Cardiac Procedures in Patients With a Body Mass Index Exceeding 45: Outcomes and Long-Term Results

doi:10.1016/j.athoracsur.2007.03.024

The Annals of Thoracic Surgery

Volume 84, Issue 1, July 2007, Pages 3-9

Presented at the Fifty-third Annual Meeting of the Southern Thoracic Surgical Association, Tucson, AZ, Nov 8–11, 2006.

https://doi.org/10.1016/j.athoracsur.2007.03.024 Get rights and content

Background

Obesity has become a public health crisis. Although prior studies in obese patients undergoing cardiac surgical procedures have shown variable effects on outcomes, data are limited for extremely obese patients (body mass index [BMI] ≥ 45). We undertook this study to evaluate outcomes in this cohort.

Methods

A retrospective analysis was performed on 14,571 patients in our database who underwent cardiac operations from 1992 to 2005. Patient demographics, comorbidities, and outcomes were recorded. A univariate analysis between two groups: BMI 21 to 34.9 and BMI 45 or more was performed. Logistic regression models were used to identify independent risk factors for 30-day mortality. Long-term follow-up of the extreme obese group was achieved.

Results

We identified 128 extreme obese patients, and 480 patients with a BMI of 21.0 to 34.9 were randomly selected for comparison. Univariate analysis showed significant differences in age, gender, and multiple comorbidities, as well as in cardiopulmonary bypass and cross-clamp times, operative procedure, and transfusion requirements. Extreme obese patients had a higher incidence of infection, acute renal failure, and 30-day mortality. Logistic regression analysis showed BMI, preoperative renal insufficiency, and transfusion status to be independent risk factors for 30-day mortality. Follow-up data did not reveal significant functional improvements. Long-term survival was 33.6% at 12 years.

Conclusions

Extreme obese patients undergoing cardiac surgical procedures have higher perioperative morbidity and mortality compared with a lower BMI group. BMI and preoperative renal insufficiency increase mortality in both groups, whereas transfusion does so only in the extreme obese. These patients can realize acceptable outcomes from cardiac procedures, but continue to suffer from the comorbidities of obesity.

Section snippets

Material and Methods

A retrospective analysis was performed on 14,571 patients in our Adult Cardiac Surgery Database who underwent cardiac operations at the Brody School of Medicine, East Carolina University from 1992 to 2005. The University and Medical Center Institutional Review Board Committee approved the study and waived individual patient consent. In follow-up, all extreme obese patients that were contacted by telephone gave informed consent.

We identified 169 patients with a BMI of 45 or more who had

Results

All patients in both groups were operated on in the same institution by the same group of surgeons. All patients underwent standard median sternotomy, cardiopulmonary bypass with mild or moderate hypothermia, and cardioplegic arrest with crystalloid/blood cardioplegic solution, delivered either antegrade, retrograde, or both. This is our standard intraoperative myocardial protection protocol. Sternotomies were closed with single stainless steel wire used in a simple or figure-of-eight

Comment

This retrospective analysis reports on a small but potentially increasing subset of adult cardiac surgery patients, namely, the extreme obese with a BMI of 45 or more. Because this was an observational study, we chose a control group that best represented a contemporary cardiac surgical population at our facility rather than a case–control study with the purpose of matching independent variables.

A BMI of 35 to 40 has been the upper limit for analysis in most reported studies, with only one

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No more broken hearts: weight loss after bariatric surgery returns patients’ postoperative risk to baseline following coronary surgery
2017, Surgery for Obesity and Related Diseases
The obesity epidemic is associated with a rise in coronary surgeries because obesity is a risk factor for coronary artery disease. Bariatric surgery is linked to improvement in cardiovascular co-morbidities and left ventricular function. No studies have investigated survival advantage in postoperative bariatric patients after coronary surgery.
To determine if there is a benefit after coronary surgery in patients who have previously undergone bariatric surgery.
National Inpatient Sample.
We performed a retrospective, cross-sectional analysis of the National Inpatient Sample database from 2003 to 2010. We selected bariatric surgical patients who later underwent coronary surgery (n = 257). A comparison of postoperative complications and mortality after coronary surgery were compared with controls (n = 1442) using χ² tests, linear regression analysis, and multivariate logistical regression models.
A subset population was identified as having undergone coronary surgery (n = 1699); of this population, 257 patients had previously undergone bariatric surgery. They were compared with 1442 controls. The majority was male (67.2%), white (82.6%), and treated in an urban environment (96.8%). Patients with bariatric surgery assumed the risk of postoperative complications after coronary surgery that was associated with their new body mass index (BMI) (BMI<25 kg/m²: odds ratio (OR) 1.01, 95% CI .76–1.34, P = .94; BMI 25 to<35 kg/m²: OR .20, 95% CI .02–².16, P = .19; BMI≥35 kg/m²: OR>999.9, 95% CI .18 to>999.9, P = .07). Length of stay was significantly longer in postbariatric patients (BMI<25, OR 1.62, 95% CI 1.14–2.30, P = .007).
Postoperative bariatric patients have a return to baseline risk of morbidity and mortality after coronary surgery.
In-hospital outcomes of percutaneous coronary interventions in extremely obese and normal-weight patients: Findings from the NCDR (national cardiovascular data registry)
2013, Journal of the American College of Cardiology
The purpose of this study was to compare in-hospital outcomes of percutaneous coronary intervention (PCI) in extreme obesity (EO) (body mass index [BMI] ≥40 kg/m²) with those of normal-weight (NW) patients and to examine the influence of access site on outcomes.
Little is known about the outcomes of PCI in EO patients.
We analyzed CathPCI Registry data from patients who underwent radial or femoral PCI and were discharged between July 2009 and June 2011 and compared in-hospital outcomes of EO (N = 83,861) with those of NW patients (BMI 20 to 25 kg/m²; N = 217,616). Outcomes included in-hospital mortality and procedural and bleeding complications. Multivariable logistic regression models were used to assess the independent association of EO with outcomes, using previously validated risk models derived from the CathPCI Registry. The role of access site was specifically examined.
Compared with NW patients, EO patients were younger (median age 60 vs. 69 years), more likely female (47% vs. 37%), and more likely African American (12% vs. 7%). EO patients had lower unadjusted mortality (1.2% vs. 2.0%); however, after multivariable adjustment, EO was independently associated with increased risk of in-hospital mortality (odds ratio: 1.22; 95% CI: 1.08 to 1.39) in those presenting with ST-segment elevation myocardial infarction (STEMI). Access site had no effect on bleeding or outcome.
EO patients who underwent PCI were younger and had less bleeding compared with NW patients. After multivariable adjustment for risk, EO was independently associated with higher in-hospital mortality overall and particularly in the patients undergoing STEMI.
Morbid obesity is associated with increased resource utilization in coronary artery bypass grafting
2012, Annals of Thoracic Surgery
Studies have shown good outcomes for morbidly obese patients who undergo cardiac surgery. However, little is known about how much additional resource utilization treating these challenging patients requires. We hypothesized that morbidly obese patients (body mass index ≥40 kg/m²) undergoing coronary artery bypass grafting needed longer operating room times and had longer hospital and intensive care unit stays than non–morbidly obese patients.
We reviewed data from all morbidly obese patients (n = 56, body mass index = 42.7 ± 2.6 kg/m²) who underwent coronary artery bypass grafting at our institution between 1999 and 2009. These patients' outcomes were compared with those of non–morbidly obese patients (n = 168, body mass index = 30.0 ± 2.8 kg/m²) who were propensity-matched 3:1 with the morbidly obese patients.
Of the 14 preoperative characteristics examined, only 1, creatinine level, differed significantly between the two groups (p = 0.02). Intraoperative and postoperative complication rates and the mortality rate were similar between groups (p > 0.09). However, morbidly obese patients had longer operating times (449 ± 70 versus 420 ± 59 minutes; p = 0.002), intensive care unit stays (5.2 versus 3.3 days; p < 0.005), and postoperative hospital stays (14.2 versus 9.5 days; p < 0.005) than the non–morbidly obese patients.
Although good outcomes can be achieved for morbidly obese patients who undergo coronary artery bypass grafting, these patients require considerably more resource utilization in the operating room and intensive care unit, and they spend more time in the hospital after surgery. At a cardiac surgical operating room cost of approximately $50 per minute and $4,500 per intensive care unit day, the financial implications for morbidly obese patients who need coronary artery bypass grafting are not insignificant.
The impact of body mass index on morbidity and short- and long-term mortality in cardiac valvular surgery
2011, Journal of Thoracic and Cardiovascular Surgery
Citation Excerpt :
No study to date has examined the relationship between BMI and outcomes in patients undergoing strictly cardiac valvular procedures. Similar to prior studies on this topic, the current study showed that obese patients (BMI > 35) had a higher incidence of certain morbidities and resource use after valvular surgery.19,20 They experienced longer cardiopulmonary bypass times, longer aortic crossclamp times, and a higher rate of intraoperative balloon counterpulsation.
Limited data exist on patients with cardiac cachexia or morbid obesity presenting for valvular heart surgery. The objective of this study was to investigate the relationship between body mass index and morbidity and mortality after valvular surgery.
A retrospective review of 4247 patients undergoing valvular surgery from 1996 to 2008 at Emory University Healthcare Hospitals was performed. Patients were divided into 3 groups: body mass index 24 or less (group 1, n = 1527), body mass index 25 to 35 (group 2, n = 2284), and body mass index 36 or more (group 3, n = 436). Data were analyzed using multivariable regression analysis, adjusted for 10 preoperative covariates. A smooth kernel regression curve was generated using body mass index and in-hospital mortality as variables. Long-term survival comparisons were made using adjusted Cox proportional hazards regression models and Kaplan–Meier product-limit estimates. Kaplan–Meier curves were generated that provide survival estimates for long-term mortality using the Social Security Death Index.
Patients in group 3 were significantly younger (group 1, 61.7 ± 16.1 years; group 2, 61.9 ± 13.6; group 3, 57.5 ± 13.0; P < .001) and more likely to be female (group 1, 778/1527 [51.0%]; group 2, 912/2284 [39.9%]; group 3, 240/436 [55.0%]; P < .001). Mean ejection fractions were similar among groups (P = .51). Patients in group 2 had significantly shorter postoperative length of stay (group 1, 9.6 ± 10.3 days; group 2, 8.7 ± 8.2 days; group 3, 10.8 ± 11.0 days; P < .001). In-hospital mortality for the entire cohort was 5.8% (245/4247), and by group was 111 of 1527 (7.3%) in group 1, 110 of 2284 (4.8%) in group 2, and 24 of 436 (5.5%) in group 3 (P = .006). Actual survival at 1, 3, 5, and 10 years was significantly lower in group 1 (P < .001). A lower body mass index was a significant independent predictor for both in-hospital and long-term mortality.
Patients with body mass index 24 or less are at significantly increased risk of in-hospital and long-term mortality after cardiac valvular surgery. This high-risk patient population warrants careful risk stratification and options for less-invasive valve therapies.
Albumin is a better predictor of outcomes than body mass index following coronary artery bypass grafting
2011, Surgery
Citation Excerpt :
Furthermore, albumin participates in cholesterol efflux from peripheral tissues and contributes to the overall cholesterol efflux along with contributions from high-density lipoproteins. Analyses from 14,571 cardiac surgery patients between 1992 and 2005 found that extremely obese patients (BMI ≥45 kg/m2) have higher perioperative morbidity and mortality compared with a lower BMI group (BMI 24–34.9 kg/m2).4 Patients with elevated BMI can realize acceptable outcomes from cardiac procedures, but continue to suffer from the comorbidities of obesity.
Body mass index (BMI) influences risk in coronary artery bypass grafting (CABG) patients, but albumin level is not collected by the Society of Thoracic Surgeons database. We postulate that preoperative albumin is a better predictor of mortality than BMI following CABG.
BMI from patients with serum albumin level within 6 months of isolated CABG during 1995–2010 from our institutional databases were identified. Patients were stratified by National Heart, Lung, and Blood Institute (NHLBI) BMI class, and by preoperative albumin. Regression models were used to assess predictors of morbidity and mortality.
We analyzed 2,794 isolated CABG patients at our institution. Unadjusted mortality was highest with lowest BMI (P ≤ .05), and in patients with 2–3 g/dL albumin (P = .02). Ejection fraction (EF) and intra-aortic balloon pump (IABP) use were similar despite BMI; however, EF was lowest and IABP use highest in the 2–3 g/dL albumin group (P < .001, respectively). Unlike BMI groups, increasing albumin was associated with lower major complication rates (P = .001). Similarly, adjusted mortality was not influenced by BMI (AOR 0.97, 95% CI 0.93–1.02), but increasing albumin levels reduced the adjusted odds of death (AOR 0.61, 95% CI 0.42–0.90).
Albumin, more than body mass index, is associated with mortality and morbidity in isolated CABG recipients and may be a better indicator for outcomes.
Patient blood management during cardiac surgery: Do we have enough evidence for clinical practice?
2011, Journal of Thoracic and Cardiovascular Surgery

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Original articleCardiovascularCardiac Procedures in Patients With a Body Mass Index Exceeding 45: Outcomes and Long-Term Results

Background

Methods

Results

Conclusions

Section snippets

Material and Methods

Results

Comment

Lancet

Mayo Clin Proc

J Am Coll Cardiol

Crit Care Resusc

Ann Thorac Surg

J Am Coll Cardiol

Ann Thorac Surg

Actual causes of death in the United States 2000

JAMA

Prevalence of overweight and obesity in the United States 1999–2004

JAMA

Overweight, obesity and mortality in a large prospective cohort of persons 50 to 71 years old

N Engl J Med

Health consequences of visceral obesity

Ann Med

Incidence and clinical characteristics of metabolic syndrome in patients with coronary artery disease

Coron Artery Dis

Original article
Cardiovascular
Cardiac Procedures in Patients With a Body Mass Index Exceeding 45: Outcomes and Long-Term Results