Medical history, clinical data, drug therapy, Angina Canadian Cardiovascular Society (CCS) classification, Seattle Angina Questionnaire (SAQ), quality of life estimation by EuroQoL scale, detailed evaluation of angina attacks (frequency, intensity, duration of episodes; nitrates assumption) according to a structured diary, number of hospitalizations, emergency room (ER) admissions and cardiological visits in the previous 6 months and treadmill exercise stress test results will be obtained at the baseline visit.