Obesity and long-term clinical and economic outcomes in coronary artery disease patients

Abstract

Objective: Obesity is an important risk factor for coronary artery disease (CAD); however, its effect on acute coronary syndrome (ACS) patients' long-term clinical and economic outcomes has not been quantified. We assessed the impact of increasing body mass index (BMI) on 10-year outcomes for ACS patients.

Research methods and procedures: ACS patients with significant CAD receiving an initial cardiac catheterization at Duke University Medical Center between 1986 and 1997 were included. Patients with a BMI < 18.5 kg/m(2) were excluded; the remaining patients were classified by BMI as normal, overweight, obese, or very obese. Medical costs were estimated from a prior ACS clinical trial with costs adjusted to 1997 dollars and discounted at 3% per annum.

Results: There were 9405 patients with data available for analysis. Follow-up was complete on >95% of patients. Patients who were obese at baseline increased from 20% to 33% between 1986 and 1997. Increased BMI was associated with younger age, multi-morbidity, and less severe CAD at baseline. It was also associated with more clinical events, higher cumulative inpatient medical costs, and significant differences in unadjusted survival at 10 years. However, it was not associated with differences in 10-year survival after adjusting for baseline characteristic differences.

Discussion: Obese ACS patients are younger and are hospitalized more frequently during the first 10 years of their illness than are non-obese patients. They also incur higher cumulative inpatient medical costs, especially the very obese. These findings highlight the opportunities for therapeutic benefit that aggressive weight management and secondary prevention may provide this population.