The effect of comorbid illness on mortality outcomes in cardiac surgery.
OBJECTIVE
Comorbid conditions are associated with the risk of death from coronary artery bypass graft surgery.


METHODS
Prospective cohort study data were collected on patient and disease characteristics and comorbid conditions including hypertension, diabetes, obesity, vascular disease, chronic obstructive pulmonary disease, cancer (excluding nonmelanoma skin cancer), dialysis-dependent renal failure, liver disease, and dementia. Statistical analysis used logistic regression for the calculation of adjusted odds ratios (ORs) and 95% confidence intervals (CIs).


METHODS
Regional cardiac surgery database.


METHODS
A total of 27,239 consecutive patients undergoing isolated coronary artery bypass graft surgery.


METHODS
In-hospital mortality rate.


RESULTS
The prevalence of comorbid conditions was as follows: hypertension, 64.3%; diabetes, 30.1%; obesity, 24.6%; severe obesity, 7.2%; vascular disease, 18.3%; chronic obstructive pulmonary disease, 10.9%; peptic ulcer, 7.5%; cancer, 3.8%; renal failure, 1.5%; liver disease, 0.6%; and dementia, 0.1%. After adjustment for patient and disease characteristics, including age, sex, previous cardiac surgery, priority of surgery, degree of left main coronary stenosis, number of diseased coronary arteries, and left ventricular ejection fraction, the following comorbid conditions were significant predictors of in-hospital mortality: diabetes (OR, 1.19; 95% CI, 1.01-1.40; P =.03), vascular disease (OR, 1.67; 95% CI, 1.41-1.97; P<.001), chronic obstructive pulmonary disease (OR, 1.57; 95% CI, 1.29-1.91; P<.001), peptic ulcer (OR, 1.34; 95% CI, 1.05-1.71; P =.02), and dialysis-dependent renal failure (OR, 3.68; 95% CI, 2.65-5.13; P<.001). There was no significant association between in-hospital mortality and hypertension, obesity or severe obesity, cancer, liver disease, or dementia.


CONCLUSIONS
Even after adjustment for other patient and disease characteristics, comorbid conditions (especially diabetes, vascular disease, chronic obstructive pulmonary disease, peptic ulcer disease, and dialysis-dependent renal failure) are associated with significantly increased risk of death after coronary artery bypass graft surgery.
Clough
Robert A
RA
Department of Surgery, Eastern Maine Medical Center, Bangor, 04401, USA. rclough@nehi.org
Leavitt
Bruce J
BJ
Morton
Jeremy R
JR
Plume
Stephen K
SK
Hernandez
Felix
F
Nugent
William
W
Lahey
Stephen J
SJ
Ross
Cathy S
CS
O'Connor
Gerald T
GT
D015331:Cohort Studies; D015897:Comorbidity; D001026:Coronary Artery Bypass / Q000401:mortality*; D017052:Hospital Mortality; D006801:Humans; D015999:Multivariate Analysis; D016017:Odds Ratio; D011446:Prospective Studies