Switching between ticagrelor and clopidogrel in patients who underwent percutaneous coronary intervention: insight into contemporary practice in Chinese patients.

Ticagrelor has been proved to be more effective than clopidogrel; however, little is known about the switching between ticagrelor and clopidogrel in real-world clinical practice. We assessed the prevalence, related factors, dose bridging, compliance, and short-term outcomes of in-hospital switching between ticagrelor and clopidogrel in consecutively recruited patients treated by ticagrelor after percutaneous coronary intervention (PCI). A total of 417 eligible patients administrated with ticagrelor in-hospital after PCI were recruited. Switching between ticagrelor and clopidogrel occurred in 362 (86.8%) patients, with 318 (76.3%) from clopidogrel to ticagrelor occurring mainly after PCI and 44 (10.6%) from ticagrelor to clopidogrel primarily at discharge. History of cerebrovascular disease, final diagnosis of acute coronary syndrome, left main disease, ostial lesion, co-administration with warfarin, CYP2C19 loss-of-function alleles' carriage status, and ticagrelor-related dyspnoea emerged as related factors for the switching between clopidogrel and ticagrelor. Dose bridging between clopidogrel loading dose and ticagrelor maintenance dose (MD) was more frequent in patients switching from clopidogrel to ticagrelor, while the bridging between ticagrelor MD and clopidogrel MD was more likely to occur in patients switched from ticagrelor to clopidogrel. At 6 month follow-up, poor compliance was observed in patients from clopidogrel to ticagrelor (64.8%) or treated only by ticagrelor (50.9%), but perfect compliance in patients from ticagrelor to clopidogrel (100%). After excluding the cases with incompliance, patients switching from ticagrelor to clopidogrel had a relatively lower bleeding risk in comparison with patients with constant ticagrelor treatment and those switching from clopidogrel to ticagrelor (29.5% vs. 50.0% vs. 46.6%, adjusted P = 0.02). In-hospital switching between ticagrelor and clopidogrel is frequent in patients undergoing PCI. In comparison with constant ticagrelor treatment, switching from clopidogrel to ticagrelor in ischaemic high-risk patients confers similar antiplatelet efficacy and safety, while switching from ticagrelor to clopidogrel in ischaemic low-risk patients relates to lower hazard for bleeding events.