Abstract Body (Do not enter title and authors here): Background: The prevalence of obesity is increasing worldwide reaching epidemic proportions. Obesity increases the risk of coronary artery disease (CAD), but there is little prospective evidence about the effect of obesity on the risk of cardiac death in CAD patients.
Aim: We aimed to investigate the effect of obesity and the risk of cardiac death in a prospective cohort of CAD patients.
Methods: We have prospectively enrolled 1,946 patients with CAD (mean age 66.9±8.6, 68% male), with a mean follow-up of 8.7±2.2 years. BMI was measured at baseline and was categorized into 4 groups: 1) BMI 18.5-24.9 kg/m² (normal weight, reference group), 2) BMI 25-29.9 kg/m² (overweight), 3) BMI 30-34.9 kg/m² (class 1 obesity), and 4) BMI >35 kg/m² (class 2 obesity). The primary endpoint was cardiac death and secondary endpoints were sudden cardiac death/arrest (SCD/SCA), non-sudden cardiac death, non-cardiac death, and heart failure (HF) hospitalization. Statistical analysis was performed with Cox regression and was adjusted for age, sex, type 2 diabetes, CCS class, kidney function (eGFR), systolic and diastolic blood pressure, LDL, smoking, SYNTAX score, and left ventricle ejection fraction.
Results: The prevalence of BMI 18.5-24.9 kg/m² was 18.5% (n=359), BMI 25-29.9 kg/m² was 47.8% (n=929), BMI 30-34.9 kg/m² was 24.0% (n=466), and BMI>35 kg/m² was 9.7% (n=189). During the follow-up, cardiac death occurred in 156 subjects, SCD/SCA in 75 subjects, non-sudden cardiac death in 81 subjects, and non-cardiac death in 197 subjects. BMI >35 kg/m² was associated with an increased trend of cardiac death (adjusted HR 1.92, 95% CI 0.92-4.01; p=0.08) and an increased risk of non-sudden cardiac death (adjusted HR 4.11, 95% CI 1.58-10.68; p=0.004) and HF hospitalization (adjusted HR 2.83, 95% CI 1.06-7-54; p=0.04), but not with SCD/SCA (adjusted HR 0.79, 95% CI 0.24-2.56; p=0.69) or noncardiac death (adjusted HR 0.85, 95% CI 0.43-1.69; p=0.64). The risk of cardiac death or secondary endpoints was not increased in patients with overweight or class 1 obesity.
Conclusions: Class 2 obesity was associated with an increased risk of non-sudden cardiac death and heart failure hospitalization among CAD patients. Obesity may have adverse long-term effects on cardiac function and prognosis among CAD patients, supporting the benefit of optimal weight control therapy.