Impact of body mass index on the outcome of patients with multivessel disease randomized to either coronary artery bypass grafting or stenting in the ARTS trial: The obesity paradox II?

Influence of Obesity on Short-Term Surgical Outcomes in HFrEF Patients Undergoing CABG: A Retrospective Multicenter Study

Background: This retrospective multicenter study investigates the impact of obesity on short-term surgical outcomes in patients with heart failure and reduced ejection fraction (HFrEF) undergoing coronary artery bypass grafting (CABG). Given the rising global prevalence of obesity and its known cardiovascular implications, understanding its specific effects in high-risk groups like HFrEF patients is crucial. Methods: The study analyzed data from 574 patients undergoing CABG across four German university hospitals from 2017 to 2023. Patients were stratified into 'normal weight' (n = 163) and 'obese' (n = 158) categories based on BMI (WHO classification). Data on demographics, clinical measurements, health status, cardiac history, intraoperative management, postoperative outcomes, and laboratory insights were collected and analyzed using Chi-square, ANOVA, Kruskal-Wallis, and binary logistic regression. Results: Key findings are a significant higher mortality rate (6.96% vs. 3.68%, p = 0.049) and younger age in obese patients (mean age 65.84 vs. 69.15 years, p = 0.003). Gender distribution showed no significant difference. Clinical assessment scores like EuroScore II and STS Score indicated no differences. Paradoxically, the preoperative left ventricular ejection fraction (LVEF) was higher in the obese group (32.04% vs. 30.34%, p = 0.026). The prevalence of hypertension, COPD, hyperlipidemia, and other comorbidities did not significantly differ. Intraoperatively, obese patients required more packed red blood cells (p = 0.026), indicating a greater need for transfusion. Postoperatively, the obese group experienced longer hospital stays (median 14 vs. 13 days, p = 0.041) and higher ventilation times (median 16 vs. 13 h, p = 0.049). The incidence of acute kidney injury (AKI) (17.72% vs. 9.20%, p = 0.048) and delirium (p = 0.016) was significantly higher, while, for diabetes prevalence, there was an indicating a trend towards significance (p = 0.051) in the obesity group, while other complications like sepsis, and the need for ECLS were similar across groups. Conclusions: The study reveals that obesity significantly worsens short-term outcomes in HFrEF patients undergoing CABG, increasing risks like mortality, kidney insufficiency, and postoperative delirium. These findings highlight the urgent need for personalized care, from surgical planning to postoperative strategies, to improve outcomes for this high-risk group, urging further tailored research.

The impact of sex, body mass index and chronic kidney disease on outcomes following percutaneous coronary intervention

OBJECTIVE

This study sought to evaluate 1) the relationship between body mass index (BMI), chronic kidney disease (CKD) and bleeding complications in patients undergoing percutaneous coronary intervention (PCI); and 2) whether CKD modified the effect of BMI on major bleeding and major adverse cardiac and cerebrovascular events (MACCE).

BACKGROUND

The interaction of CKD, sex and BMI in patients undergoing PCI is unclear.

METHODS

Between 2010 and 2018, a total of 31,116 patients underwent PCI at six New York metropolitan area hospitals. Bleeding complications were classified by the Bleeding Academic Research Consortium (BARC). Major bleeding was defined as BARC≥3. MACCE was the composite of in-hospital death; myocardial infarction; cerebrovascular events and major bleeding complications. Interaction on multiplicative scales was assessed adjusting for other factors. A three-way multiplicative interaction between BMI, CKD and sex were considered and evaluated for both endpoints of primary interest (BARC≥3 and MACCE).

RESULTS

Patients with BARC≥3 bleeding were older (p < 0.0001) and more likely female (p < 0.0001). A 3-way interaction existed between sex, BMI, and CKD on BARC≥3 (p = 0.02). Specifically, the effect of CKD status on odds of BARC≥3 depended on BMI group among males, whereas BMI did modify the relationship between CKD and BARC≥3 among females; after stratification by sex, a significant interaction between BMI and CKD was present in females (p = 0.03) but not in males (p = 0.43). Among females without CKD, normal BMI patients had the greatest odds of BARC≥3 compared to obese or overweight females. Contrasted to females without CKD, among females with CKD there was no significant increased odds of BARC≥3 in normal BMI patients compared to obese or overweight females. However, overweight females with CKD had a significantly increased odds of BARC≥3 compared to obese females with CKD. Furthermore, obese females with CKD had significantly greater BARC≥3 odds compared to obese females without CKD. Similarly, overweight females with CKD had an increased odds of BARC≥3 compared to overweight females without CKD. No significant interactions were found for the odds of MACCE.

CONCLUSION

In patients undergoing PCI, there was evidence of a significant and complex 3-way interaction between BMI, CKD and sex for major bleeding events. The predicted probability of major bleeding was greater for females than for male patients, and for both sexes, greater among those with CKD, but BMI group influences these probabilities. Obese females with kidney disease had the lowest incidence of bleeding complications when compared with overweight or normal weight female patients undergoing PCI. This interaction was not seen in the male group or for MACCE. Furthermore, age, cardiogenic shock, STEMI and use of IABP/Impella were each independently associated with odds of major bleeding (among both males and females) and MACCE.

Does obesity predict morbidity and mortality amongst patients undergoing transfemoral amputations?

BACKGROUND

We investigated the role of obesity on morbidity and mortality in patients undergoing above knee amputation.

METHODS

Data of 4225 patients undergoing AKAs was extracted from NIS Database (2016-2019) for a retrospectively matched case-control study and were grouped into; Non-obese (N-Ob-BMI <29.9 kg/m²; n = 1413), class I/II obese (Ob-I/II-BMI: 30-39.9 kg/m²; n = 1413), and class III obese groups (Ob-IIIBMI > 40; n = 1399). Morbidity, mortality, length of stay, and hospital charges were analyzed.

RESULTS

Blood loss anemia (OR = 1.42; 95% CI = 1.19-1.64), superficial SSI (OR = 5.10; 95% CI = 1.4717.63) and acute kidney injury (AKI- OR = 1.42; 95% CI = 1.21-1.67) were higher in Ob-III patients. Mortality was 5.8%, 4.5%, and 6.4% in N-Ob, Ob-I/II and Ob-III patients (p < 0.001; Ob-I/II vs. Ob-III), respectively. Hospital LOS was 3 days higher in Ob-III (16.1 ± 18.0), comparatively resulting in $25,481 higher inpatient-hospital charge.

CONCLUSION

Patients in Ob-III group were noted to have increased morbidity, higher LOS, and inpatient-hospital cost.

Morbidity and Mortality in Non-Obese Compared to Different Classes of Obesity in Patients Undergoing Transtibial Amputations

This study assesses the effect of obesity classes on outcomes and inpatient-hospital-cost compared to non-obese individuals undergoing below-knee amputations (BKAs). Retrospective matched-case controlled study performed on data from NIS Database. We identified three groups: N-Ob (BMI < 29.9 kg/m2; n = 3104), Ob-I/II (BMI: 30 to 39.9 kg/m2; n = 3107), and Ob-III (BMI > 40; n = 3092); matched for gender, comorbidities, tobacco use and elective vs. emergent surgery. Differences in morbidity, mortality, hospital length of stay (LOS), and total inpatient cost were analyzed. Blood loss anemia was more common in Ob-III compared to Ob-I/II patients (OR = 1.2; 95% CI = 1.1−1.4); blood transfusions were less commonly required in Ob-I/II (OR = 0.8; 95% CI = 0.7−0.9) comparatively; Ob-I/II encountered pneumonia less frequently (OR = 0.9; 95% CI = 0.4−0.9), whereas myocardial infarction was more frequent (OR = 7.0; 95% CI = 2.1−23.6) compared to N-Ob patients. Acute renal failure is more frequent in Ob-I/II (OR = 1.2; 95% CI = 1.0−1.3) and Ob-III (OR = 1.8; 95% CI = 1.6−1.9) compared to the N-Ob cohort. LOS was higher in N-Ob (13.1 ± 12.8 days) and Ob-III (13.5 ± 12.4 d) compared to Ob-I/II cohort (11.8 ± 10.1 d; p < 0.001). Mortality was 2.8%, 1.4%, and 2.9% (p < 0.001) for N-Ob, Ob-I/II, and Ob-III, respectively. Hospital charges were $22,025 higher in the Ob-III cohort. Ob-I/II is protective against peri-operative complications and death, whereas hospital cost is substantially higher in Ob-III patients undergoing BKAs.

The association between different body mass index levels and midterm surgical revascularization outcomes

Background

There are conflicting results regarding the relationship between overweight/obesity and the outcomes of coronary artery bypass graft surgery (CABG), termed “the obesity paradox”. This study aimed to evaluate the effects of body mass index (BMI) on the midterm outcomes of CABG.

Methods

This historical cohort study included all patients who underwent isolated CABG at our center between 2007 and 2016. The patients were divided into five categories based on their preoperative BMIs (kg/m²): 18.5≤BMI<25, 25≤BMI<30, 30≤BMI<35, 35≤BMI<40, and BMI≥40. Patients with BMIs below 18.5 kg/m² were excluded. The endpoints of this study were all-cause mortality and major adverse cardio-cerebrovascular events (MACCEs), comprising acute coronary syndromes, cerebrovascular accidents, and all-cause mortality at five years. For the assessment of the linearity of the relationship between continuous BMI and the outcomes, plots for time varying hazard ratio of BMI with outcomes were provided.

Results

Of 17 751 patients (BMI = 27.30 ±4.17 kg/m²) who underwent isolated CABG at our center, 17 602 patients (mean age = 61.16±9.47 y, 75.4% male) were included in this study. Multivariable analysis demonstrated that patients with pre-obesity and normal weight had similar outcomes, whereas patients with preoperative BMIs exceeding 30 kg/m² kg/m² had a significantly higher risk of 5-year all-cause mortality and 5-year MACCEs than those with pre-obesity. Additionally, a positive association existed between obesity degree and all-cause mortality and MACCEs. Further, BMIs of 40 kg/m² or higher showed a trend toward higher MACCE risks (adjusted hazard ratio, 1.32; 95% confidence interval, 0.89 to 1.95), possibly due to the small sample size. A nonlinear, albeit negligible, association was also found between continuous BMI and the study endpoints.

Conclusions

Our findings suggest that preoperative obesity (BMI>30 kg/m²) in patients who survive early after CABG is associated with an increased risk of 5-year all-cause mortality and 5-year MACCEs. These findings indicate that physicians and cardiac surgeons should encourage patients with high BMIs to reduce weight for risk modification.

Underweight patients are the highest risk body mass index group for perioperative adverse events following stand-alone anterior lumbar interbody fusion

BACKGROUND CONTEXT

Prior studies investigating the association between Body Mass Index (BMI) and patient outcomes following spine surgery have had inconsistent conclusions, likely owing to insufficient power, confounding variables, and varying definitions and cutoffs for BMI categories (eg, underweight, overweight, obese, etc.). Further, few studies have considered outcomes among low BMI cohorts.

PURPOSE

The current study analyzes how anterior lumbar interbody fusion (ALIF) perioperative outcomes vary along the BMI spectrum, using World Health Organization (WHO) categories of BMI.

STUDY DESIGN/SETTING

A retrospective cohort study.

PATIENT SAMPLE

Patients undergoing stand-alone one or two-level anterior lumbar interbody fusion (ALIF) found in the 2005-2018 American College of Surgeons National Surgical Quality Improvement Program (NSQIP) databases.

OUTCOME MEASURES

Thirty-day adverse events, hospital readmissions, post-operative infections, and mortality.

METHODS

Stand-alone one or two-level ALIF surgical cases were identified and extracted from the 2005-2018 National Surgical Quality Improvement Program (NSQIP) database. Posterior cases and those primary diagnoses of trauma, tumor, infection, or emergency presentation were excluded. Patients were then binned into WHO guidelines of BMI. The incidence of adverse outcomes within 30-day post-operation was defined. Odds ratios of adverse outcomes, normalized to the average risk of normal-weight subjects (BMI 18.5-24.9 kg/m³), were calculated. Multivariate analysis was then performed controlling for patient factors.

RESULTS

In total, 13,710 ALIF patients were included in the study. Incidence of adverse events was elevated in both the underweight (BMI<18.5 kg/m³) and super morbidly obese (>50 kg/m³), however, multivariate risks for adverse events and postoperative infection were elevated for underweight patients beyond those found in any other BMI category. No effect was noted in these identical variables between normal, overweight, obese class 1, or even obese class 2 patients. Multivariate analysis also found overweight patients to show a slightly protective trend against mortality while the super morbidly obese had elevated odds.

CONCLUSIONS

Underweight patients are at greater odds of experiencing postoperative adverse events than normal, overweight, obese class 1, or even obese class 2 patients. The present study identifies underweight patients as an at-risk population that should be given additional consideration by health systems and physicians, as is already done for those on the other side of the BMI spectrum.

Body mass index and postoperative mortality in patients undergoing coronary artery bypass graft surgery plus valve replacement: a retrospective cohort study

Background

The relationship between body mass index (BMI) and postoperative mortality in patients who undergo coronary artery bypass graft (CABG) surgery plus valve replacement is uncertain. We aimed to investigate the association between body mass index (BMI) and postoperative mortality among patients who simultaneously underwent both CABG surgery plus valve replacement.

Methods

We retrospectively analyzed 1976 patients who underwent CABG surgery at our hospital between January 2017 and April 2021, including 202 patients who underwent valve replacement surgery during the same period. We analyzed the relationship between BMI and postoperative mortality. The relationship between BMI and postoperative mortality was assessed using smooth curve fitting and a Multiple logistic regression model.

Results

The results of smoothing curve fitting showed that BMI and postoperative mortality had a non-linear relationship, and the resulting curve exhibited a two-stage change and a breakpoint. Postoperative mortality is higher in patients that have a body mass index above 25 kg/m² compared to patients having a body mass index between 18 and 25 kg/m².

Conclusions

Our study found a non-linear relationship between BMI and postoperative mortality in patients undergoing CABG plus valve replacement after adjusting for potential confounders. The causal relationship between BMI and postoperative mortality still requires further investigations.

Cardiovascular risk stratification by coronary computed tomography angiography imaging: current state-of-the-art

Current cardiovascular risk stratification by use of clinical risk score systems or plasma biomarkers is good but less than satisfactory in identifying patients at residual risk for coronary events. Recent clinical evidence puts now further emphasis on the role of coronary anatomy assessment by coronary computed tomography angiography (CCTA) for the management of patients with stable ischaemic heart disease. Available computed tomography (CT) technology allows the quantification of plaque burden, identification of high-risk plaques, or the functional assessment of coronary lesions for ischaemia detection and revascularization for refractory angina symptoms. The current CT armamentum is also further enhanced by perivascular Fat Attenuation Index (FAI), a non-invasive metric of coronary inflammation, which allows for the first time the direct quantification of the residual vascular inflammatory burden. Machine learning and radiomic features' extraction and spectral CT for tissue characterization are also expected to maximize the diagnostic and prognostic yield of CCTA. The combination of anatomical, functional, and biological information on coronary circulation by CCTA offers a unique toolkit for the risk stratification of patients, and patient selection for targeted aggressive prevention strategies. We hereby provide a review of the current state-of-the art in the field and discuss how integrating the full capacities of CCTA into clinical care pathways opens new opportunities for the tailored management of coronary artery disease.

Obesity Paradox of All-Cause Mortality in 4,133 Patients Treated with Coronary Revascularization

Objectives

The purpose of this study was to determine whether there is a dose-response relationship between body mass index (BMI) and all-cause mortality in patients after coronary revascularization.

Methods

The MIMIC-III database (version 1.4) was used as the sample population. For variables with less than 10% of values missing, we used the mice package of R software for multiple imputations. Cox regression was used to determine the risk factors of all-cause mortality in patients. RCSs were used to observe the relationship between BMI and all-cause mortality. Additional subgroup and sensitivity analyses were also performed to explore whether the conclusion can be applied to specific groups.

Results

Both univariate and multivariate Cox models indicated that the mortality risk was lower for overweight patients than for normal-weight patients (P < 0.05). In RCS models, BMI had a U-shaped relationship with all-cause mortality of patients after coronary artery bypass grafting (CABG) (P for nonlinearity = 0.0028). There was a weak U-shaped relationship between BMI and all-cause mortality after percutaneous coronary intervention (PCI), but the nonlinear relationship between these two parameters was not significant (P for nonlinearity = 0.1756).

Conclusions

The obesity paradox does exist in patients treated with CABG and PCI. RCS analysis indicated that there was a U-shaped relationship between BMI and all-cause mortality in patients after CABG. After sex stratification, the relationship between BMI and all-cause mortality in male patients who received PCI was L-shaped, while the nonlinear relationship among females was not significant.

Association of body mass index with outcomes after thoracic endovascular aortic repair in the vascular quality initiative

OBJECTIVE

Although several studies have evaluated the impact of obesity on outcomes after abdominal aortic aneurysm repair, literature examining this association in thoracic endovascular aortic repair (TEVAR) is sparse. Here, we use a multi-institutional, international database to assess the role of body mass index (BMI) on adverse outcomes in patients who underwent TEVAR for descending thoracic aortic aneurysms (DTAA) and type B dissections (TBD).

METHODS

A retrospective review of all patients who underwent TEVAR for DTAA or TBD from August 2014 to August 2020 was performed. Patients who were underweight (BMI <18.5 kg/m²) or obese (BMI ≥30 kg/m²) were compared with those of normal weight (≥18.5 to <30 kg/m²). Adjustment for confounding was done with multivariable logistic regression or Cox proportional hazards regression as appropriate for studying postoperative or 1-year outcomes. Primary outcomes were 30-day and 1-year mortality. Other outcomes included any postoperative complication, stroke, and spinal cord ischemia.

RESULTS

A total of 3423 participants were included in the study, of whom 3.3% (n = 113) were underweight, 65.9% (n = 2253) had normal weight, and 30.8% (n = 1053) were obese. Compared with normal weight, there was no significant difference in 30-day mortality in underweight patients (odds ratio [OR], 1.81; 95% confidence interval [CI], 0.80-4.14; P = .156). Obese patients who underwent TEVAR for TBD had a 2.7-fold increase in the odds of 30-day mortality compared with normal weight (OR, 2.67; 95% CI, 1.52-4.68; P = .001). Obese and normal weight patients with DTAA had equivalent odds of 30-day mortality (OR, 1.32; 95% CI, 0.79-2.23; P = .292). The adjusted hazard of 1-year mortality was 2-fold higher in underweight patients compared with normal weight (hazard ratio, 2.15; 95% CI, 1.41-3.29; P < .001), driven by a higher risk of mortality among patients with thoracic aortic aneurysm (OR, 2.62; 95% CI, 1.63-4.21; P < .001). There was no significant difference in 1-year mortality risk between normal weight and obesity in both DTAA (OR, 0.77; 95% CI, 0.54-1.09; P = .146) and TBD (OR, 1.26; 95% CI, 0.85-1.86; P = .248).

CONCLUSIONS

In this study, obese patients who underwent TEVAR for DTAA had comparable 30-day and 1-year mortality risk as normal weight individuals. Obese patients who underwent TEVAR for TBD demonstrated a 2.7-fold increase in the odds of 30-day mortality, but equivalent mortality risk as normal weight patients at 1 year. TEVAR represents a safe minimally invasive option for treatment of DTAA in obese patients. Future work should be directed toward minimizing perioperative mortality among patients with TBD to optimize TEVAR outcomes.

The Obesity Paradox in Elderly Patients Undergoing Emergency Surgery: A Nationwide Analysis

BACKGROUND

Obesity has long been considered a risk factor for postoperative adverse events in surgery. We sought to study the impact of body mass index (BMI) on the clinical outcomes of the high-risk emergency general surgery (EGS) elderly patients.

METHODS

All EGS ≥65 years old patients in the 2007-2016 ACS-NSQIP database, identified using the variables 'emergency' and 'surgspec,' were included. Patients were classified into five groups: normal weight: BMI <25 kg/m², overweight: BMI ≥25 kg/m² and <30 kg/m², Class I: BMI ≥30 kg/m² and <35 kg/m², Class II: BMI ≥35 kg/m² and <40 kg/m², and Class III: BMI ≥40 kg/m². Patients with BMI<18.5 kg/m² were excluded. Multivariable logistic regression models were built to assess the relationship between obesity and 30-day postoperative mortality, overall morbidity, and individual postoperative complications after adjusting for demographics (e.g., age, gender), comorbidities (e.g., diabetes mellitus, heart failure), laboratory tests (e.g., white blood cell count, albumin), and operative complexity (e.g., ASA classification).

RESULTS

A total of 78,704 patients were included, of which 26,011 were overweight (33.1%), 13,897 (17.6%) had Class I obesity, 5904 (7.5%) had Class II obesity, and 4490 (5.7%) had Class III obesity. On multivariable analyses, compared to the nonobese, patients who are overweight or with Class I-III obesity paradoxically had a lower risk of mortality, bleeding requiring transfusion, pneumonia, stroke and myocardial infarction (MI). Additionally, the incidence of MI and stroke decreased in a stepwise fashion as BMI progressed from overweight to severely obese (MI: OR: 0.84 [0.73-0.95], OR: 0.73 [0.62-0.86], OR: 0.66 [0.52-0.83], OR: 0.51 [0.38-0.68]; stroke: OR: 0.80 [0.65-0.99], OR: 0.79 [0.62-1.02], OR: 0.71 [0.50-1.00], OR: 0.43 [0.28-0.68]).

CONCLUSION

In our study of elderly EGS patients, overweight and obese patients had a lower risk of mortality, bleeding requiring transfusion, pneumonia, reintubation, stroke, and MI. Further studies are needed to confirm and investigate the obesity paradox in this patient population.

Body mass index and mortality in patients with severe coronary artery diseases: A cohort study from China

BACKGROUND AND AIMS

It is still controversial whether obesity and overweight increase the risk of mortality for patients with coronary artery disease. The current study aimed to investigate the relationship between body mass index (BMI) and mortality in patients with triple-vessel disease (TVD).

METHODS AND RESULTS

From April 2004 to February 2011, 8943 patients with angiographically confirmed TVD were consecutively enrolled. Patients were divided into five groups according to BMI: underweight (<18.5 kg/m²), normal weight (18.5-23.9 kg/m²), overweight: (24-27.9 kg/m²), mild obesity (28-31.9 kg/m²), and severe obesity (≥32 kg/m²). The primary end point was all-cause death. Subgroup analysis was performed for treatment strategies: revascularization and medical treatment alone. During a median follow-up of 7.5 years, lower risks of mortality were observed in patients with overweight (adjusted HR 0.85, 95% CI 0.75-0.97) and mild obesity (adjusted HR 0.83, 95% CI 0.69-1.00) compared to those with normal weight. Polynomial Cox regression suggested a U-shape association between BMI and adjusted mortality risk. In the revascularization subgroup, there was a significantly higher mortality risk in patients with severe obesity (adjusted HR 1.57, 95% CI 1.03-2.40) than in those with normal weight. While in the medical treatment subgroup, mortality risk decreased as BMI increased, with the lowest risk being observed in patients with severe obesity.

CONCLUSION

There is a U-shape relationship between BMI and all-cause death in patients with TVD, with increased risks among both underweight and severely obese patients. This relationship may be influenced by treatment strategies.

The effect of body mass index on outcomes following severe blunt chest trauma

INTRODUCTION

Obesity has been described as a significant risk factor for adverse outcomes in hospitalized patients. However, recent literature reports an "obesity paradox", suggesting that obesity may have a protective effect in a subset of surgical and critically ill patients. The present study assesses the effect of body mass index (BMI) on outcomes following severe isolated blunt chest trauma.

METHODS

This was a TQIP database study including patients with severe isolated blunt chest injury (chest AIS 3-5, extrathoracic AIS <3). Patients were excluded for age <20 or >89, death on arrival, facility transfer, or BMI <10 or >55. Patients were divided into five groups according to BMI: underweight (BMI <18.5), normal weight (18.5-24.9), overweight (25.0-29.9), obesity class 1 (30.0-34.9), obesity class 2 (35.0-39.9) and obesity class 3 (≥40.0). Logistic regression models were constructed to evaluate the effect of BMI on outcomes.

RESULTS

28,820 patients met criteria for inclusion in the analysis. After multivariable analysis, underweight patients as well as obesity class 2 and 3 patients had a significantly higher mortality (OR 1.86 [95% CI, 1.12-3.10], OR 1.48 [95% CI, 1.02-2.16], and OR 1.60 [95% CI, 1.03-2.50]), respectively. Underweight patients had significantly higher risk of overall complications as compared to normal weight patients (OR 1.58 [95% CI, 1.34-1.88]). Obesity class 2 and 3 were independently associated with increased respiratory complications (OR 1.60 [95% CI, 1.27-2.01] and OR 1.58 [95% CI, 1.20-2.09], respectively) and all classes of overweight and obese patients were associated with increased risk of VTE complications (OR 1.68 [95% CI, 1.23-2.27], OR 1.98 [95% CI, 1.42-2.77], OR 2.32 [95% CI, 1.55-3.48], OR 2.02 [95% CI, 1.23-3.33], respectively for overweight and obesity class 1, 2, 3).

CONCLUSIONS

The obesity paradox does not extend to severe blunt chest trauma. Underweight and obesity class 2 and 3 patients have worse mortality than normal weight patients. Obesity was independently associated with an increased risk of pulmonary and VTE complications.

Abdominal adiposity assessed using CT angiography associates with acute kidney injury after trans-catheter aortic valve replacement

AIM

To determine if there is an association between area-based visceral abdominal adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAT), and abdominal circumference measured on computed tomography (CT) angiography before trans-catheter aortic valve replacement (TAVR) and post-TAVR acute kidney injury (AKI).

MATERIALS AND METHODS

In this retrospective cohort study of 106 TAVR patients, SAT and VAT areas and abdominal circumference was measured on a single CT section at L4 vertebral level. Univariate comparisons between patients who did and did not develop AKI were undertaken for radiological measurements. Multivariable logistic regression was used to assess association between CT measurements and the development of post-TAVR AKI.

RESULTS

Post-TAVR AKI occurred in 20 of 106 patients (19%). In univariate comparisons, body mass index (BMI) did not differ significantly between patients who did and did not develop AKI (p=0.14); however, VAT+SAT (443.2±163.7 versus 351±168.7 cm²; p=0.03), VAT (213.9±110.6 versus 153.9±96.1 cm²; p=0.03), and outer abdominal circumference (100.2±14.4 cm versus 91.8±13.3 cm; p=0.02) were significantly higher in the patients who did not develop post-TAVR AKI. These three measures on pre-TAVR CT angiogram remained significantly associated with reduced post-TAVR AKI with a lower incidence of post-TAVR AKI after multivariable adjustment for pre-TAVR estimated glomerular filtration rate and patient height (p<0.05).

CONCLUSION

This study found that increased abdominal obesity as assessed by measures on pre-TAVR CT angiogram is associated with a significantly lower incidence of AKI.

Isolated severe blunt traumatic brain injury: effect of obesity on outcomes

OBJECTIVE

Obesity has been widely reported to confer significant morbidity and mortality in both medical and surgical patients. However, contemporary data indicate that obesity may confer protection after both critical illness and certain types of major surgery. The authors hypothesized that this "obesity paradox" may apply to patients with isolated severe blunt traumatic brain injuries (TBIs).

METHODS

The Trauma Quality Improvement Program (TQIP) database was queried for patients with isolated severe blunt TBI (head Abbreviated Injury Scale [AIS] score 3-5, all other body areas AIS < 3). Patient data were divided based on WHO classification levels for BMI: underweight (< 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), obesity class 1 (30.0-34.9 kg/m2), obesity class 2 (35.0-39.9 kg/m2), and obesity class 3 (≥ 40.0 kg/m2). The role of BMI in patient outcomes was assessed using regression models.

RESULTS

In total, 103,280 patients were identified with isolated severe blunt TBI. Data were excluded for patients aged < 20 or > 89 years or with BMI < 10 or > 55 kg/m2 and for patients who were transferred from another treatment center or who showed no signs of life upon presentation, leaving data from 38,446 patients for analysis. Obesity was not found to confer a survival advantage on univariate analysis. On multivariate analysis, underweight patients as well as obesity class 1 and 3 patients had a higher rate of mortality (OR 1.86, 95% CI 1.48-2.34; OR 1.18, 95% CI 1.01-1.37; and OR 1.41, 95% CI 1.03-1.93, respectively). Increased obesity class was associated with an increased risk of respiratory complications (obesity class 1: OR 1.19, 95% CI 1.03-1.37; obesity class 2: OR 1.30, 95% CI 1.05-1.62; obesity class 3: OR 1.55, 95% CI 1.18-2.05) and thromboembolic complications (overweight: OR 1.43, 95% CI 1.16-1.76; obesity class 1: OR 1.45, 95% CI 1.11-1.88; obesity class 2: OR 1.55, 95% CI 1.05-2.29) despite a decreased risk of overall complications (obesity class 2: OR 0.82, 95% CI 0.73-0.92; obesity class 3: OR 0.83, 95% CI 0.72-0.97). Underweight patients had a significantly increased risk of overall complications (OR 1.39, 95% CI 1.24-1.57).

CONCLUSIONS

Although there was an obesity-associated decrease in overall complications, the study data did not demonstrate a paradoxical protective effect of obesity on mortality after isolated severe blunt TBI. Obese patients with isolated severe blunt TBI are at increased risk of respiratory and venous thromboembolic complications. However, underweight patients appear to be at highest risk after severe blunt TBI, with significantly increased risks of morbidity and mortality.

Adiposity in relation to readmission and all-cause mortality following coronary artery bypass grafting: A systematic review and meta-analysis

This study systemically reviewed evidence linking adiposity to readmission and all-cause mortality in post-coronary artery bypass grafting (CABG) patients. Keyword/reference search was performed in PubMed, Web of Science, CINAHL, and Cochrane Library for articles published before June, 2018. Eligibility criteria included study designs: experimental/observational studies; subjects: adult patients undergoing CABG; and outcomes: hospital/clinic readmissions, and short-term (≤30 days) and mid-to-long-term (>30 days) all-cause mortality. Seventy-two studies were identified. Meta-analysis showed that the odds of post-CABG readmission among patients with overweight was 30% lower than their normal-weight counterparts and the odds of mid-to-long-term post-CABG mortality among patients with overweight were 20% lower than their normal-weight counterparts. In contrast, no difference in post-CABG readmission rate was found between patients with obesity and their nonobese counterparts; no difference in short-term or in-hospital post-CABG mortality rate was found between patients with overweight or obesity and their normal-weight counterparts; and no difference in mid-to-long-term post-CABG mortality rate was found between patients with obesity and their normal-weight counterparts. In conclusion, patients with overweight but not obesity had a lower readmission and mid-to-long-term mortality rate following CABG relative to their normal-weight counterparts. Preoperative weight loss may not be advised to patients with overweight undergoing CABG.

Impact of Obesity on Postoperative Outcomes following cardiac Surgery (The OPOS study): rationale and design of an investigator-initiated prospective study

INTRODUCTION

Increasing levels of obesity worldwide have led to a rise in the prevalence of obesity-related complications including cardiovascular risk factors such as diabetes, hypertension and dyslipidaemia. Healthcare providers believe that overweight and obese cardiac surgery patients are more likely to experience adverse postoperative outcomes. The body mass index (BMI) is the primary measure of obesity in clinical practice, without accounting for a patient's level of cardiopulmonary fitness or muscle mass. The objective of this study is to determine whether fitness capacity of obese cardiac surgical patients and biomarkers, alone or in combination, will help identify patients at risk for adverse outcomes when undergoing cardiac surgery.

METHODS AND ANALYSIS

Patients between the ages of 18 and 75 years undergoing elective cardiac surgery are consented to participate in this prospective observational study. Patients will be invited to participate in measures of obesity, functional capacity and exercise capacity assessments, quality of life questionnaires, and blood and tissue sampling for biomarker analysis. The endpoints evaluated are measures other than BMI that could be predictive of short-term and long-term postoperative outcomes. Clinical outcomes of interest are prolonged ventilation, hospital length of stay, renal failure and all-cause mortality. Biomarkers of interest will largely focus on metabolism (lipids, amino acids) and inflammation (adipokines, cytokines and chemokines).

ETHICS AND DISSEMINATION

This study has been approved by the institutional review board at the Horizon Health Network. On completion of the study, the results shall be disseminated through conference presentations and publications in peer-reviewed journals. Additionally, the report shall also be diffused more broadly to the general public and the cardiovascular community.

TRIAL REGISTRATION NUMBER

NCT03248921.

Does body mass index truly affect mortality and cardiovascular outcomes in patients after coronary revascularization with percutaneous coronary intervention or coronary artery bypass graft? A systematic review and network meta-analysis

BACKGROUND

Obesity, a comorbid medical condition, is usually observed in patients with established coronary artery disease. Paradoxically, patients with a higher body mass index (BMI) usually have better clinical outcomes after coronary revascularization.

METHODS

We searched five online databases through December 2017. We identified studies reporting the rate of all-cause mortality or cardiovascular-related outcomes among patients after coronary revascularization with percutaneous coronary intervention or coronary artery bypass graft based on various BMI categories. Network meta-analysis was performed using Bayesian methods.

RESULTS

Sixty-five records involving 865,774 participants were included in our study. A U-shaped association was observed across BMI categories for all-cause mortality. Using normal weight as the reference, all-cause mortality was increased for (relative risk [RR]: 2.4; 95% credibility interval [CrI]: 2.1-2.7) patients with underweight, whereas it was lowered in patients with overweight, obese, and severely obese. This association remained significant in many subgroups. We also observed that the risk of major adverse cardiovascular events (MACE) was lowest among patients with overweight. Furthermore, patients with underweight were associated with greater risks of myocardial infarction (RR: 1.9; 95% CrI: 1.4-2.5), cardiovascular-related mortality (RR: 2.8; 95% CrI: 1.6-4.7), stroke (RR: 2.0; 95% CrI: 1.3-3.3) and heart failure (RR: 1.7; 95% CrI: 1.1-2.7) compared with normal weight patients; no significant association was observed among individuals with higher BMI.

CONCLUSIONS

The 'obesity paradox' does exist in patients after coronary revascularization, especially for patients with post-percutaneous coronary intervention. All-cause mortality in patients with high BMI is significantly lower compared with patients with normal weight. Furthermore, patients with underweight experience higher rates of cardiovascular outcomes compared with patients with normal weight.

The effect of obesity on long-term survival and health-related quality of life after coronary artery bypass grafting: a 12-year follow-up

OBJECTIVE

The proportion of obese patients undergoing coronary artery bypass graft (CABG) surgery is increasing. In this study, our main objective was to assess the effect of obesity on long-term mortality and changes in quality of life (QoL) after GABG.

MATERIALS AND METHODS

Data of 508 patients who underwent isolated GABG were prospectively collected. RAND-36 Health Survey (RAND-36) was used as an indicator of QoL. BMI was used to assess obesity, and the analysis was based primarily on two patient groups: BMI less than 30 kg/m (408 patients) and BMI of at least 30 (100 patients). All assessments were made preoperatively and repeated 1 and 12 years after CABG surgery. The follow-up of the cohort was complete in 95 and 84% of the alive patients at 1 and 12 years, respectively.

RESULTS

Thirty-day, 1-year, and 10-year survival rates were 99.0, 97.0, and 78.0%, respectively, in the obese and 98.0, 96.8, and 79.2%, respectively, in the nonobese group. Obese showed significant (P<0.05) improvements only in four and nonobese in seven of eight RAND-36 dimensions of QoL. In both obese and nonobese patients, improved RAND-36 physical component summary and mental component summary scores were seen in comparison with the preoperative values. Yet, obese patients had a more pronounced diminution in their physical component summary and mental component summary scores, whereas nonobese patients maintained their physical and mental health status better.

CONCLUSION

Despite an on-going decline in 12 years after the CABG, both patient groups showed improvements in their health status in comparison with preoperative values. Obese patients gained less benefit in terms of QoL dimension, but there was no significant difference in overall mortality in the long-term follow-up.

Can cannibalizing cancer cells challenge classic cell death classification?

In this issue of the Biomedical Journal, we learn about a novel are still largely mysterious mechanism of cell death that is challenging classification systems of cell death pathways and could have important implications for future cancer therapy. We also learn of a promising biomarker to stratify patients into risk groups after stroke. Finally, this issue also includes two studies investigating factors that influence outcome after heart surgery.

No correlation between body mass index and 30-day prognostic outcome in Asians with acute ST-elevation myocardial infarction undergoing primary coronary intervention

BACKGROUND

This study investigated whether body mass index (BMI) was a risk factor predictive of 30-day prognostic outcome in Asians with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

MATERIAL AND METHODS

Data regarding the impact of BMI on the prognostic outcome in Asian populations after acute STEMI is scarce. A number of 925 STEMI patients were divided into three groups according to the BMI: normal weight (<25 kg/m²), overweight (≥25.0 to <30.0 kg/m²) and obese (≥30.0 kg/m²).

RESULTS

The obese group was significantly younger with significantly higher incidences of smoking and diabetes mellitus. The incidences of multi-vessel disease, final thrombolysis in myocardial infarction (TIMI)-3 flow, advanced Killip score, advance congestive heart failure, 30-day mortality and combined 30-day major adverse clinical outcome (MACO) did not differ among the three groups. Multiple regression analysis showed the age, unsuccessful reperfusion and lower left ventricular ejection fraction were most significant and independent predictor of 30-day mortality.

CONCLUSION

BMI is not a predictor of 30-day prognostic outcome in Asians with STEMI undergoing primary PCI.

Body-Weight Fluctuations and Outcomes in Coronary Disease

BACKGROUND

Body-weight fluctuation is a risk factor for death and coronary events in patients without cardiovascular disease. It is not known whether variability in body weight affects outcomes in patients with coronary artery disease.

METHODS

We determined intraindividual fluctuations in body weight from baseline weight and follow-up visits and performed a post hoc analysis of the Treating to New Targets trial, which involved assessment of the efficacy and safety of lowering low-density lipoprotein cholesterol levels with atorvastatin. The primary outcome was any coronary event (a composite of death from coronary heart disease, nonfatal myocardial infarction, resuscitated cardiac arrest, revascularization, or angina). Secondary outcomes were any cardiovascular event (a composite of any coronary event, a cerebrovascular event, peripheral vascular disease, or heart failure), death, myocardial infarction, or stroke.

RESULTS

Among 9509 participants, after adjustment for risk factors, baseline lipid levels, mean body weight, and weight change, each increase of 1 SD in body-weight variability (measured according to average successive variability and used as a time-dependent covariate) was associated with an increase in the risk of any coronary event (2091 events; hazard ratio, 1.04; 95% confidence interval [CI], 1.01 to 1.07; P=0.01), any cardiovascular event (2727 events; hazard ratio, 1.04; 95% CI, 1.02 to 1.07; P<0.001), and death (487 events; hazard ratio,1.09; 95% CI, 1.07 to 1.12; P<0.001). Among patients in the quintile with the highest variation in body weight, the risk of a coronary event was 64% higher, the risk of a cardiovascular event 85% higher, death 124% higher, myocardial infarction 117% higher, and stroke 136% higher than it was among those in the quintile with the lowest variation in body weight in adjusted models.

CONCLUSIONS

Among participants with coronary artery disease, fluctuation in body weight was associated with higher mortality and a higher rate of cardiovascular events independent of traditional cardiovascular risk factors. (Funded by Pfizer; ClinicalTrials.gov number, NCT00327691 .).

The effects of body mass index on complications and mortality after emergency abdominal operations: The obesity paradox

BACKGROUND

Recent literature suggests that obesity is protective in critically illness. This study addresses the effect of BMI on outcomes after emergency abdominal surgery (EAS).

METHODS

Retrospective, ACS-NSQIP analysis. All patients that underwent EAS were included. The study population was divided into five groups based on BMI; regression models were used to evaluate the role of obesity in morbidity and mortality.

RESULTS

101,078 patients underwent EAS; morbidity and mortality were 19.5% and 4.5%, respectively. Adjusted mortality was higher in underweight patients (AOR 1.92), but significantly lower in all obesity groups (AOR's 0.73, 0.66, 0.70, 0.70 respectively). Underweight and class III obesity was associated with increased complications (AOR 1.47 and 1.30), while mild obesity was protective (AOR 0.92).

CONCLUSIONS

Underweight patients undergoing EAS have increased morbidity and mortality. Although class III obesity is associated with increased morbidity, overweight and class I obesity were protective. All grades of obesity may be protective against mortality after EAS relative to normal weight patients.

Outcomes and long-term survival of coronary artery surgery: The controversial role of opium as risk marker

AIM

To study survival in isolated coronary artery bypass graft (CABG) patients and to evaluate the impact of preoperative chronic opium consumption on long-term outcome.

METHODS

Cohort of 566 isolated CABG patients as Tehran Heart Center cardiac output measurement was conducted. Daily evaluation until discharge as well as 4- and 12-mo and 6.5-year follow-up information for survival status were fulfilled for all patients. Long-term 6.5-year overall and opium-stratified survival, adjusted survival curves based on opium consumption as well as possible predictors of all-cause mortality using multiple cox regression were determined by statistical analysis.

RESULTS

Six point five-year overall survival was 91.8%; 86.6% in opium consumers and 92.7% in non-opium consumers (P = 0.035). Patients with positive history of opium consumption significantly tended to have lower ejection fraction (EF), higher creatinine level and higher prevalence of myocardial infarction. Multiple predictors of all-cause mortality included age, body mass index, EF, diabetes mellitus and cerebrovascular accident. The hazard ratio (HR) of 2.09 for the risk of mortality in opium addicted patients with a borderline P value (P = 0.052) was calculated in this model. Further adjustment with stratification based on smoking and opium addiction reduced the HR to 1.20 (P = 0.355).

CONCLUSION

Simultaneous impact of smoking as a confounding variable in most of the patients prevents from definitive judgment on the role of opium as an independent contributing factor in worse long-term survival of CABG patients in addition to advanced age, low EF, diabetes mellitus and cerebrovascular accident. Meanwhile, our findings do not confirm any cardio protective role for opium to improve outcome in coronary patients with the history of smoking. Further studies are needed to clarify pure effect of opium and warrant the aforementioned findings.

From the BMI paradox to the obesity paradox: the obesity-mortality association in coronary heart disease

Despite a strong association between body weight and mortality in the general population, clinical evidence suggests better clinical outcome of overweight or obese individuals with established coronary heart disease. This finding has been termed the 'obesity paradox', but its existence remains a point of debate, because it is mostly observed when body mass index (BMI) is used to define obesity. Inherent limitations of BMI as an index of adiposity, as well as methodological biases and the presence of confounding factors, may account for the observed findings of clinical studies. In this review, our aim is to present the data that support the presence of a BMI paradox in coronary heart disease and then explore whether next to a BMI paradox a true obesity paradox exists as well. We conclude by attempting to link the obesity paradox notion to available translational research data supporting a 'healthy', protective adipose tissue phenotype. © 2016 World Obesity.

Significance of Epicardial and Intrathoracic Adipose Tissue Volume among Type 1 Diabetes Patients in the DCCT/EDIC: A Pilot Study

INTRODUCTION

Type 1 diabetes (T1DM) patients are at increased risk of coronary artery disease (CAD). This pilot study sought to evaluate the relationship between epicardial adipose tissue (EAT) and intra-thoracic adipose tissue (IAT) volumes and cardio-metabolic risk factors in T1DM.

METHOD

EAT/IAT volumes in 100 patients, underwent non-contrast cardiac computed tomography in the Diabetes Control and Complications Trial /Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study were measured by a certified reader. Fat was defined as pixels' density of -30 to -190 Hounsfield Unit. The associations were assessed using-Pearson partial correlation and linear regression models adjusted for gender and age with inverse probability sample weighting.

RESULTS

The weighted mean age was 43 years (range 32-57) and 53% were male. Adjusted for gender, Pearson correlation analysis showed a significant correlation between age and EAT/IAT volumes (both p<0.001). After adjusting for gender and age, participants with greater BMI, higher waist to hip ratio (WTH), higher weighted HbA1c, elevated triglyceride level, and a history of albumin excretion rate of equal or greater than 300 mg/d (AER≥300) or end stage renal disease (ESRD) had significantly larger EAT/IAT volumes.

CONCLUSION

T1DM patients with greater BMI, WTH ratio, weighted HbA1c level, triglyceride level and AER≥300/ESRD had significantly larger EAT/IAT volumes. Larger sample size studies are recommended to evaluate independency.

Study on correlation of obesity with short-term prognosis in acute myocardial infarction

BACKGROUND

Obese patients with established coronary artery disease have reduced mortality compared to normal or low body mass index (BMI) patients. The reason for the relation is not yet clearly understood. We sought to evaluate the association of BMI and waist circumference (WC) at the time of presentation in patients with myocardial infarction (MI) with one-year adverse cardiac events.

METHODS

In this prospective cohort study, we included consecutive patients with acute MI admitted to a tertiary care hospital during a period of one year. Upon admission, BMI and WC were measured. Patients were followed-up for a period of one year and the primary composite outcome of death or non-fatal MI was correlated with BMI and WC categories.

RESULTS

There were 703 patients (males 559 (79.5%)). Combined non-fatal MI and death at one year was 128 (18.2%). Incidence of primary outcome was 25.0% in low BMI group, 19.9% in normal BMI group, 13.1% in overweight group, 13.4% in class I obese, and 11.1% in class II obese groups. In univariate analysis, the inverse correlation was significant (p value=0.007). In one-year follow-up period, 12.8% in high and 20.8% in normal WC groups had primary outcome (p value=0.01). Both BMI and WC lost their predictive value in multivariate analysis.

CONCLUSIONS

Low BMI and normal WC were associated with a worse short-term outcome in patients with acute MI. Neither BMI nor WC independently predicted cardiac events or death after acute MI.

Does an Obesity Paradox Really Exist After Cardiovascular Intervention?: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Observational Studies

Several studies have shown the existence of an obesity paradox after Percutaneous Coronary Intervention (PCI). However, other studies have shown its absence. This study sought to perform a systematic review and meta-analysis of studies comparing the mortality risk between high body mass index patients and normal weight patients after PCI.We have searched PubMed, Embase, and Chinese medical journal for randomized controlled trials (RCTs) and observational studies published between the year 2000 and 2015 by typing the keywords "percutaneous coronary intervention" and "obesity paradox." The main outcome was "all-cause mortality". RevMan 5.3 software was used to calculate the risk ratio (RR) with 95% confidence interval (CI) to express the pooled effect on discontinuous variables.Twenty-two studies have been included in this meta-analysis consisting of a total of 242,377 patients with 73,143 normal weight patients, 103,608 overweight, and 65,626 obese patients. Younger age, higher cardiovascular risk factors and the intensive use of medications have mainly been observed among obese patients followed by overweight and normal weight patients respectively. In-hospital, 12 months and ≥ 1 year (long-term) mortality risks were significantly lower in the overweight and obese groups with (RR: 0.67; 95% CI: 0.63-0.72, P < 0.00001) and (RR: 0.60; 95% CI: 0.56-0.65, P < 0.00001) respectively in the in-hospital follow-up (RR: 0.62; 95% CI: 0.55-0.71 and 0.57; 95% CI: 0.52-0.63, P < 0.00001) at 12 months, and (RR: 0.70; 95% CI: 0.64-0.76; P < 0.00001) and (RR: 0.80; 95% CI: 0.71-0.91, P = 0.0006) respectively for the long-term follow-up after PCI.This "obesity paradox" does exist after PCI. The mortality in overweight and obese patients is really significantly lower compared to the normal weight patients. However, the exact reasons for this phenomenon need further exploration and research in the future.

The associations of "fatness," "fitness," and physical activity with all-cause mortality in older adults: A systematic review

OBJECTIVE

This review explored whether cardiorespiratory fitness or physical activity act as either confounders or effect modifiers of the relationship between adiposity markers and all-cause mortality in older adults.

METHODS

Systematic searches were carried out to identify observational studies that examined the association of adiposity markers (BMI, waist circumference, and waist-hip ratio) with all-cause mortality in adults aged ≥ 60 which took into account cardiorespiratory fitness or physical activity. Data from each included study was analyzed to produce a graphical representation of this relationship.

RESULTS

Fourteen of the fifteen identified studies found that increasing BMI had a non-positive association with all-cause mortality, with persistence of the obesity paradox despite adjustment for physical activity or cardiorespiratory fitness. Physical activity measurement methods were all subjective and often unvalidated. The two studies stratifying for cardiorespiratory fitness did not find that fitness had a significant impact on the relationship between excess adiposity and mortality but found that overweight and fit people had better survival than normal-weight unfit people,

CONCLUSIONS

The predominant use of poor physical activity measurement suggests that studies are currently not adequately accounting for possible physical activity confounding. More studies are needed for addressing the modification of the relationship between adiposity markers and mortality by cardiorespiratory fitness.

Relationship of body mass index with total mortality, cardiovascular mortality, and myocardial infarction after coronary revascularization: evidence from a meta-analysis

OBJECTIVE

To investigate the relationship of body mass index (BMI) with total mortality, cardiovascular (CV) mortality, and myocardial infarction (MI) after coronary revascularization procedures (coronary artery bypass grafting [CABG] and percutaneous coronary intervention [PCI]).

PATIENTS AND METHODS

Systematic search of studies was conducted using PubMed, CINAHL, Cochran CENTRAL, Scopus, and the Web of Science databases. We identified studies reporting the rate of MI, CV mortality, and total mortality among coronary artery disease patients' postcoronary revascularization procedures in various BMI categories: less than 20 (underweight), 20-24.9 (normal reference), 25-29.9 (overweight), 30-34.9 (obese), and 35 or more (severely obese). Event rates were compared using a random effects model assuming interstudy heterogeneity.

RESULTS

A total of 36 studies (12 CABG; 26 PCI) were selected for final analyses. The risk of total mortality (relative risk [RR], 2.59; 95% CI, 2.09-3.21), CV mortality (RR, 2.67; 95% CI, 1.63-4.39), and MI (RR, 1.79; 95% CI, 1.28-2.50) was highest among patients with low BMI at the end of a mean follow-up period of 1.7 years. The risk of CV mortality was lowest among overweight patients (RR, 0.81; 95% CI, 0.68-0.95). Increasing degree of adiposity as assessed by BMI had a neutral effect on the risk of MI for overweight (RR, 0.92; 95% CI, 0.84-1.01), obese (RR, 0.99; 95% CI, 0.85-1.15), and severely obese (RR, 0.93; 95% CI, 0.78-1.11) patients.

CONCLUSION

After coronary artery disease revascularization procedures (PCI and CABG), the risk of total mortality, CV mortality, and MI was highest among underweight patients as defined by low BMI and CV mortality was lowest among overweight patients.

Interventions for coronary artery disease (surgery vs angioplasty) in diabetic patients

Patients with diabetes develop more widespread and more severe atherosclerotic coronary artery disease than patients without diabetes. Medical management of this coronary disease is inferior to revascularization for more complex or more widespread disease. Revascularization by percutaneous intervention (PCI) for patients with diabetes is associated with high mortality and complication rates. Surgical revascularization by coronary artery bypass grafting, yields superior results to PCI for patients with diabetes and coronary artery disease. Patients with diabetes benefit from the same medical management of their coronary artery disease and secondary risk modification as patients without diabetes.

Mild obesity is protective after severe burn injury

OBJECTIVE

To assess the impact of obesity on morbidity and mortality in severely burned patients.

BACKGROUND

Despite the increasing number of people with obesity, little is known about the impact of obesity on postburn outcomes.

METHODS

A total of 405 patients were prospectively enrolled as part of the multicenter trial Inflammation and the Host Response to Injury Glue Grant with the following inclusion criteria: 0 to 89 years of age, admitted within 96 hours after injury, and more than 20% total body surface area burn requiring at least 1 surgical intervention. Body mass index was used in adult patients to stratify according to World Health Organization definitions: less than 18.5 (underweight), 18.5 to 29.9 (normal weight), 30 to 34.9 (obese I), 35 to 39.9 (obese II), and body mass index more than 40 (obese III). Pediatric patients (2 to ≤18 years of age) were stratified by using the Centers for Disease Control and Prevention and World Health Organization body mass index-for-age growth charts to obtain a percentile ranking and then grouped as underweight (<5th percentile), normal weight (5th percentile to <95th percentile), and obese (≥95th percentile). The primary outcome was mortality and secondary outcomes were clinical markers of patient recovery, for example, multiorgan function, infections, sepsis, and length of stay.

RESULTS

A total of 273 patients had normal weight, 116 were obese, and 16 were underweight; underweight patients were excluded from the analyses because of insufficient patient numbers. There were no differences in primary and secondary outcomes when normal weight patients were compared with obese patients. Further stratification in pediatric and adult patients showed similar results. However, when adult patients were stratified in obesity categories, log-rank analysis showed improved survival in the obese I group and higher mortality in the obese III group compared with obese I group (P < 0.05).

CONCLUSIONS

Overall, obesity was not associated with increased morbidity and mortality. Subgroup analysis revealed that patients with mild obesity have the best survival, whereas morbidly obese patients have the highest mortality. (NCT00257244).

Risk of a recurrent cardiovascular event in individuals with type 2 diabetes or intermediate hyperglycemia: the Hoorn Study

OBJECTIVE

To investigate risk of a recurrent cardiovascular event and its predictors in a population-based cohort.

RESEARCH DESIGN AND METHODS

Participants of the Hoorn Study who had experienced a first cardiovascular event after baseline (n = 336) were followed with respect to a recurrent event. Absolute risk of a recurrent event was calculated for individuals with normal glucose metabolism, intermediate hyperglycemia, and type 2 diabetes. Cox regression models were used to investigate which variables, measured before the first vascular event, predicted a recurrent event using the stepwise backward procedure.

RESULTS

During a median follow-up of 4.1 years, 44% (n = 148) of the population developed a recurrent vascular event. The rate of recurrent events per 100 person-years was 7.2 (95% CI 5.8-8.7) in individuals with normal glucose metabolism, compared with 9.8 (6.6-14.0) in individuals with intermediate hyperglycemia and 12.5 (8.5-17.6) in individuals with type 2 diabetes. Higher age (hazard ratio 1.02 [95% CI 1.00-1.04]), male sex (1.56 [1.08-2.25]), waist circumference (1.02 [1.02-1.03]), higher systolic blood pressure (1.01 [1.01-1.02]), higher HbA1c (%, 1.13 [0.97-1.31]/ mmol/mol, 1.01 [1.00-1.03]), and family history of myocardial infarction (1.38 [0.96-2.00]) predicted a recurrent cardiovascular event.

CONCLUSIONS

Individuals with type 2 diabetes, but not individuals with intermediate hyperglycemia, are at increased risk for a recurrent vascular event compared with individuals with normal glucose metabolism. In people with a history of cardiovascular disease, people at increased risk of a recurrent event can be identified based on the patient's risk profile before the first event.

New insights into the true nature of the obesity paradox and the lower cardiovascular risk

Obesity is considered a major risk factor for cardiovascular disease, hypertension, and diabetes by National and International Committees. For this reason, they advocate weight loss and prevention of obesity. However, several studies in patients with established coronary artery disease (CAD), congestive heart failure, and hypertension have shown an inverse relationship between obesity and mortality, the so called "obesity paradox," whereas other studies have not shown such a relationship. In studies showing the obesity paradox (OP), body mass index (BMI) was used, almost exclusively as an index of obesity, although is a poor discriminator of total body fatness. Recent studies using better indices of obesity such as waist circumference (WC) and waist to hip ratio (WHR) have shown that high WC and WHR were directly and positively associated with higher event rate and total mortality in these patients. Because the OP could convey the wrong message in obese patients, the validity and true nature of the OP will be examined in this concise review. A Medline search of the English literature was performed between 2000 and September 2012, and 46 pertinent articles were selected for this review. The majority of these studies do not support an OP and those that do have used almost exclusively BMI as an index of obesity. Therefore, based on recent studies using other indices of body fat distribution, such as WC and WHR, besides BMI, the true existence of OP has been questioned and needs to be confirmed by future studies.

The interaction of exercise ability and body mass index upon long-term outcomes among patients undergoing stress-rest perfusion single-photon emission computed tomography imaging

BACKGROUND

The obesity paradox has been reported in several populations of patients with cardiovascular disease. Recent data have shown that physical fitness may attenuate the obesity paradox. Patients who undergo pharmacologic stress testing are known to have a higher risk of mortality than those who can exercise. The purpose of this study is to determine the interaction of obesity and exercise ability on survival among patients with a normal stress-rest single-photon emission computed tomography (SPECT).

METHODS

A total of 5,203 (60 ± 13 years, male 37%) patients without a history of heart disease and a normal stress-rest SPECT between the years 1995 and 2010 were included in this analysis. Body mass index categories were defined according to the World Health Organization classification: normal weight, 18.5 to 24.9 kg/m(2); overweight, 25 to 29.9 kg/m(2); and obese, ≥30 kg/m(2). Patients were divided into 3 groups based on their ability to exercise: those who reached ≥6 METs on exercise, those who attained a level of <6 METs, and those who required pharmacologic stress. Patients in each of these fitness groups were further divided into 3 subgroups based on their body mass index.

RESULTS

There were 939 (18%) deaths during a mean follow-up of 8.1 ± 4.1 years, for an overall event rate of 2.3%/y. Both exercise to ≥6 METs and being obese were associated with lower mortality. Adjusted multivariate analysis using the obese high-fit patients as the reference showed a wide heterogeneity in annualized mortality rates according to exercise and weight status, with annualized event rates which varied from 0.6%/y in the obese subjects who were physically fit to 5.3%/y among healthy subjects who underwent pharmacologic stress testing (P < .001).

CONCLUSIONS

Stress mode and body weight impacted long-term survival in patients with a normal stress SPECT. The benefit of being physically fit was evident in all weight groups, as was the adverse effect of being unable to exercise. However, with regard to body weight, there was a paradoxical survival advantage for those patients who were overweight and obese, regardless of their exercise ability.

The corpulent phenotype-how the brain maximizes survival in stressful environments

The reactivity of the stress system may change during the life course. In many—but not all—humans the stress reactivity decreases, once the individual is chronically exposed to a stressful and unsafe environment (e.g., poverty, work with high demands, unhappy martial relationship). Such an adaptation is referred to as habituation. Stress habituation allows alleviating the burden of chronic stress, particularly cardiovascular morbidity and mortality. Interestingly, two recent experiments demonstrated low stress reactivity during a mental or psychosocial challenge in subjects with a high body mass. In this focused review we attempt to integrate these experimental findings in a larger context. Are these data compatible with data sets showing a prolonged life expectancy in corpulent people? From the perspective of neuroenergetics, we here raise the question whether “obesity” is unhealthy at all. Is the corpulent phenotype possibly the result of “adaptive phenotypic plasticity” allowing optimized survival in stressful environments?

The impact of wait list body mass index changes on the outcome after liver transplantation

Obesity is associated with poor health outcomes in the general population, but the evidence surrounding the effect of body mass index (BMI) on postliver transplantation survival is contradictory. The aim of this study was to assess the impact of wait list BMI and BMI changes on the outcomes after liver transplantation. Using the Scientific Registry of Transplant Recipients, we compared survival among different BMI categories and examined the impact of wait list BMI changes on post-transplantation mortality for patients undergoing liver transplantation. Cox proportional hazards multivariate regression was carried out to adjust for confounding factors. Among 38 194 recipients, underweight patients had a poorer survival compared with normal weight (HR = 1.3, 95% CI: 1.13-1.49). Conversely, overweight and mildly obese men experienced better survival rates compared with their lean counterparts (HR = 0.9, 95% CI: 0.84-0.96, and HR = 0.86, 95% CI: 0.79-0.93 respectively). Female patients gaining weight over 18.5 kg/m(2) while on the wait list showed improving outcomes (HR = 0.46, (95% CI: 0.28-0.76)) compared with those remaining underweight. This study supports the harmful impact of underweight on postliver transplant survival, and highlights the need for a specific monitoring and management of candidates with BMIs close to 18.5 kg/m(2) . Obesity does not constitute an absolute contraindication to liver transplantation.

Obesity, health status, and 7-year mortality in percutaneous coronary intervention: in search of an explanation for the obesity paradox

BACKGROUND

Obesity is a growing health problem and is associated with adverse outcomes in coronary artery disease (CAD). However, recent studies have shown better survival in cardiovascular patients with overweight or obesity, which has been referred to as the "obesity paradox". As there is no clear understanding of the phenomenon, we examined the association between body mass index (BMI) and all-cause mortality in patients treated with percutaneous coronary intervention (PCI) at 7-year follow-up, and the potential role of health status in explaining the obesity paradox.

METHODS

Consecutive PCI patients (72.5% men; mean age 62.0 ± 11.2 years, range [27-90]years) from the Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry completed the 36-item short-form health survey (SF-36) to assess health status at baseline. Patients were classified into a normal weight, overweight or obesity group.

RESULTS

The prevalence of normal weight was 34.7% (354/1019), overweight was seen in 45.9% (468/1019) of patients, and 19.3% (197/1019) was obese. After a median follow-up of 7.0 ± 1.7 years, 163 deaths (16.0%) from any cause were recorded. Cumulative hazard functions differed significantly for the obese and overweight group when compared to the normal weight group (log-rank X(2)=6.59, p<0.05). In multivariable analysis, overweight, but not obesity, remained associated with a lower risk for all-cause mortality (HR=0.60, 95%CI [0.42-0.86], p=0.005). Additionally, after adding the 8 health status SF-36 domains to the multivariate model, the association between overweight and mortality remained unchanged.

CONCLUSION

In our study population overweight, but not obesity, was associated with a lower risk for 7-year mortality in PCI patients. Health status as measured with the SF-36 did not seem to play a role in explaining the obesity paradox.