Response to Clopidogrel With Proton Pump Inhibitors: Safe or Not?

Mehta A. et al.

To the Editor:

We read with interest Mehta et al's review article, “Clopidogrel and Proton Pump Inhibitors: Safe or Not?”1 The authors conducted literature research on both prospective and retrospective data and concluded that there is little evidence to suggest an interaction between clopidogrel and proton pump inhibitors (PPIs). We wish to share the findings at our unit.

We undertook an observational retrospective study of 188 consecutive patients (122 non–ST‐segment elevation myocardial infarction, 66 ST‐segment elevation myocardial infarction) treated with dual antiplatelet therapy (DAT) following acute coronary syndrome (ACS) over a period of 1 year. Patients were divided in 2 groups: PPI group (patients on DAT and PPI, n = 96) and control group (patients on DAT only, n = 88). The end point was recurrence of ACS or death 12 months after the index coronary event.

Clopidogrel and aspirin were discontinued in 4 patients due to gastrointestinal bleeding, and these patients were therefore excluded from the study. Data were analyzed in 184 patients. There were 66% males and 34% females; 73% were Caucasian and 27% Asian. The mean age of the patients was 67 years (range, 24–96 years). In the PPI group, 10 patients (10/96, 10.4%) were readmitted with further myocardial infarction (6 on lansoprazole and 4 on pantoprazole). In the control group, 2 patients (2/88, 2.3%) were readmitted with a further myocardial infarction. Using the test of independent proportion, this difference in the rate of recurrence of coronary event was statistically significant (P = 0.025, 95% confidence interval: 1.3–15.0).

Our data suggest a possible interaction between clopidogrel and PPI, and we disagree with Mehta et al on this. However, we do agree that a large, randomized, placebo‐controlled trial is needed to further investigate this possible interaction.