Obesity and coronary artery surgery

The impact of obesity on surgical outcomes in patients undergoing emergency laparotomy for high-risk abdominal emergencies

BACKGROUND

Obesity has been shown to increase the rates of morbidity and occasionally mortality in patients undergoing nonbariatric elective surgery. However, little is known about the impact of obesity on outcomes after surgery for high-risk abdominal emergencies.

METHODS

A single-center retrospective evaluation of outcomes in high-risk abdominal emergency patients categorized by body mass index (BMI) was conducted. Patient demographics, comorbidities, and operative details were analyzed. Patients with normal weight (BMI 18.5-24.9) served as comparators. Multivariable linear and logistic regression analyses were performed to assess the impact of obesity on surgical outcomes.

RESULTS

In total, 886 patients with BMI < 18.5 (underweight; n = 50), 18.5-24.9 (normal weight; n = 306), 25-29.9 (overweight; n = 336) and ≥ 30 (obese; n = 194) based on the World Health Organization (WHO) weight classification criteria met the inclusion criteria. Compared to normal-weight patients, patients with overweight and obesity were older and more likely to be male. The rates of comorbidity (100% vs 91.2%, p =  < 0.0001), morbidity (77.8% vs 65.6%, p = 0.003), and in-hospital mortality (44.8% vs 30.4%, p = 0.001) were all higher in patients with obesity than in normal-weight patients. Patients with obesity had an increased intensive care unit length of stay (ICU LOS) (13 days vs 9 days, p = 0.019) and hospital LOS (21.4 days vs 18.1 days, p = 0.081) and prolonged ventilation (39.1% vs 19.6%, p = 0.003). As BMI deviated from the normal range, the morbidity and mortality rates increased incrementally, with the highest morbidity (87.9%) and mortality (54.5%) rates observed in morbidly obese patients (BMI ≥ 40).

CONCLUSIONS

Patients with obesity were the most likely to have coexisting conditions, experience postoperative complications, and die during the first admission following EL for high-risk abdominal emergencies.

Influence of Body Mass Index on Outcomes of Patients Undergoing Surgery for Acute Aortic Dissection: A Propensity-Matched Analysis

To determine whether body mass index ≥30 kg/m² affects morbidity and mortality rates in patients undergoing surgery for type A acute aortic dissection, we conducted a retrospective study of 201 patients with type A dissection. Patients were divided into 2 groups according to body mass index (BMI): nonobese (BMI, <30 kg/m²; 158 patients) and obese (BMI, ≥30 kg/m²; 43 patients). Propensity score matching was used to reduce selection bias. The overall mortality rate was 19% (38/201 patients). The perioperative mortality rate was higher in the obese group, both in the overall cohort (33% vs 15%; P=0.01) and in the propensity-matched cohort (32% vs 12%; P=0.039). In the propensity-matched cohort, patients with obesity had higher rates of low cardiac output syndrome (26% vs 6%; P=0.045) and pulmonary complications (32% vs 9%; P=0.033) than those without obesity. The overall 5-year survival rates were 52.5% ± 7.8% in the obese group and 70.3% ± 4.4% in the nonobese group (P=0.036). In the propensity-matched cohort, the 5-year survival rates were 54.3% ± 8.9% in the obese group and 81.6% ± 6.8% in the nonobese group (P=0.018). Patients with obesity (BMI, ≥30 kg/m²) who underwent surgery for type A acute aortic dissection had higher operative mortality rates and an increased risk of low cardiac output syndrome, pulmonary complications, and other postoperative morbidities than did patients without obesity. Additional extensive studies are needed to confirm our findings.

Categorizing body mass index biases assessment of the association with post-coronary artery bypass graft mortality

OBJECTIVES

The high prevalence of obesity makes accurately estimating the impact of anthropometric measures on cardiac surgery outcomes critical. The Society of Thoracic Surgeons coronary artery bypass graft (CABG) surgery risk model includes body surface area (as a continuous variable, using spline functions), but most studies apply various categorizations of body mass index (BMI)-contributing to the contradictory published findings. We assessed the association between BMI (modelled as a continuous variable without assumptions of linearity) and CABG operative mortality and examined the impact of applying previous studies' BMI modelling strategies.

METHODS

We identified 25 studies investigating the BMI-operative mortality association: 22 categorized BMI, 2 as a linear continuous variable,1 used spline functions. Our cohort of 12 715 consecutive patients underwent isolated CABG at 32 cardiac surgery programmes in North Texas from 1 January 2008-31 December 2012. BMI was modelled using restricted cubic spline functions in a propensity-adjusted model (controlling for Society of Thoracic Surgeons risk factors) estimating operative mortality. The analysis was repeated using each categorization identified and modelling BMI as a linear continuous variable.

RESULTS

BMI (modelled with a restricted cubic spline) was significantly associated with operative mortality (P < 0.0001). Risk was lowest for BMI near 30 kg/m2 and highest below 20 kg/m2 and above 40 kg/m2. No categorization, nor the linear continuous model, fully captured this association.

CONCLUSIONS

BMI is strongly associated with CABG operative mortality. Categorizing BMI (or assuming a linear relationship) heavily biases estimates of its association with post-CABG mortality. In general, smoothing techniques should be used for all continuous risk factors to avoid bias.

Obese ICU Patients

This project described prospectively obese, critically ill patients and the resources critical care nurses used to care for these challenging patients. It also examined the relationship between resources used by nurses and patient outcomes, including complications and length of stay. Forty-three participants were enrolled. Patients with a body mass index (BMI) 40 kg/m2 used the majority of equipment and personnel resources and experienced a prolonged length of stay. The most common equipment used was a specialty bed or mattress; the most common complications were related to the pulmonary system. Initial use of multiple resources may indicate a patient at risk for adverse outcomes. Nurses can use findings to anticipate care needs and develop interventions, such as optimal positioning, to avoid adverse outcomes.

A BMI >35 does not protect patients undergoing cardiac bypass surgery from red blood cell transfusion

The effect of obesity on allogeneic intraoperative blood product transfusion in patients undergoing coronary artery bypass graft surgery (CABG) is poorly understood. We analyzed the influence of obesity on the risk of intraoperative red blood cell (RBC) transfusion among 45,200 consecutive non-reoperative CABG procedures from a multi-institutional perfusion database. A body mass index (BMI) in obese I category was associated with a 9.9% decrease in transfusion risk (p<0.05). Compared to patients with a normal BMI, obese I and obese III patients do not have any change in the relative risk of RBC transfusion. Overweight and mild obesity have a protective role in reducing intraoperative blood transfusion during cardiopulmonary bypass (CPB) surgery. However, logistic regression analysis showed that much of the observed reduction in transfusion rates for obese patients can be accounted for by other known confounds. The lack of a linear effect of increasing BMI on blood transfusion risk is a novel finding and warrants further investigation.

Body Mass Index, Outcomes, and Mortality Following Cardiac Surgery in Ontario, Canada

BACKGROUND

The "obesity paradox" reflects an observed relationship between obesity and decreased morbidity and mortality, suggesting improved health outcomes for obese individuals. Studies examining the relationship between high body mass index (BMI) and adverse outcomes after cardiac surgery have reported conflicting results.

METHODS AND RESULTS

The study population (N=78 762) was comprised of adult patients who had undergone first-time coronary artery bypass (CABG) or combined CABG/aortic valve replacement (AVR) surgery from April 1, 1998 to October 31, 2011 in Ontario (data from the Institute for Clinical Evaluative Sciences). Perioperative outcomes and 5-year mortality among pre-defined BMI (kg/m(2)) categories (underweight <20, normal weight 20 to 24.9, overweight 25 to 29.9, obese 30 to 34.9, morbidly obese >34.9) were compared using Bivariate analyses and Cox multivariate regression analysis to investigate multiple confounders on the relationship between BMI and adverse outcomes. A reverse J-shaped curve was found between BMI and mortality with their respective hazard ratios. Independent of confounding variables, 30-day, 1-year, and 5-year survival rates were highest for the obese group of patients (99.1% [95% Confidence Interval {CI}, 98.9 to 99.2], 97.6% [95% CI, 97.3 to 97.8], and 90.0% [95% CI, 89.5 to 90.5], respectively), and perioperative complications lowest. Underweight and morbidly obese patients had higher mortality and incidence of adverse outcomes.

CONCLUSIONS

Overweight and obese patients had lower mortality and adverse perioperative outcomes after cardiac surgery compared with normal weight, underweight, and morbidly obese patients. The "obesity paradox" was confirmed for overweight and moderately obese patients. This may impact health resource planning, shifting the focus to morbidly obese and underweight patients prior to, during, and after cardiac surgery.

Postoperative hypoxia and length of intensive care unit stay after cardiac surgery: the underweight paradox?

OBJECTIVE

Cardiac operations with cardiopulmonary bypass can be associated with postoperative lung dysfunction. The present study investigates the incidence of postoperative hypoxia after cardiac surgery, its relationship with the length of intensive care unit stay, and the role of body mass index in determining postoperative hypoxia and intensive care unit length of stay.

DESIGN

Single-center, retrospective study.

SETTING

University Hospital. Patients. Adult patients (N = 5,023) who underwent cardiac surgery with CPB.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

According to the body mass index, patients were attributed to six classes, and obesity was defined as a body mass index >30. POH was defined as a PaO2/FiO2 ratio <200 at the arrival in the intensive care unit. Postoperative hypoxia was detected in 1,536 patients (30.6%). Obesity was an independent risk factor for postoperative hypoxia (odds ratio 2.4, 95% confidence interval 2.05-2.78, P = 0.001) and postoperative hypoxia was a determinant of intensive care unit length of stay. There is a significant inverse correlation between body mass index and PaO2/FiO2 ratio, with the risk of postoperative hypoxia increasing by 1.7 folds per each incremental body mass index class. The relationship between body mass index and intensive care unit length of stay is U-shaped, with longer intensive care unit stay in underweight patients and moderate-morbid obese patients.

CONCLUSIONS

Obese patients are at higher risk for postoperative hypoxia, but this leads to a prolonged intensive care unit stay only for moderate-morbid obese patients. Obese patients are partially protected against the deleterious effects of hemodilution and transfusions. Underweight patients present the "paradox" of a better lung gas exchange but a longer intensive care unit stay. This is probably due to a higher severity of their cardiac disease.

The classification of obesity disease in logistic regression and neural network methods

The aim of this study is to establish an automated system to recognize and to follow-up obesity. In this study, the areas affected from obesity were examined with a classification considering the divergent arteries and body mass index of 30 healthy and 52 obese people by using two different mathematical models such as the traditional statistical method based on logistic regression and a multilayer perception (MLP) neural network, and then classifying performances of logistic regression and neural network were compared. As a result of this comparison, it is observed that the classifying performance of neural network is better than logistic regression; also the reasons of this result were examined. Furthermore, after these classifications it is observed that in obesity the body mass index is more affected than the divergent arteries.

Influence of body mass index on the efficacy of revascularization in patients with coronary artery disease

OBJECTIVE

We examined the effect of body mass index on the association between revascularization strategy and survival in patients with coronary artery disease.

METHODS

Using the Duke Database for Cardiovascular Disease, we selected 22,877 patients who underwent cardiac catheterization from January 1986 to August 2004 and were found to have significant coronary artery disease. Patients were categorized into three coronary disease management groups: no revascularization, percutaneous coronary intervention, and coronary artery bypass surgery. Propensity scoring was used to control for coronary artery revascularization strategy. The relationship between body mass index, coronary disease treatment, and survival was assessed via Cox multivariable models adjusting for baseline demographic, clinical, and angiographic characteristics.

RESULTS

The median body mass index was 27.2 kg/m(2) (24.4-30.4) in the overall cohort, 27.1 kg/m(2) (24.1-30.3) in the no revacularization group, 27.4 kg/m(2) (24.8-30.9) in the percutaneous intervention group, and 26.9 kg/m(2) (24.4-30.1) in the coronary bypass group. Body mass index was a significant, but weak, predictor of revascularization, with higher indexes predicting lower rates of coronary bypass. Thirty-day survival did not differ across body mass indexes among treatment groups, but survival curves appeared to separate over longer-term follow-up. An inverted U-shaped survival function was noted across all time points after 30 days, with the lowest risk of death at a body mass index of approximately 26 kg/m(2) (independent of revascularization strategy). Coronary bypass was associated with the highest survival at all later time points, whereas no revascularization was associated with the lowest.

CONCLUSIONS

Extremes of body mass index are associated with lower long-term survival in patients with significant coronary disease. Revascularization, particularly with coronary bypass, is consistently associated with the best survival across the spectrum of body mass indexes.

The influence of body mass index obesity status on vascular surgery 30-day morbidity and mortality

OBJECTIVE

Mild obesity may have a protective effect against some diseases, termed an "obesity paradox." This study examined the effect of body mass index (Kg/m(2) BMI) on surgical 30-day morbidity and mortality in patients undergoing vascular surgical procedures.

METHODS

As part of the National Surgical Quality Improvement Program (NSQIP), demographic and clinical risk variables, mortality, and 22 defined complications (morbidity) were obtained over three years from vascular services at 14 medical centers. At each medical center, patients from the operative schedule were prospectively and systematically enrolled according to NSQIP protocols. Outcomes and risk variables were compared across NIH-defined obesity classes (underweight [BMI<or=18.5], normal [18.5<BMI<25], overweight [25<BMI<or=30], obese I [30<BMI<or=35], obese II [35<BMI<or=40], and obese III [BMI>40]) using analysis of variance and means comparisons. Logistic regression was used to control for other risk factors.

RESULTS

Vascular procedures in 7,543 patients included lower extremity revascularization (24.6%), aneurysm repair (17.4%), cerebrovascular procedures (17.3%), amputations (9.4%), and "other" procedures (31.3%). In the entire cohort, there were 1,659 (22.0%) patients with complications and 295 (3.9%) deaths. Risk factors of hypertension and diabetes increased with BMI (analysis of variance [ANOVA] P < .05) as expected; smoking, disseminated cancer, and stroke decreased (ANOVA P < .01). Twenty other risk factors, as well as mortality and morbidity, had "U" or "J"-shaped distributions with the highest incidence in underweight and/or obese class III extremes but reduced minimums in overweight or obese I classes (ANOVA P < .05). After controlling for age, gender, and operation type, mortality risk remained lowest in obese class I patients (Odds ratio [OR] 0.63, P = .023) while morbidity risk was highest in obese class III patients (OR 1.70, P = .0003), due to wound infection, thromboembolism, and renal complications.

CONCLUSION

Underweight patients have poorer outcomes and class III obesity is associated with increased morbidity. Mildly obese patients have reduced co-morbid illness, surprisingly even less than normal-class patients, with correspondingly reduced mortality. Mild obesity is not a risk factor for 30-day outcomes after vascular surgery and confers an advantage.

Categorizing BMI may lead to biased results in studies investigating in-hospital mortality after isolated CABG

OBJECTIVE

To investigate how categorizing body mass index (BMI) into weight classes can impact the assessment of the relationship between BMI and in-hospital mortality after coronary artery bypass graft (CABG) surgery.

STUDY DESIGN AND SETTING

BMI-mortality (in-hospital) relationship was assessed in 5,762 patients who underwent isolated CABG at Baylor University Medical Center (Dallas, TX) from January 1, 1997 to November 30, 2003. Different ways of modeling BMI were used to investigate this association in a propensity-adjusted model, controlling for risk factors identified by the Society of Thoracic Surgeons (STS) and other clinical/nonclinical details.

RESULTS

A highly significant (P=0.003) association between BMI (modeled with a restricted cubic spline) and mortality was found. Reduced risk of in-hospital mortality was observed for subjects with BMI in the low-30s as compared with patients with BMI in the mid-20s or over 40 kg/m(2). Results were strongly affected by the way BMI was specified in the multivariable model. Only five of the 10 BMI categorizations considered produced significant results, and these results did not fully determine the effect of BMI on mortality.

CONCLUSIONS

BMI categorization critically impacts study results. Conceivably, findings of other studies investigating BMI and adverse outcomes after CABG may be similarly affected. Investigators should consider smoothing techniques to avoid categorization.

Comparison of pre- and postoperative pulmonary function in obese and non-obese female patients undergoing coronary artery bypass graft surgery

OBJECTIVE AND BACKGROUND

Various studies have suggested that body size and in-hospital mortality are related. However, only a few analysed the effects of obesity on pulmonary complications following coronary artery bypass graft surgery (CABG). The purpose of the present study was to assess early changes in lung volumes, respiratory complications and arterial blood gas tension following CABG in obese women.

METHODS

Pulmonary function tests (PFTs), treadmill exercise capacity tests (TM), arterial blood gases and pulmonary complications were studied in 124 obese (mean age 57.2+/-5.8 years) and 108 non-obese (mean age 58.6+/-5.9 years) female patients undergoing elective CABG. PFT, TM tests, arterial blood gas analyses and CXR were performed in the preoperative and postoperative periods and pulmonary complications were recorded. Breathing and coughing exercises, early ambulation and pulmonary clearing techniques were used by physical therapists to prevent pulmonary complications after CABG surgery.

RESULTS

Postoperative PFT and TM tests deteriorated significantly in both groups (P<0.0001). The deterioration in the obese group was highly significant. The postoperative deterioration of blood gas measurements in obese patients was also statistically significant compared to non-obese patients. Early pulmonary complications developed in 21 (16.94%) of the obese patients and in 10 (9.25%) of non-obese patients. Duration of mechanical ventilation, intensive care unit and hospital stays were longer compared to the non-obese patients (P=0.008, P<0.0001, P=0.0386, respectively).

CONCLUSION

Obesity has a detrimental effect on pulmonary function, exercise capacity, blood gas measurements and complications rates in postoperative period following CABG surgery.

Effect of body mass index on risk of long-term mortality following coronary artery bypass grafting

The effect of obesity on long-term mortality after coronary artery bypass grafting (CABG) remains inconclusive, partly due to methodologic issues in previous studies. We examined the effect of obesity on long-term mortality (up to a 6-year follow-up) in adult patients with a body mass index (BMI) > or =18.5 kg/m2 who underwent CABG at Baylor University Medical Center (Dallas, Texas) between January 1998 and August 1999 (n = 1,209). Unadjusted analysis indicated a strong association between BMI and long-term mortality (p = 0.001), with a decreased risk of mortality associated with increasing BMI. After adjusting for factors shown to be confounders of this relation (age, diabetes mellitus, chronic obstructive lung disease, renal failure, ejection fraction, and left main disease), the estimated association was no longer significant (p = 0.425). In conclusion, the apparent survival benefit associated with higher BMI became nonsignificant when the relation between mortality and BMI was adjusted, first for age and then for diabetes mellitus, chronic obstructive lung disease, renal failure, ejection fraction, and left main disease. This relation was masked in the crude analysis primarily by the effect of age. Patients with a high BMI were typically younger than patients with a lower BMI, suggesting that physicians and surgeons may only recommend/perform CABG for patients with a high BMI with an otherwise lower risk profile.

Is Obesity a Risk Factor for Mortality in Coronary Artery Bypass Surgery?

Background— The published articles examining obesity and CABG surgery contain conflicting results about the role of body mass index (BMI) as a risk factor for in-hospital mortality.

Methods and Results— We studied 16 218 patients who underwent isolated CABG in the Providence Health System Cardiovascular Study Group database from 1997 to 2003. The effect of BMI on in-hospital mortality was assessed by logistic regression, with BMI group (underweight, normal, overweight, and 3 subgroups of obesity) as a categorical variable or transformations, including fractional polynomials, of BMI as a continuous variable. BMI was not a statistically significant risk factor for mortality in any of these assessments. However, using cumulative sum techniques, we found that the lowest risk-adjusted CABG in-hospital mortality was in the high-normal and that overweight BMI subgroup patients with lower or higher BMI had slightly increased mortality.

Conclusions— Body size is not a significant risk factor for CABG mortality, but the lowest mortality is found in the high-normal and overweight subgroups compared with obese and underweight.

Obesity and the risk of early and late mortality after coronary artery bypass graft surgery

BACKGROUND

Obesity is often considered to be a significant risk factor for postoperative mortality when selecting candidates for coronary artery bypass grafting (CABG).

METHODS

We included all patients undergoing a first isolated CABG at the Karolinska Hospital in Stockholm, Sweden, between 1980 and 1995 (n = 6728). Patients were categorized on the basis of body mass index (BMI): non-overweight (BMI <25 kg/m2), overweight (25 kg/m2 < or = BMI <30 kg/m2), and obese (BMI > or =30 kg/m2). Multivariate Cox regression was used to assess the risk of re-operation for bleeding, deep sternal wound infection, and early (< or =30 days) and late (< or =5 years) mortality rates.

RESULTS

The average length of follow-up was 6.5 years. There were 252 re-operations for bleeding, 53 deep sternal wound infections, and 628 deaths. Patients who were obese had a significantly lower risk of re-operation for bleeding (risk ratio [RR], 0.32; 95% CI, 0.19-0.53), but a greater risk of deep sternal wound infection (RR, 2.66; 95% CI, 1.21-5.88) compared with patients who were not overweight. However, patients who were obese and patients who were not overweight experienced similar 30-day (RR, 0.65; 95% CI, 0.34-1.27), 1-year (RR, 0.56; 95% CI, 0.29-1.10), and 5-year mortality rates (RR, 0.91; 95% CI, 0.66-1.25). Results for patients who were overweight were consistent with those of patients who were obese.

CONCLUSION

Patients who are obese are not at a greater risk of early and late mortality after CABG compared with patients who are not overweight, although they appear to have a lower risk of re-operation for bleeding and a greater risk of deep sternal wound infection. Therefore, obesity per se is not a contraindication for CABG.

Preoperative pulmonary assessment of the older adult

Postoperative pulmonary complications in the elderly are common and are a significant source of morbidity, mortality, and prolonged length of stay. Risk factors differ from the well-known risk factors for cardiac complications and can be divided into patient- and procedure-related factors. Patient-related factors include COPD, recent cigarette use, poor general health status as defined by Goldman or ASA class, dependent functional status, and laboratory parameters including abnormal chest radiograph, renal insufficiency, and low serum albumin. Age is a minor risk factor when adjusted for comorbidities and confers approximately a two-fold increase in risk. Elderly patients who are otherwise acceptable surgical candidates should not be denied surgery based solely on age and concern for postoperative pulmonary complications. The surgical site is the single most important predictor of pulmonary complications. High-risk surgeries include thoracic, upper abdominal, aortic, neurosurgery, and peripheral vascular. Other procedure-related risk factors include surgery lasting longer than 3 hours, the use of general anesthesia, pancuronium use, and emergency surgery. Clinicians should not recommend routine preoperative spirometry before high-risk surgery because it is no more accurate in predicting risk than clinical evaluation. Patients who might benefit from preoperative spirometry include those who have unexplained dyspnea or exercise intolerance and those who have COPD or asthma in whom uncertainty exists as to the status of airflow obstruction when compared with baseline. After identifying patients at risk for postoperative pulmonary complications, clinicians can recommend strategies to reduce risk throughout the operative period. In addition to minimizing or avoiding the above risk factors, optimization of COPD or asthma, deep breathing exercises, incentive spirometry, and epidural local anesthetics reduce the risk of postoperative pulmonary complications in elderly surgical patients.

The impact of body mass index on short- and long-term outcomes inpatients undergoing coronary revascularization. Insights from the bypass angioplasty revascularization investigation (BARI)

OBJECTIVES

We sought to investigate the impact of body mass index (BMI) on short- and long-term outcomes after initial revascularization with percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass graft surgery (CABG).

BACKGROUND

Equivocal results exist on the impact of BMI on the risk of in-hospital complications after PTCA or CABG, and no long-term mortality data exist from a large series of revascularized patients.

METHODS

From the randomized series and observational registry of the Bypass Angioplasty Revascularization Investigation (BARI), 2,108 patients who had PTCA and 1,526 patients who had CABG were evaluated by taking their BMI at study entry. They were classified as follows: low (< 20 kg/m(2)), normal (20 to 24.9 kg/m(2)), overweight (25 to 29.9 kg/m(2)), class I obese (30 to 34.9 kg/m(2)) and class II/III obese (greater-than-or-equal 35 kg/m(2)). In-hospital complications and short- and long-term mortalities were compared between levels of BMI within each mode of initial revascularization.

RESULTS

Among patients who had PTCA, each unit increase in BMI was associated with a 5.5% lower adjusted risk of a major in-hospital event (death, myocardial infarction, stroke, coma); among patients who had CABG, no difference in the in-hospital outcome was observed according to BMI. In contrast, BMI was not associated with five-year mortality in the PTCA group; among the CABG group, adjusted relative risks of five-year cardiac mortality according to levels of BMI were 0.0 (low), 1.0 (normal), 2.02 (overweight), 3.16 (class I obese) and 4.85 (class II/III obese) (linear p < 0.001).

CONCLUSIONS

Body mass index appears to have a differential impact on short- and long-term outcomes after coronary revascularization. These results underscore the need for further research to identify factors responsible for the apparent short-term protective effect of a higher BMI in patients undergoing PTCA and to study the impact of weight reduction on the long-term survival of obese patients undergoing CABG.