in a large retrospective insurance claims study.
SOURCE: AMERICAN GASTROENTEROLOGICAL ASSOCIATION
Over a median follow-up of 2-3 months, estimated weighted risks of first-ever MI were low and similar regardless of whether patients started PPIs or histamine2 receptor antagonists (H2RAs), reported Suzanne N. Landi of the University of North Carolina at Chapel Hill, and her associates. “Contrary to prior literature, our analyses do not indicate increased risk of MI in PPI initiators compared to histamine2-receptor antagonist initiators,” they wrote in the March issue of Gastroenterology.
Epidemiologic studies have produced mixed findings on PPI use and MI risk. Animal models and ex vivo studies of human tissue indicate that PPIs might harm coronary vessels by increasing plasma levels of asymmetrical dimethylarginine, which counteracts the vasoprotective activity of endothelial nitrous oxide synthase, the investigators noted. To further assess PPIs and risk of MI while minimizing potential confounding, they studied new users of either prescription PPIs or an active comparator, prescription H2RAs. The dataset included administrative claims for more than 5 million patients with no MI history who were enrolled in commercial insurance plans or Medicare Supplemental Insurance plans. The study data spanned from 2001 to 2014, and patients were followed from their initial antacid prescription until they either developed a first-ever MI, stopped their medication, or left their insurance plan. Median follow-up times were 60 days in patients with commercial insurance and 96 days in patients with Medicare Supplemental Insurance, which employers provide for individuals who are at least 65 years old.
After controlling for numerous measurable clinical and demographic confounders, the estimated 12-month risk of MI was about 2 cases per 1,000 commercially insured patients and about 8 cases per 1,000 Medicare Supplemental Insurance enrollees. The estimated 12-month risk of MI did not significantly differ between users of PPIs and H2RAs, regardless of whether they were enrolled in commercial insurance plans (weighted risk difference per 1,000 users, –0.08; 95% confidence interval, –0.51 to 0.36) or Medicare Supplemental Insurance (weighted risk difference per 1,000 users, –0.45; 95% CI, –1.53 to 0.58) plans.