Factors associated with platelet reactivity (PR) during ticagrelor maintenance dose (MD) are not well defined. We aimed to examine factors that influence levels of PR during chronic ticagrelor therapy.

We performed individual participant data meta-analysis of 445 patients from 8 studies who had PR assessment with the VerifyNow P2Y₁₂ assay (Accumetrics, Inc, San Diego, CA) while on ticagrelor 90 mg twice a day MD for at least 14 days.

Distribution of PR during ticagrelor MD was highly skewed toward lower values. No case of high PR (≥230 P2Y₁₂ reaction units [PRU]) was observed. Age and body mass index (BMI) positively affected PR, with every increase in decade and 5 units of BMI resulting in 7.9% and 4.1% increase in PR, respectively. Current smoking status negatively affected PR with 13.7% decrease in PR in current smokers, compared with nonsmokers. Low PR (LPR) was defined as the lowest quartile of PR values (<10 PRU). In multivariate analysis, diabetes mellitus and age >70 years were independently associated with lower probability for LPR with a relative risk (95% CIs) of 0.570 (0.361-0.899) and 0.554 (0.325-0.944), P = .016 and P = .030, respectively.

Age, BMI, and current smoking status affect PR during ticagrelor MD. Diabetes mellitus and age >70 years were found to be associated with lower probability for LPR. Further research is required to assess the clinical implications of these findings in ticagrelor-treated patients.