Evaluation of Ambulatory Monitoring of Patients After High-risk Acute Coronary Syndrome Using Two Different Systems: Biomonitor-2 and Kardia Mobile

Inclusion Criteria: * Patient is able to understand the nature of study and has provided written informed consent. * Patient with Acute Coronary Syndrome, with or without elevation of the ST segment at the EKG (the last with elevation of troponins). * Patient with coronariography at the episode of ACS showing severe lesions treated with stent. * Patient with risk index for 6-month mortality (GRACE score) of more than 118. * Patient with risk index for stroke (CHA2DS2-VACS score) of more than 2. Exclusion Criteria: * Patient with history of AF. * Patient with episodes of AF during admission at the current episode. * Patient with pacemaker or ICD (implantable cardioverter-defibrillator) previously. * Patient with indication of pacemaker or ICD in current or short-term phase. * Patient is participating in another interventional clinical investigation. * Patient is pregnant or breast feeding. * Patient´s life-expectancy is less than 24 months.