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

The Burden of Obesity in Cardiac Surgery: A 14 years' Follow-Up of 14.754 Patients

Aims

The prevalence of obesity is rapidly increasing during the past decades. While previous research has focused on the early outcome after cardiac surgery or specific complications, the current study covers the whole burden of obesity in the field of cardiac surgery over short term and long term. Endpoints of the study were all-cause mortality, perioperative outcome, and wound-healing disorders (WHDs).

Methods

14.754 consecutive patients who underwent cardiac surgery over a 14 years' time period were analyzed. BMI classifications were used according to the WHO definition.

Results

Mean survival was 11.95 years ± 0.1; CI 95% [12.04-12.14]. After adjustment for clinical baseline characteristics, obesity classes' I-III (obesity) did not affect 30-day mortality or all-cause mortality during the whole observational period. After adjustment for known risk factors, the risk for WHDs doubled at least in obesity patients as follows: obesity I (OR = 2.06; CI 95% [1.7-2.5]; p < 0.0001), obesity II (OR = 2.5; CI 95% [1.83-3.41]; p < 0.0001), and obesity III (OR = 4.12; CI 95% [2.52-6.74]; p < 0.0001). The same applies to the risk for sternal reconstruction that is substantially elevated in obesity I (OR = 2.23; CI 95% [1.75-2.83]; p < 0.0001), obesity II (OR = 2.81; CI 95% [1.91-4.13]; p < 0.0001), and obesity III (OR = 2.31; CI 95% [1.08-4.97]; p=0.03). No significant correlation could be found between obesity and major adverse events in the perioperative course like renal failure, ventilation >24 h, re-exploration, or cerebrovascular events.

Conclusions

Cardiac surgery is safe in obesity as short- and long-term mortality are not increased, and major adverse events during the perioperative course are similar to control patients. The burden of obesity lies in substantially increased rates of wound-healing disorders and sternal reconstructions.

Investigation of the Association between Bilateral Selective Anterograde Cerebral Perfusion and Postoperative Ischemic Stroke in Obese Patients with Emergency Surgery for Acute Type A Aortic Dissection

Background and objectives: The relationship between cerebral perfusion and new postoperative ischemic stroke in obese patients is not well defined. The aim of this study was to investigate the association between selective bilateral anterograde cerebral perfusion and new postoperative ischemic stroke in obese patients with emergency surgery for acute type A aortic dissection. Materials and methods: A total of 292 patients with emergency surgery for acute type A aortic dissection were included in this study. Patients with hemorrhagic stroke or ischemic stroke with severe neurological dysfunction at admission that were not candidates for surgery; patients who died in the first 48 h after intensive care admission and patients with incomplete medical records were excluded. Results: The mean age was 59.42 ± 10.68 years and the mean Euroscore was 9.12 ± 1.63. Obesity was present in 76.4%, the incidence of new postoperative ischemic stroke was 27.5%, and the postoperative mortality rate was 26.7%. The mean cardiopulmonary bypass time was 206.81 ± 75.48 min, the aortic cross-clamp time was 118.2 ± 46.42 min, and 90% of cases required cerebral perfusion. The mean cerebral perfusion time was 30.8 ± 24.41 min. Obese patients had a higher frequency of in-hospital death (p = 0.009), smoking (p = 0.036), hypertension (p = 0.023), left common carotid artery dissection (p < 0.001), right common carotid artery dissection (p = 0.029), femoral artery cannulation (p = 0.026), aortic root replacement (p = 0.009), aortic valve replacement (p = 0.005) and early reintervention for bleeding (p = 0.004). Using logistic regression, selective bilateral anterograde cerebral perfusion over 40 min in obese patients was independently associated with new postoperative ischemic stroke (OR = 2.35; 95%CI = 1.36-4.86; p = 0.021). Conclusions: A patient-tailored strategy for cerebral perfusion should be considered in obese patients, considering the high atheromatous burden of the supra-aortic vessels in these patients and the potential risk of atheromatous embolization associated with this technique.

PreScheck Team Study: prehabilitation clinic as an effective patient management tool in elective cardiac surgery

INTRODUCTION

The main purpose of the study was to assess the impact of preoperative interdisciplinary assessment by the PreScheck Team on optimization of the final selection for elective cardiac surgery.

MATERIAL AND METHODS

This is a single-centre prospective observational study. The examined population consisted of 933 adult patients planned for cardiac surgery. After the exclusion of urgent operations, the study group consisted of 288 patients planned for elective cardiac surgery within 3 months from 1.01.2023 with PreScheck assessment (PreScheck Team group 2) and a control group of 311 patients scheduled for elective cardiac surgery between 1.03.2022 and 30.06.2022 (4 months), without preoperative interdiscipli-nary assessment (No PreScheck Team group 2).

RESULTS

Fifty-two patients (18.06%) from the study group were finally excluded from the surgery on the scheduled date. In 46 patients (88.46%) the temporary or permanent exclusion from surgery was a result of PreScheck Team assessment. In the control group 42 patients (13.5%) did not undergo surgery on the scheduled date. Twenty-seven of those patients (8.97%) were permanently excluded from cardiac surgery after admission to the hospital and required additional tests before the final clinical decision, with total hospitalization time of 146 days.

CONCLUSIONS

Pre Surgery Check (PreScheck) Team is an original concept that combines classical preoperative assessment and an outpatient prehabilitation clinic. The approach we are proposing here should be a complementary stage in the process of selection for elective cardiac surgery, in addition to the Heart Team recommendation. This two-step decision-making enables real individual risk assessment, selection of the most suitable intervention and better use of medical resources.

Sarcopenia Adversely Affects Outcomes following Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Sarcopenia is a degenerative condition characterised by the loss of skeletal muscle mass and strength. Its impact on cardiac surgery outcomes remains poorly investigated. This meta-analysis aims to provide a comprehensive synthesis of the available evidence to determine the effect of sarcopenia on cardiac surgery outcomes.

METHODS

A systematic review and meta-analysis followed PRISMA guidelines from inception to April 2023 in EMBASE, MEDLINE, Cochrane database, and Google Scholar. Twelve studies involving 2717 patients undergoing cardiac surgery were included. Primary outcomes were early and late mortality; secondary outcomes included surgical time, infection rates, and functional outcomes. Statistical analyses were performed using appropriate methods.

RESULTS

Sarcopenic patients (906 patients) had a significantly higher risk of early mortality (OR: 2.40, 95% CI: 1.44 to 3.99, p = 0.0007) and late mortality (OR: 2.65, 95% CI: 1.57 to 4.48, p = 0.0003) compared to non-sarcopenic patients (1811 patients). There were no significant differences in overall surgical time or infection rates. However, sarcopenic patients had longer ICU stays, higher rates of renal dialysis, care home discharge, and longer intubation times.

CONCLUSION

Sarcopenia significantly increases the risk of early and late mortality following cardiac surgery, and sarcopenic patients also experience poorer functional outcomes.

Sarcopenia Best Predicts Complications in Free Flap Breast Reconstruction

Breast reconstruction remains a major component of the plastic surgeon's repertoire, especially free-flap breast reconstruction (FFBR), though this is a high-risk surgery in which patient selection is paramount. Preoperative predictors of complication remain mixed in their utility. We sought to determine whether the sarcopenia score, a validated measure of physiologic health, outperforms the body mass index (BMI) and modified frailty index (mFI) in terms of predicting outcomes.

Methods

All patients with at least 6-months follow-up and imaging of the abdomen who underwent FFBR from 2013 to 2022 were included in this study. Appropriate preoperative and postoperative data were included, and sarcopenia scores were extracted from imaging. Complications were defined as any unexpected outcome that required a return to the operating room or readmission. Statistical analysis and regression were performed.

Results

In total, 299 patients were included. Patients were split into groups, based on sarcopenia scores. Patients with lower sarcopenia had significantly more complications than those with higher scores. BMI and mFI both did not correlate with complication rates. Sarcopenia was the only independent predictor of complication severity when other factors were controlled for in a multivariate regression model.

Conclusions

Sarcopenia correlates with the presence of severe complications in patients who undergo FFBR in a stronger fashion to BMI and the mFI. Thus, sarcopenia should be considered in the preoperative evaluation in patients undergoing FFBR.

Exploring the Applicability of General Dietary Recommendations for People Affected by Obesity

(1) Obesity has emerged as a major public health challenge with increasing prevalence globally. The General Dietary Behavior Inventory (GDBI) was developed based on official dietary recommendations. However, little is known about whether general dietary recommendations also apply to people affected by obesity and whether the GDBI can be used appropriately. (2) A cross-sectional study was conducted. A total of 458 people meeting the inclusion criteria participated in the study. The assessment consisted of the GDBI and behavioral, dietary, and health-related variables. We used descriptive analysis to examine the item characteristics of the GDBI and inferential statistics to investigate the associations between the GDBI score and behavioral, dietary, and health-related outcomes. (3) Several items of the GDBI were concerned by ceiling effects. A higher GDBI score (indicating a higher adherence to dietary recommendations) was related to higher age, higher nutrition knowledge, more restrained eating behavior, lower impulsivity, and higher body mass index. There were no associations between the GDBI score and reported physical and mental health or quality of life. (4) The GDBI showed inconsistent relationships with the study outcomes. General dietary recommendations do not appear to be applicable to people with obesity. Hence, there is an urgent need for specific recommendations and subsequent assessments of behavioral adherence for people affected by obesity.

The effects of a structured physiotherapy program on pulmonary function and walking capacity in obese and non-obese adults undergoing cardiac surgery

BACKGROUND: Obesity is thought to be a risk factor for cardiopulmonary diseases due to changed pulmonary mechanics. It also drastically lowers functional capability in both males and females. A routine physiotherapy program has been shown to be effective in the prevention and treatment of cardiopulmonary diseases. It also significantly increases functional capacity following coronary artery bypass grafting. However, the effect of a structured physiotherapy program in obese and non-obese patients has not been well explored. As such, the objective of this study is to determine the effect of a standardized physiotherapy program on pulmonary function and walking capacity in obese and non-obese patients undergoing coronary artery bypass grafting. METHODS: A prospective study was conducted on 50 obese (age 57.2 ± 6.3 Y) and non-obese (age 56.6 ± 5.7 Y) adults who were schedule for coronary artery bypass grafting. Their body mass index was used to separate them into two groups. Both groups followed a structured physiotherapy program from day 1 to day 7 post cardiac surgery. Both groups underwent spirometry test at baseline (preoperatively) and after day 4 and day 7 postoperatively as well as a six-minute walk test at baseline and on day 7 postoperatively. RESULTS: At baseline, obese individuals had significantly lower pulmonary and physical functioning. On postoperative day 4, both groups deteriorated, although the obese group deterioration was worse, in most of the pulmonary parameters. On postoperative day 7, both groups improved, though the non-obese group improved at a faster rate. In contrary, it was observed that the obese group improved more rapidly in terms of functional capacity. CONCLUSIONS: The study indicated that the outcomes of a structured physiotherapy program following coronary artery bypass grafting were different for persons who were obese compared to those who were not. Adipose tissue variations surrounding the rib cage, diaphragm, and visceral cavity may account for the observed rate of change between the two groups. Therefore, it is apparent that a new strategy for managing obese individuals who have undergone CABG is required.

The relation of aortic dimensions and obesity in adults with Marfan or Loeys-Dietz syndrome

Background

Aortic aneurysm and aortic dissection can have a major impact on the life expectancy of Marfan syndrome (MFS) or Loeys-Dietz syndrome (LDS) patients. Although obesity can influence the development of aortic complications, evidence on whether obesity influences the development of aortic aneurysm or dissection in MFS and LDS is limited. The aim of the present study was to elucidate the relationship between aortic size and body composition, assessed by modern bioelectrical impedance analysis (BIA) in MFS/LDS-patients.

Methods

In this exploratory cross-sectional study in MFS or LDS patients, enrolled between June 2020 and May 2022, 34 patients received modern BIA and magnetic resonance imaging (MRI) (n=32) or computed tomography (CT) imaging (n=2) of the entire aorta. A P value of <0.05 was considered significant.

Results

Fifty-one patients (66% female; mean age: 37.7±11.7; range, 17-68 years) with MFS or LDS were enrolled; 34 patients, 27 with MFS and 7 with LDS, underwent aortic MRI or CT scanning. The mean aortic length was 503.7±58.7 mm, and the mean thoracic aortic length and abdominal aortic length were 351.5±52.4 and 152.2±27.4 mm, respectively. The aortic bulb and the ascending aorta were measured only in the non-surgically repaired patients. Fifteen MFS (88.2%) and two LDS (40.0%) patients had an aortic aneurysm. In these, the aortic bulb tended to be larger in MFS than in LDS patients [42.6×41.9×41.2 vs. 37.8×37.4×36.8 mm; P=0.07 (-1.1; 9.1); P=0.07 (-1.2; 8.4); P=0.07 (-1.5; 7.9)]. BIA revealed mean body fat levels of 31.6%±8.7% (range, 9.5-53.5%), indicating that 18 patients (52.9%) were obese. There was a significant correlation between body fat content and thoracic aortic length (R=-0.377; P=0.02), muscle mass and total aortic length (R=0.359; P=0.03), thoracic aortic length (R=0.399; P=0.02), extracellular mass (ECM), and total aortic length (R=0.354; P=0.04), and connective tissue and aortic diameters at the aortic arch (R=0.511; P=0.002), aortic isthmus (R=0.565; P<0.001), and abdominal aorta (R=0.486; P=0.004). Older age was correlated with wider aortic arch, isthmus, and abdominal aorta. Male patients had a longer aorta.

Conclusions

While a slender habitus is commonly known for MFS and LDS patients, our data show that many MFS and LDS patients (especially female) do not fit this phenotypic characteristic and are obese, which is associated with a more severe aortic phenotype. This topic should be included in the clinical assessment of affected MFS and LDS patients, in addition to measurement of the aortic diameters. Physicians should systematically screen MFS and LDS patients for obesity, educate them about the potential risk of resulting aortic complications, and encourage them to adopt a healthy lifestyle, that includes (mild) exercise and a balanced diet.

Impact of body mass index on postoperative oxygenation impairment in patients with acute aortic syndrome

Objective: Oxygenation impairment is a common complication of acute aortic syndrome (AAS) patients after surgical repair. The aim of this study is to identify the relationship between body mass index (BMI) and the risk of postoperative oxygenation impairment in AAS patients.

Methods: A total of 227 consecutive patients who were diagnosed as AAS and underwent surgical repair were recruited. They were divided into two groups based on the postoperative oxygenation impairment (non-oxygenation impairment group and oxygenation impairment group). Logistic regression was conducted to evaluate the association between BMI and the risk of oxygenation impairment after surgery. Dose-response curve and subgroup analysis were used to test the reliability of the results of regression analysis. A meta-analysis was then performed to further confirm these results using Pubmed, Embase, and Web of Science databases.

Results: For the retrospective study, a significant association was observed after adjusting for a series of variables. BMI was significantly correlated with postoperative oxygenation impairment in patients with AAS (OR, 95% CI, P: 1.27, 1.17–1.46, 0.001). Compared with the normal weight group (18.5 kg/m² ≤ BMI <23.0 kg/m²), patients with excessive BMI were at a higher risk of oxygenation impairment for the overweight group (23.0 kg/m² ≤ BMI <25 kg/m²) and obesity group (BMI ≥25 kg/m²) (OR, 95% CI, P: 4.96, 1.62–15.15, 0.005; 9.51, 3.06–29.57, <0.001). The dose-response curve showed that the risk of oxygenation impairment after surgery increased with the increased BMI. Besides, subgroup analysis showed that AAS patients who have an excess weight with a TNF-α ≥ 8.1 pg/ml carried an excess risk of postoperative oxygenation impairment. For the meta-analysis, the pooled result also indicated that AAS patients with high BMI had a significantly increased risk of oxygenation impairment after surgery (OR, 95% CI, P: 1.40, 1.18–1.66, 0.001).

Conclusion: Excessive BMI was an independent risk factor for AAS with postoperative oxygenation impairment.

Does the "obesity paradox" exist after transcatheter aortic valve implantation?

Background

Transcatheter aortic valve implantation (TAVI) for symptomatic aortic stenosis is considered a minimally invasive procedure. Body mass index (BMI) has been rarely evaluated for pulmonary complications after TAVI. This study aimed to assess the influence of BMI on pulmonary complications and other related outcomes after TAVI.

Methods

The clinical data of 109 patients who underwent TAVI in our hospital from May 2018 to April 2021 were retrospectively analyzed. Patients were divided into three groups according to BMI: low weight (BMI < 21.9 kg/m², n = 27), middle weight (BMI 21.9–27.0 kg/m², n = 55), and high weight (BMI > 27.0 kg/m², n = 27); and two groups according to vascular access: through the femoral artery (TF-TAVI, n = 94) and through the transapical route (TA-TAVI, n = 15). Procedure endpoints, procedure success, and adverse outcomes were evaluated according to the Valve Academic Research Consortium (VARC)-2 definitions.

Results

High-weight patients had a higher proportion of older (p < 0.001) and previous percutaneous coronary interventions (p = 0.026), a higher percentage of diabetes mellitus (p = 0.026) and frailty (p = 0.032), and lower glomerular filtration rate (p = 0.024). Procedure success was similar among the three groups. The 30-day all-cause mortality of patients with low-, middle-, and high weights was 3.7% (1/27), 5.5% (3/55), and 3.7% (1/27), respectively. In the multivariable analysis, middle- and high-weight patients exhibited similar overall mortality (middle weight vs. low weight, p = 0.500; high weight vs. low weight, p = 0.738) and similar intubation time compared with low-weight patients (9.1 ± 7.3 h vs. 8.9 ± 6.0 h vs. 8.7 ± 4.2 h in high-, middle-, and low-weight patients, respectively, p = 0.872). Although high-weight patients had a lower PaO₂/FiO₂ ratio than low-weight patients at baseline, transitional extubation, and post extubation 12th hour (p = 0.038, 0.030, 0.043, respectively), there were no differences for post extubation 24th hour, post extubation 48th hour, and post extubation 72nd hour (p = 0.856, 0.896, 0.873, respectively). Chronic lung disease [odds ratio (OR) 8.038, p = 0.001] rather than high weight (OR 2.768, p = 0.235) or middle weight (OR 2.226, p = 0.157) affected postoperative PaO₂/FiO₂ after TAVI.

Conclusions

We did not find the existence of an obesity paradox after TAVI. BMI had no effect on postoperative intubation time. Patients with a higher BMI should be treated similarly without the need to deliberately extend the intubation time for TAVI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01910-x.

Bioelectrical Impedance Analysis as a Contemporary Biomarker of Obesity in Adults with Marfan- or Loeys-Dietz-Syndrome

Background

It is clinically widely overlooked that many patients with Marfan- (MFS) or Loeys-Dietz-Syndrome (LDS) are obese. While anthropometric routine parameters are not very suitable, the modern Bioelectrical Impedance Analysis (BIA) seems superior for the acquisition of reliable noninvasive assessment of body composition of patients. The aim of the study was to assess the body composition of patients with MFS/LDS by BIA in order to detect occult obesity, which may be a risk marker for aortic or vascular complications.

Methods

In this exploratory cross-sectional study, 50 patients (66% female; mean age: 37.7 ± 11.7 [range: 17-64] years) with a molecular genetic (n = 45; 90%) or clinical (n = 5; 10%) proven diagnosis of MFS or LDS were enrolled between June 2020 and February 2022. All BIA-measurements were performed with the Multifrequence-Impedance-Analyzer Nutriguard-MS (Data Input, Poecking, Germany).

Results

The MFS/LDS collective was significantly different from an age-, sex-, and BMI-adjusted control in terms of body fat, percent cellularity, body cell mass, extra cellular mass/body cell mass index, and phase angle (all p < 0.05). The mean BIA-measured bodyfat was 31.7 ± 8.7% [range: 9.5-53.5%], while the mean calculated BMI of the included patients was 23.0 ± 4.8 kg/ m 2 [range: 15.2-41.9 kg/ m 2 ]. Therefore, using the obesity cut-off values for the body fat percentage of 25% in men and 35% in women, the BIA classifies as many as 28 patients (56.0%) as obese. In contrast only 12 patients (24.0%) were pre-obese, respectively 3 (6.0%) obese by BMI. The significant difference (p < 0.001) had an accordance of 42.7%. Overall, 15 patients (13 MFS; 2 LDS) had previous aortic surgery (n = 14) and/or interventional treatment (n = 2) for aortic complications (aneurysm, aortic dissection). 11 out of these 15 (73.3%) were currently classified as obese by BIA.

Conclusions

The fact that many patients with MFS or LDS are obese is widely unknown, although obesity may be associated with impaired vascular endothelial function and an increased risk of cardiovascular complications. Also, in patients with MFS/LDS, BIA allows a reliable assessment of the body composition beyond the normal anthropometric parameters, such as BMI. In the future, BIA-data possibly may be of particular importance for the assessment of the vascular risk of MFS/LDS patients, besides the aortic diameters.

Bariatric Surgery as the One Route to Achieving Donor Heart Transplantation in a Patient with a Left-Ventricular Assist Device

Bariatric and metabolic surgery is currently the most effective procedure of achieving and maintaining weight loss. In the case under discussion, a 48-year-old male patient with heart insufficiency and an implanted left-ventricular assist device (LVAD) wanted to reduce his high BMI (48.6 kg/m2), so as to qualify for the heart transplant waiting list. According to the guidelines, he underwent all the required preoperative testing, which included psychosomatic clarifications, determination of endocrinological causes, and a nutritional consultation. During laparoscopic sleeve gastrectomy, a cardiac technician was present to support the anesthetist. After inserting 3 trocars with no complications, the greater curvature was mobilized using Medtronic's bipolar electrothermal vessel-sealing instrument, LigaSure™. The resection was performed with an Ethicon™ endostapler. Postoperative monitoring showed no signs of hemorrhage. The patient's BMI on the day of surgery was 46.8 kg/m2 and consecutively fell to 26.7 kg/m2 1 year after the procedure. Follow-up appointments revealed that the patient was fit and in good health. Thus, the patient's aim of being listed on the transplant list was fulfilled, and at the time of this writing, he is ready to be matched with an organ donor. Because high-BMI patients with inserted LVADs are less likely to receive a donor graft and must remain longer on transplant waiting lists than normal-weight patients, bariatric and metabolic weight loss surgery may lead to a speedier resolution for these high-risk patients.

Stress CMR in patients with obesity: insights from the Stress CMR Perfusion Imaging in the United States (SPINS) registry

AIMS

Non-invasive assessment and risk stratification of coronary artery disease in patients with large body habitus is challenging. We aim to examine whether body mass index (BMI) modifies the prognostic value and diagnostic utility of stress cardiac magnetic resonance imaging (CMR) in a multicentre registry.

METHODS AND RESULTS

The SPINS Registry enrolled consecutive intermediate-risk patients who presented with a clinical indication for stress CMR in the USA between 2008 and 2013. Baseline demographic data including BMI, CMR indices, and ratings of study quality were collected. Primary outcome was defined by a composite of cardiovascular death and non-fatal myocardial infarction. Of the 2345 patients with available BMI included in the SPINS cohort, 1177 (50%) met criteria for obesity (BMI ≥ 30) with 531 (23%) at or above Class 2 obesity (BMI ≥ 35). In all BMI categories, >95% of studies were of diagnostic quality for cine, perfusion, and late gadolinium enhancement (LGE) sequences. At a median follow-up of 5.4 years, those without ischaemia and LGE experienced a low annual rate of hard events (<1%), across all BMI strata. In patients with obesity, both ischaemia [hazard ratio (HR): 2.14; 95% confidence interval (CI): 1.30-3.50; P = 0.003] and LGE (HR: 3.09; 95% CI: 1.83-5.22; P < 0.001) maintained strong adjusted association with the primary outcome in a multivariable Cox regression model. Downstream referral rates to coronary angiography, revascularization, and cost of care spent on ischaemia testing did not significantly differ within the BMI categories.

CONCLUSION

In this large multicentre registry, elevated BMI did not negatively impact the diagnostic quality and the effectiveness of risk stratification of patients referred for stress CMR.

Impact of body mass index on early and mid-term outcomes after surgery for acute Stanford type A aortic dissection

Background

Obesity is dramatically increasing worldwide, and more obese patients may develop aortic dissection and present for surgical repair. The study aims to analyse the impact of body mass index (BMI) on surgical outcomes in patients with acute Stanford type A aortic dissection (ATAAD).

Methods

From January 2017 to June 2019, the clinical data of 268 ATAAD patients in a single centre were retrospectively reviewed. They were divided into three groups based on the BMI: normal weight (BMI 18.5 to < 25 kg/m², n = 110), overweight (BMI 25 to < 30 kg/m², n = 114) and obese (BMI ≥30 kg/m², n = 44).

Results

There was no statistical difference among the three groups in terms of the composite adverse events including 30-day mortality, stroke, paraplegia, renal failure, hepatic failure, reintubation or tracheotomy and low cardiac output syndrome (20.9% vs 21.9% vs 18.2% for normal, overweight and obese, respectively; P = 0.882). No significant difference was found in the mid-term survival among the three groups. The proportion of prolonged ventilation was highest in the obese group followed by the overweight and normal groups (59.1% vs 45.6% vs 34.5%, respectively; P = 0.017). Multivariable logistic regression analysis suggested that BMI was not associated with the composite adverse events, while BMI ≥30 kg/m² was an independent risk factor for prolonged ventilation (OR 2.261; 95% CI 1.056–4.838; P = 0.036).

Conclusions

BMI had no effect on the early major adverse outcomes and mid-term survival after surgery for ATAAD. Satisfactory surgical outcomes can be obtained in patients with ATAAD at all weights.

Impact of Body Mass Index on Outcome of Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Obesity is highly prevalent in patients with obstructive hypertrophic cardiomyopathy (HCM). In this study, we investigated the impact of body mass index (BMI) in patients undergoing septal myectomy (SM) for obstructive HCM.

METHODS

We reviewed 2,746 patients who underwent transaortic SM for obstructive HCM from February 1993 through September 2018. Patients were stratified into 3 groups based on BMI (normal weight < 25 kg/m², overweight 25 to < 30 kg/m², and obese ≥ 30 kg/m²).

RESULTS

Preoperatively, median left ventricular outflow tract (LVOT) gradient was 58 mmHg, and there was no difference in gradients across BMI strata (P=0.35). Obese patients had lower percentage with moderate or greater mitral valve regurgitation (45.8%) compared to normal (52.9%) and overweight (55.4%) patients (P<0.001). However, patients with higher BMI were more likely to have New York Heart Association class III/IV limitation at presentation (P<0.001). After myectomy, both anteroseptal thickness (P=0.115) and LVOT gradient (P=0.210) did not differ between groups. There were 14 (0.5%) deaths < 30 days postoperatively and the risk was similar across BMI strata (P=0.448). Model-estimated changes in average BMI at 10 years post procedure showed stratum-specific increases ranging from 0.60 to 1.56 kg/m². During a median (IQR) follow-up of 7.2 (3.2-13.3) years, higher BMI was associated with reduced survival after adjusting for baseline covariates (P=0.001).

CONCLUSIONS

Septal myectomy is safe and effective in HCM patients with obesity, but risk of late mortality increased with increasing BMI. Attention to risk factor management through weight loss may improve late results after SM.

Clinical Outcomes of Subcutaneous and Visceral Adipose Tissue Characteristics Assessed in Patients Underwent Transcatheter Aortic Valve Replacement

BACKGROUND

Adipose tissue (AT) characteristics are considered to be a marker for predicting clinical outcomes. This study aimed to investigate the prognostic value of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) computed tomography (CT) assessment in patients who underwent transcatheter aortic valve replacement (TAVR).

METHODS

We used the Japanese multicentre registry data of 1372 patients (age: 84.5 ± 5.0 years, women: 70.6%) who underwent TAVR. The SAT and VAT were assessed according to the preprocedural CT area and density. Baseline characteristics and clinical outcomes were compared based on the differences in AT characteristics. The independent associations with all-cause mortality after TAVR were evaluated according to the CT area and density of AT.

RESULTS

Low-volume area of SAT and VAT was associated with worse clinical outcomes compared with high-volume area of SAT and VAT in patients who underwent TAVR (log-rank test P = 0.016 and P = 0.014). High CT density of SAT and VAT was associated with increasing mortality in comparison with low CT density of SAT and VAT (log-rank test P < 0.001 and P = 0.007). The Cox regression multivariate analysis demonstrated the independent association of increased all-cause mortality in the high SAT and VAT density (hazard ratio [HR]: 1.41, 95% confidence interval [CI]: 1.06-1.88, P = 0.019, and HR: 1.34, 95% CI: 1.03-1.76, P = 0.031, respectively), but not in the low SAT and VAT area (HR: 0.85, 95% CI: 0.74-1.29, P = 0.85, and HR: 0.78, 95% CI: 0.60-1.03, P = 0.085, respectively).

CONCLUSIONS

CT-derived AT characteristics, particularly the qualitative assessments, were useful for predicting the prognosis in patients after TAVR.

Minimally invasive aortic valve surgery in obese patients: Can the bigger afford the smaller?

BACKGROUND

Ministernotomy and right minithoracotomy are well-known minimally invasive approaches for aortic valve replacement (AVR); however, controversial opinions exist for their utilization in obese patients. The aim of this study is to check a potential positive role of minimally invasive surgery in this population.

METHODS

From January 2010 to November 2019, 613 obese patients (defined by a body mass index ≥30) underwent isolated AVR at our institution. Surgical approach included standard median sternotomy (176 patients), partial upper sternotomy (271 patients), or right anterior minithoracotomy (166 patients). Intra- and postoperative data were retrospectively collected.

RESULTS

Patients treated with minimally invasive approaches had shorter cardiopulmonary bypass time (p = .012) and aortic cross-clamp time (p = .022), mainly due to the higher utilization of sutureless valve implantation. They also presented advantages in terms of reduced postoperative ventilation time (p = .010), incidence of wound infection (p = .009), need of inotropic support (p = .004), and blood transfusion (p = .001). The univariable logistic regression showed the traditional full sternotomy approach as compared with ministernotomy (p = .026), active smoking (p = .009), peripheral vascular disease (p = .003), ejection fraction (p = .026), as well Logistic European system for cardiac operative risk evaluation (EuroSCORE; p = .015) as factors associated with hospital mortality. The multivariable logistic regression adjusted for the logistic EuroSCORE revealed that surgical approaches do not influence hospital mortality.

CONCLUSIONS

Obese patients with severe aortic valve pathology can be treated with minimally invasive approaches offering a less biological insult and reduced postoperative complications, but without impact on hospital mortality.

Factors Associated With Early Extubation After Cardiac Surgery: A Retrospective Single-Center Experience

OBJECTIVES

To identify factors associated with early extubation in cardiac surgery patients.

DESIGN

Single center, retrospective.

SETTING

Tertiary university hospital.

PARTICIPANTS

The study comprised 8,872 adult patients who underwent cardiothoracic surgery from 2011-2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 8,872 patients, 2,950 (33%) were extubated within six hours after surgery. Early extubated patients were younger, had a higher body mass index (BMI), were more likely to be male, and were fast-track designated. These patients more frequently underwent isolated coronary artery bypass graft, isolated valve, or adult congenital surgeries than did late extubated patients. Early extubated patients had a greater incidence of coronary artery disease (CAD) and anxiety and a higher left ventricular ejection fraction. They also were less likely to have difficult intubation or require mechanical circulatory support, reintubation, or readmission. Analysis of the 8,872 patients showed that male sex (odds ratio [OR] 1.222, 95% confidence interval [CI] 1.096-1.363), a BMI >30 kg/m² (OR 1.702, 95% CI 1.475-1.965), undergoing isolated valve surgery (OR 1.187, 95% CI 1.060-1.328), and having a fast-track designation (OR 1.455, 95% CI 1.208-1.751) and CAD (OR 1.122, 95% CI 1.005-1.253) were associated with early extubation. Data on intensive care unit (ICU) admission after surgery were available only from 2014-2018. Within this subgroup of 5,977 patients, variables associated with early extubation included male sex (OR 1.356, 95% CI 1.193-1.541), BMI >30 kg/m² (OR 1.267, 95% CI 1.084-1.480), daytime admission to the ICU (OR 1.712, 95% CI 1.527-1.919), and fast-track designation (OR 1.423, 95% CI 1.123-1.802).

CONCLUSIONS

Male sex; a BMI >30 kg/m²; undergoing isolated valve surgery; and having a fast-track designation, CAD, and daytime admission to the ICU are associated with early extubation.

Safety of High-Dose Unfractionated Heparin for Prophylaxis of Venous Thromboembolism in Hospitalized Obese Patients

BACKGROUND

Optimal dosing of unfractionated heparin (UFH) for thromboprophylaxis in the obese patient population is uncertain because of their high-risk, prothrombotic state and a complexity of pharmacokinetic considerations. Literature on the appropriateness of the use of a higher dose UFH regimen remains unclear and inconsistent.

OBJECTIVE

To evaluate the safety of the use of 7500 units every 8 hours (high-dose) of subcutaneous UFH compared with the use of 5000 units every 8 hours (standard-dose) of subcutaneous UFH for thromboprophylaxis in obese patients (defined as BMI ≥30 kg/m²).

METHODS

In a retrospective cohort study, 326 adult patients were included, with a BMI ≥30 kg/m², who were admitted to a large, urban academic medical center between September 1, 2015, and September 1, 2018. Patients received either high-dose or standard-dose UFH for at least 48 hours. The primary end point was the incidence rate of bleeding events, defined as a ≥2-g/dL fall in hemoglobin level or receipt of transfusion of 2 or more units of packed red blood cells (pRBCs) from the start of the UFH order.

RESULTS

The incidence rate of bleeding was significantly higher in those who received high-dose UFH (43%) compared with those who received standard-dose UFH (29%; P = 0.008). No significant difference was found between venous thromboembolism event rates.

CONCLUSION AND RELEVANCE

High-dose UFH was associated with an increased bleeding event rate compared with standard-dose UFH in patients with a BMI ≥30 kg/m². This raises safety concerns about the appropriateness of utilizing this regimen in this population.

Pulmonary complications following cardiac surgery

Coronary heart disease is a common diseases of atherosclerosis. Despite the development of noninvasive therapies and the advancement of pharmacological methods and extensive drug regimens, coronary artery bypass grafting surgery is still the ultimate treatment option in many patients. Among the various complications following open heart surgery, one of the common difficulties is pulmonary complications associated with subsequent morbidity and mortality, which should be studied according to preoperative, perioperative, and postoperative factors. Preoperative factors include genetics, age, family history of pulmonary disease, smoking, coexisting disease, etc. Perioperative factors include surgical procedures like sternotomy incision, cardioplegia, and internal mammary artery harvesting; anaesthesia procedure effects like pulmonary collapse, maintenance drugs and morphine administration; and cardiopulmonary bypass pump by systemic inflammatory response syndromes. And finally, postoperative factors, especially mediastinitis and the role of nursing in the intensive care unit. Pulmonary complications after cardiac surgery include atelectasis, pleural effusions, pneumonia, pulmonary oedema, cardiogenic pulmonary oedema, acute respiratory distress syndrome, pulmonary embolism, phrenic nerve injury, pneumothorax, sternal wound infection, and mediastinitis, with different outbreaks in patients reported. Although the preoperative, perioperative, and postoperative factors play an important role in the occurrence of these complications, the preoperative factors, as factors that can be adjusted, should be considered more than the others and explained to the patient, and the preoperative patient’s assessment should be noted. Also, postoperative care with the goal of reducing infections and pulmonary complications should be addressed by the nursing team.

Impact of a Higher Body Mass Index on Prolonged Intubation in Patients Undergoing Surgery for Acute Thoracic Aortic Dissection

BACKGROUND

In recent years, obese patients presenting with acute thoracic aortic dissection have not been uncommon and there are often pulmonary complications among them. Whether a higher body mass index (BMI) is associated with more pulmonary complications or even a higher mortality rate has yet to be determined. This study aimed to evaluate the effects of higher BMI on pulmonary complications and other surgical outcomes.

METHODS

A total of 404 patients who underwent acute thoracic aortic dissection surgery were retrospectively studied. They were divided into three groups based on their BMI: normal weight (BMI 18.5 to <25 kg/m², n=173), overweight (BMI 25 to <30 kg/m², n=145) and obese (BMI ≥30 kg/m², n=86). Clinical data were collected and analysed among groups.

RESULTS

No statistical significance was detected among the groups for postoperative complications, in-hospital mortality and hospital or ICU stay, except for prolonged intubation, the proportion of which was highest in the obese group followed by the overweight and normal groups (40.7% vs 29% vs 11%, respectively; p<0.001). Furthermore, logistic regression analysis showed that postoperative renal failure (OR=16.984) and cardiopulmonary bypass time (OR=1.013) were independent risk factors for in-hospital mortality, while higher BMI (OR=7.148 for BMI ≥25 and 18.967 for BMI ≥30), transfused red blood cells (OR=1.004), and postoperative renal failure (OR=7.386) were independent risk factors for prolonged ventilation (p<0.05).

CONCLUSION

Body mass index had no effect on in-hospital mortality but may be closely correlated with prolonged intubation for patients undergoing aortic dissection surgery. This finding suggests that these patients should receive more aggressive pulmonary management.

Adverse Outcomes in Obese Cardiac Surgery Patients Correlates With Altered Branched-Chain Amino Acid Catabolism in Adipose Tissue and Heart

Background: Predicting relapses of post-operative complications in obese patients who undergo cardiac surgery is significantly complicated by persistent metabolic maladaptation associated with obesity. Despite studies supporting the linkages of increased systemic branched-chain amino acids (BCAAs) driving the pathogenesis of obesity, metabolome wide studies have either supported or challenged association of circulating BCAAs with cardiovascular diseases (CVDs). Objective: We interrogated whether BCAA catabolic changes precipitated by obesity in the heart and adipose tissue can be reliable prognosticators of adverse outcomes following cardiac surgery. Our study specifically clarified the correlation between BCAA catabolizing enzymes, cellular BCAAs and branched-chain keto acids (BCKAs) with the severity of cardiometabolic outcomes in obese patients pre and post cardiac surgery. Methods: Male and female patients of ages between 44 and 75 were stratified across different body mass index (BMI) (non-obese = 17, pre-obese = 19, obese class I = 14, class II = 17, class III = 12) and blood, atrial appendage (AA), and subcutaneous adipose tissue (SAT) collected during cardiac surgery. Plasma and intracellular BCAAs and BC ketoacids (BCKAs), tissue mRNA and protein expression and activity of BCAA catabolizing enzymes were assessed and correlated with clinical parameters. Results: Intramyocellular, but not systemic, BCAAs increased with BMI in cardiac surgery patients. In SAT, from class III obese patients, mRNA and protein expression of BCAA catabolic enzymes and BCKA dehydrogenase (BCKDH) enzyme activity was decreased. Within AA, a concomitant increase in mRNA levels of BCAA metabolizing enzymes was observed, independent of changes in BCKDH protein expression or activity. BMI, indices of tissue dysfunction and duration of hospital stay following surgery correlated with BCAA metabolizing enzyme expression and metabolite levels in AA and SAT. Conclusion: This study proposes that in a setting of obesity, dysregulated BCAA catabolism could be an effective surrogate to determine cardiac surgery outcomes and plausibly predict premature re-hospitalization.

Obese trauma patients have increased need for dialysis

PURPOSE

Obesity is a risk factor for the development of acute kidney injury but its effect on the need for dialysis in trauma has not been elucidated. Additionally, the contribution that obesity has towards risk of mortality in trauma is unclear. We hypothesized that patients with a higher body mass index (BMI) will have a higher risk for need of dialysis and mortality after trauma.

METHODS

This is a retrospective analysis using the National Trauma Data Bank. All patients ≥ 8 years old were grouped based on BMI: normal (18.5-24.99 kg/m²), obese (30-34.99 kg/m²), severely obese (35-39.99 kg/m²) and morbidly obese (≥ 40 kg/m²). The primary outcome was hemodialysis initiation. The secondary outcome was mortality during the index hospitalization.

RESULTS

From 988,988 trauma patients, 571,507 (57.8%) had a normal BMI, 233,340 (23.6%) were obese, 94,708 (9.6%) were severely obese, and 89,433 (9.0%) were morbidly obese. The overall rate of hemodialysis was 0.3%. After adjusting for covariates, we found that obese (OR 1.36, CI 1.22-1.52, p < 0.001), severely obese (OR 1.89, CI 1.66-2.15, p < 0.001) and morbidly obese (OR 2.04, CI 1.82-2.29, p < 0.001) patients had a stepwise increased need for hemodialysis after trauma. Obese patients had decreased (OR 0.92, CI 0.88-0.95, p < 0.001), severely obese had similar (OR 1.02, CI 0.97-1.08, p = 0.50) and morbidly obese patients had increased (OR 1.06, CI 1.01-1.12, p = 0.011) risk of mortality after trauma.

CONCLUSIONS

Obesity was associated with an increased risk for dialysis after trauma. Mortality risk was reduced in obese, similar in severely obese, and increased in morbidly obese trauma patients suggesting an inflection threshold BMI for risk of mortality in trauma.