Association of Valproic Acid Use With Post-Myocardial Infarction Heart Failure Development: A Meta-Analysis of Two Retrospective Case–Control Studies

BACKGROUND: Despite advances in treatments, myocardial infarction (MI) remains a significant cause of morbidity and mortality worldwide. Our team has previously shown that valproic acid (VPA) is cardio-protective when administered to rats post-MI. The aim of this study was to investigate the association of VPA use with post-MI heart failure (HF) development in humans. METHODS: This study was a random effects meta-analysis of two retrospective case–control studies collected from electronic health record (Michigan Medicine) and claims data (OptumInsight). Cases with an active prescription for VPA at the time of their MI were matched 1:4 to controls not taking VPA at the time of their MI by multiple demographic and clinical characteristics. The primary outcome, time-to-HF development, was analyzed using the Fine-Gray competing risks model of any VPA prescription versus no VPA prescription. An exploratory analysis was conducted to evaluate the association of different VPA doses (1000 mg/day vs <1000 mg/day vs 0 mg/day VPA). RESULTS: In total, the datasets included 1313 patients (249 cases and 1064 controls). In the meta-analysis, any dose of VPA during an MI tended to be protective against incident HF post-MI (HR = 0.87; 95% CI = 0.72–1.01). However, when stratified by dose, high-dose VPA (1000 mg/day) significantly associated with 30% reduction in risk for HF post-MI (HR = 0.70; 95% CI = 0.49–0.91), whereas low-dose VPA (<1000 mg/day) did not (HR 0.95; 95% CI = 0.78–1.13). CONCLUSION: VPA doses ≥1000 mg/day may provide post-MI cardio-protection resulting in a reduced incidence of HF.