In this randomized trial, 180 patients presenting with an acute coronary syndrome will be recruited and randomized into SGMT versus standard therapy (without sleep study) groups. Both groups will be treated with a guideline-mandated therapy for acute coronary syndrome (including regular cardiology outpatient clinic visits after discharge). In those allocated to SGMT, an overnight sleep study using a level 3 portable diagnostic device will be carried out. Those with OSA (an estimated 75% according to the pilot data) will be treated with CPAP and behavioral therapy. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels will be measured before hospital discharge and at 6-month follow-up. The 10-year risk of cardiovascular mortality based on the European cardiovascular risk score (SCORE), which includes age, sex, smoking status, systolic blood pressure, and serum total cholesterol or total/high-density lipoprotein (HDL)-cholesterol ratio, will be determined at baseline and at 6-month follow-up.