Incidence and outcome of switching of oral platelet P2Y12 receptor inhibitors in patients with acute coronary syndromes undergoing percutaneous coronary intervention: the SCOPE registry. 
In patients with acute coronary syndromes (ACS) undergoing a percutaneous coronary intervention (PCI), switching of oral P2Y12 receptor inhibitors may frequently occur.  We aimed to assess the current incidence of switching of oral P2Y12 receptor inhibitors and its safety in consecutive ACS patients undergoing PCI over a three-month period.  The SCOPE registry was a multicentre, observational, prospective study.  A total of 1,363 consecutive patients were enrolled in 39 PCI centres across Italy.  Switching of oral antiplatelet therapies occurred in 2.3% in the cathlab, 3.3% at discharge and 5.1% at follow-up.  The cumulative incidence of major adverse cerebrovascular events (MACE) and net adverse cerebrovascular events (NACE: a combination of MACE and bleeding events) was 1.6% and 5.6%, respectively.  Among patients receiving an upgrade switching (change from old to novel P2Y12 receptor inhibitors), no ischaemic or bleeding events occurred during the whole study period.  On the other hand, downgrade switching (from novel to old P2Y12 receptor inhibitors) was an independent predictor of NACE (OR 5.3; CI: 2.1-18.2; p=0.04).  Switching of oral antiplatelet therapies is not uncommon among ACS patients undergoing PCI.  Notably, switching from clopidogrel to novel P2Y12 receptor inhibitors appears safe, while a downgrade switching in early phases of ACS is associated with adverse clinical events.