Background: Coronary artery disease is one the most common and fatal disease worldwide. The primary management of CAD is medical however, coronary artery bypass graft (CABG) is a reliable method of treatment. The present study was vonducted with the aim of determining the effect of coronary artery bypass graft on exercise test and ejection fraction in patients with coronary artery disease.

Materials and methods: This clinical trial was performed on 40 patients candidated for CABG. All patients had undertaken exercise test and echocardiography before and 3-6 months after the surgery. McNemar and paired t-test were used for data analysis.

Results: The study population included 28 males and 12 females with the mean age of 59.2 years. The mean ejection fraction of the left ventricle (LVEF) was about 50% before and after the surgery that did not show any significant difference. Mean time of exercise test was 6.79±1.7 and 8.3±1.7 minutes before and after the surgery, respectively (p<0.0001). The prevalence of dyspnea, angina pectoris and positive ET were 62.5, 82.5, and 92.5% before and 17.5, 17.5, and 37.5% after the surgery that revealed a significant difference (P<0.01).

Conclusion: CABG shows positive changes on dyspnea, pectoris angina, and ET tolerance improvement, however, could not change ejection fraction. Further studies are strongly suggested.