Efficacy assessment of ticagrelor versus clopidogrel in Chinese patients with acute coronary syndrome undergoing percutaneous coronary intervention by data mining and machine-learning decision tree approaches

What is known and Objective Although ticagrelor has been well-known to improve clinical outcomes in patients undergoing percutaneous coronary intervention (PCI), and its effectiveness and safety have not been well evaluated in Chinese patients. This study aimed to evaluate the effectiveness and safety of ticagrelor in Chinese patients. In order to find potential effect modifiers on the drug effects, a decision tree method was performed to detect interactions between treatment and patient characteristics in an automatic and systematic manner. Methods This retrospective study included acute coronary syndrome (ACS) patients who underwent PCI and received either ticagrelor (N = 250) or clopidogrel (N = 291) while hospitalized between August 2014 and August 2015. After propensity score matching, Kaplan-Meier analysis was used to study the event-free survival against major adverse cardiovascular events (MACE, primary efficacy outcome, defined as the composite of cardiac death, non-fatal myocardial infarction [MI], stroke, restenosis and target vessel revascularization [TVR]), re-hospitalization, the need for urgent re-PCI (secondary efficacy outcome) and bleeding events (safety outcome) within 12 months of the PCI date. To search for effect modifiers of the two antiplatelet therapies, a machine-learning decision tree algorithm was conducted to predict re-hospitalization status. Results After propensity score matching (N = 442), ticagrelor and clopidogrel had no significant difference in MACE, re-hospitalization and bleeding. The decision tree analysis showed that the number of diseased vessels modulated the effect of ticagrelor and clopidogrel on re-hospitalization rates. In single-vessel disease (SVD) patients, ticagrelor was associated with lower hazards than clopidogrel for all efficacy outcomes: MACE (HR = 0.190, 95% CI: 0.042-0.866), re-hospitalization (HR = 0.296, 95% CI: 0.108-0.808), urgent re-PCI (HR = 0.249, 95% CI: 0.069-0.895), bleeding (HR = 1.006, 95% CI: 0.063-16.129). However, in multi-vessel disease (MVD) patients, the two treatments did not show significant difference. What is New and Conclusion In the general patient population, there was no significant difference between ticagrelor and clopidogrel on the hazard of MACE. However, ticagrelor achieved a better effectiveness than clopidogrel in patients with SVD. This pilot study provides scientific basis to call for a large-scale prospective study in this population.