The purpose of this study is to determine whether the intervention for newly diagnosed abnormal glucose tolerance after coronary stenting will improve the long-term clinical outcome.

Recent studies have demonstrated that newly diagnosed abnormal glucose tolerance (AGT; diabetes mellitus and impaired glucose tolerance) are common among the patients with ischemic heart disease. Several large cohort studies indicate that people with prediabetic conditions, such as impaired glucose tolerance, have a raised risk of future cardiovascular disease. Intervention with acarbose can prevent myocardial infarction and cardiovascular disease in type 2 diabetic and IGT patients. However, the effect of acarbose to secondary prevention of myocardial infarction or cardiovascular events in patients with newly diagnosed AGT after coronary stenting remains unclear. The purpose of the present study is to determine whether the intervention to such abnormalities after coronary stenting will improve the long-term clinical outcome. This is a opened, randomized study to compare acarbose versus a standard lifestyle modification. Patients will have a 1:1 chance of receiving acarbose versus the standard lifestyle modification. There is some research evidence that suggests acarbose may improve clinical outcome in patients with type 2 diabetes and in IGT patients.

Inclusion Criteria:

• Within 8 weeks since implantation of coronary artery stents for stable angina pectoris or acute coronary syndrome.
• Abnormal glucose tolerance according to a 75 g oral glucose tolerance test (OGTT).
• HbA1c is less than 6.5%.
• Age is between 20 and 75 years (at time of consent).
• Patients who can give informed consent themselves in writing.

Exclusion Criteria:

• Patients with abnormal glucose tolerance caused by other organic disorders such as pancreatitis, hemochromatosis, post pancreatectomy, hyperthyroidism, Cushing syndrome, Prader-Willi syndrome, etc.
• Patients with planned angioplasty.
• Patients with uncontrollable congestive heart failure.
• Less than 6 months since last episode of cerebral infarction.
• Patients who have received medication for diabetes mellitus before.
• AST (GOT) exceeding 100 IU/L or ALT (GPT) exceeding 100 IU/L.
• Creatinine exceeding 2 mg/dl.
• Patients with a history of ileus or less than 6 months since celiotomy.
• Pregnant women or those who plan to become pregnant, or are in the lactation period.
• Habitual drinker (more than 100 ml/day of alcohol).
• Patients with a history of gastrectomy.
• Patients for whom it is impossible to follow up for 5 years.
• Any other reason that the clinical supervisors or clinical researchers may have for considering a case unsuitable for the study.