The association between body mass index and outcome after coronary artery bypass grafting operations

Impact of body mass index on perioperative mortality of acute stanford type A aortic dissection: a systematic review and meta-analysis

BACKGROUND

Obesity may increase perioperative mortality of acute Stanford type A aortic dissection (ATAAD). However, the available evidence was limited. This study aimed to systematically review published literatures about body mass index (BMI) and perioperative mortality of ATAAD.

METHODS

Electronic literature search was conducted in PubMed, Medline, Embase and Cochrane Library databases. All observational studies that investigated BMI and perioperative mortality of ATAAD were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model. Meta-regression analysis was performed to assess the effects of different clinical variables on BMI and perioperative mortality of ATAAD. Sensitivity analysis was performed to determine the sources of heterogeneity. Egger's linear regression method and funnel plot were used to determine the publication bias.

RESULTS

A total of 12 studies with 5,522 patients were eligible and included in this meta-analysis. Pooled analysis showed that perioperative mortality of ATAAD increased by 22% for each 1 kg/m2 increase in BMI (OR = 1.22, 95% CI: 1.10-1.35). Univariable meta-regression analysis indicated that age and female gender significantly modified the association between BMI and perioperative mortality of ATAAD in a positive manner (meta-regression on age: coefficient = 0.04, P = 0.04; meta-regression on female gender: coefficient = 0.02, P = 0.03). Neither significant heterogeneity nor publication bias were found among included studies.

CONCLUSIONS

BMI is closely associated with perioperative mortality of ATAAD. Optimal perioperative management needs to be further explored and individualized for obese patient with ATAAD, especially in elderly and female populations.

TRIAL REGISTRATION

PROSPERO (CRD42022358619). BMI and perioperative mortality of ATAAD.

Transcatheter versus surgical aortic valve replacement in patients with morbid obesity: a multicentre propensity score-matched analysis

BACKGROUND

Morbidly obese (MO) patients are increasingly undergoing transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) for severe aortic stenosis (AS). However, the best therapeutic strategy for these patients remains a matter for debate.

AIMS

Our aim was to compare the periprocedural and mid-term outcomes in MO patients undergoing TAVR versus SAVR.

METHODS

A multicentre retrospective study including consecutive MO patients (body mass index ≥40 kg/m², or ≥35 kg/m² with obesity-related comorbidities) from 18 centres undergoing either TAVR (n=860) or biological SAVR (n=696) for severe AS was performed. Propensity score matching resulted in 362 pairs.

RESULTS

After matching, periprocedural complications, including blood transfusion (14.1% versus 48.1%; p<0.001), stage 2-3 acute kidney injury (3.99% versus 10.1%; p=0.002), hospital-acquired pneumonia (1.7% versus 5.8%; p=0.005) and access site infection (1.5% versus 5.5%; p=0.013), were more common in the SAVR group, as was moderate to severe patient-prosthesis mismatch (PPM; 9.9% versus 39.4%; p<0.001). TAVR patients more frequently required permanent pacemaker implantation (14.4% versus 5.6%; p<0.001) and had higher rates of ≥moderate residual aortic regurgitation (3.3% versus 0%; p=0.001). SAVR was an independent predictor of moderate to severe PPM (hazard ratio [HR] 1.80, 95% confidence interval [CI]: 1.25-2.59; p=0.002), while TAVR was not. In-hospital mortality was not different between groups (3.9% for TAVR versus 6.1% for SAVR; p=0.171). Two-year outcomes (including all-cause and cardiovascular mortality, and readmissions) were similar in both groups (log-rank p>0.05 for all comparisons). Predictors of all-cause 2-year mortality differed between the groups; moderate to severe PPM was a predictor following SAVR (HR 1.78, 95% CI: 1.10-2.88; p=0.018) but not following TAVR (p=0.737).

CONCLUSIONS

SAVR and TAVR offer similar mid-term outcomes in MO patients with severe AS, however, TAVR offers some advantages in terms of periprocedural morbidity.

Does the anthropometric profile influence infection morbidity after coronary artery bypass grafting?

BACKGROUND

Infection after cardiovascular surgery is multifactorial. We sought to determine whether the anthropometric profile influences the occurrence of infection after isolated coronary artery bypass grafting (CABG).

METHODS

Between January 2011 and June 2016, 1777 consecutive adult patients were submitted to isolated coronary artery bypass grafting. Mean age was 61.7 ± 9.8 years and 1193 (67.1%) were males. Patients were divided into four groups according to the body mass index (BMI) classification: underweight (BMI < 18.5 kg/m² ; N = 17, 0.9%), normal range (BMI: 18.5-24.99 kg/m² ; N = 522, 29.4%), overweight (BMI: 25-29.99 kg/m² ; N = 796, 44.8%), and obese (BMI > 30 kg/m² ; N = 430, 24.2%). In-hospital outcomes were compared and independent predictors of infection were obtained through multiple Poisson regression with a robust variation.

RESULTS

Independent predictors of any infection morbidity were female sex (relative ratio [RR], 1.47; p = .002), age > 60 years (RR, 1.85; p < .0001), cardiopulmonary bypass > 120 min (RR, 1.89; p = .0007), preoperative myocardial infarction < 30 days (RR, 1.37; p = .01), diabetes mellitus (RR, 1.59; p = .0003), ejection fraction < 48% (RR, 2.12; p < .0001), and blood transfusion (RR, 1.55; p = .0008). Among other variables, obesity, as well as diabetes mellitus, were independent predictors of superficial and deep sternal wound infection.

CONCLUSIONS

Other factors rather than the anthropometric profile are more important in determining the occurrence of any infection after CABG. However, surgical site infection has occurred more frequently in obese patients. Appropriate patient selection, control of modifiable factors, and application of surgical bundles would minimize this important complication.

Dose-Response Meta-Analysis of the Impact of Body Mass Index on Mortality in the Intensive Care Unit

INTRODUCTION

Both low and high body mass index (BMI) are associated with mortality in the intensive care unit (ICU). Although many studies have been done to determine the relationship between BMI and risk of mortality in the ICU, their results were inconsistent. This study aimed to conduct a dose-response meta-analysis of published observational studies to assess the effect of BMI on the risk of mortality in patients admitted to the ICU.

METHODS

PubMed, Scopus, and Google Scholar were searched to identify articles up to May 2019. A total of 31 relevant articles, with 238,961 patients and a follow-up period of 1 month to 11 years, were analyzed.

RESULTS

Linear analysis showed a 0.6% decrease in mortality rate per unit (kg/m² ) increase in BMI (odds ratio: 0.99; 95% CI, 0.98-0.99). In addition, nonlinear analysis showed a decrease in risk of mortality for a BMI of 35 (P < .001) and then increased the risk of mortality with a BMI > 35 (P < .001).

CONCLUSION

This dose-response meta-analysis revealed that a BMI ≤ 35 can be a protective agent against mortality, but a BMI > 35 is a life-threatening factor in patients admitted to the ICU.

Association of body mass index and all-cause mortality in patients after cardiac surgery: A dose-response meta-analysis

Ample studies have reported the effect of body mass index (BMI) on the prognosis of patients undergoing cardiac surgery, but the results remain inconsistent. Therefore, we aimed to conduct a dose-response meta-analysis to clarify the relationship between BMI and all-cause mortality in this population. A systematic search was performed in the PubMed and Embase databases through April 2019 for studies that reported the impact of BMI on all-cause mortality in patients after cardiac surgery. Pooled risk ratios (RRs) were calculated using a random-effects model. Non-linear associations were explored with restricted cubic spline models. Forty-one studies with a total of 54,300 cases/1,774,387 patients were included. The pooled RR for all-cause mortality was 0.93 (95% CI 0.89-0.97) for every 5-unit increment in BMI, indicating that higher BMI did not increase the risk of all-cause mortality in patients after cardiac surgery. A U-shaped association with the nadir of risk at a BMI of 25-27.5 kg/m² was observed, as well as a higher mortality risk for the underweight and the extremely obese patients. The subgroup analysis revealed that this phenomenon remained regardless of mean age, surgery type, geographic location and number of cases. Overall, for patients after cardiac surgery, a slightly higher BMI may be instrumental in survival, whereas underweight and extreme obesity is associated with a worse prognosis.

The Impact of Obesity on Mortality and Other Outcomes in Patients With Nonvariceal Upper Gastrointestinal Hemorrhage in the United States

GOALS

To quantify in patients with nonvariceal upper gastrointestinal hemorrhage (NVUGIH) the relationship between obesity and mortality, disease severity, treatment modalities, and resource utilization.

BACKGROUND

NVUGIH is the most common gastrointestinal emergency.

STUDY

Adults with a principal diagnosis of NVUGIH were selected from the 2014 National Inpatient Sample. The primary outcome was in-hospital mortality. Secondary outcomes were hemorrhagic shock, prolonged mechanical ventilation (PMV), upper endoscopy [esophagogastroduodenoscopy (EGD)], radiologic treatment, surgery, length of hospital stay (LOS), and total hospitalization costs and charges. Confounders were adjusted for using multivariable regression analyses.

RESULTS

In total, 227,480 admissions with NVUGIH were included, 11.70% of whom were obese. Obese and nonobese patients had similar odds of mortality (aOR: 0.88; 95% confidence interval [CI]: 0.69-1.12; P=0.30), EGD within 24 hours of admission (aOR: 0.95; CI: 0.89-1.01; P=0.10), radiologic treatment (aOR: 1.06; CI: 0.82-1.35; P=0.66), and surgery (aOR: 1.27; CI: 0.94-1.70; P=0.11). However, obese patients had higher odds of shock (aOR: 1.30; CI: 1.14-1.49; P<0.01), PMV (aOR: 1.39; CI: 1.18-1.62; P<0.01), undergoing an EGD (aOR: 1.27; CI: 1.16-1.40; P<0.01), needing endoscopic therapy (aOR: 1.18; CI: 1.09-1.27; P<0.01), a longer LOS (0.31 d; CI: 0.16-0.46 d; P<0.01), higher costs ($1075; CI: $636-$1514; P<0.01), and higher charges ($4084; CI: $2060-$6110; P<0.01) compared with nonobese patients.

CONCLUSIONS

Obesity is not an independent predictor of NVUGIH mortality. However, obesity is associated with a more severe disease course (shock and PMV), higher rates of EGD and endoscopic therapy use, and significant increases in resource utilization (hospital LOS, total hospitalization costs, and charges).

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.

No more broken hearts: weight loss after bariatric surgery returns patients' postoperative risk to baseline following coronary surgery

BACKGROUND

The obesity epidemic is associated with a rise in coronary surgeries because obesity is a risk factor for coronary artery disease. Bariatric surgery is linked to improvement in cardiovascular co-morbidities and left ventricular function. No studies have investigated survival advantage in postoperative bariatric patients after coronary surgery.

OBJECTIVES

To determine if there is a benefit after coronary surgery in patients who have previously undergone bariatric surgery.

SETTING

National Inpatient Sample.

METHODS

We performed a retrospective, cross-sectional analysis of the National Inpatient Sample database from 2003 to 2010. We selected bariatric surgical patients who later underwent coronary surgery (n = 257). A comparison of postoperative complications and mortality after coronary surgery were compared with controls (n = 1442) using χ² tests, linear regression analysis, and multivariate logistical regression models.

RESULTS

A subset population was identified as having undergone coronary surgery (n = 1699); of this population, 257 patients had previously undergone bariatric surgery. They were compared with 1442 controls. The majority was male (67.2%), white (82.6%), and treated in an urban environment (96.8%). Patients with bariatric surgery assumed the risk of postoperative complications after coronary surgery that was associated with their new body mass index (BMI) (BMI<25 kg/m²: odds ratio (OR) 1.01, 95% CI .76-1.34, P = .94; BMI 25 to<35 kg/m²: OR .20, 95% CI .02-².16, P = .19; BMI≥35 kg/m²: OR>999.9, 95% CI .18 to>999.9, P = .07). Length of stay was significantly longer in postbariatric patients (BMI<25, OR 1.62, 95% CI 1.14-2.30, P = .007).

CONCLUSIONS

Postoperative bariatric patients have a return to baseline risk of morbidity and mortality after coronary surgery.