The Effects of Obesity on Mortality Following Coronary Artery Bypass Graft Surgery: A Retrospective Study from a Single Center in China

Ventricular Epicardial Adipose Distribution on Human Hearts: 3-Dimensional Reconstructions and Quantitative Assessments

Epicardial interventions have forged new frontiers in cardiac ablation and device therapies. Healthy human hearts typically present with significant adipose tissue layers superficial to the ventricular myocardium and may hinder success or increase the complexities of epicardial interventions. We quantitatively evaluated the distribution of epicardial adipose tissue on the surface of human hearts and provided high-fidelity 3-dimensional reconstructions of these epicardial adipose tissue layers. The regional thickness of adipose tissues was analyzed at 51 anatomical reference points surrounding both ventricles and compared to specific patient demographics. Adipose deposits on the human hearts displayed characteristic patterns, with the thickest accumulations along the interventricular septa (anterior, 9.01 ± 0.50 mm; posterior, 6.78 ± 0.50 mm) and the right ventricular margin (7.44 ± 0.57 mm). We provide one of the most complete characterizations of human epicardial adipose location and relative layer thickness. These results are considered fundamental for an underlying anatomic understanding when performing procedures within the pericardial space.

The effect of body mass index on short-term outcomes in patients undergoing off-pump coronary artery bypass grafting surgery: a retrospective study from a single cardiovascular center

OBJECTIVE

This study is designed to investigate the impact of body mass index (BMI) on the short-term outcomes of patients undergoing off-pump coronary artery bypass graft (OPCAB) surgery.

METHODS

Data was obtained from 1006 Chinese patients who underwent isolated, primary OPCAB at a high-traffic cardiovascular center during 2020. Subjects were categorized, by BMI, into a low & normal weight (LN) group (BMI < 24 kg/m2), an overweight (OVW) group (24 ≤ BMI < 28 kg/m2), and an obese (OBS) group (BMI ≥ 28 kg/m2). Information pertaining to patients' short-term outcomes (including incidence of mortality and morbidities; duration of postoperative mechanical ventilation; length of stay in the ICU and hospital; postoperative bleeding; etc.) were extracted, and the data from each group were compared.

RESULTS

The incidences of in-hospital mortality and morbidities were similar for all three groups. The volume of fluid infusion, postoperative bleeding within 24 h and total bleeding in LN group were higher than those in the OBS group (P < 0.001). The hemoglobin level was lower in the LN group than that in the OBS group (P < 0.001). Duration of mechanical ventilation and length of stay in the ICU in the LN group were longer than those in the OBS group (P < 0.001).

CONCLUSIONS

Our results demonstrate that BMI is not significantly related with short-term outcomes in OPCAB patients. However, we suggest that OPCAB patients with low-normal BMI are more susceptible to post-operative blood loss.

Increasing obesity is associated with lower postoperative bleeding in coronary bypass patients

OBJECTIVE

Despite inherent comorbidities, obese cardiac surgical patients paradoxically had shown lower morbidity and mortality, although the nature of this association is still unclear. Thus, the authors intended in this large registry-based study to investigate the impact of obesity on short- and long-term postoperative outcomes, focusing on bleeding and transfusion requirements.

DESIGN

Retrospective registry study.

SETTING

Three university hospitals.

PARTICIPANTS

A cohort of 12,330 prospectively compiled data from coronary bypass grafting patients undergoing surgery between 2007 to 2020 were retrieved from the Western Denmark Heart Registry.

INTERVENTIONS

The parameters were analyzed to assess the association between body mass index (BMI) and the selected outcome parameters.

MEASUREMENTS AND MAIN RESULTS

The crude data showed a clear statistically significant association in postoperative drainage from 637 (418-1108) mL in underweight patients with BMI <18.5 kg/m² to 427 (295-620) mL in severely obese patients with BMI ≥40 kg/m² (p < 0.0001, Kruskal-Wallis). Further, 50.0% of patients with BMI <18.5 received an average of 451 mL/m² in red blood cell transfusions, compared to 16.7% of patients with BMI >40 receiving 84 mL/m². The obese groups were less often submitted to reexploration due to bleeding, and fewer received perioperative hemostatics, inotropes, and vasoconstrictors. The crude data showed increasing 30-day and 6-month mortality with lower BMI, whereas the one-year mortality showed a V-shaped pattern, but BMI had no independent impact on mortality in logistic regression analysis.

CONCLUSION

Patients with high BMI may carry protection against postoperative bleeding after cardiac surgery, probably secondary to an inherent hypercoagulable state, whereas underweight patients carry a higher risk of bleeding and worse outcomes.

Comparative Analysis of Early Postoperative Period in Patients with Total Arterial Revascularization and Conventional Coronary Artery Bypass Grafting

The use of total arterial myocardial revascularization in patients with multivessel lesions of the coronary arteries has a number of advantages, namely the duration of functioning or patency of the grafts. The level of total arterial myocardial revascularization implementation in developed and developing countries remains quite low. The aim. Based on the analysis of our own experience, to determine the influence of the technique of total arterial revascularization on the frequency of complications in the early postoperative period. Materials and methods. From February 22, 2016 to December 24, 2020, 390 consecutive patients were operated at the Ukrainian Children’s Cardiac Center. The patients were divided into two groups: participants of the group I underwent total arterial myocardial revascularization, and those includedin the group II underwent conventional coronary artery bypass grafting (CABG). The inclusion criteria were: ischemic heart disease, stable angina or exertional angina, multivascular coronary artery disease, absence of valvular pathology. Results. There was zero 30-day mortality in both groups. The frequency of postoperative bleeding was higher in group II and amounted to 1.6%. Surgical wound complications (infection) were also more common in the group II: 1.2% versus 0.69% (p=0.906) in the group I. Similarly, laboratory parameters such as the level of creatine kinase-MB were almost identical. Conclusions. Total arterial myocardial revascularization is a safe method with good immediate results. The frequency of complications in total arterial myocardial revascularizationdoes not differ from that in conventional CABG. For a wider application of the total arterial myocardial revascularization,it is necessary to continue toconduct studies of the remote postoperative period.

Impacts of metabolic disorders on short- and long-term mortality after coronary artery surgery in the elderly

BACKGROUND

Elderly patients undergoing cardiac operation often suffer various metabolic comorbidities, such as diabetes mellitus (DM) and obesity. The metabolic disorders in these individuals are widely considered to be possible predisposing factors for unfavourable prognosis. This retrospective study was aimed to determine the association of metabolic diseases with the mortality of elderly patients after coronary artery bypass grafting (CABG) and to identify the protective or risk factors related to their short- and long-term survival.

METHODS

Totally 684 patients aged 75 years or above undergoing isolated CABG were evaluated retrospectively. There were two groups depending on the body mass index (BMI): an overweight and obesity group (n = 354) and a normal weight and lean group (n = 330). Propensity score matching (PSM) was performed to adjust baseline clinical characteristics, which reduced confounding bias. The short-term postoperative mortality was tested via logistic regression. Kaplan-Meier and Cox regression analyses were done to compute the overall survival in each group and to identify relevant variables associated with all-cause mortality, respectively.

RESULTS

The prevalence rates of metabolic comorbidities in the total cohort were: diabetes mellitus (32.5%), overweight or obesity (51.8%) and hypertension (72.8%). The 30-day postoperative mortality was 5.1% and the long-term mortality was 15.25% at a median 46.2-month follow-up (1.0-178.6 months). The 30-day postoperative mortality was relevant to DM, diseased coronary arteries, New York Heart Association class, intra-aortic balloon pump and emergency surgery. The long-term mortality was negatively associated with overweight and obesity. Univariate and multivariate logistic regression recognized DM as an adverse factor related with 30-day postoperative mortality whether before or after PSM. The long-term mortality was not significantly relevant with DM (HR = 0.753, 95% CI 0.402-1.411). Overweight or obesity was not the risk factor of 30-day postoperative mortality (OR = 1.284, 95% CI 0.426-3.868), but was the protective factor of long-term survival (HR = 0.512, 95% CI 0.279-0.939).

CONCLUSIONS

The "obesity paradox" exists regarding the prognosis of individuals aged ≥ 75, which was presented as lower long-term mortality no matter from all cause or cardio-cerebrovascular cause in patients with BMI ≥ 24. Trial registration ChiCTR2200061869 (05/07/2022).

Impact of Obesity on Early In-Hospital Outcomes after Coronary Artery Bypass Grafting Surgery in Acute Coronary Syndrome: A Propensity Score Matching Analysis

Recent advances in perioperative care have considerably improved outcomes after coronary artery bypass graft (CABG) surgery. However, obesity can increase postoperative complication rates and can lead to increased morbidity and mortality. Between June 2011 and October 2019, a total of 1375 patients with acute coronary syndrome (ACS) underwent cardiac surgery and were retrospectively analyzed. Patients were divided into 2 groups: non-obese (body mass index (BMI) < 30 kg/m2, n = 967) and obese (BMI ≥ 30 kg/m2, n = 379). Underweight patients (n = 29) were excluded from the analysis. To compare the unequal patient groups, a propensity score-based matching (PSM) was applied (non-obese group (n = 372) vs. obese group (n = 372)). The mean age of the mentioned groups was 67 ± 10 (non-obese group) vs. 66 ± 10 (obese group) years, p = 0.724. All-cause in-hospital mortality did not significantly differ between the groups before PSM (p = 0.566) and after PSM (p = 0.780). The median length of ICU (p = 0.306 before PSM and p = 0.538 after PSM) and hospital stay (p = 0.795 before PSM and p = 0.131 after PSM) was not significantly higher in the obese group compared with the non-obese group. No significant differences regarding further postoperative parameters were observed between the unadjusted and the adjusted group. Obesity does not predict increased all-cause in-hospital mortality in patients undergoing CABG procedure. Therefore, CABG is a safe procedure for overweight patients.

Predictive Ability of European Heart Surgery Risk Assessment System II (EuroSCORE II) and the Society of Thoracic Surgeons (STS) Score for in-Hospital and Medium-Term Mortality of Patients Undergoing Coronary Artery Bypass Grafting

Objective

To evaluate the powers of European Heart Surgery Risk Assessment System II (EuroSCORE II) and the Society of Thoracic Surgeons (STS) score in predicting in-hospital and medium-term mortality of patients undergoing coronary artery bypass grafting (CABG).

Methods

Totally 1628 Chinese patients were included between January 2000 and January 2018. Their perioperative clinical data were collected and the patients were closely followed up. According to the length of follow-up time, the total cohort was divided into 1-year, 2-year, 3-year, 4-year and 5-year groups. The in-hospital and medium-term risk prediction of EuroSCORE II and STS score were comparatively assessed by calibration, discrimination, decision curve analysis (DCA), net reclassification index (NRI), integrated discrimination improvement (IDI) and Bland-Altman analysis.

Results

About 36 (2.21%) patients died during hospitalization. Both EuroSCORE II and STS score performed extremely well in predicting in-hospital mortality (area under curve = 0.900 and 0.879, respectively). However, calibration and discrimination analyses showed gradual decrease when these two risk evaluation systems were used to predict mortality during the follow-up period. At the same time, the predictive ability of EuroSCORE II was better than STS score. DCA curves showed that the performances of the two evaluation systems were roughly equal between the threshold probability of 0% to 20%. The percentage of correct reclassification of EuroSCORE II was 21.64% higher than that of STS score in predicting 2-year postoperative mortality. The IDI index showed that the predictive capabilities of these two systems were roughly equivalent. Bland-Altman analysis showed no significant difference between the values of the two systems.

Conclusion

EuroSCORE II and STS score have excellent predictive powers in predicting in-hospital mortality of patients undergoing CABG. In particular, EuroSCORE II is superior in calibration and discrimination. The prediction efficiency of the two risk evaluation systems is still acceptable for two-year postoperative mortality, but decreases year by year.