High on-clopidogrel platelet reactivity was associated with an increased risk of MACE in patients with ≥2 risk factors (HR 3.7, p=0.0003), with the risk magnitude dependent on baseline risk levels.
Meta-Analysis (n=6,478)
Does the predictive value of on-clopidogrel platelet reactivity for MACE depend on the patient's baseline cardiovascular risk level?
The predictive value of on-clopidogrel platelet reactivity for MACE is strongly dependent on the patient's baseline cardiovascular risk level, suggesting PR testing may be most useful in higher-risk patients.
Hazard Ratio: 3.7
p-value: p=0.0003
Prior studies have shown an association between high on-clopidogrel platelet reactivity (PR) and the risk of major adverse cardiovascular events (MACE). However, large intervention trials on PR-tailored treatments have been neutral. The role and usefulness of PR with regard to levels of cardiovascular risk are unclear. We undertook a systematic review and meta-analysis of individual patient data on MACE outcomes (acute coronary syndromes (ACS), ischaemic strokes, and vascular deaths) in relation to PR and its interaction with cardiovascular risk levels. PR was determined using ADP-induced light transmission aggregometry with a primary concentration of 20 µM ADP. Thirteen prospective studies totaled 6,478 clopidogrel-treated patients who experienced 421 MACE (6.5 %) during a median follow-up of 12 months. The strength of the association between the risk of MACE and PR increased significantly (p=0.04) with the number of risk factors present (age> 75 years, ACS at inclusion, diabetes, and hypertension). No association was detected in patients with no risk factor (p=0.48). In patients presenting one risk factor, only high-PR was associated with an increased risk of MACE (HR 3.2, p=0.001). In patients presenting ≥ 2 risk factors, the increase of risk started from medium-PR (medium-PR: HR=2.9, p=0.0004; high-PR: HR=3.7, p=0.0003). PR allowed the reclassification of 44 % of the total population to a different risk level for the outcome of MACE, mostly in intermediate or high risk patients. In conclusion, the magnitude of the association between PR and MACE risk is strongly dependent on the level of cardiovascular risk faced by patients on clopidogrel.
Fontana et al. (Thu,) conducted a meta-analysis in Patients on clopidogrel (n=6,478). High on-clopidogrel platelet reactivity vs. Low/normal platelet reactivity was evaluated on MACE (acute coronary syndromes, ischaemic strokes, and vascular deaths) (HR 3.7, p=0.0003). High on-clopidogrel platelet reactivity was associated with an increased risk of MACE in patients with ≥2 risk factors (HR 3.7, p=0.0003), with the risk magnitude dependent on baseline risk levels.