Comparison of myocardial perfusion between the users of two antiepileptic medications: valproate vs. carbamazepine

Objective(s): The prevalence of coronary artery disease (CAD) is high in patients with epilepsy using antiepileptic drugs (AED). Epilepsy, AED, or the type and duration of AED use , may contribute to higher CAD risk.In this study, myocardial perfusion imaging (MPI) was compared between patients using carbamazepine and valproate.Method: Out of ۷۳ patients receiving carbamazepine or valproate monotherapy for more than ۲ years, visited at a tertiary referral clinic, ۳۲ patients participated in a ۲-day stress and rest phases MPI. For each phase, ۱۵-۲۵ mCi ۹۹mTc-MIBI was injected, at peak exercise or by pharmacologic stimulation for the stress phase. SPECT with cardiac gating was done by a dual-head gamma camera and processed and quantified. Scans with at least one definite reversible hypo-perfusion segment were considered abnormal.Results: Seventeen patients received carbamazepine monotherapy and ۱۵ valproates. Age and duration of AED use were similar between the groups. Two scans were abnormal (۶.۳%) both in valproate group (۱۳.۳%). Duration of AED use was higher in patients with abnormal scans. In patients receiving monotherapy >۲ years, the frequency of abnormal MPI was similar between groups (P-value=۰.۱۲).  In patients receiving monotherapy > ۵ years, prevalence of abnormal MPI was higher in the valproate group (۲۸.۶% vs. ۰.۰%; P-value=۰.۰۴۲). Considering valproate subgroup, ischemic patients had higher duration of AED use, comparing with the normal patients (۱۷.۰±۴.۲ vs. ۶.۴±۴.۸, P-value=۰.۰۱۴).Conclusion: MPIs were abnormal in patients receiving valproate after ۵ years compared to patients receiving carbamazepine. Long-term valproate use may increase the risk of CAD.