Sham CPAP mimicked all the characteristics of a true CPAP except for the null pressure, which was recently used as the placebo to study CPAP effect. Therefore, using this optimized placebo, we propose this double-blind, control randomized trial (1) To determine the prevalence of OSA in patients of first-time AMI in acute phase; (2) To determine the impact of CPAP treatment on the prognosis of AMI; (3) Determine how the OSA affects patients with MI in acute and chronic phase and vice versa, which is dissected from mechanical basis and molecular basis.