This study was designed to investigate the impact of body mass index (BMI) on short- and long-term outcomes after initial revascularization with coronary artery bypass graft (CABG) surgery. 4916 Chinese who consecutively underwent isolated, primary CABG at the Cardiovascular Institute of Fuwai Hospital from January 1, 1999 to December 31, 2005 were included in this study. They were classified based on BMI as follows: underweight: <18.5 kg/m2, normal weight: 18.5 to 23.9 kg/m2, overweight: 24 to 27.9 kg/m2, obesity: 28 to 32 kg/m2, and severe obesity: >32 kg/m2. Short (in-hospital) and long-term (5-years) major post-operative complications and mortalities were compared among various BMI groups after initial revascularization. Multiple regression analysis of five years follow-up of clinical end points indicated that various BMI groups were not associated with significant differences in 5 years mortality and MACCE, however, old age, smoking, hypertension, myocardial infarction and heart failure were the risk factor for the mortality. In this large-scale study with long term follow-up after primary CABG in an exclusively ethnic Chinese population, we found that different BMI groups were not significantly associated with 5-years mortality and MACCE, however, old age, smoking, hypertension, myocardial infarction and heart failure were the risk factors of post-operative mortality, and old age, hypertension and heart failure increased the rate of MACCE.
    PLoS ONE 04/2014; 9(4):e95223. DOI:10.1371/journal.pone.0095223 · 3.23 Impact Factor
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    • "Several risk factors for deep and superficial wound healing disturbances after cardiac surgery like obesity [6], diabetes mellitus, re-operation and use of both mammary arteries as grafts for coronary bypass surgery have been identified. The high morbidity, mortality and costs associated with postoperative wound disturbances make advances that can reduce postoperative wound complications attractive to the cardiothoracic surgeon. "
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    ABSTRACT: BACKGROUND: Surgical site wound complications following cardiothoracic surgery are associated with increased costs, morbidity, and mortality. Several factors have been shown to be associated with an increase in deep and superficial wound healing problems. Recent publications have suggested protective effects of topical autologous blood components with regard to wound healing disturbances after various surgical procedures. The aim of this retrospective analysis was to assess the impact of autologous fibrin glue on surgical site complications in high-risk coronary artery bypass graft patients. METHODS: 1394 consecutive patients who underwent CABG surgery from a single centre were included in the study. Autologous fibrin glue was used in 122 patients (8.8%) with elevated risk for wound complications according to institutional guidelines. The demography of both groups was compared and the following outcome variables were analyzed: deep sternal wound infection, sternal re-wiring, bleeding, re- exploration rate, and the use of a vacuum assisted closure system. RESULTS: No treatment-related adverse events were noted. The group of patients who received autologous fibrin sealant had significantly higher BMI levels, included more diabetics and repeat cardiac procedures and they underwent percutaneous coronary intervention more often. Furthermore, they were more likely to receive bilateral mammary artery grafts. Despite the high-risk profile of the Fibrin glue group rates of revision, deep sternal wound healing problems tended to be lower than in the control group. CONCLUSIONS: In our experience autologous fibrin glue does not invoke any adverse events and serves as a useful adjunct to haemostasis in cardiac surgery. However, the incidence of wound disturbances was similar in both arms of the study. In light of the ever-increasing clinical use a prospective randomized controlled trial examining the impact of autologous fibrin glue is warranted.
    European Surgery 10/2011; 43(5):309-314. DOI:10.1007/s10353-011-0039-6 · 0.27 Impact Factor
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