Interaction between the effects of proton pump inhibitors and aspirin on gastric wall sestamibi uptake on myocardial perfusion imaging

Abstract

BackgroundIncreased gastric wall activity on myocardial perfusion imaging (MPI) is associated with proton pump inhibitor (PPI) therapy; however, the mechanism is unknown. We proposed a role for gastric mucosal prostaglandin synthesis and asked whether concurrent use of aspirin would antagonize this effect. MethodsAn observational study was performed of 319 patients undergoing technetium-99m sestamibi (MIBI) rest/stress MPI. We assessed the effects of taking PPIs, aspirin and their interaction on the principle outcome of clinically significant gastric wall activity. ResultsThe outcome was observed in 13% of patients taking neither a PPI nor aspirin, 22% of those taking aspirin only, 51% taking a PPI only and 33% of those taking both. Adjusted odd ratios (95% confidence intervals) were 6.3 (CI 2.8-14.0; p < .001) for taking a PPI only, 1.8 (CI 0.8-3.9; p = .16) for taking aspirin only, and 3.0 (CI 1.4-6.5; p = .005) for taking the combination of a PPI and aspirin. There was evidence of negative statistical interaction between the two drug effects using additive (p = .006) and multiplicative (p = .016) scales. ConclusionsPPI use was strongly associated with enhanced gastric wall activity on MPI; however, concurrent aspirin appears to reduce the effect. Enhanced local prostaglandin synthesis may mediate the PPI effect.