Dual Antiplatelet Therapy represents the main therapy for patients presenting with chronic coronary syndromes and undergoing elective PCI. However, most of these patients are not properly covered in terms of inhibition of platelets aggregation at the time of PCI, and are exposed to an higher risk of microvascular damage which in turns might be responsible of residual symptoms persistence and the findings of residual ischemia at the non-invasive tests. In naïve patients, cangrelor can be administered at the time of PCI potentially protecting coronary microcirculation. The aim of this randomized study is indeed to evaluate the use of Cangrelor as compared with standard practice (with Clopidogrel) in terms of incidence of coronary microvascular dysfunction following elective PCI of functionally significant intermediate coronary stenoses. All consecutive patients, fulfilling inclusion and exclusion criteria, will be enrolled and both FFR and CFR/IMR will be measured before and after PCI. Platelet reactivity will be also evaluated mainly during PCI procedure. At 30 days of follow up, patients will be interrogated about symptoms persistence and will be asked to complete the specific Seattle Angina Questionaty (SAQ7). At 3 months a SPECT could be performed in order to evaluate the presence of residual ischemic area in the myocardial territory downstream to the treated vessel. With this study we will be able to evaluate the potential benefit of using Cangrelor, as compared with standard therapy with Clopidogrel, in terms of protection of coronary microcirculation during elective PCI and reduction of both residual symptoms and ischemia at clinical follow up.