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

Body Weight's Role in Infective Endocarditis Surgery

Objective: to investigate how body mass index (BMI) affects the outcome in patients treated surgically for infective endocarditis (IE). Methods: This is a single-center observational analysis of consecutive patients treated surgically for IE. We divided the cohort into six groups, according to the WHO classification of BMI, and performed subsequent outcome analysis. Results: The patient population consisted of 17 (2.6%) underweight, 249 (38.3%) normal weight, 252 (38.8%) overweight, 83 (12.8%) class I obese, 28 (4.3%) class II obese, and 21 (3.8%) class III, or morbidly obese, patients. The median age of the entire cohort was 64.5 [52.5-73.6] years. While only 168 (25.9%) patients were female, women significantly more often exhibited extremes in regards to BMI, including underweight (47.1%) and morbid obesity (52.4%), p = 0.026. Class II and III obese patients displayed more postoperative acute kidney injury (47.9%), p = 0.003, more sternal wound infection (12.9%), p < 0.001, worse 30-day survival (20.4%), p = 0.031, and worse long-term survival, p = 0.026, compared to the results for the other groups. However, the multivariable analysis did not identify obesity as an independent risk factor for 30-day mortality, with an odds ratio of 1.257 [0.613-2.579], p = 0.533. Rather, age > 60, reduced LVEF < 30%, staphylococcal infection, and prosthetic valve endocarditis correlated with mortality. While BMI showed poor discrimination in predicting 30-day mortality on the ROC curve (AUC = 0.609), it showed a fair degree of discrimination in predicting sternal wound infection (AUC = 0.723). Conclusions: Obesity was associated with increased comorbidities, complications, and higher postoperative mortality in IE patients, but it is not an independent mortality risk factor. While BMI is a poor predictor of death, it is a good predictor of sternal wound infections.

Outcomes of Surgical Versus Transcatheter Aortic Valve Replacement in Obese Patients: A Systematic Review and Meta-Analysis

Transcatheter aortic valve implantation (TAVI) has been increasingly preferred over surgical aortic valve replacement (SAVR) for treating patients with severe aortic stenosis and intermediate to high surgical risk. Recent studies have indicated that obesity may confer protective benefits in cardiac surgery, known as the obesity paradox. We conducted a systematic review and meta-analysis to explore how obesity influences outcomes of TAVI versus SAVR. We searched and reviewed relevant studies comparing TAVI and SAVR in obese patients with aortic stenosis indexed in PubMed, Embase, and Scopus databases. Data from 5 studies with 16,161 patients (TAVI, n = 2951; SAVR, n = 13,210) were included. There was a lower incidence of postprocedural in-hospital mortality [risk ratio (RR), 0.64; 95% confidence interval (CI), 0.41-0.98; P = 0.04], acute kidney injury (RR, 0.53; 95% CI, 0.38-0.73; P = 0.0001), and shorter duration of in-hospital stay (mean difference: -3.35; 95% CI, -4.93 to -1.76; P = 0.0001) in TAVI versus SAVR. There was no significant difference in the risk of postoperative stroke (RR, 0.93; 95% CI, 0.29-3.02; P = 0.91), major bleeding (RR, 0.71; 95% CI, 0.47-1.07; P = 0.10), and myocardial infarction (RR, 0.64; 95% CI, 0.39-1.06; P = 0.08) between TAVI and SAVR. Higher incidences of PPM implantation (RR, 2.0; 95% CI, 1.38-2.90; P = 0.0003) and major vascular complications (RR, 1.51; 95% CI, 1.01-2.27; P = 0.05) were observed with TAVI. In obese patients, TAVI offers similar results as in the general population when compared with SAVR, except for increased vascular complications. An individualized approach can lead to optimal outcomes in this subpopulation.

Association Between Body Mass Index, Obesity, and Clinical Outcomes Following Coronary Artery Bypass Grafting in Brazil: An Analysis of One Year of Follow-up of BYPASS Registry Patients

OBJECTIVE

To investigate the association between body mass index (BMI), obesity, clinical outcomes, and mortality following coronary artery bypass grafting (CABG) in Brazil using a large sample with one year of follow-up from the Brazilian Registry of Cardiovascular Surgeries in Adults (or BYPASS) Registry database.

METHODS

A multicenter cohort-study enrolled 2,589 patients submitted to isolated CABG and divided them into normal weight (BMI 20.0-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), and obesity (BMI > 30.0 kg/m2) groups. Inpatient postoperative outcomes included the most frequently described complications and events. Collected post-discharge outcomes included rehospitalization and mortality rates within 30 days, six months, and one year of follow-up.

RESULTS

Sternal wound infections (SWI) rate was higher in obese compared to normal-weight patients (relative risk [RR]=5.89, 95% confidence interval [CI]=2.37-17.82; P=0.001). Rehospitalization rates in six months after discharge were higher in obesity and overweight groups than in normal weight group (χ=6.03, P=0.049); obese patients presented a 2.2-fold increase in the risk for rehospitalization within six months compared to normal-weight patients (RR=2.16, 95% CI=1.17-4.09; P=0.045). Postoperative complications and mortality rates did not differ among groups during time periods.

CONCLUSION

Obesity increased the risk for SWI, leading to higher rehospitalization rates and need for surgical interventions within six months following CABG. Age, female sex, and diabetes were associated with a higher risk of mortality. The obesity paradox remains controversial since BMI may not be sufficient to assess postoperative risk in light of more complex and dynamic evaluations of body composition and physical fitness.

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.

Operative Time is Associated With Postoperative Complications After Pulmonary Lobectomy

OBJECTIVE

To investigate the association between operative time and postoperative outcomes.

BACKGROUND

The association between operative time and morbidity after pulmonary lobectomy has not been characterized fully.

METHODS

Patients who underwent pulmonary lobectomy for primary lung cancer at our institution from 2010 to 2018 were reviewed. Exclusion criteria included clinical stage ≥IIb disease, conversion to thoracotomy, and previous ipsilateral lung treatment. Operative time was measured from incision to closure. Relationships between operative time and outcomes were quantified using multivariable mixed-effects models with surgeon-level random effects.

RESULTS

In total, 1651 patients were included. The median age was 68 years (interquartile range, 61-74), and 63% of patients were women. Median operative time was 3.2 hours (interquartile range, 2.7-3.8) for all cases, 3.0 hours for open procedures, 3.3 hours for video-assisted thoracoscopies, and 3.3 hours for robotic procedures ( P =0.0002). Overall, 488 patients (30%) experienced a complication; 77 patients (5%) had a major complication (grade ≥3), and 5 patients (0.3%) died within 30 days of discharge. On multivariable analysis, operative time was associated with higher odds of any complication [odds ratio per hour, 1.37; 95% confidence interval (CI), 1.20-1.57; P <0.0001] and major complication (odds ratio per hour, 1.41; 95% CI, 1.21-1.64; P <0.0001). Operative time was also associated with longer hospital length of stay (β, 1.09; 95% CI, 1.04-1.14; P =0.001).

CONCLUSIONS

Longer operative time was associated with worse outcomes in patients who underwent lobectomy. Operative time is a potential risk factor to consider in the perioperative phase.

Integrative multiomics analysis of neointima proliferation in human saphenous vein: implications for bypass graft disease

Introduction

Human saphenous veins (SV) are widely used as grafts in coronary artery bypass (CABG) surgery but often fail due to neointima proliferation (NP). NP involves complex interplay between vascular smooth muscle cells (VSMC) and fibroblasts. Little is known, however, regarding the transcriptomic and proteomic dynamics of NP. Here, we performed multi-omics analysis in an ex vivo tissue culture model of NP in human SV procured for CABG surgery.

Methods and results

Histological examination demonstrated significant elastin degradation and NP (indicated by increased neointima area and neointima/media ratio) in SV subjected to tissue culture. Analysis of data from 73 patients suggest that the process of SV adaptation and NP may differ according to sex and body mass index. RNA sequencing confirmed upregulation of pro-inflammatory and proliferation-related genes during NP and identified novel processes, including increased cellular stress and DNA damage responses, which may reflect tissue trauma associated with SV harvesting. Proteomic analysis identified upregulated extracellular matrix-related and coagulation/thrombosis proteins and downregulated metabolic proteins. Spatial transcriptomics detected transdifferentiating VSMC in the intima on the day of harvesting and highlighted dynamic alterations in fibroblast and VSMC phenotype and behavior during NP. Specifically, we identified new cell subpopulations contributing to NP, including SPP1 + , LGALS3 + VSMC and MMP2 + , MMP14 + fibroblasts.

Conclusion

Dynamic alterations of gene and protein expression occur during NP in human SV. Identification of the human-specific molecular and cellular mechanisms may provide novel insight into SV bypass graft disease.

Body mass index effect on long-term survival after coronary artery bypass surgery: a competing risk analysis

OBJECTIVES

The aim of this sudy was to investigate the presence of an obesity paradox on the long-term mortality of patients undergoing primary isolated coronary artery bypass surgery and to uncover whether any discrepancy found could be attributable to cardiovascular or noncardiovascular causes.

METHODS

Retrospective analysis of 5242 consecutive patients with body mass index (BMI) over 18.5 kg/m2 undergoing primary isolated coronary artery bypass surgery, performed from 2000 to 2015, in a Portuguese level III Hospital. The primary end point was long-term all-cause mortality. Secondary outcomes were long-term cause-specific mortality (cardiovascular and noncardiovascular). We fitted overall, and cause-specific hazard models, with BMI forced both as a categorical (using World Health Organization predefined cutoffs) and as a continuous variable.

RESULTS

Follow-up was 99.7% complete. The median follow-up time was 12.79 years (interquartile range, 9.51-16.61). The cumulative incidence functions failed to uncover any difference in 15-year all-cause (log-rank test, P = 0.400), cardiovascular (Gray's test, P = 0.996) and noncardiovascular mortality (Gray's test, P = 0.305) between BMI categories. Likewise, extensive multivariable-adjusted Cox regression and cause-specific hazards models failed to demonstrate in-between category differences, with BMI forced as a categorical variable. On the other hand, using BMI as a continuous variable, the model identified the optimal BMI as between 25.8 and 30.3 kg/m2 (nadir around 28.9 kg/m2), albeit this was dependent on the definition of the reference value.

CONCLUSIONS

In this longitudinal, population-level analysis of patients undergoing isolated primary coronary artery bypass grafting, we could not attest to any protective effect of obesity on long-term survival.

Obesity is associated with postoperative outcomes in patients undergoing cardiac surgery: a cohort study

BACKGROUND

The purpose of present study was to determine whether obesity was associated with increased adverse outcomes after cardiac surgery.

METHODS

This is a retrospective cohort study from a large international database called the Medical Information Mart for Intensive Care III (MIMIC-III). Patients who underwent cardiac surgery and greater than 18 years old were divided into either nonobese (BMI < 30 kg/m²) or obese (BMI ≥ 30 kg/m²). The primary outcome of this study was 28-day mortality from the date of operation. Secondary outcomes included ICU mortality, 1-year mortality, incidence of postoperative atrial fibrillation (POAF), hospital length of stay (HOS_LOS) and ventilation-free days within 28 days (VFD_28).

RESULTS

Multivariate logistic regression analysis revealed a negative effect of obesity on 28-day mortality, with an adjusted odds ratio (OR) of 1.57 (95% CI 1.14-2.16; p = 0.005). The association remained significant when PSM analysis and double robust analysis with all covariates were performed. In terms of 28-day mortality, the mediating effect of longer ventilation duration on obese patients was noticeable, and the proportion of the effect mediated was 8.2% (95% CI 2.1-25.5%; p = 0.012).

CONCLUSIONS

Among patients with cardiac surgery, obesity is associated with higher 28-day mortality. The longer ventilation duration may have mediated this effect. In future, considering the elevated incidence of the obese patients undergoing cardiac surgery, obesity stat should be included as one of the predictive variables for stratification of perioperative death risk.

[Endoscopic intragastric injection of botulinum toxin in the treatment of patients with morbid obesity: opportunities and prospects]

The authors consider modern epidemiological and demographic data on morbid obesity. Literature review is devoted to non-surgical treatment of patients with morbid obesity. The authors analyze the results of experimental and clinical studies on endoscopic intragastric injection of botulinum toxin and bariatric efficacy of this approach. The indications for endoscopic intragastric injection of botulinum toxin and advantages of this technique are clearly formulated. The authors identified the most significant criteria for objective assessment of clinical effectiveness of endoscopic intragastral injection of botulinum toxin, as well as scientific and methodological principles necessary for this technique. Clinical efficacy of intragastric injection of botulinum toxin including overweight loss, anorexigenic and gastroparetic effects indicates inconsistent results and certain unresolved problems. Thus, large-scale multiple-center randomized controlled trials and multivariate analysis are required to determine the role of endoscopic intragastric injection of botulinum toxin in complex treatment of patients with morbid obesity.

Pre-Habilitation of Cardiac Surgical Patients, Part 2: Frailty, Malnutrition, Respiratory disease, Alcohol/Smoking cessation and Depression

The concept of "pre-habilitation" comprises screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgeries, but may have profound impacts on outcomes, particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of pre-habilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision-making. In this second part of a two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized at out center for cardiac presurgical care. This second installment will focus on alcohol and smoking cessation and the management of frailty, malnutrition, respiratory disease, and depression.

Echocardiographic Probability of Pulmonary Hypertension in Cardiac Surgery Patients—Occurrence and Association with Respiratory Adverse Events—An Observational Prospective Single-Center Study

Background: Pulmonary hypertension (PH) is an independent risk factor of increased morbidity and mortality in cardiac surgery patients (CS). The most common cause underlying PH is left ventricular (LV) diastolic dysfunction. This study aimed to evaluate the echocardiographic probability of PH in patients undergoing CS and its correlation with postoperative respiratory adverse events (RAE). Methods: The echocardiographic probability of PH and its correlation with LV diastolic dysfunction was assessed in 56 consecutive adult patients who were qualified for coronary artery bypass grafting (CABG). Later, the postoperative RAE (such as pneumonia, pulmonary congestion, or hypoxemia), the length of intensive care unit (ICU) treatment and mortality in groups with moderate or high (PH-m/h) and low (PH-l) probability of pulmonary hypertension were examined. Results: PH-m/h was observed in 29 patients, of whom 65.5 % had LV diastolic dysfunction stage II or III. A significantly higher occurrence of RAE was observed in the PH-m/h group as compared to the PH-l group. There were no differences between the PH-m/h and PH-l patient groups regarding the in-hospital length of stay or mortality. Conclusions: High or intermediate probability of PH is common in cardiac surgical patients with left ventricular diastolic dysfunction and correlates with respiratory adverse events.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Quality of Life After Umbilical Hernia Repair

BACKGROUND

Mesh is beneficial in the repair of umbilical hernias. But it may cause chronic pain due to inflammatory reactions, which may impair the patient's quality of life.

OBJECTIVES

To assess and compare the quality of life of patients following umbilical hernia repair with and without mesh.

METHODS

 During the study period, 45 patients underwent umbilical hernia repair. The study was conducted at King Abdul-Aziz University Hospital (KAUH), KSA. Data were collected using medical records, and each patient was contacted by telephone, to fill the "Carolina Comfort Scale (CCS)" survey. The survey assesses the grade of pain, sensation of mesh, and movement limitation in different situations.

RESULTS

A non-significant difference was found between mean quality of life (QOL) scores of mesh and non-mesh groups. The relationship between CCS and gender was not significant in both groups. However, males had significantly higher CCS scores in mesh-treated cases. There was no statistically significant relationship between CCS and comorbidity, nationality, or symptoms. The overall CCS score did not differ statistically between mesh-treated and non-mesh-treated cases.  Conclusion: The CCS score did not differ between mesh-treated and non-mesh-treated cases. It is suggested that future multicentric studies with a larger sample size be conducted.

A Risk Score for Predicting Long-Term Mortality Following Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) comprises 15-30% of all bypass grafting surgeries. The currently available perioperative scores such as Euroscore and STS score do not specifically predict long-term mortality after off-pump procedures. The neutrophil-to-lymphocyte ratio (NLR) is one of the new, easily accessible markers of inflammation with proven predictive value in cardiovascular diseases. We aimed to develop the first risk score for long-term mortality after OPCAB and to determine if the perioperative value of NLR predicts long-term mortality in OPCAB patients.

METHODS

In total, 440 consecutive patients with multivessel stable coronary artery disease undergoing OPCAB were recruited. Differential leukocyte counts were obtained by a routine hematology analyzer. Data regarding mortality during a median follow-up time of 5.3 years were obtained from the Polish National Health Service database. An independent population of 242 patients served as a validation cohort.

RESULTS

All-cause mortality was influenced by different clinical risk factors. In multivariate regression analysis, chronic obstructive pulmonary disease, stroke history, post-operative NLR and LVEF were independent predictors of mortality. Combing all independent predictors predicted long-term all-cause mortality with 68.5% sensitivity and 71.5% specificity (AUC = 0.704, p < 0.001). After weighing these variables according to their estimates in a multivariate regression model, we developed a score to predict mortality in patients undergoing OPCAB (PREDICT-OPCAB Score, ranging from 0 to 10). Patients with a high score were at higher risk of mortality within the median 5.3 years of follow-up (score 0-3: 8.3%; 4-6: 27.0%; 7-10: 40.0%; p < 0.001 for score 0-3 vs. 4-6 and 7-10). This association was confirmed in the validation cohort.

CONCLUSIONS

We developed and validated the first simplified risk score to predict mortality following OPCAB based on easily accessible clinical factors. This risk score can be used when obtaining a patient's informed consent and as an aid in determining treatment.

Survival After Orthotopic Heart Transplantation In Patients With BMI > = 35 With And Without Diabetes

BACKGROUND

OHT recipients with a BMI > = 35 have worse survival than those with a BMI < 35. Diabetes is a risk factor for mortality. We evaluated the impact of diabetes on mortality rates after OHT in patients with a BMI > 35.

METHODS

Patients > 18 years who underwent OHT 2008-2017 with a BMI > = 35 were identified in the UNOS database. Recipient and donor characteristics were compared. A Kaplan Meier analysis was performed. A multivariable Cox proportional hazards model examined the relationship between diabetes and survival. The equivalence of survival outcomes was examined by an unadjusted Cox proportional hazards model and the two one-sided test procedure, using a pre-specified equivalence region.

RESULTS

Patients with diabetes were older, had a higher creatinine, lower bilirubin, fewer months on the waitlist, and the donor was less likely to be on inotropes. Kaplan-Meier analysis showed no difference in patient survival. Recipient factors associated with an increased risk of death were increasing bilirubin and machine ventilation. Increasing ischemic time resulted in an increased hazard of death. Long-term survival outcomes were equivalent.

CONCLUSIONS

In OHT recipients with a BMI >35, there is no statistical difference in longterm survival in recipients with or without diabetes. These results encourage continued consideration for OHT in patients BMI >35 with coexisting diabetes. This article is protected by copyright. All rights reserved.

Association of body mass index with in-hospital major adverse outcomes in acute type A aortic dissection patients in Fujian Province, China: a retrospective study

Background

Abnormal body mass index (BMI) has been related to a higher risk of adverse outcomes in patients undergoing cardiac surgery. However, the effects of BMI in patients with acute type A aortic dissection (AAAD) on postoperative outcomes remain unclear. This study aimed to explore the relationships between BMI and in-hospital major adverse outcomes (MAO) in AAAD patients.

Methods

Patients who underwent AAAD surgery at Cardiac Medical Center of Fujian Province from June 2013 to March 2020 were retrospectively evaluated. They were divided into three groups on the basis of Chinese BMI classification established by the World Health Organization: normal weight group (BMI 18.5–23.9 kg/m²), overweight group (BMI 24–27.9 kg/m²), and obese group (BMI >28 kg/m²). Patients’ baseline characteristics, preoperative, operative, and postoperative data were collected. A multivariable logistic regression analysis model was performed to identify the association between BMI and MAO in AAAD patients.

Results

Of 777 cases, 31.9% were normal weight, 52.5% were overweight, and 15.6% were obese. A total of 160(20.6%) patients died in-hospital. There was a significant difference between the three groups for MAO (62.9% vs 72.1% vs 77.7%, respectively, P = 0.006). The incidence of postoperative complications did not differ among the three groups, except for postoperative bleeding, and prolonged mechanical ventilation, the proportion of which were higher in the overweight and obese groups. Besides, multivariable logistic regression analysis demonstrated that a higher risk of MAO in the overweight [odds ratios (ORs):1.475, 95%CI:1.006–2.162], and obese patients (ORs:2.147, 95%CI:1.219–3.782) with reference to the normal weight patients, and age, white blood cell, prior stroke and cardiopulmonary bypass time were also associated with in-hospital MAO (P<0.05).

Conclusions

BMI is independently associated with higher in-hospital MAO in patients who underwent AAAD surgery.

Weight impacts 1-year congenital heart surgery outcomes independent of race/ethnicity and payer

Body mass index, race/ethnicity, and payer status are associated with operative mortality in congenital heart disease (CHD). Interactions between these predictors and impacts on longer term outcomes are less well understood. We studied the effect of body mass index, race/ethnicity, and payer on 1-year outcomes following elective CHD surgery and tested the degree to which race/ethnicity and payer explained the effects of body mass index. Patients aged 2-25 years who underwent elective CHD surgery at our centre from 2010 to 2017 were included. We assessed 1-year unplanned cardiac re-admissions, re-interventions, and mortality. Step-wise, multivariable logistic regression was performed.Of the 929 patients, 10.4% were underweight, 14.9% overweight, and 8.5% obese. Non-white race/ethnicity comprised 40.4% and public insurance 29.8%. Only 0.5% died prior to hospital discharge with one additional death in the first post-operative year. Amongst patients with continuous follow-up, unplanned re-admission and re-intervention rates were 14.7% and 12.3%, respectively. In multivariable analyses adjusting for surgical complexity and surgeon, obese, overweight, and underweight patients had higher odds of re-admission than normal-weight patients (OR 1.40, p = 0.026; OR 1.77, p < 0.001; OR 1.44, p = 0.008). Underweight patients had more than twice the odds of re-intervention compared with normal weight (OR 2.12, p < 0.001). These associations persisted after adjusting for race/ethnicity, payer, and surgeon.Pre-operative obese, overweight, and underweight body mass index were associated with unplanned re-admission and/or re-intervention 1-year following elective CHD surgery, even after accounting for race/ethnicity and payer status. Body mass index may be an important modifiable risk factor prior to CHD surgery.

Overweight is associated with better one-year survival in elderly patients after cardiac surgery: a retrospective analysis of the MIMIC-III database

Background

The relationship of body mass index (BMI) to short- and long-term outcomes after cardiac surgery remains controversial, and the dose-response relationship between BMI and mortality in patients receiving cardiac surgery is unclear. Furthermore, the influence of age, concomitant disease, and types of surgery on the prognostic role of BMI has yet to be determined.

Methods

A retrospective cohort study with 6,473 adult patients receiving cardiac surgery was conducted using the Multiparameter Intelligent Monitoring in Intensive Care (MIMIC-III) database. Multivariate Cox proportional hazard analysis and multivariate logistic regression analysis were used to assess the association of BMI with 1-year and in-hospital mortality. Restricted cubic regression splines were used to evaluate the effect of BMI as a continuous variable and to determine appropriate cut points. Subgroup analyses were performed based on age, hypertension and types of surgery.

Results

The baseline characteristics of patients differed between BMI categories. On multivariable analysis, overweight patients (BMI 25–30 kg/m²) had a lower 1-year mortality [hazard ratio (HR) =0.660, 95% confidence interval (CI): 0.516–0.843, P=0.001] when compared with normal weight patients (BMI 18.5–25 kg/m²). For patients with BMI <30 kg/m², each 1 kg/m² BMI increase was independently associated with a significant decrease in the 1-year mortality risk (HR =0.936, 95% CI: 0.899–0.975, P=0.002), while in patients with BMI ≥30 kg/m², an increase in BMI did not increase the 1-year mortality risk (HR =1.032, 95% CI: 0.998–1.067, P=0.064). Subgroup analyses suggested the protective effect of overweight on post-cardiac surgery survival was confined to patients with advanced age (>60 years), hypertension and those undergoing isolated coronary artery bypass grafting (CABG).

Conclusions

Overweight was associated with better 1-year survival in patients after cardiac surgery when compared to normal weight. The protective effect of overweight on post-cardiac surgery survival was confined to elderly patients (>60 years).

Impact of body mass index on surgical coronary revascularization for ischaemic heart failure: insights from STICHES

Aims

Patients with obesity and ischaemic heart failure may counter‐intuitively have better outcomes compared with patients with normal body weight due to an ‘obesity paradox’. This study sought to determine if body mass index (BMI) impacts the treatment effects or safety outcomes of the treatment of ischaemic heart failure with coronary artery bypass grafting (CABG).

Methods and results

We obtained and reviewed the Surgical Treatment of Ischaemic Heart Failure (STICHES) data for 1212 patients. We categorized obesity by the World Health Organization (WHO) classes to define baseline characteristics and test for treatment interactions for the primary and secondary STICHES outcomes by treatment groups. While CABG decreased the risk of death, there was no evidence of treatment interaction by BMI per 5 kg/m² (P = 0.83) or WHO obesity class. For the overall cohort, there was no interaction by WHO obesity class for the cumulative incidence of death in either the medical therapy or CABG plus medical therapy (P‐interaction = 0.90). There was a non‐significant trend for higher BMI and a lower risk of death [hazard ratio 0.92, 95% confidence interval (CI) 0.85–1.00, P = 0.051]. Increasing body size (per 5 kg/m²) was associated with return to the operating room (odds ratio 2.48, 95% CI 1.45–4.26, P < 0.001) and infectious mediastinitis (odds ratio 2.09, 95% CI 1.10–3.97, P = 0.024) at 30 days but not other 30 day safety outcomes.

Conclusions

The benefit of CABG vs. medical therapy for ischaemic heart failure was consistent regardless of BMI or WHO obesity class for death or secondary clinical outcomes. However, higher BMI was associated with some short‐term post‐CABG complications.

The effects of body mass index on outcomes for patients undergoing surgical aortic valve replacement

Background

Most of the studies of obesity and postoperative outcome have looked predominantly at coronary artery bypass grafting with fewer focused on valvular disease. The purpose of this study was to compare the outcomes of patients undergoing aortic valve replacement stratified by body mass index (BMI, kg/m^2).

Methods

The Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry captured 4780 aortic valve replacements in Alberta, Canada from January 2004 to December 2018. All recipients were stratified by BMI into five groups (BMI: < 20, 20–24.9, 25–29.9, 30–34.9, and > = 35). Log-rank test and Cox regression were used to examine the crude and adjusted survival differences.

Results

Intra-operative clamp time and pump time were similar among the five groups. Significant statistical differences between groups existed for the incidence of isolated AVR, AVR and CABG, hemorrhage, septic infection, and deep sternal infection (p < 0.05). While there was no significant statistical difference in the mortality rate across the BMI groups, the underweight AVR patients (BMI < 20) were associated with increased hazard ratio (1.519; 95% confidence interval: 1.028–2.245) with regards to all-cause mortality at the longest follow-up compared with normal weight patients.

Conclusion

Overweight and obese patients should be considered as readily for AVR as normal BMI patients.

Phenotypes of Sarcopenic Obesity: Exploring the Effects on Peri-Muscular Fat, the Obesity Paradox, Hormone-Related Responses and the Clinical Implications

Sarcopenic obesity combines the words sarcopenia and obesity. This definition of obesity should be better differentiated between visceral and subcutaneous fat phenotypes. For this reason, this review lays the foundation for defining the subcutaneous and the visceral fat into the context of sarcopenia. Thus, the review aims to explore the missing links on pathogenesis of visceral fat and its relationship on age: defining the peri-muscular fat as a new entity and the subcutaneous fat as a first factor that leads to the obesity paradox. Last but not least, this review underlines and motivates the mechanisms of the hormonal responses and anti-inflammatory adipokines responsible for the clinical implications of sarcopenic visceral obesity, describing factor by factor the multiple axis between the visceral fat-sarcopenia and all mortality outcomes linked to cancer, diabetes, cardiovascular diseases, cirrhosis, polycystic ovary, disability and postoperative complications.

The Association Between Obesity and Risk of Acute Kidney Injury After Cardiac Surgery

OBJECTIVE

To determine the relationship between obesity and the risk of AKI after cardiac surgery (CS-AKI) in a cohort study.

METHODS

A total of 1,601 patients undergoing cardiac surgery were collected and their incidence of CS-AKI was recorded. They were divided into underweight, normal weight, overweight, and obese groups. Logistic regression was used to estimate the association between BMI (body mass index) and CS-AKI risk. Then, a meta-analysis of published cohort studies was conducted to confirm this result using PubMed and Embase databases.

RESULTS

A significant association was observed in this independent cohort after adjusting age, gender, hypertension and New York Heart Association classification (NYHA) class. Compared with normal BMI group (18.5 ≤ BMI < 24.0), the individuals with aberrant BMI level had an increased AKI risk (OR: 1.68, 95% CI: 1.01-2.78) for BMI < 18.5 group and (OR: 1.43, 95% CI: 0.96-2.15) for BMI ≥ 28.0. Interestingly, the U-shape curve showed the CS-AKI risk reduced with the increasing of BMI when BMI ≤ 24.0. As BMI increases with BMI > 24.0, the risk of developing CS-AKI increased significantly. In the confirmed meta-analysis, compared with normal weight, overweight group with cardiac surgery had higher AKI risk (OR: 1.28, 95% CI: 1.16-1.41, P_{heterogeneity} = 0.49). The similar association was found in obesity subgroup (OR: 1.79, 95% CI: 1.57-2.03, P_{heterogeneity} = 0.42).

CONCLUSION

In conclusion, the results suggested that abnormal BMI was a risk factor for CS-AKI independently.

Effect of obesity and underweight status on the hospital-acquired functional decline in patients with cardiovascular surgery: an analysis of data from a prospective observational multicenter cohort study

OBJECTS

The aim of this study was to determine the association between underweight or obese status and hospital- acquired functional decline (HAFD) following cardiovascular surgery.

METHODS

We performed a retrospective, observational, multicenter cohort study of cardiovascular surgery patients between April, 2010, and June, 2017. Body mass index (BMI) was categorized into four classes: underweight group (< 18.5 kg/m²), normal weight group (18.5 to < 25 kg/m²), overweight group (25 to < 30 kg/m²), and obese group (≥ 30 kg/m²). HAFD was defined as a decrease of at least one point on the short physical performance battery score at discharge, compared with the preoperative score.

RESULTS

A total of 3,850 adult patients were included in the analysis data set (median age 72 years, 35% female). A total of 811 (21.0%) patients demonstrated HAFD: 27.2% in the underweight group, 21.3% in the normal weight group, 18.8% in the overweight group, and 19.3% in the obese group. The relative risk for HAFD was 1.381 (95% CI 1.052-1.814) for the underweight group versus the normal weight group, although that is comparable to the obese group after adjustment by confounding factors. Analyses of subgroup interactions showed that the relative risk of HAFD in the obese group compared with the normal group was higher in patients with muscle wasting (p < 0.05).

CONCLUSION

HAFD was significantly worse for underweight patients following cardiovascular surgery. In contrast, obese status was not associated with HAFD, exclusive of the obese patients with muscle wasting.

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.

Physiological and pharmacological effects of melatonin on remote ischemic perconditioning after myocardial ischemia-reperfusion injury in rats: Role of Cybb, Fas, NfκB, Irisin signaling pathway

It has been found that remote organ/limb temporary ischemia, known as remote ischemic conditioning, can provide protection against the formation of lethal ischemic outcome. Current evidence suggests that aging and age-releated comorbidities impair the cardioprotective effects of conditionings. In conjuction with aging, decrease in melatonin synthesis from pineal gland can have role in the pathogenesis of aging and age-related cardiovascular diseases. In this study, we investigated the effects of remote ischemic perconditioning (RIPerC) and physiological and pharmacological concentrations of melatonin on the infarct size, Fas gene, cytochrome b-245 beta chain (Cybb) gene, nuclear factor-kappa B (NfκB), and irisin using an in vivo model of myocardial ischemia/reperfusion (I/R) injury. Sprague-Dawley rats that were divided into two groups first as non-pinealectomized (Non-Px) and pinealectomized (Px), and then (a) Control; (b) I/R (30-minute ischemia, 120-minute reperfusion caused by left coronary artery ligation); (c) I/R + RIPerC (when myocardial ischemia initiated, three cycles of 5-minute occlusion followed by 5-minute reperfusion); (d) I/R + Mel; (e) Px; (f) Px + I/R; (g) Px + I/R + RIPerC; (h) Px + I/R + RIPerC + Mel groups. The infarct size was determined by TTC staining and analyzed by the ImageJ program. Molecular parameters were evaluated by qRT-PCR and Western blot. Results showed that increased infarct size in Non-Px groups decreased with RIPerC and melatonin. However, increased infarct size in Px groups was decreased minimally with RIPerC and significantly decreased with RIPerC + Melatonin. Fold change in Fas gene was associated with the infarct size. RIPerC and melatonin reduced expressions of Cybb, NfκB, and irisin genes. The physiological release and pharmacological concentration of melatonin may improve protective effect of RIPerC against I/R-induced infarct size by modulating Cybb, Fas, NfκB, Irisin signaling pathways.

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.

Combination of red blood cell distribution width and body mass index (COR-BMI) predicts in-hospital mortality in patients with different diagnoses?

Background

The combination of red blood cell distribution width and body mass index (COR-BMI) is indicated as a new prognostic index of survival in patients with laryngeal cancer. However, the ability of this prediction in other types of cancer or whether its use can be expanded to non-oncological patients is unknown. The aim of this study was to investigate the prediction of prognosis of in-hospital mortality of the COR-BMI in oncological and non-oncological patients.

Methods

A retrospective study was performed with all hospitalized patients between 2014 and 2016, totaling 2930 patients, 262 oncological and 2668 non-oncological. The COR-BMI was divided into three classes: 0, RDW ≤ 13.1% and BMI ≥ 25 kg/m²; 1, RDW ≤ 13.1% and BMI < 18.5 or ≥ 18.5 but < 25 kg/m² and RDW > 13.1% and BMI ≥ 18.5 but < 25 or BMI ≥ 25 kg/m²; and 2, RDW > 13.1% and BMI < 18.5 kg/m². In order to analyze the relationship between COR-BMI and in-hospital mortality in the studied population, the Cox Proportional Hazards Model was used in a multivariate analysis based on a conceptual model.

Results

The COR-BMI was an independent predictor of in-hospital mortality in non-oncological patients (1 versus 0: HR = 3.34; CI = 1.60–6.96, p = 0.001; 2 versus 0: HR = 3.38; CI = 1.22–9.39, p = 0.019). The survival rate of these patients was lower among those with the highest scores on the COR-BMI. This prediction was not found in oncological patients.

Conclusion

The present study suggests that the COR-BMI may have its practical use expanded to non-oncological patients as an independent predictor of in-hospital mortality.

Impact of type 2 diabetes mellitus in the utilization and in-hospital outcomes of surgical mitral valve replacement in Spain (2001-2015)

Background

The main aims of this study were to examine the incidence and in-hospital outcomes of mechanical and bioprosthetic surgical mitral valve replacement (SMVR) among patients with and without T2DM.

Methods

We performed a retrospective study using the Spanish National Hospital Discharge Database from 2001 to 2015. We included patients with SMVR codified in their discharge report. We grouped admissions by diabetes status. Propensity score matching (PSM) was used to compare outcomes of isolated SMVR.

Results

We identified 42,937 patients (16.41% with T2DM). Incidence rates of mechanical and bioprosthetic SMVR were higher among T2DM patients than among non-T2DM patients. In both groups of patients, the use of bioprosthetic SMVR increased over time. The use of mechanical valves remained stable among T2DM patients. In T2DM and non-T2DM patients with mechanical SMVR, in hospital mortality (IHM) and MACCE decreased significantly (p < 0.001) from 2001 to 2015. T2DM patients had an overall 11.37% IHM, compared with 10.76% among non-T2DM patients (p = 0.176). Regarding MACCE figures were 14.72% vs. 14.22% (p = 0.320) after mechanical SMVR. Total crude IHM were 14.29% for T2DM patients and 15.13% for those without T2DM with bioprosthetic SMVR (p = 0.165) and 18.22 vs. 19.64%, for a MACCE (p = 0.185). Using PSM we found that the IHM and the MACCE of isolated SMVR did not differ significantly between patients with or without T2DM beside the type of valve replacement. Among T2DM patients, those who received bioprosthetic valves had higher IHM (14.29% vs. 11.37%; p = 0.003) and a higher rate of MACCE (18.22% vs. 14.72%; p = 0.001) than T2DM patients with mechanical SMVR.

Conclusions

In Spain from 2001 to 2015, the incidence rates of hospitalization to undergo mechanical or bioprosthetic SMVR were higher among the population suffering T2DM than among the non-T2DM population. In both groups of patients the use of bioprosthetic SMVR increased over time and the use of mechanical valves remained stable in T2DM. T2DM patients have IHM and MACCE after mechanical and bioprosthetic SMVR which are not significantly different to those found among non-diabetic patients. Among T2DM patients, the crude IHM was significantly higher in those who received a bioprosthetic SMVR than those with mechanical SMVR.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0866-5) contains supplementary material, which is available to authorized users.

Impact of Body Mass Index on Short- and Long-Term Outcomes After Isolated First-Time Surgical Aortic Valve Replacement for Aortic Stenosis

OBJECTIVE

To ascertain whether body mass index (BMI) has a clinical effect on short- and long-term postoperative outcomes after surgical aortic valve replacement in patients with severe aortic stenosis.

DESIGN

Single-center, retrospective study.

SETTING

Tertiary referral hospital.

PARTICIPANTS

The study comprised 1,561 patients who underwent isolated first-time aortic valve replacement between 2005 and 2012.

INTERVENTIONS

Fourteen underweight patients were removed from the analysis. The remaining patients were divided into the following 4 groups according to their BMI: 418 as normal weight (≥18.5 to <25 kg/m²), 629 as overweight (≥25 to <30 kg/m²), 342 as obese (≥30 to <35 kg/m²), and 158 as very obese (≥35 kg/m²). Early mortality and postoperative complications were compared, and long-term survival rates were investigated.

MEASUREMENT AND MAIN RESULTS

Thirty-day mortality was higher in the normal weight group but did not reach statistical significance (p = 0.054), and the incidence of postoperative complications was not different for cerebrovascular accident (p = 0.70), re-sternotomy for bleeding (p = 0.17), sternal wound infection (p = 0.07), and dialysis (p = 0.07). With a mean follow-up time of 4.92 ± 2.82 years, survival rate was better in the overweight group. A Cox proportional hazard model found BMI inversely correlated with long-term mortality when analyzed in a univariable fashion (hazard ratio 0.95; p = 0.009), but this apparent protective effect disappeared when adjusted for preoperative covariates (hazard ratio 0.98, 95% confidence interval 0.96-1.004; p = 0.12).

CONCLUSION

Once adjusted for preoperative characteristics, obesity does not represent an independent predictor for long-term survival rates. There was a higher incidence of 30-day mortality in the normal weight group compared with the overweight and very obese groups. The incidence of deep sternal wound infection was higher in very obese patients.

Validation of the Fitbit Flex in an Acute Post-Cardiac Surgery Patient Population

Purpose: This study examined the validity of the Fitbit Flex activity monitor for step count and distance walked among post-cardiac surgery patients. Method: Participants (n=20) from a major urban cardiac surgery centre were recruited 1-2 days before hospital discharge. The Fitbit Flex step count and distance walked outputs and video recording of each participant performing the 6-minute walk test were collected. Fitbit Flex output was compared with criterion measures of manual step count obtained from the video recording and manual measurement of distance walked. Statistical analysis compared the output and criterion measures using paired sample t-tests, Pearson correlation coefficients, Lin's concordance correlations, and Bland-Altman plots. Sub-analysis compared slower walking (<0.8 m/s; n=11) and faster walking (≥0.8 m/s; n=8) group speeds (1 participant was excluded from analysis). Results: Steps counted and distance walked were significantly different between the Fitbit Flex outputs and criterion measures (p<0.05). The Fitbit Flex steps counted and distance walked showed moderate association with manual measure steps counted (r=0.67) and distance walked (r=0.45). Lin's concordance coefficients revealed a lack of agreement between the Fitbit Flex and the criterion measurement of both steps counted (concordance correlation coefficient [CCC]=0.43) and distance walked (CCC=0.36). The percentage of relative error was -18.6 (SD 22.7) for steps counted and 25.4 (SD 45.8) for distance walked. Conclusions: The Fitbit Flex activity monitor was not a valid measure of step count and distance walked in this sample of post-cardiac surgery patients. The lack of agreement between outputs and criterion measures suggests the Fitbit Flex alone would not be an acceptable clinical outcome measure for monitoring walking progression in the early postoperative period.

Diagnostic evaluation of risk for bleeding in cardiac surgery with extracorporeal circulation

OBJECTIVE

to identify the risk factors associated with cases of excessive bleeding in patients submitted to cardiac surgery with extracorporeal circulation.

METHOD

case-control study on the factors of risk for bleeding based on the analysis of data from the medical charts of 216 patients submitted to cardiac surgery with elective extracorporeal circulation during a three-year period.

RESULTS

variables that are commonly associated with excessive bleeding in studies in the field were analyzed, and the following were considered as risk factors for the nursing diagnosis "risk for bleeding" (00206) in cardiac surgery with extracorporeal circulation: Body mass index lower than 26.35kg/m² (Odds ratio = 3.64); Extracorporeal circulation longer than 90 minutes (Odds ratio = 3.57); Hypothermia lower than 32°C (Odds ratio = 2.86); Metabolic acidosis (Odds ratio = 3.50) and Activated partial thromboplastin time longer than 40 seconds (Odds ratio= 2.55).

CONCLUSION

such variables may be clinical indicators of an operational nature for a better characterization of the risk factor "treatment regimen" and a refinement of knowledge related to coagulopathy induced by extracorporeal circulation, which is currently presumably incorporated into the "treatment regimen" category of the nursing diagnostic classification by NANDA International, Inc.

Differential Signature of Obesity in the Relationship with Acute Kidney Injury and Mortality after Coronary Artery Bypass Grafting

BACKGROUND

Obesity is related to several comorbidities and mortality, but its relationship with acute kidney injury (AKI) and long-term mortality remain undetermined in patients undergoing coronary artery bypass grafting.

METHODS

Data from 3,018 patients (age ≥ 18 years) who underwent coronary artery bypass graft surgery from two tertiary referral centers were retrospectively reviewed between 2004 and 2015. Obesity was defined using the body mass index, according to the World Health Organization's recommendation. The odds and hazard ratios in post-surgical, AKI, and all-cause mortality were calculated after adjustment for multiple covariates. Patients were followed for 90 ± 40.9 months (maximum: 13 years).

RESULTS

Among the cohort, 37.4%, 2.4%, 21.1%, 35.1%, and 4.0% of patients were classified as normal weight, underweight, overweight-at-risk, obese I, and obese II, respectively. Post-surgical AKI developed in 799 patients (26.5%). Patients in the obese groups (overweight-at-risk to obese II) had a higher risk of AKI than did those in the normal-weight group. During the follow-up period, 787 patients (26.1%) died. Underweight patients had a higher risk of mortality than did normal-weight patients, whereas overweight-at-risk, obese I, and obese II patients showed better survival rates.

CONCLUSION

After coronary artery bypass graft surgery, obese patients encountered a high risk of AKI, and underweight patients exhibited a low chance of survival. Awareness of both obese and underweight statuses should be raised in these patients.

Mortality and morbidity of patients on the waiting list for coronary artery bypass graft surgery

OBJECTIVES

The public health care system in Brazil has extensive waiting lists of patients requiring complex operations such as coronary artery bypass grafting (CABG). The purpose of this study was to identify the mortality and morbidity rates of the patients awaiting CABG and identify predictors of adverse events and their association with perioperative outcomes.

METHODS

We conducted a retrospective analysis of outpatient medical records of patients referred for this elective procedure in Rio de Janeiro, Brazil. Excluded from the study were records of patients with any of the following: an indication for urgent surgery, unstable angina or concomitant surgical valvular disease or subsequent transfer to clinical or percutaneous therapy.

RESULTS

A total of 274 patients were identified and met the inclusion criteria, with a median waiting time for an operation of 142.7 days. While waiting for CABG surgery, 31 (11.3%) patients died of any cause and 42 (15.3%) patients had a serious cardiac event (death, myocardial infarction or unstable angina). Of the 22 (8%) incidents of acute myocardial infarction, 8 (2.9%) were non-fatal and 14 (5.1%) were fatal. There was a greater risk of death awaiting CABG surgery in patients with a left ventricular ejection fraction below 45% (hazard ratio = 2.33, 95% confidence interval 1.02-5.32; P = 0.039). The operative mortality rate was 5.8%. Although there was no evidence of worse perioperative outcomes in patients with prolonged waiting times for an operation, there was an association between waiting more than 16 weeks for an operation and death while on the list.

CONCLUSIONS

Extensive waiting periods for CABG contribute to higher mortality and morbidity rates, especially in patients with left ventricular dysfunction.

Association Between Obesity and Cardiovascular Outcomes: A Systematic Review and Meta-analysis of Mendelian Randomization Studies

IMPORTANCE

Although dyslipidemia has been consistently shown to be associated with atherogenesis, an association between obesity and cardiovascular disease outcomes remains controversial. Mendelian randomization can minimize confounding if variables are randomly and equally distributed in the population of interest.

OBJECTIVE

To assess evidence from mendelian randomization studies to provide a less biased estimate of any association between obesity and cardiovascular outcomes.

DATA SOURCES

Systematic searches of MEDLINE and Scopus from database inception until January 2018, supplemented with manual searches of the included reference lists.

STUDY SELECTION

Studies that used mendelian randomization methods to assess the association between any measure of obesity and the incidence of cardiovascular events and those that reported odds ratios (ORs) with 95% CIs estimated using an instrumental variable method were included. The 5 studies included in the final analysis were based on a consensus among 3 authors.

DATA EXTRACTION AND SYNTHESIS

Two investigators independently extracted study characteristics using a standard form and pooled data using a random-effects model. The Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline was followed.

MAIN OUTCOMES AND MEASURES

Obesity associated with type 2 diabetes, coronary artery disease, or stroke. The hypothesis was formulated prior to data collection.

RESULTS

Of 4660 potentially relevant articles, 2511 titles were screened. Seven studies were included in the systematic review, and 5 studies with 881 692 participants were eligible to be included in the meta-analysis. Pooled estimates revealed that obesity was significantly associated with an increased risk of type 2 diabetes (OR, 1.67; 95% CI, 1.30-2.14; P < .001; I2 = 93%) and coronary artery disease (OR, 1.20; 95% CI, 1.02-1.41; P = .03; I2 = 87%). No association between obesity and stroke was found (OR, 1.02; 95% CI, 0.95-1.09; P = .65; I2 = 0%).

CONCLUSIONS AND RELEVANCE

The present meta-analysis suggests that obesity is associated with type 2 diabetes and coronary artery disease. Although this analysis of mendelian randomization studies does not prove causality, it is supportive of a causal association. Hence, health care practitioners should continue to emphasize weight reduction to combat coronary artery disease.

Utilization of Emergency and Hospitalization Care after Coronary Artery Bypass Surgery for Patients with Ischemic Heart Disease

This retrospective follow-up study explored the status of patients with myocardial infarction with regard to the likelihood of being readmitted to the hospital within 30 days after undergoing coronary artery bypass surgery (CABG) and their survival status within one year of the procedure.The rate of readmission within 30 days was 10.7% (167/1,575), primarily due to surgical wound infection (11.3% of readmission cases), ischemic heart disease (10.3%), and heart failure (8.7%). The readmission group consisted mainly of older males with a high comorbidity index. No significant differences existed between the two groups with regard to case distribution, hospital level, tenure of physicians, or teaching status of the hospitals. Most subsequent emergency department visits one month after surgery involved older male patients with a high comorbidity index. Compared to patients in the non-emergency group, those in the emergency group had longer hospital stays but lower mortality rates. Males constituted a higher proportion of survivors at one year post CABG, with age and comorbidity index being the primary variables affecting the risk of death.The National Health Insurance may adopt the policy of increasing payments for medical institutions that avoid readmission within 30 days post CABG in order to encourage better patient care and avoid the costs associated with readmission.

Myocardial ischaemia reperfusion injury: the challenge of translating ischaemic and anaesthetic protection from animal models to humans

Myocardial ischaemia reperfusion injury is the leading cause of death in patients with cardiovascular disease. Interventions such as ischaemic pre and postconditioning protect against myocardial ischaemia reperfusion injury. Certain anaesthesia drugs and opioids can produce the same effects, which led to an initial flurry of excitement given the extensive use of these drugs in surgery. The underlying mechanisms have since been extensively studied in experimental animal models but attempts to translate these findings to clinical settings have resulted in contradictory results. There are a number of reasons for this such as dose response, the intensity of the ischaemic stimulus applied, the duration of ischaemia and lost or diminished cardioprotection in common co-morbidities such as diabetes and senescence. This review focuses on current knowledge regarding myocardial ischaemia reperfusion injury and cardioprotective interventions both in experimental animal studies and in clinical trials.

Implications of obesity in cardiac surgery: pattern of referral, physiopathology, complications, prognosis

A U-shaped relationship between body mass index (BMI) and outcomes emerged after cardiac surgery. This review analyses the physio pathologic basis of obesity related complications and evaluates prognostic implications. Both leaner and morbid obese should be considered pre-operatively rather than reactively and, when referred for elective surgery, should undergo a focused metabolic status management, and a thorough evaluation of health status. Adherence to sound surgical principles, and tailored patient blood management and perioperative care are mandatory.

Ameliorative effect of sevoflurane on endoplasmic reticulum stress mediates cardioprotection against ischemia-reperfusion injury 1

We aimed to investigate whether the cardioprotection of sevoflurane against ischemia-reperfusion (IR) injury is via inhibiting endoplasmic reticulum stress. The rat in vivo model of myocardial IR injury was induced by ligation of the left anterior descending coronary artery. Sevoflurane significantly ameliorated the reduced cardiac function, increased infarct size, and elevated troponin I level and lactate dehydrogenase activity in plasma induced by IR injury. Sevoflurane suppressed the IR-induced myocardial apoptosis. The increased protein levels of glucose-regulated protein 78 and C/EBP homologous protein (CHOP) after myocardial IR were significantly reduced by sevoflurane. The protein levels of phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (PERK), phosphorylated eukaryotic initiation factor 2 (eIF2α), and activating transcription factor 4 (ATF4) were significantly increased in rats with IR and attenuated by sevoflurane treatment. The phosphorylation of Akt was further activated by sevoflurane. The cardioprotection of sevoflurane could be blocked by wortmannin, a PI3K/Akt inhibitor. Our results suggest that the cardioprotection of sevoflurane against IR injury might be mediated by suppressing PERK/eIF2a/ATF4/CHOP signaling via activating the Akt pathway, which helps in understanding the novel mechanism of the cardioprotection of sevoflurane.

Can Patient Selection Explain the Obesity Paradox in Orthopaedic Hip Surgery? An Analysis of the ACS-NSQIP Registry

BACKGROUND

The "obesity paradox" is a phenomenon described in prior research in which patients who are obese have been shown to have lower postoperative mortality and morbidity compared with normal-weight individuals. The paradox is that clinical experience suggests that obesity is a risk factor for difficult wound healing and adverse cardiovascular outcomes. We suspect that the obesity paradox may reflect selection bias in which only the healthiest patients who are obese are offered surgery, whereas nonobese surgical patients are comprised of both healthy and unhealthy individuals. We questioned whether the obesity paradox (decreased mortality for patients who are obese) would be present in nonurgent hip surgery in which patients can be carefully selected for surgery but absent in urgent hip surgery where patient selection is minimized.

QUESTIONS/PURPOSES

(1) What is the association between obesity and postoperative mortality in urgent and nonurgent hip surgery? (2) How is obesity associated with individual postoperative complications in urgent and nonurgent hip surgery? (3) How is underweight status associated with postoperative mortality and complications in urgent and nonurgent hip surgery?

METHODS

We used 2011 to 2014 data from the American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) to identify all adults who underwent nonurgent hip surgery (n = 63,148) and urgent hip surgery (n = 29,047). We used logistic regression models, controlling for covariants including age, sex, anesthesia risk, and comorbidities, to examine the relationship between body mass _index (BMI) category (classified as underweight < 18.5 kg/m, normal 18.5-24.9 kg/m, overweight 25-29.9 kg/m, obese 30-39.9 kg/m, and morbidly obese > 40 kg/m) and adverse outcomes including 30-day mortality and surgical complications including wound complications and cardiovascular events.

RESULTS

For patients undergoing nonurgent hip surgery, regression models demonstrate that patients who are morbidly obese were less likely to die within 30 days after surgery (odds ratio [OR], 0.12; 95% confidence interval [CI], 0.01-0.57; p = 0.038) compared with patients with normal BMI, consistent with the obesity paradox. For patients undergoing urgent hip surgery, patients who are morbidly obese had similar odds of death within 30 days compared with patients with normal BMI (OR, 1.18; 95% CI, 0.76-1.76; p = 0.54). Patients who are morbidly obese had higher odds of wound complications in both nonurgent (OR, 4.93; 95% CI, 3.68-6.65; p < 0.001) and urgent cohorts (OR, 4.85; 95% CI, 3.27-7.01; p < 0.001) compared with normal-weight patients. Underweight patients were more likely to die within 30 days in both nonurgent (OR, 3.79; 95% CI, 1.10-9.97; p = 0.015) and urgent cohorts (OR, 1.47; 95% CI, 1.23-1.75; p < 0.001) compared with normal-weight patients.

CONCLUSIONS

Patients who are morbidly obese appear to have a reduced risk of death in 30 days after nonurgent hip surgery, but not for urgent hip surgery. Our results suggest that the obesity paradox may be an artifact of selection bias introduced by careful selection of the healthiest patients who are obese for elective hip surgery. Surgeons should continue to consider obesity a risk factor for postoperative mortality and complications such as wound infections for both urgent and nonurgent surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

MicroRNA‑221‑3p contributes to cardiomyocyte injury in H2O2‑treated H9c2 cells and a rat model of myocardial ischemia‑reperfusion by targeting p57

Myocardial ischemia‑reperfusion (I/R) injury is a major cause of cardiovascular disease worldwide, and microRNAs have been implicated in the regulation of pathological and physiological processes in myocardial I/R injury. The present study aimed to investigate the role of microRNA (miR)‑221‑3p in myocardial I/R injury. Cell death and lactate dehydrogenase (LDH) activity were increased in hydrogen peroxide (H2O2)‑treated H9c2 cells, as measured by flow cytometry and an LDH detection kit. The expression of miR‑221‑3p was elevated in H2O2‑incubated cells and in remote areas of the rat I/R model, examined using reverse transcription‑quantitative polymerase chain reaction analysis. The overexpression of miR‑221‑3p enhanced the number of propidium iodide (PI)+ cells and the activity of LDH in H2O2‑treated cells. In I/R‑induced rats, the overexpression of miR‑221‑3p promoted the number of myosin+ cells and inhibited the fractional shortening of left ventricular diameter (FSLVD%). The results showed that the expression of p57 at the gene and protein levels was decreased in H9c2 cells incubated with H2O2 and in rats subjected to I/R surgery; the expression of p57 decreased following the overexpression of miR‑221‑3p. Subsequently, the hypothesis that p57 was the direct target of miR‑221‑3p was confirmed by performing a dual‑luciferase reporter assay. Finally, to examine the function of p57 in myocardial impairment, p57 was transfected into H9c2 cells and administered to the rats prior to undergoing H2O2 treatment and I/R surgery, respectively. The results indicated that p57 attenuated the number of PI+ cells and the activity of LDH in H2O2‑treated cells, whereas p57 downregulated the number of myosin+ cells and upregulated FSLVD% in the I/R‑treated rats. Therefore, these findings suggested that miR‑221‑3p exacerbated the H2O2‑induced myocardial damage in H9c2 cells and myocardial I/R injury in the rat model by modulating p57.