Impact of Body Weight on Outcomes of Patients Undergoing Coronary Artery Bypass Grafting

Impact of Body Mass Index on Mortality in Patients Undergoing Coronary Artery Bypass Grafting: a Retrospective Cohort Study

All consecutive patients who underwent isolated coronary artery bypass grafting (CABG) at our institution from 2014 to 2020 were included. Patients were divided into 6 groups according to body mass index (BMI): underweight (BMI <20.0 kg/m2), normal weight (BMI 20.0-24.9 kg/m2), overweight (BMI, 25-29.9 kg/m2), obesity class I (BMI 30-34.9 kg/m2), obesity class II (BMI 35-39.9 kg/m2) and obesity class III (BMI >40 kg/m2). The long-term mortality was analyzed as primary end-point. The univariable and multivariable analysis was performed using logistic regression modeling.

Study Overview

• Status: Completed
• Conditions: Coronary Artery Disease; Obesity; Angina Pectoris; Coronary; Ischemic
• Intervention / Treatment: Procedure: coronary artery bypass grafting

Detailed Description

All consecutive patients aged above eighteen who underwent isolated CABG were enrolled. Patients operated on- and off-pump were included. We reviewed elective, urgent, emergency and salvage surgeries. Patients with any additional concomitant surgical procedures were excluded.

Patients were divided into 6 groups according to body mass index (BMI): underweight (BMI <20.0 kg/m2), normal weight (BMI 20.0-24.9 kg/m2), overweight (BMI, 25-29.9 kg/m2), obesity class I (BMI 30-34.9 kg/m2), obesity class II (BMI 35-39.9 kg/m2) and obesity class III (BMI >40 kg/m2).

The primary endpoint was long-term mortality. The secondary end-point was the rate of sternal wound infections.

Summary statistics were calculated. Continuous data are described as the median, with the interquartile range in parentheses, while categorical data are shown as numbers with percentages. Differences between groups for normally distributed, continuous variables were determined using the one-way analysis of variance with Holm-Sidak post-hoc test. The Kruskal Wallis test was used for the analysis of non-normally distributed continuous variables with Dunn's test for post hoc comparison. The chi-squared test was used for the analysis of categorical variables. Bonferoni's correction was used for post-hoc analysis. The univariable analysis was performed using logistic regression. For multivariable analysis a logistic regression model was performed, with mortality or wound infection as the dependent variable, and all other characteristics summarized in the table 1 as independent variables. The backward conditional selection was used for modeling with variables with score statistics <0.1 included in the model. Significance was assessed at p<0.05. Multiple imputation was not used to adjust for missing data. The number of valid entries for each variable and alterations in the sample size for specific analyses are described.

Analyses were performed using IBM SPSS Version 22.0 and MedCalc Version 19.4.1.

• Study Type: Observational
• Enrollment (Actual): 6448

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

all consecutive patients undergoing isolated CABG

Description

Inclusion Criteria:

• patients undergoing isolated CABG

Exclusion Criteria:

any concomitant additional surgical procedures

Study Plan

How is the study designed?

Number of groups / cohorts

6

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
underweight; BMI <20.0 kg/m2	Procedure: coronary artery bypass grafting; surgical coronary revascularization
normal weight; BMI 20.0-24.9 kg/m2	Procedure: coronary artery bypass grafting; surgical coronary revascularization
overweight; BMI 25-29.9 kg/m2	Procedure: coronary artery bypass grafting; surgical coronary revascularization
obesity class I; BMI 30-34.9 kg/m2	Procedure: coronary artery bypass grafting; surgical coronary revascularization
obesity class II; BMI 35-39.9 kg/m2	Procedure: coronary artery bypass grafting; surgical coronary revascularization
obesity class III; BMI >40 kg/m2	Procedure: coronary artery bypass grafting; surgical coronary revascularization

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
long-term mortality	2014-2022

Secondary Outcome Measures

Outcome Measure	Time Frame
sternal wound infection rate	2014-2022

Collaborators and Investigators

• Sponsor: Medical University of Silesia

Study record dates

Study Major Dates

• Study Start: January 1, 2014
• Primary Completion (Actual): September 30, 2020
• Study Completion (Actual): February 1, 2022

Study Registration Dates

• First Submitted: September 2, 2024
• First Submitted That Met QC Criteria: September 23, 2024
• First Posted (Actual): September 26, 2024

Study Record Updates

• Last Update Posted (Actual): September 26, 2024
• Last Update Submitted That Met QC Criteria: September 23, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Keywords: body mass index; obesity; mortality; coronary artery bypass grafting
• Additional Relevant MeSH Terms: Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Pain; Neurologic Manifestations; Coronary Disease; Chest Pain; Coronary Artery Disease; Angina Pectoris
• Other Study ID Numbers: BNW-1-065/N/3/K

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No