Background: A recent ex vivo study suggests that the metabolic activation of clopidogrel is catalyzed by cytochrom P450 (CYP) 3A4 and is competitively inhibited by atorvastatin, but not pravastatin.
Objective: To determine whether the incidence of procedure-related myocardial injury, assessed by cardiac troponin T (cTnT) release, is altered when clopidogrel is coadministered with a statin that is predominantly CYP3A4-metabolized.
Methods and results: Of the 211 consecutive patients who underwent coronary stenting after pretreatment with clopidogrel, 114 were receiving a CYP3A4-metabolized statin (59 simvastatin and 55 atorvastatin, Group 1), and 37 were receiving a non-CYP3A4-metabolized statin (30 pravastatin and 7 fluvastatin, Group 2) whereas 60 patients were not taking any statins (Control). All were troponin-negative before the procedure. The overall incidence of postprocedural cTnT positivity (> 0.10 ng/ml) was 30.8%. Group 2 patients were less likely to exhibit cTnT rise relative to Group 1 patients (8% versus 41.6%; p = 0.004) and relative to controls (8% versus 32.5%; p < 0.001). Multivariate analysis identified the use of a non-CYP3A4-metabolized statin before coronary stenting as the sole independent predictor for lower incidence of procedure-related cTnT elevation with estimated Odds ratios of 0.16 relative to no statin therapy (95% CI: 0.04-0.59; p = 0.006) and 0.18 relative to CYP3A4-metabolized statin therapy (95 CI: 0.053-0.637; p = 0.008)
Conclusion: Benefit derived from the preprocedural use of pravastatin and fluvastatin but not atorvastatin and simvastatin suggest that the ex vivo finding of a negative interaction when coadministering a CYP3A4-metabolized statin with clopidogrel may be of clinical significance.