Patients with and ESS score ≤ 10 will be included in the study and will undergo a cardio-respiratory polygraphy. Patients with an AHI ≥ 15 h-1 will be randomized to CPAP treatment or conservative. Patients with and AHÍ < 15 h-1 will be followed as standard management according to cardiovascular protocols and will be evaluated as a reference group. Therefore, the study will have three groups, with a total of 1,864 patients, as follows: patients with an AHI ≥ 15 h-1 will be randomized to CPAP treatment (Group 1) (n=632) or conservative treatment (Group 2) (n=632). Patients with an AHI < 15 h-1 that will be followed as a reference group (Group 3) (n=600).